2016 postgraduate symposium for environmental … · optimization of fat yield from rambutan ......

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Proceedings of

Postgraduate Symposium on

Green Engineering & Technology 2016

Editors:

Nadia Razali

Sabrina Karim

Salem S. Abu Amr

Indok Nurul Hasyimah Mohd Amin

Kelly Yong Tau Len

Khairul Faizal Pa’ee

Robert Thomas Bachmann

Sheela Subramanian

UNIVERSITI KUALA LUMPUR PUBLISHING

1016, Jalan Sultan Ismail,

50250 Kuala Lumpur, Malaysia

iii

First Publication 2016

©Copyright by Universiti Kuala Lumpur Publishing 2016

All rights reserved. No part of this publication may be reproduced or distributed in

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prior written consent of Universiti Kuala Lumpur Publishing Unit, including in any

network or other electronic storage or transmission, or broadcast for distance

learning.

Published by

UNIVERSITI KUALA LUMPUR PUBLISHING

1016, Jalan Sultan Ismail, 50250 Kuala Lumpur Malaysia

iv

PREFACE

The Postgraduate Symposium on Green Engineering and

Technology 2016 (PSGET 2016) was held on 7 November

2016 at Malacca International Trade Centre. This event is

UniKL’s own homegrown postgraduate symposium. The

postgraduate symposium aims to improve the visibility of

students and their research projects on a larger scale and

celebrate their achievements. This symposium is a

platform for research students (Master and PhD) to present

their research and to initiate critical discussion about their concept, materials, media

and approaches with a broad scholarly audience.

The tagline “Researcher as Agent of Change” shows that researchers at post-

graduate level are not just pursuing for another certificate but they are also capable

to transform the world into a better place by solving an environmental issue to

discovering new source of energy. It is also to encourage the graduates to choose a

career path as a researcher after graduating.

In this first edition, the symposium had 42 papers presented (oral and poster) from

all over the world. From that amount, 34 papers were published for this proceeding.

This is very encouraging as the organizer envisaged this symposium to be an

international platform for academia discussion. The papers covered vast themes of

green technology such as Environmental, Sustainable & Clean Technologies, Built

Environment, Bioengineering (Bioprocesses, Biocatalysts, Bio-products), Food and

Agricultural Based Technology & Products and Renewable Energy.

All in all, PSGET 2016 was very successful. The plenary speech lectures and the

paper presentations bridged the gap between the different fields of green engineering

and technology, making it possible for non-experts in a given area to gain insight

into new areas. Most importantly, PSGET 2016 has opened up new opportunities

through many fruitful discussions and exchanges that lead towards further

development in the field of green engineering and technology.

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KEYNOTE SPEAKER : EXCELLENCE IN POSTGRADUATE

STUDIES

Teaching/learning at postgraduate level

is very different from the traditional

teaching methods usually employed at

school and undergraduate levels. It is

very much an individualistic, self-

motivated and directed form of learning

with guidance/mentoring provided more

or less on a need basis. The question is

does one need to be a genius to be

successful in getting a postgraduate

degree, either at Master’s or Doctorate levels? A survey carried out among some

Malaysian university professors are of the opinion that intelligence, critical thinking,

discipline, endurance and independence are among the necessary ingredients for

success at postgraduate level studies, but not necessarily in that order. This paper

will discuss various issues contributing to success in postgraduate research degrees.

This will be benchmarked against the characteristics and research path of recent

Nobel Prize winners which led to their reaching the pinnacle of scientific

recognition.

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TABLE OF CONTENTS

PREFACE .................................................................................................................................... IV

KEYNOTE SPEAKER : EXCELLENCE IN POSTGRADUATE STUDIES ....................... V

TABLE OF CONTENTS ........................................................................................................... VI

OPTIMIZATION OF FAT YIELD FROM RAMBUTAN (NEPHELIUM LAPPACEUM L.)

SEED UNDER CONVECTIVE DRYING.................................................................................. 1

A FEASIBILITY STUDY OF LATRINE CONSTRUCTION FOR BLACK WATER IN

GUBENG DISTRICT, SURABAYA, EAST JAVA, INDONESIA ........................................ 12

AUTOMOBILE KIT USING JATROPHA OIL AS FUEL IN COMPRESSION IGNITION

ENGINES: DESIGN AND SHORT-RUN TEST ..................................................................... 21

DETERMINATION OF NAPIER GRASS FIBER YIELD FROM DIFFERENT RETTING

PROCESS TREATMENTS ....................................................................................................... 29

DETERMINATION OF MECHANICAL PROPERTIES OF OIL PALM FROND (OPF)

FIBER CEMENT BOARD ........................................................................................................ 39

ANALYSIS OF TEMPERATURE CHANGING PATTERN IN THAILAND USING

LINEAR REGRESSION MODEL ............................................................................................ 46

PATTERNS OF SOLAR RADIATION ABSORPTION IN USA USING STATISTICAL

MODEL ....................................................................................................................................... 55

THERMO-PHYSICAL PROPERTIES OF NANOCARBON PARTICLES IN ETHYLENE

GLYCOL AND DEIONIZED WATER ................................................................................... 64

EFFICIENT REMOVAL OF GRAPHENE OXIDE QUANTUM DOTS (GOQDS) FROM

NATURAL WATER BY PEI-MODIFIED SILICA NANOCOMPOSITES ........................ 79

EVALUATION OF LIGHT RARE EARTH ELEMENTS (LREES) IN CASTOR OIL AND

LILAC TASSEL FLOWER PLANT GROWN IN CONTAMINATED SOIL FROM

ABANDONED MINES IN PERAK, MALAYSIA .................................................................. 88

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NOVEL MAGNETIC BIOCHAR FOR THE REMOVAL OF 6 OCPS FROM

WASTEWATER ......................................................................................................................... 96

STUDY OF AMD AND HEAVY METAL CONTAMINATION IN ACTIVE AND

ABANDONED IRON MINING IN PAHANG ....................................................................... 103

THEORETICAL REVIEW ON SUCCESS FACTOR AFFECTING COMPETENCIES OF

CIVIL ENGINEER ................................................................................................................... 111

SUPERCRITICAL CO2 EXTRACTION OF NEEM SEED OIL: A COST COMPARISON

STUDY WITH SOXHLET EXTRACTION AT LAB SCALE ............................................ 122

POTENTIAL ROLES OF BIOCHAR IN ANAEROBIC DIGESTION OF PALM OIL

MILL EFFLUENT.................................................................................................................... 135

EFFECT OF SOLVENT AND LEAVES CONDITION ON THE CONCENTRATION OF

QUERCETIN EXTRACTED FROM MURRAYA KOENGII BY USING SOXHLET

EXTRACTION METHOD. ..................................................................................................... 144

LIQUID FUEL PRODUCTION FROM PYROLYSIS OF PLASTIC WASTES AS

PROMISING FUTURE ALTERNATIVE ENERGY RESOURCES .................................. 150

STUDY THE PROPERTIES OF CONCRETE AS RADIATION SHIELDING .............. 161

STUDY ON ACID PRE-TREATMENT OF SAGO PITH WASTE FOR GLUCOSE

PRODUCTION ......................................................................................................................... 172

DESIGN FORWARD: BIOMIMICRY APPROACH IN SUSTAINABLE LANDSCAPE

ECOLOGY ................................................................................................................................ 185

ACCUMULATION OF METAL (CD, CR, CU, NI AND PB) CONTAMINATED WATER

USING BACOPA MONNIERI, LILAEOPSIS BRASILIENSIS, HEMIANTHUS

CALLITRICHOIDES AND GLOSSOSTIGMA ELATINOIDES ........................................... 191

DO DURIAN WOOD BIOCHAR AND LIQUID FISH FERTILIZER AFFECT DURIAN

PLANT GROWTH (DURIO ZIBETHINUS L.) IN PEAT MOSS? - A HORTICULTURAL

NURSERY STUDY ................................................................................................................... 210

DESIGN OF EXPERIMENTAL TEST-RIG TO INVESTIGATE TURBULENCE IN

OSCILLATORY FLOW USED IN THERMOACOUSTICS. ............................................. 231

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INSTRUMENTATION FOR STUDYING THE TURBULENCE CHARACTERISTIC IN

OSCILLATORY FLOW USED IN THERMOACOUSTICS: A REVIEW ....................... 240

INTEGRATED TREATMENT OF LEACHATE BY USING CALCITE FILTRATION

AND CONSTRUCTED WETLAND ...................................................................................... 246

REMOVAL OF ANTIBIOTICS BY ADSORPTION ONTO MAGNETIC BIOCHAR ... 255

INDUSTRIAL CONTROLLER TUNING AND EMPIRICAL MODEL OF HEAT

EXCHANGER SYSTEM ......................................................................................................... 263

STUDIES ON COD AND COLOUR REDUCTION IN POME USING CHEMICALLY

ACTIVATED EFB CARBON ................................................................................................. 274

THE LOW-CARBON TECHNOLOGY: EXPERT VIEW TOWARDS TECHNOLOGY

EXPECTATION TO ENCOURAGE MALAYSIA URBAN RESIDENTS CARBON-

CAPABILITY BEHAVIOUR .................................................................................................. 282

2016 Postgraduate Symposium for Environmental Engineering Technology

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OPTIMIZATION OF FAT YIELD FROM RAMBUTAN

(NEPHELIUM LAPPACEUM L.) SEED UNDER CONVECTIVE

DRYING

So’bah Ahmad1a, Mohd Shamsul Anuar1b, Farah Saleena Taip1c and Rosnah Shamsudin1d 1Department of Process and Food Engineering, Faculty of Engineering, Universiti Putra Malaysia,

43400 UPM Serdang, Selangor

*Corresponding Author E-mail: [email protected]

ABSTRACT

The optimization of the process variable; temperature and drying time, under convective drying in

an automatic electric oven were studied for the rambutan clone R4 seed fat yield. The optimization

conducted using response surface methodology central composite design of experiment. The result

indicated both process variables have positive effect upon fat yield within studied range. However,

drying time exhibited a higher positive effect in increasing the fat yield. The optimum drying

condition was obtained at 54.02 oC for 36.52 h drying time yielding 38.65% fat yield. The response

surface methodology used in this study was able to predict the optimum drying condition for fat

yield of rambutan seed clone R4 via linear and square mathematical model with higher adjusted

coefficient determination (𝑅2 ) 0.918. Hence, the models gave good prediction of the fat yield

obtained from the rambutan clone R4 seeds under the experimental conditions used in this study.

Key Words: Optimum drying condition; Automatic electric oven; Rambutan seed; Fat yield

1. INTRODUCTION

Rambutan is a seasonal fruit crop with diversity functions. It highly in nutrient (Solís et al., 2010;

Sirisompong et al., 2011) and their seed extracts have chemical composition that fit to be used in

food (Mei et al., 2014; Zzaman et al., 2014) and cosmetics (Lourith et.al , 2016). Its extract is also

potentially beneficial as anti- adipogenesis and antidiabetic agents and this claimed was statiscally

supported by clinical testing on their ability in reducing blood glucose and body weight in mice

(Rahayu et al., 2013; Soeng et al., 2015). Futhermore, the ability of its extract to demonstrate as

antioxidant and α – glucosidase inhibitory due to higher content of active compound also may

strongly support its activity as anti- adipogenesis and antidiabetic agents. Therefore, its activity in

addressing major diseases among Malaysian is indisputable. However, due to the nature of a

seasonal fruit crops and also the multiplicity in its functions; the need in continuous supply beyond

their seasonal peak is extremely sought. Accordingly, an extensive study on its function and

transforming the findings into industry application also seems realistic. The simplest approach in

term of technical requirement to make it available throughout the year can only be seen through

drying process. Hence, this study will focus on rambutan seed drying process to enrich the previous

findings that obviously highlighted on their usability as well as to fill up their lack in sustainability.

mailto:[email protected]


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Drying is moisture removal process to achieve equilibrium moisture level that is safe from

microorganism’s multiplication as well as physicochemical degradation at specified temperature

and a relative humidity (Hall, 1980). Therefore, as quite often drying process is adopted as pre-

treatment to prolong time span of agriculture crop, thus a different drying approach of rambutan

seed will be focused in this study. The different approach involves the improvement of the drying

process through the optimization of convective drying process using an automatic electric drying

oven. Adopting response surface methodology tool in drying optimization of automatic electric

oven for rambutan seed clone R4 is a novel attempt to minimise experimental works as well as to

promote cost effective. The selection of rambutan seed clone R4 is due to its higher fat content as

stated by Augustin and Chua (1988). Therefore, as higher yielding of fat extracted are required

due to all industrial need came from their fat extracted thus clone R4 was selected.

This paper aims to determine the optimum drying condition of rambutan seed clone R4

under convective drying by automatic electric oven based on fat yield. The relationship between

the independent factors and response is established through mathematical model to estimate the

fat yield. In addition, the effect of temperature and drying time upon fat yield were also determined.

Hopefully, this study will boost up the confident level among manufacturer to translate the

previous research findings into industrial applications according to their functionality. Due to it

expected to provide the optimum drying condition of rambutan seed clone R4 with higher fat

yielding, thus, greatly seem if it will be a turning point to rambutan seed revolution. Then,

rambutan seed fat extracted will be considered as an alternative raw material to support primary

sources in attempting to reduce production cost as well as diminish global food crisis.

2. MATERIALS AND METHODS

2.1. Materials

Rambutan fruit clone R4 was obtained from University Agricultural Park, TPU, Universiti Putra

Malaysia (Serdang, Selangor). After harvesting, the fruits were manually deskinned and deseeded

before being stored in zip-lock polyethylene plastic bags at 4 °C in chiller (Protech SD-700,

Saintifik Maju, Malaysia) prior to drying. For the oil extraction process, n-hexane used was

supplied by Fisher Scientific (Malaysia).

2.2. Drying Process

An automatic electric oven model OF-22GW (Jelotech, Korea) was used to dry the rambutan seed

clone R4 up to equilibrium moisture content. The initial moisture content was measured according

to standard methods for the analysis of oils, fats and derivatives of IUPAC 6th edition (Paquot,

1979). Each drying runs were performed at different temperatures (40 – 650C) and drying times

(32 – 43 h) according to the central composite design experimental design given in Table 1. The

moisture loss of seed was determined by weight loss using an analytical balance AY220

(Shimadzu, Japan) with a precision of 0.0001 g for every 20 minutes time interval until the weight

loss is less than 0.0005 g.


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2.3. Optimization Process Optimization tool used in this study is the response surface methodology (Minitab 16, US). Two

independent factors: temperature (𝑋1) and drying time (𝑋2) in the range of 40-65 °C and 32 - 43 h

were selected based on a preliminary screening process. The central composite design composed of 13

treatments including 22 factorial points, four axial point (α = 1.414) and 5 repetitions at the centre

point. The design of experiments and dependent variable values are presented in Table 1. Three

replicates were performed for each experimental run. The effects of the temperature and the drying

time will be measured via multiple regressions as describe in Eq. (1);

𝑌=𝛽0+𝛽1𝑋1+𝛽2𝑋2+𝛽3𝑋12+𝛽4𝑋22+𝛽5𝑋1𝑋2 (1)

𝛽0,1 𝑎𝑛𝑑 𝛽2 = linear terms

𝛽0,1,𝛽2 𝑎𝑛𝑑 𝛽5 = linear and interaction terms

𝛽0,1,𝛽2,𝛽3𝑎𝑛𝑑 𝛽4 = linear and square terms

𝛽0,1,𝛽2,𝛽3,𝛽4𝑎𝑛𝑑𝛽5 = full quadratic terms

Table 1 Design of experiments and dependent values

2.4. Fat Yield Determination

Once the sample completely dried, it was first necessary to cool down in desiccators prior were finely

ground using a laboratory mill 120 (Translab, Malaysia). The ground seed is then sieved (Endecott,

London) to obtain uniform particle sizes less than 500μm. The dried powder seed were defatted with

n – hexane in 1: 10 (seed powder : solvent) ratio for 8 h at a temperature of 70-80 oC in a Soxhlet

apparatus. An organic solution was evaporated by using a rotary evaporator to near dryness. Each

flask was then placed in the oven at 105oC for 1 hour, and afterwards kept in desiccators, cooled

up to room temperature and weighted. The fat yield was calculated as a percentage of the dry


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where, 𝑎 is the weight of the round bottom flask after extraction, 𝑏 is the weight of the round

bottom flask before extraction and 𝑐 is the weight of the sample before extraction (dried sample).

2.5. Data Analysis

The accuracy and validity of the optimum drying point is verified using a t- test between the

predicted and experimental data, and insignificant differences (P value > 0.05) must be obtained.

Insignificant difference is needed to ensure that the optimum point obtained is accurate, reliable,

repeatable and robust. The relationship between the independent variables and responses were

obtained through the analysis of variance (ANOVA) with Fisher comparison.

3. RESULTS AND DISCUSSION

3.1. Optimum Drying Condition

Three goals namely, target, maximum and minimum are used to determine an optimum point. Each

goal has two points; namely lower and upper that needs to be determined based on the lowest and the

highest response value from two different groups known as the experimental data (Fat yield) and the

predicted data (FITS). FITS is a simulation data generated via the software based on the experimental

data. In addition, each goal should also have a target value. The target value is the value that is aimed

by the user and it is different for each goal. Target value for the target goal is one point less than the

upper value, the value for maximum goal is the same as the upper value and value for minimum goal

is the same as the lower value. The lower and upper value refers to the highest and lowest values for

the experimental and FITS data set. Response optimizer will give a predicted response for each data

set together with the optimum condition (global solution) for every goal. Global solution is the best

optimum condition based on both data sets that were predetermined through the target. For example,

in the maximum goal, the global solution will provide the best conditions to obtain maximum fat yield

based on both data sets and vice versa. Thus, the result that is obtained through the response optimizer

is one optimum point of global solution and two predicted response values for every goal. Only one

predicted response required for each goal and it must be chosen from the two predicted responses that

have been given. The predicted response will be selected based on the response that can give the lowest

difference between the predicted value and target. All the predicted responses and optimum conditions

for each goal are shown in Table 2. Then, all the predicted responses and optimum conditions chosen

must be evaluated whether it is feasible or not before proceeding to validation. Feasibility can be

determined through the overlaid contour plot as shown in Figure 1.

The optimum point will be sketched in the overlaid contour plot and if that point is located in

the unshaded region then it is feasible and is ready to be validated and if placed in the shaded region,

hence it is not feasible and should be removed from being selected as an optimum point. Figure 1

clearly shows the minimum and maximum goals were not feasible as their optimum point placed in

shaded region and both the proposed optimum point were removed from as being the optimal points.

Therefore, an optimum drying condition for the rambutan seed clone R4 was found to be at 54.02 oC

drying temperature and 36.52 h drying time with 38.65% fat yield. This optimum point is proposed


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from the target goal. Even though the optimum point not given the maximum predicted fat yield, it is

still at the maximum range as the difference between optimum point proposed from target and

maximum goal is 0.23% in fat yield and it is less than 1%. As the difference is very small, thus, it can

be assumed that a target goal also provide a maximum predicted response. The insignificant differences

on predicted response obtained from these two goals by given P value > 0.05 (one – way ANOVA, P

value 0.423) for both variables tested also statistically support that both predicted response are within

in maximum range. A possible explanation for this might be that both variables between target and

maximum goals were different as only 4.8 minutes in drying time and 1.79oC for temperature (see

Table 2). Relatively small differences of the contributing factors (temperature and drying time) most

probably caused the relatively tiny changes on responses. Furthermore, the direct effects of temperature

and drying time on fat yield have not been closely examined. To date, previous studies have revealed

a correlation between temperature and moisture content as well as moisture content and fat yield

(Chimplee and Klinkesorn, 2015; Sirisompong et al., 2011). Therefore, the positive correlation

between temperature and drying time on fat yield that found in this study is interesting because it can

be postulated as indirect explanation for both correlations and theory that have been published

previously. It can thus be suggested that as temperature and drying time increases the fat yield also

increased at similar level of moisture content. Therefore, a small difference in temperature and drying

time from the target goal was not fail to provide a predicted response fat yield within the maximum

range. Accuracy, repeatable, reproducible and robust upon predicted response fat yield will be

determined by at least three repetitions of proposed optimum condition. Verification was carried out

at the proposed optimum drying point and found no significant differences were detected between the

repeated and predicted fat yield by given P value > 0.05 (one - sample T-test, P value 0.628). Thus,

the proposed optimum drying point obtained in this study is accurate, reliable and repeatable.

Table 2 Comparison values of target for different goals and values for predicted responses


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Figure 1 Overlaid contour plot for optimization drying process of rambutan seed clone R4 (a)

Minimum; (b) Maximum (c) Target . Indicator: *- The data obtained were round up for two decimal

points (see Table 2)


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3.2. Model fitting

All terms in Eq. 1 can be observed in Table 3. According to Table 3, linear and square terms and full

quadratic term exhibit higher coefficient of determination (𝑅2) which describes both independent

factors affect the fat yield perfectly by giving the value of determination coefficient (𝑅2) 0.941 and

0.942 However, there is an opinion that stated the use of coefficient of determination (𝑅2) do not fully

show the perfect relationship between factors and response due to the fact that described a higher value

of (𝑅2) can be easily obtained by simply adding the number of terms that are tested in one relationship.

As number of term increased, the coefficient of determination (𝑅2) is also increased. It can briefly

described in this study where linear and linear and interaction which has only two terms showed a

lower value coefficient of determination (𝑅2) compared to linear and square and full quadratic whose

total term 5 had a higher value of coefficient of determination (𝑅2). Therefore, currently, researchers

starts to use adjusted determination coefficient (adjusted (𝑅2 )) as an indicator to determine the

relationship between factors and response in order to improve accuracy and also lowers the error in the

research. Adjusted (𝑅2 ) able to improve the accuracy in describing the relationship between the factor

and response as the coefficient determination given was based a correlation between additional terms

upon existing term. Hence, adjusted coefficient of determination (𝑅2 ) value was not directly increased,

however, it take after a comparison of variance of additional factors with existing variable occurred

and makes the adjusted coefficient of determination (adjusted (𝑅2 )) is more appropriate to be used as

indicator in selecting the optimal design in order to obtain the best model to illustrate the relationship

between factors and response. Thus, based on the adjusted (𝑅2 ), the best model to describe the

relationship between temperature and drying time on fat yield is linear and square model with given

an adjusted (𝑅2 ) is 0.911. Besides, a lower PRESS value in this model that represents the best model

in fitting each data point with experimental design also made linear and squared be the best model. In

addition, insignificant value of lack of fits testing (0.169) also supports linear and square as the best

model in this study. The insignificant value of lack of fits testing refers to regression and order model

obtained is correct. This selection is the best since it given higher number of significant terms (5 terms)

as equal to full quadratic model and also has significant value for the regression with reading P value

< 0.05. Therefore, the best model represents the relationship between temperature and drying time

upon percentage of fat yield was clearly shown in Eq. (3) as followed;

Y = 7.563 X1 + 21.552 X2 - 0.072X12 - 0.294X22 – 553.836 (3)

where, 𝑌 is fat yield (%), 𝑋1 is temperature (oC) and 𝑋2 is drying time (h). The model obtained may

provide a baseline data for enhancement drying condition of rambutan seed clone R4 under convective

drying influences.


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3.3. Effect of variables on fat Yield

The mathematical model obtained in Eq. 3 shows clearly the drying time (𝑋2) gives a relatively

stronger effect than the temperature (𝑋1), represented by a higher coefficient for the drying time

(21.552) in comparison with the temperature (7.563). The experimental data also supports this

findings as shown in Table 4, whereby no statistically significant changes in the fat yield were

found at constant drying times at 34.75 and 40.25 h when the temperature were varied from 46.25

to 58.75 oC. Hence, the entire fat yields are within the same range for these particular experimental

ranges. However, in general both factors have a positive effect on fat yield. This is clearly

demonstrated by the smooth circular distribution in the contour plot in Figure 2(a). Moving from

lower to higher fat yields, the circles were growing in parallel with the increase in the drying time

and temperature. In addition, the full umbrella-shaped of surface contour plot in Figure 2(b) as

well as the positive coefficients in the mathematical model in Eq. (3) is also obviously portray the

positive effects of the variables on the fat yield.

Table 4 Relationship of both factors on Fat yield (one-way ANOVA) at specified temperature (oC)

and time (h)

Table 3 Model analysis


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Figure 2 Contour and surface plot for target fat yield in optimization process (a) contour plot

(b) surface plot


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4. CONCLUSION

Returning to the question posed at the beginning of this study, it is now possible to state that

the optimum drying condition of rambutan seed clone R4 under convective drying by automatic

electric oven based on fat yield were found to be at the temperature of 54.02 oC and 36.52 h

drying time by generated model predicted a 38.65% fat yield. The study has also shown that

the second order polynomial or more precisely linear and square provide an appropriate

mathematical description of rambutan seed clone R4 under convective drying process by

automatic electric oven. This study also has identified both variables made a significant

difference to fat yield within studied range. The new correlation between temperature and

drying time on fat yield should help to improve predictions of the impact of process variable

on fat yield in rambutan seed clone R4 that can be adapted to further aid the extraction of fat

from other agricultural crops under convective drying influences.

5. ACKNOWLEDGEMENTS

The authors are grateful to financial support received through Universiti Putra Malaysia via

IPS research grant (vote no: 9464600) and Ministry Higher Education Malaysia as well as

Universiti Teknologi Mara Malaysia via young academic training scheme sponsorship.

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Chimplee S, Klinkesorn U (2015). Thin-layer drying model of rambutan (Nephelium

lappaceum L.) kernel and its application in fat extraction process. International Journal of

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Hall C W (1980). Drying and Storage of Agricultural Crops. Wesport, Connecticut: The AVI

publishing company, INC.

Lourith N, Kanlayavattanakul M, Mongkonpaibool K, Butsaratrakool T, Chinmuang T (2016).

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Rahayu L, Zakir L, Keban SA (2013). The effect of rambutan seed ( Nephelium lappaceum L

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Sirisompong W, Jirapakkul W, Klinkesorn U (2011). Response surface optimization and

characteristics of rambutan (Nephelium lappaceum L.) kernel fat by hexane extraction.

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Soeng S, Evacuasiany E, Widowati W, Fauziah N (2015). Antioxidant and hypoglycemic

activities of extract and fractions of Rambutan seeds ( Nephelium lappaceum L. ).

Biomedical Engineering, 1(1), 13–18.

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Bazúa C (2010). Composition, phase behavior and thermal stability of natural edible fat

from rambutan (Nephelium lappaceum L.) seed. Bioresource Technology, 101(2), 799–803.

Zzaman W, Issara U, Febrianto N, Yang T (2014). Fatty acid composition, rheological

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A FEASIBILITY STUDY OF LATRINE CONSTRUCTION

FOR BLACK WATER IN GUBENG DISTRICT, SURABAYA,

EAST JAVA, INDONESIA

Intan Permata Laksmi1 and Eddy Setiadi Soedjono2

1 Institut Teknologi Sepuluh Nopember, Indonesia – student, email: [email protected]

2 Institut Teknologi Sepuluh Nopember, Indonesia – Lecturer, email: [email protected]

ABSTRACT

Recently, issues regarding the Open Defecation (OD) behavior has not been resolved. Surabaya

Mayor issued a circular mayor to immediately realize a clean environment, healthy and towards

the area of Open Defecation Free (ODF). Gubeng is one of the districts in Surabaya located

near the center of government. However, based on the reports from Mojo and Pucang Sewu

Community Health Centre there are still 486 Family Head (FH) with OD behavior. This study

aims to determine the factors that influence people's decision to behave OD. The result of the

analysis of social aspect will answer the purpose of research, which will then be used as a

deciding factor in choosing the type of healthy latrine which will be discussed in the technical

aspect. Data for the social aspect by distributing questionnaires to 83 respondents from a total

of 486 Family Head with OD behavior. The social analysis result showed that the inhibiting

factor in OD behavior is the factor of land, where the study located in a densely populated

location so that the existence of land to put a septic tank is not available. The most crucial factor

is the economic factor where most of the income of the people in Gubeng district is under

minimum salary in Surabaya. Therefore, it is suggested to select 3-1 latrine type for its

economic factor, the manufacturing cost is relatively cheaper and then from the land factor, it

requires only 1.3 m2.

Key Words: Latrine, Open Defecation Free, Septic tank, Surabaya.

1 INTRODUCTION

Problem regarding to sanitation in Indonesia, especially the behavior of Open Defecation (OD)

has become a major topic in several national and international policies. Based on Milestones

Sustainable Development Goal's (SDGs), each country is expected to realize 100% sanitation

access for its population as listed on Goal 6 in 2030. National Medium Term Development Plan

Year 2014-2019 is targeting that by the end of 2019, Indonesia has to reach Universal Access

(UA). Thus, in 2019 the Indonesian living in urban and rural areas have already had 100%

access towards safe drinking water source and proper sanitation facility.

Data obtained until June 2016 showed that out of 514 districts/city in Indonesia there

are 5 Districts/City that are already declared as an Open Defecation Free (ODF) District/City

are Grobogan, Pacitan, Ngawi, Magetan and Madiun (Web-1). In response to this problem, the

mayor of Surabaya issued a circular mayor on accelerating the achievement of the MDG's, with

the first point of the declaration of ODF. In the Circular of Surabaya Mayor number


13

443/310/436.6.3/ 2015, one of the point is to immediately realize a clean environment, healthy

and towards the Village of Open Defecation Free (ODF Village).

Surabaya has 31 districts, 163 villages, and 62 health centre (Surabaya in Figures, 2015).

From 163 existing villages, only 30 villages were declared itself as an ODF Village. The area

of this study is Gubeng District, Surabaya. Besides its location that close to the centre of

Surabaya government, Gubeng is a district with a health facility, Dr. Soetomo Hospital, so it

needs a healthy and clean environment to prevent the environment from germs. In this study,

there will be an identification towards the inhibiting factors on OD-behaved community, then

the selection of the appropriate healthy latrine technology option to be applied next.

Sanitation is a part of environmental health science including how individuals or

communities manner and attempt to control and to maintain the external environment that are

harmful for health and which could threaten human survival (Zafirah, 2012). Meanwhile,

according to Kamus Besar Bahasa Indonesia (KBBI), sanitation is an attempt to foster and

create a proper condition the field of health, especially in public health.

There are two types of public behavior in Indonesia regarding to sanitation activity

particularly in defecation activity, those are open defecation and open defecation free. Open

Defecation (OD) is a condition where people still practice an open defecation in the river, the

garden, the sea or in other open places. While Open Defecation Free (ODF) is a condition where

people have not practiced open defecation, which is in the river, the garden, the sea, or in other

open places. A village is considered as an Open Defecation Free (ODF) by these following

criteria:

1. All people have already defecated and throw feces in the latrine;

2. No human feces around the environment;

3. An effort to improve the latrine quality towards healthy latrine;

4. There is the imposition of punishment, regulation or other effort by community to prevent

OD;

5. There is a general monitoring mechanism that created by community to achieve 100%

families to have healthy latrine.

Local sanitation system or best known as the on-site sanitation system is a system where

the wastewater treatment facility is located within the boundary of land owned, this facility is

an individual sanitation facility such as septic tank or pit (Ministry of Public Works, 2013).

Wastewater treatment technology of households with local systems typically use a septic tank.

Septic tank is a watertight room that serves to accommodate/to treat household waste water

with a slow flow rate and resulting in precipitation and decomposition opportunity of organic

materials by anaerobic microbe. In septic tank utilization, it needs a flowing water, a permeable

soil types and a deep enough ground water so that the impregnation system is progressing well.

Therefore, the septic tank is suitable for use in areas that have a clean water supply well with a

piping system or local shallow well, the soil conditions that can pass water, a deep enough

water surface location, and a low population density approximately does not exceed 200

persons/ha (Bintek, 2011).

A Healthy latrine has the following criteria:

1. It does not pollute the water (water bodies, ground water)

2. It does not pollute the soil surface (water absorption)


14

3. Free of insects

4. Odorless and convenient

5. Safe to use by the user

6. Easy to clean and do not cause interference to the user

7. No cause an irreverent view

The construction of healthy latrine have 5 main elements which are closet, septic tank,

ventilation, manhole and absorption. A proper closet is a swan neck closet model. The

advantage of this model is that there will always water in its neck to prevent odors into the air

and also prevent insects or flies to in and out. While septic tank served as sludge treatment

place (not just container) and include all of the waste water that come from the closet (black

water). Manhole is used to monitor when the septic tank will be drained, then drainage will

past the manhole. In addition, field/absorption well serves to absorb water as a barrier/filter in

order not to contaminate groundwater.

Septic tank shape does not affect the process or the working draft of the septic tank.

Therefore, planners are able to use cylindrical or rectangular septic tank. Septic tank is divided

into two types based on the type of wastewater that goes into it, that are mixed system and

separate system septic tank. A mixed septic tank system is a septic tank that receives the waste

water not only sludge from the closet but also from the rest of bathing, washing or other

household activities. Meanwhile, a separate septic tank system is a septic tank that receives

sludge from latrine only.

Healthy Latrine Technology Option

1. Type 3-3-1

This type consists of two septic tanks with a height of 1.5 m (equal to the number 3 buis

concrete with a high of 0.5 meters each stacked) and one with a high absorption of 0.5 m, a

diameter of 80 cm using a third

2. Type 2-2-1

This type consists of two septic tanks with a height of 1 m (equal to the number 2 buis concrete

piled 0.5 m) with a diameter of 80 cm and a height of 0.5 m catchment and a diameter of 80

cm

3. Type 3-1

This type consists of one septic tank 1.5 m high with a diameter of 80 cm and 1 absorption

height of 0.5 m with a diameter of 80 cm

4. Type 2-1

This type consists of one septic tank 1 m high with a diameter of 80 cm and a catchment of 0.5

m in diameter 80 cm (MoH RI, 2008).


In this study, the aspect being analyzed is the social and technical aspects. The primary data

collection method is done by implementing field observations, giving questionnaires, and also

interviewing the respondents. Thus, the respondents are determined by using Slovin formula,

as shown in Eqs (1) below:


15

(1)

Where:

n = the number of sample

N = the number of population

e = margin of error tolerance (0.1 to 0.01)

Determining the number of sample in this study is using the value of e = 0.1, which means the

result of the data collection has a valid level of 90% of research (Basri, 2012). The calculation

method for the number of sample on each type of questionnaire,

• The total number of OD-behaved community for OD questionnaire = 486 KK

• The calculation of the number of sample: Total sample of OD questionnaire =

(486 / (1+ (486x (0.1 2))) = 82.935 ≈ 83 respondents.

• Furthermore, to determine the number of sample or the respondent of each village is done

by using random sampling systematic method, where the total population of each village

is used as a percent value, then the result of slovin formula calculation is multiplied by the

percentage value of each village and the results were used as a sample/respondent number.

This following calculation is a calculation sample for determining the number of sample/

respondent:

The calculation sample for Airlangga Village

Total number of OD Family Head in Airlangga Village = 55 Family Head

Percentage of OD Family Head in Airlangga Village as this following:

Total number of OD Family Head x 100%

= 55 FH/486 FH x 100%

= 11%

So that the number of respondent in Airlangga Village as this following:

Percentage of OD Family Head in Airlangga x Number of total sample for OD

Questionnaires

= 11% x 83 respondents

= 9.39 ≈ 10 respondents

To be more detail, the calculation result can be seen in this following table:


16

Table 1 The Number of Research Respondent

No Village Total (FH) OD FH Percentage of

OD FH

Number of OD

Respondents

1 Airlangga 6.683 55 11% 10

2 Mojo 14.183 85 17% 15

3 Gubeng 4.732 50 10% 8

4 Kertajaya 7.860 267 55% 45

5 Pucang Sewu 4.630 29 6% 5

6 Baratajaya 5.143 0 0% 0

Total 43.231 486 83

Source: Puskesmas Mojo and Pucang Sewu, 2016.

Calculation Results, 2016.

Data analysis method is done gradually, starting from the stage of identifying problem

and sanitary implementation problem, and then proceeds with the technical aspect. For field

observation data or survey related to technical aspect, after all the data collected, the first step

to do is to identify the factor which makes OD-behaved community. The next step is the

planning of sanitation technology options by observing the questionnaire result. From those, it

can be seen the main constraint in community, the environmental condition, and also the

community ability.


The type of respondents’ work are grouped into five work options. In the questionnaire for OD-

behaved community, the first position with the highest percentage approximately 41% are self-

employed/entrepreneur. The second position approximately 29% working as a casual laborer,

approximately 27% working as a private employee, retiree 2% and civil servant 1%. The family

income is closely related to the job of the family head or the bread winner. Place and work

position are the key of how much revenue/income of a person. Assessment on the respondent

income is approximately between less than Rp 500.000 up to Rp. 6.000.000 or more. For OD-

behaved community questionnaire, the income is approximately between Rp 500.001 - Rp

1.000.000 that is 30%. The income of Rp 1.000.001 - Rp 1.500.000 is 21% and Family Head

(FH) with an income less than Rp 500.000 is approximately 20%, then the income of Rp

1.500.001 - Rp 2.000.000 is approximately 17% and 12% is the income of over 2.000.001. In

this study, the community income is an influential factor since this study will discuss the

community ability to build a healthy latrine. In the Ministry of Work and Public Housing

Regulation No. 20/PRT/M/2014 on the financing of home ownership simple criteria are

referred as Low-Income Communities is the community who have limited purchasing power

with a monthly income of Rp 4.000.000 while the data obtained indicate that all respondents

had an income below Rp 4.000.000, so that it can be said that all respondents for OD-behaved

community questionnaire is the Low-Income Communities. Based on the East Java Governor

Regulation Number 68 in 2015 on district/city minimum wage in East Java in 2016, the City

Minimum Wage in Surabaya is approximately Rp 3.045.000. It shows that almost all the

respondents’ income are under City Minimum Wage in Surabaya.


17

Land and home ownership status of respondents for OD-behaved community

questionnaire is approximately 80% state that the house they occupy is now a self-owned, while

19% state that they contract or rent the house annually. If they do not have a land or a house

(monthly or annually rent), then they will not concern about the environment around the land

or the house. Similarly, the existence of healthy latrine place they occupy, they will not care

about the presence or absence of healthy latrine.

All respondents have had a swan neck closet, but for feces disposal, the respondents

claimed that they do not throw towards interceptor or septic tank. As many as 18% of

respondents know that the closet disposal is from their closet to drainage pipeline/trench in

front or of their house, while the other 82% know that the disposal is from their closet to the

river.

The reason that makes people still not having a healthy latrine is because of financial

problem which is already known that the majority of people income are in the category of

lowincome community. To meet basic needs such as food, clothing and housing, people have

been working too hard, instead they have to set aside money to build latrine that cost

approximately more than Rp 1.000.000. In addition to financial factor, land factor also

influence people to build healthy latrine. Land limitation is a challenge for densely populated

urban communities to build healthy latrine, which should really pay attention to the

environment so as not to pollute the environment. In addition, land ownership also be an

interesting thing where a lot of houses for rent, but without healthy latrine (septic tank) so that

people who rent the house did not feel that the development of healthy latrine is the

responsibility of the homeowner. Community knowledge about the importance of keeping the

environment also affect decision-making, where most people feel that the river to throw a

household waste water is still able to accommodate their waste water so that they do not want

to be bothered to build latrine.

Septic tank is a type of fecal individual containers in accordance with the requirements

of protecting the environment. In Gubeng which has a high population density, the use of pit is

not recommended because it will pollute the environment and able to cause diseases for the

environment. The use of septic tanks should also be considered in order not to pollute the

environment, seen from the security of top lid, a waterproof wall and a ventilation. Septic tank

should be drained at least 1 time in 3-10 years or depending on the volume of the septic tank

owned and the number of people who use it. The top lid septic tank must be made strong in

order not to collapse or subsidence, and also had to be opened/has a manhole to simplify the

process of draining, septic tank wall must also be waterproof so that waste water is able to flow

first so it can reduce environmental pollution. Ventilation on septic tank also need to be

considered as a feasibility assessment of healthy latrine. Ventilation is useful to remove residual

gas from the anaerobic process occurs in a septic tank in the form of methane gas. It will cause

an odor and explode if this gas does not throw.

Based on the questionnaire result in which some respondents did not build latrine is due

to financial factor and limited land, then the choice of sanitation technology option can use a

septic tank-tubular type 3-1, where the septic tank is composed of two pieces of tube.The first

tube is a septic tank tube with a depth of 1.5 m and a second tube is an absorption well with a

depth of 0.5 m. A healthy larine type 3-1 is the right choice because it safe from landslides. As

the data collected, Gubeng has Alluvial soil types with thick ground between 10-18 meters.

Even if Gubeng is a prone flooding area, but it also recede quickly so it does not disturb the

surrounding. Moreover, the 3-1 type is an affordable technology option in terms of finance and


18

the usage period is longer than 2-1 type. Limited land is also a plus point in using this option

because it requires land approximately 1.6 m x 0.8 m or 1.3 m2. The advantage and disadvantage

of each type of technology options can be seen in Table 2.

Table 2 The Comparison of Latrine Type

Type of Latrine Advantages Disadvantage

Type 3-3-1 - A longer draining period - An expensive construction

cost

- A more stable building due to its

depth of 1.5 m

- Requires large land

Type 2-2-1 - A longer draining period - An expensive construction

cost

- Requires large land

- A less stable building due to

its depth of 1 m

Type 3-1 - Requires an incomprehensive

land

- The draining period is not

longer than the type 3-3-1 or

2-2-1 - A more stable building due to its

depth of 1.5 m

- The price of construction is more

affordable compared to the type 3-

3-1 or 2-2-1

Type 2-1 - Requires an incomprehensive

land

- A faster draining

- A cheap construction cost - A less stable building due to

its depth of 1 m

Source: Analysis, 2016

Septic tanks should be built inside the house but there must be provisions that need to

be considered when putting a septic tank in the house. The manhole on septic tank is still made

for draining activity, with a width suitable with the Water Closet (WC) suction pipe WC or as

big as tiles/ceramic size of 30x30 cm. In addition septic tank vent pipe must also existed by

pointing to the outside of the house in order not to make odor inside the house. Up to now,

there is no rule that regulate the setting of septic tank inside the house, but many people in

Indonesia build it inside for the lack of land as the existing problem in Gubeng.

The development of healthy latrine technology 3-1 type using a directly printed buis

concrete on the spot because it is stronger and not easy to leak compared to finished concrete

buis and attached. PVC pipes are used to connect the closet with a 3 inch diameter of septic

tank and fitted with a slope of 2% of the length of pipe installed in accordance with SNI 03-

2398-2002. At the top of the septic tank will be installed a vent, where the measure used in the

installation of ventilation pipes which refers to the SNI 03-2398-2002, that is 2 inch diameter

of pipe and a minimum height of 25 cm from the ground. A planned septic tank has a

height/depth of 1.5 m in accordance with the SNI 03-2398-2002. While the diameter is 0.8 m

in accordance of Ministry of Health direction.


19

This capacity calculation is to determine the maximum usage period of the planned

septic tank. It should be noticed that the number of human sludge per year is 30

liters/person/year (IKK Sanitation Improvement Programme, 1987).

• Assumed one house there are 5 people

• The volume of sludge per year (one house)

= 5 x 30 liter/person/year

= 150 liters/year

= 0.15 m 3

• Buis Concrete Diameter = 80 cm = 0.8 m

• Height/depth of the septic tank (h) = 150 cm = 1.5 m

• Septic tank volume types 3-1

= 3.14 xr 2 x (h 30 cm)

= 3.14 x (0.4) 2 x (1.5 to 0.3)

= 0.60288 m 3

(The figure is 30 cm high free board and also high surveillance on septic tank).

• Septic Tank Capacity Type 3-1

= 0.60288 m 3 / 0.15 m 3

= 4.019 years = 4 Years 2 months

The capacity for each type of latrine technology is designed for long periods of use 3-5 years

for each draining (SNI 03-2398-2002). The calculation of this capacity could have missed the

fact, because the actual capacity depends on the use of septic tank and the amount of incoming

sludge.

4 .CONCLUSION

The factor influence some residents in Gubeng still doing OD-behaved and do not build a

simple healthy latrine is because of the lack of knowledge on the importance of environmental

health, then the lack of land and economic/financial are also become the inhibiting factor where

most of residents income are under the City Minimum Wage in Surabaya. Based on the

questionnaire result for people with OD-behaved, as seen from the social factors that constrain

the existing environment as well as the number of sanitation technology options that are used

by people in Gubeng, it takes Healthy Latrine Technology Option type 3-1 to be chosen.

REFERENCES

Anonim, 2008. Millennium Development Goals (MDG’s), Jakarta.

Anonim, 2015. Surabaya in Figure 2015. Badan Pusat Statistika, Surabaya.

Anonim, SNI Number 03-2398-2002 about Tata Cara Perencanaan Tangki Septik

Dengan Sistem Resapan.

Anonim. 2014. Kamus Besar Bahasa Indonesia. Jakarta.


20

Basri, Seta, 2012. Menentukan Jumlah sampel penelitian Menggunakan taraf Keyakinan

Penelitian, Jakarta

Bintek, Kementrian Pekerjaan Umum, 2011. Air Limbah Domestik: Dasar-Dasar Teknik dan

Pengelolaan Air Limbah, Direktorat Jenderal Cipta Karya, Jakarta.

East Java Governor Regulation Number 68 in 2015 about Upah Minimum Kabupaten/Kota di

Jawa Timur Tahun 2016

IKK Sanitation Improvement Programme, 1987, Laporan Perkembangan Ibu Kota Kecamatan,

Jakarta.

Kementrian Pekerjaan Umum, 2013. Tata Cara Pengoperasian IPLT Sistem Kolam. Jawa

Tengah: Satuan Kerja Pengembangan Penyehatan Lingkungan Pemukiman Jawa Tengah,

Jogjakarta.

Ministry of Health Regulation, Number. 852/Menkes/SK/IX/2008 about Strategi

Nasional Sanitasi Total Berbasis Masyarakat (STBM)

Ministry of Public Work Regulation, 2013. Tata Cara Pengoperasian IPLT Sistem

Kolam, Jawa Tengah: Satuan Kerja Pengembangan Penyehatan Lingkungan

Permukiman Jawa Tengah, Yogyakarta.

Ministry of Work and Public Housing Regulation No. 20/PRT/M/2014 about Fasilitas

Likuiditas Pembiayaan Perumahan. Dalam Rangka Perolehan Rumah.

Sanitarian Puskesmas Mojo, Ibu Sulistyo Anik, Contact Person : 085692606558

Sanitarian Puskesmas Pucang Sewu, Ibu Aini, Contact Person : 085731060528

Surabaya Mayor Regulation number 443/310/436.6.3/ 2015 about Peningkatan

Kesehatan Masyarakat

Web-1 : http://stbm-indonesia.org, consulted 19 July 2015

Zafirah, T. H., 2012. Student paper: Pelaksanaan Penyelenggaraan Sanitasi Dasar Di

Pasar Tradisional Pringgan Di Kota Medan Tahun 2011. USU Sumatra.

http://stbm-indonesia.org/


21

AUTOMOBILE KIT USING JATROPHA OIL AS FUEL IN

COMPRESSION IGNITION ENGINES: DESIGN AND SHORT-

RUN TEST

Shehrbano Fatima1, Rizwan Ahmed Memon2, Imtiaz Ahmed Malik1

1Department of Industrial Engineering & Management, Mehran University of Engineering and

Technology, Jamshoro, Pakistan. 2Department of Mechanical Engineering, Mehran University of Engineering and Technology, Jamshoro,

Pakistan. Email: [email protected]

ABSTRACT

The global energy crisis is continuously compelling scientists and engineers to look for energy

extraction from renewable sources. Jatropha Curcas yields oil which has the potential to

contribute towards sustainable development of the society. The prolonged use of Jatropha

Curcas Oil results in wear and tear of the existing running engine because of its high viscosity

as compared to diesel. Viscosity reduction by blending Jatropha curcas oil with diesel is

common but this increases the average fuel cost. The compromise is to be made between the

blend ratio and overall cost. This article proposes the design of an engine modification kit which

runs on 70:30 Jatropha-Diesel blends by utilizing heat from radiator. Thermal analysis of heat

exchanger was done to calculate number of tubes and internal flow area. The engine was tested

for 30 minutes run at the average rpm of 2000 during which the temperature of Jatropha Curcas

oil increased from 25oC to a maximum of 96oC at which point it became stable. The test results

showed that the viscosity of the oil dropped down to an optimum level post the heat exchanger,

making it a more mobile fuel and suitable to be used in an unmodified compression ignition

engine.

Key Words: Engine Modification Kit, Jatropha Curcas Oil, Viscosity, C.I Engine

1 INTRODUCTION

The world’s conventional energy resources are coming to an end. Scientists and engineers are

directing their energies towards extraction of energy from renewable sources. Many vegetable

oils are capable of serving as potential alternatives sources of energy and have characteristics

quite similar to that of diesel. Jatropha Curcas is one such candidate which could contribute

towards sustainable development of the society. It is a plant that yields biodiesel that has

opportune properties making it a good candidate for clean and renewable energy production

(Openshaw, 2000).

The pure plant oil (PPO) from Jatropha has a high viscosity as compared to diesel. Thus

the prolonged use on existing compression ignition engines can cause multiple problems due

to this higher viscosity (Abadi and Omer, 2015). These problems include incomplete

combustion, increased fuel spray penetration and reduced fuel atomization, thus leading to



22

thickening of lubricating oil, permanent damage to injection equipment and high engine

deposits (Nuhu et al., 1998). In cases where existing running diesel engine is to be used, the

high viscosity would create problems in combustion, pumping and atomization in the injector

systems of the engine (Jindal, 2015). Therefore, the reduction in viscosity of Pure Plant Oil is

of prime importance so that it can serve as a promising alternative fuel in Compression Ignition

engines.

To encounter the problem of high viscosity, various methods are in practice. These

include pyrolysis, trans-esterification, blending and preheating (Kole et al., 2012). The

processes of trans-esterification and pyrolysis, reduce viscosity by changing composition and

chemical structure respectively but are complex and costly processes (Openshaw, 2000).

Blending jatropha curcas oil with less viscous fuels is another approach towards the solution to

viscosity problem but this too is costly, especially when the blend ratios are kept low (Kumari,

2009). Reducing viscosity by heating jatropha Curcas oil before injecting it into the pistons is

a more feasible approach (Ramkumar and Kirubakaran, 2016).

Agarwal in 2007 conducted a research in which he studied the emission and performance

characteristics of compression ignition (CI) engine by reducing the viscosity of Jatropha Curcas

through preheating. The data collected was analyzed for various parameters such as brake

specific fuel consumption (BSFC), CO2, CO and HC emissions, smoke opacity and thermal

efficiency. For lower blend concentrations, the performance and emission results had near

resemblance to that of mineral diesel. However, for higher blend concentrations, performance

and emissions were observed to be deviating from the behavior exhibited by diesel (Agarwal,

2007). This suggests that a compromise is to be made between the cost benefit associated with

using preheated pure plant oil and blending.

K. Pramanik studied the properties of jatropha curcas oil and various diesel fuels blends

(J/D) i.e., 30:70 J/D, 40:60 J/D, 50:50 J/D, 60:30 J/D, 70:30 J/D and pure plant oil, in

compression ignition engine. It was revealed that the pure plant oil i.e., jatropha curcas oil and

blends experienced a significant drop of viscosity at higher temperatures (Pramanik, 2003).

For this study, pure plant oil from jatropha curcas and mineral diesel were blended in the

ratios of 70:30 (volume/volume). Heating 70:30 J/D blend to temperatures approximately

above 70oC reduces the viscosity to acceptable levels (Pramanik, 2003). Preheating itself

requires input energy. For automobiles, an engine modification kit utilizing engine’s waste heat

to preheat jatropha curcas oil may serve the purpose. A modification kit based on the same


23

approach was developed and tested for this study. Complete design of the heat exchanger is

presented in this article.

2 EXPERIMENTAL PROCEDURES

2.1 Modification Kit

Two fuel tanks were installed on the system. One supplied the system with mineral diesel

during the startup because during startup, the engine temperatures are not high enough to

provide heat for preheating. The other fuel tank was the reservoir to hold PPO. A heat

exchanger was placed in between the engine and the radiator connected by the hot water exit

line. Heat transfer takes place between hot water exiting the engine and J/D blend inside the

heat exchanger to further reduce its viscosity. As soon as the temperature of J/D blend reaches

an optimum value, the three way valve operates, allowing J/D blend to enter the engine via

pump and cutting off the supply from diesel tank. The water post the heat exchanger re-enters

the engine without being passed through the radiator unless the temperature reaches 80oC at

which radiator relief valve operates to allow water to pass via radiator. A simple schematic of

the modification kit is shown in Figure 1.

Figure 1 Modification Kit for Using Jatropha Curcas Oil in Compression Ignition Engines


24

2.2 DESIGN METHODOLOGY

The required heat transfer serves as the fundamental answer to what the dimensions of a heat

exchanger should be. For this study, log mean temperature difference was calculated to find

out the effective heat transfer area which calculated number of tubes and internal flow area.

The inlet and outlet temperatures of hot water and Jatropha were assumed as under:

Initial temperature of water at inlet = 100 oC

Initial temperature of jatropha at inlet = 25 oC

Exit temperature of water = 50 oC

Exit temperature of jatropha = 90 oC

1998 model of Toyota RZ (IL) 2.0L was used for the testing. Engine manual book

revealed that mass flow rate of fuel maintains an average value of 0.2 kg/s (approx at 2000

rpm).

The diameter and thickness of the shell and tube type heat exchanger were taken as given

by the Tubular Exchanger Manufacturers Association, Inc. (TEMA) standards. These are the

international standards, readily available in the market and most commonly used for fabrication

purposes. These dimensions are given in the table number 1.

As shown, the adopted method is the conventional way for calculating the number of

tubes and internal flow area for the shell and tube type heat exchanger (Taborek, 1979). Values

for heat transfer coefficients were taken from the book J.P. Holman, Heat Transfer, 9th Edition,

McGraw-Hill, 2002. The specific heat capacity of Jatropha oil was found to be 2000 J/kg 0C

(Sundarapandian, 2007). Based on these assumptions and calculations, a counter flow shell and

tube type heat exchanger was designed and fabricated. The method is as follows.

The heat transfer equation is:

Q=U.A.(Log Mean Temperature Difference) (1)

Table 1 TEMA Standard Dimensions

Parameter Dimension

Outer Tube Diameter 6.35 mm

Inner Tube Diameter 5.35 mm

Thickness 0.5 mm

Pitch 25.4 mm, 30o

Ao 0.0204 m2/m

Ai 0.017 m2/m


25

2.2.1 Heat Duty

Q = mjCpjTi

= (20 X 103) (2 X 103) (90 – 25)

= 2.6 KW

2.2.2 Log Mean Temperature Difference

The assumed temperatures for the calculations are as indicated by figure 1.

Log Mean Temperature Difference = 16.37oC

Correction Factor (calculated from ChemSof online software) = 0.8570

Corrected Log Mean Temperature Difference = 0.8570*16.37oC

= 14.03oC

2.2.3 Overall Heat Transfer Coefficient

U = Overall heat transfer coefficient = 1/[(1/hw)(Aw/Ai) + rw(Aw/Ai) + rwall + ri + (1/hj)]

The values of all the involved variables were taken from the book Heat and Mass Transfer

A practical Approach by Yunus A. Cengel. Third addition page 636.

hw is notation for heat transfer coefficient of oil = 4500

W/m2 K hj is notation for heat transfer coefficient of J/D blend

= 1583 W/m2 K

rj is the fouling on tube side = 0.0002

m2 K/W

rwall is the resistance of the heat exchanger wall between the two fluids = 6.17 * 10-5 [12]

rw is the fouling on shell side = 0.0009

m2 K/W

The above values gave overall heat transfer coefficient i.e. U = 81.66 W/m2 K

From equation (1) Area was calculated to be 4.2 m2

2.2.4 The Number of tubes

N = A / π d L

Where,

l is the tube length = 1 meter d is outer diameter of tube = 6.35 mm n = Number of tubes n = (4.2 m2) / π (0.00635 m) (1 m) n = 211

Number of passes = 4

Therefore the number of tubes in one pass is,

n = 211/4


26

n = 52.5 tubes = 53 tubes approximately

2.2.5 Internal Flow Area

Af= π(0.172)/4

Af = 0.0454 m2

2.2.6 Internal Flow Area for a Single Pass

Af for one pass = 0.045 * 6 = 0.2732 m2

3 RESULTS AND DISCUSSION

The model employing the designed heat exchanger was tested for 30 minutes at 2000 rpm,

which was kept constant and temperatures were noted at different points in time. The

observations are depicted by figure 2. It may be noted that the temperature of J/D blend at the

outlet of heat exchanger was assumed 90oC for the calculations. However, during the test run,

the manually operated 3 way valve was made to open at 73oC, allowing J/D blend to enter the

engine. The maximum attained temperature for Jatropha at the heat exchanger outlet was

observed to be 96oC.

Figure 2 Temperature at Heat Exchanger Outlet at different points in Time

Engine test results revealed that 14 minutes after the engine startup, an automobile having this

engine modification kit installed can be made to operate on a J/D blend of 70:30 ratio provided

0

20

40

60

80

100

120

Temperature Observations at Different Points in time

Start After 14 minutes After 23 minutes


27

the rpm remains constant. However, during its operation, an automobile diesel engine runs at

varying loads and speeds which entail further refinement in the proposed design.

Moreover a prominent increase in heat exchanger dimensions i.e. number of tubes and

internal flow area shall be observed in case same approach is used to design a similar model

using 100% jatropha oil in place of J/D blend. Though the pure Jatropha Curcas Oil is more

economical but the size, dimensions and weight of the engine modification kit are critical

design parameters that contribute to increase in installation cost therefore must be paid attention

to.

4 CONCLUSIONS

The J/D blend ratio of 70:30 can easily get reduction in its viscosity to an optimum level. Oil

from Jatropha curcas has the potential to replace conventional energy resources. The pure plant

oil has a very high viscosity. Preheating it using the engine modification kit may help but the

required heat transfer area and hence the installation cost of the kit will cancel out the benefit

associated with using this biodiesel. J/D blend in the ratio of 70:30 provides a feasible solution.

However, there is always a room for improvement therefore the present design can be refined

and improved.

REFERENCES

Achal V, Kumari D, Pan X (2011). Bioremediation of Chromium Contaminated Soil by a

Brown-rot Fungus, Gloeophyllum sepiarium. Research Journal of Microbiology, 6: 166-171.

Abadi AG, Omer SM. (2015). Research article physical and chemical properties of jatropha

biodiesel. International journal of recent scientific research, 6: 5172-5174.

Agarwal A, Agarwal A.K. (2007). Performance and emissions characteristics of Jatropha oil

(preheated and blends) in a direct injection compression ignition engine. Applied Thermal

Engineering, 27: 2314–2323.

Cengel Yunus A. (2006). Heat and Mass Transfer A practical Approach. McGraw-Hill

Science/Engineering/Math. 3: 636.

Kole C, Joshi C, Shonnard D. (2012). Handbook of bioenergy crop plants. CRC Press, Boca Raton, FL.

Jindal.S. (2015). Low Cost Modification Kit for Retrofitting on Small Diesel Engines to Run

on Straight Vegetable Oils. Journal of Clean Energy Technologies, 3: 110-114.

Nuhu, I.; Sani, F.M, Rufai, I.A. (2014). Investigation of Corrosion Effects of Jatropha Biodiesel

on the Injector of an Engine Fuel System. International Journal of Engineering Trends and

Technology (IJETT). 8: 9-13.

Openshaw K. (2000). A review of Jatropha curcas: an oil plant of unfulfilled promise. Biomass

and Bioenergy. 19: 1-15


28

Pramanik.K. (2003). Properties and use of jatropha curcas oil and diesel fuel blends in

compression ignition engine. Renewable Energy. 28: 239-248.

Ramkumar.S, Kirubakaran.V. (2016). Review on Admission of Preheated Vegetable Oil in C.I.

Engine. Indian Journal of Science and Technology. 9(2): 11p.

Sundarapandian.S. (2007). Performance and Emission Analysis of Bio Diesel Operated CI

Engine. Journal of engineering, computing and architecture. 1: 1-22

Taborek J. (1979) Evolution of heat exchanger design techniques. Heat Transfer Engineering.

1: 15- 29.


29

DETERMINATION OF NAPIER GRASS FIBER YIELD FROM

DIFFERENT RETTING PROCESS TREATMENTS

Mohd Edyazuan Azni1, Che Wan Irsyaduddin Che Wan Takwa1, Zainal Abidin Mohd Yusof2, Asimi Ana

Ahmad1, Mohd Zulkhairi Abdul Rahim1, Muazzin Mupit1

1Section of Technical Foundation, Universiti Kuala Lumpur, Malaysian Institute of Chemical & Bio-Engineering

Technology (UniKL MICET), Alor Gajah, Melaka, Malaysia

2Section of Chemical Engineering Technology, Universiti Kuala Lumpur, Malaysian Institute of Chemical & Bio-

Engineering Technology (UniKL MICET), Alor Gajah, Melaka, Malaysia

ABSTRACT

This paper focus on the production of fibre from Pennisetum Purpureum or known as Napier Grass is from

three different retting process; which are water retting, biological retting, and chemical retting. From the

Napier Grass, only the leaves used which is for livestock feed. The stems were not in use so there a lot of

bio-mass being dump on the plantation area. Seeing the potential of the fiber, the project on ectracting the

fiber from Napier Grass has been done. There were three different process were used which is retting

process with water, retting process with 5% urea and retting process with 10% sodium hydroxide solution.

This paper intention is to analyze the characteristic of each type of fibre from three analysis test which are;

Thermogravimetric Analysis (TGA), single fibre tensile test, and Digital Scanning Calorimetry (DSC).

Then the pH value of the fibre cement board produced also will be tested.

Keywords: Napier grass, Water retting, Biological retting, Chemical retting

1 INTRODUCTION

From our current industry, the knowledge of natural fiber used in cement composites are largely increased

substantially. The glass fiber industry which was a great industry long time ago now have been replaced

by the natural fiber based on biodegradable resources due to the environmental issue.1 The research are

developing innovative and weight less material from the local place, and also in the cheaper price and of

course it is renewable sources.

Many literatures now discuss about various advantage of using the natural fibers in cement

composites. For example increase the flexural strength, increasing the impact toughness, increasing the

post-crack load bearing capacity and improving the bending strength.23 The natural fibers decompose at

melting point as same most with the polymers. Thus it is fascinating to study the effectiveness of fibers in

1 Larbig H, Scherzer H, Dahlke B, Poltrock R. Natural fibre reinforced foams based on renewable resources for

automotive interior applications. Journal of Cellular Plastics 1998;34 (July/August):361-79 2 Semple K, Evans D. Adverse effects of heartwood on the mechanical properties of wood-wool cement boards

manufactured from radiate pinewood. Wood Fiber Sci 1999;32:37-43. 3 Brandt AM. Cement based composite: materials, mechanical properties and performance. London:E & FN SPON; 1995.

P. 90-1


30

cement board composites. For this study, napier grass, or known as pennisetum purpureum used as the

natural fiber in the cement board composites. The napier grass fiber were extracted by three different retting

method which are; retting, chemical retting and biological retting process. The common retting process is

involving the water only, while the chemical and biological retting processes were involving urea and

sunhemp flower stalks respectively.

Besides, alkaline treatment is one of famous method that being used to removes some portion of

lignin, wax, and oils covering the exterior surface of the fiber cell wall itself. From the literature review, it

is found that 10% of NaOH solution treatment is the optimum method for result of 3 test on the fiber which

are; single tensile test, digital scanning calorimetry (DSC) test and also Thermogravatic (TGA) test4

2 MATERIALS AND METHODS

2.1 Material And Apparatus

Napier grass stem, water, 2% urea, 10% sodium hydroxide solution (NaOH) ,distilled water, water,

sunhemp stalks, sugar cane roll out machine, mallet, spray bottle, beaker container.

2.2 Methods

Fibre Preparations:

Napier Grass stem were collected from a farm at Kampung Orang Asli Bukit Payung, Alor Gajah, Melaka.

This farm was owned by Mr Halim, a retired teacher, who grows this napier grass for cattle’s and goats

feeding. The leaves / grass of Napier grass are taken for the fodder for cattle’s and goats while its stems are

thrown away. Thus, the initiative has been taken to reuse this waste stem as the fiber for the constructional

material.

Five to Six months old of Napier Grass were collected and extracted for fiber strands from the stems

or known as “canes” through two different process water retting process and chemical retting process. The

process started with water retting process where the stem is gently beaten with hammer and soaked in the

water about 4 weeks. Then stem is rolled out using sugar cane roll out machine to separate the fibers. The

fibers carefully washed with water to remove the impurities and dried in 3 hours to remove the moisture.

4 M. Hameem JA,Abdul Majid M.S,Afendi M, Idris F, Alkaline treatment and thermal properties of napier grass fibres,

2015 (August), 7-2.


31

Figure 1: Stem beaten gently

Figure 2: Soaking the stem in the water about 4 weeks

Figure 3: Rolling out the stem


32

Figure 4: The fiber extracted from the Napier Grass Stem

Then for the other treatment (chemical retting), 2% of urea solution was prepared and sprayed to the stem

for 2 days before soak the stems into the water as the previous (water retting) process. Then the stems were

taken to be rolled and separated for the fiber.

Alkaline Treatment of Napier grass fibers.

NaOH solution 10% was prepared and the napier grass from both different process soaked in the NaOH

solution at 28°C (room temperature) . The fibers immersed in the NaOH solution for 24 hours to remove

the celluloses5.

Figure 5 : NaOH solution prepared Figure 6: Alkaline Treatment of fiber

5 Kabir,M., H. Wang, F. Cardona, and T. Aravinthan. “Effect of Chemical Treatment on the Mechanical and Thermal

Properties of Hemp Fiber Reinforced Thermoset Sandwich Composites.” Incorporating Sustainable Practice in Mechanics and

Structures of Materials (2010): 439-44.


33

Physical Test

i. Single Tensile Test

The single fiber test was determined using the Universal Testing Machine LLOYD at speed

1mm/min. The gauge length was 50mm and the diameter of sample fiber around 0.16mm to 0.35mm and

length not more than 100mm.

ii. Thermogravimetric Analysis (TGA)

The samples are weighing before start the analysis. Untreated fiber (10.81mg), treated water retting

process (18.85mg) and treated chemical retting process fiber (14.77mg). The analyses were done at heating

rate of 20°C/min with starting temperature 30°C until reach 600°C. The nitrogen gas was used as

atmosphere at rate 10ml/mm. Each sample were analyse by the machine about 30 minutes duration time.

iii. Digital Scanning Calorimetry (DSC) test

Digital Scanning Calorimeter used to done the DSC test by weighing each of the sample; Untreated

fiber (4.81 mg), treated water retting process (9.00mg) and treated chemical retting process fiber (7.91mg).

The starting temperature is 30°C and final temperature set at 400°C at heating rate 10°C/min.

3 RESULT AND DISCUSSIONS

3.1 Single Fiber Tensile Test

Single fiber tensile test result is properties that important to the processing efficiency of fibers into products

and the quality of the products itself. The average tensile strength and also result for Young’s modulus of

each sample untreated, water treated, urea treated sample are presented in table 1. From the table it can be

seen that the highest strength is seen for urea treated with 10% NaOH solution of Napier grass with strength

108 MPa. The second highest is the water treated with 10% NaOH solution with 56 MPa and the least is

the untreated Napier Grass with 40MPa strength. The result shows that the urea treated with 10% alkaline

solution of Napier Grass increase its strength up to 63% from the untreated Napier Grass.

The alkaline treatment causes fibrillation to happen where the process will cause the fiber bundle to

break into smaller bundles. This small bundle help the load applied to the fibers to distribute throughout

the fiber.6 For the strength, it can be concluded that the urea treated with 10% NaOH solution Napier Grass

has higher strength rather than the water treated and the untreated Napier Grass.

For the Young’s Modulus, it are shown that urea treated also has the highest Young’s Modulus value

followed by the water treated shows that the alkali treatment affect the strength of the fiber itself. The alkali

treatment of natural fibers causes a decrease in the spiral angle of cellulose microfibils which means the

arrangement of the cellulose chains are happened and will improve the tensile strength.7

From the table 2, the average maximum stress for the Napier Grass is still slow rather than the other

fiber. The urea treated with 10% NaOH solution Napier Grass has slightly higher than the Oil Palm EFB

6 Wong, K.j., S. Zahi, K.o Low, and C.c Lim. Fracture Characterisation of Short Bamboo Fiber Reinforced Polyester

Composites. Materials & Design 31.9;2010:4147-154. 7 Taha I, Steunage L, Ziegmann G. Optimization of the alkali treatment process of date palm fibres for polymeric

composites. Compos Interface 2007;14:669-84.


34

in the term of maximum stress and Young’s Modulus and a little bit lower than the Pineaple Leaf. The

presence of urea in the treatment has slightly affected the strength of the fiber that will be analysed in the

future.

Table 1: Mechanical Properties of Samples Napier Grass

Table 2: Mechanical Properties of other natural fibers

3.2 Thermogravimetric analysis (TGA)

Thermogravimetric Analysis is presented in figure 7 below shows degradation of all samples Napier grass

fiber. From the table 3, the urea treated sample has the highest Residual Weight % which is 28.17% where

the untreated is the lowest with 20.31 %. For the urea treated sample, it is found the 1st degradation happen

at 80.95 °C and the next degradation happened at 333.96°C where at this place, the de-polymerization of

hemi cellulose and some of lignin happened.13 The last stage occurred at 412.20°C, where at this time the

8 ZuhrI mym, Sapuan SM, Ismail N. Tensile properties of single oil palm empty fruit bunch (OPEFB) fiber. Sains

Malaysiana 2009;38(4):525-9 9 Gu H. Tensile behaviors of the coir fiber and related composites after NaOH treatment. Mater Des 2009;30:3931-4 10 Al-Sulaiman FA.Mechanical properties of date palm fiber reinforced composites. Mater Design 2006;30:3931-4. 11 Okubo K, Fuji T, Yamamoto Y. Development of bamboo-based polymer composites and their mechanical properties.

Compos Part A: App Sci Manuf 2004;35:377-8 12 Arib RMN, Sapuan SM, Ahmad MMHM, Paridah MT, Khairul Zaman HMD.Mechanical properties of pineapple leaf

fiber reinforced polyporopylene composites. Mater Design 2006;27:391-96 13 Aziz SH,Ansell MP. The effect of alkalization and fiber aligment on the mechanical and thermal properties of kenaf

and hemp bast fiber composites; Part 1-polyester resin matrix. J Compos Sci Technol 2004;64:1219-30.

Treatment Untreated Water

treatment

Chemical

(Urea)Treatment

Fiber diameter (mm) 0.35 0.18 0.25

Maximum stress (Mpa) 40 56 108

Young’s Modulus(Mpa) 1834 1501 3885

Elongation at break (%) 22.80 19.05 22.72

Fiber Tensile

strength(Mpa)

Young’s Modulus

(Mpa)

Elongation at

break (%) Reference

Oil Palm EFB 71 1703 11 8

Coir (Coconut) 138.7 6 10.5 9

Palm leaves 97-196 2500-4700 2-4.5 10

Bamboo 200 - 10 11

Pineaple leaf 126.6 4405 2.2 12


35

degradation of most alpha celluloses and lignin. This is showed that the lignin is the hardest part to be

decomposed as it requires high temperature14.

Table 3: The TG Analysis of each sample Napier Grass Fibers

Figure 7: TG analysis of untreated, water treated and urea treated sample of Napier Grass Fiber

14 Kabir, M., Wang H ., Cardona and Aravinthan T. Effect of Chemical Treatment on the Mechanical and Thermal

Properties of Hemp Fiber Reinforced Thermoset Sandwich Composites. Incorporating Sustainable Practice in Mechanics and

Structures of Materials. 2010;439-44.

Sample Untreated Water Treated Urea Treated

Temperatur

e (°C)

Residual

Weight

(%)

Temperature

(°C)

Residual

Weight

(%)

Temperature

(°C)

Residual

Weight

(%)

1st

Degradation 77.42 95.37 79.77 92.07 80.95 90.77

2nd

Degradation 310.03 68.76 337.06 54.56 333.96 34.85

3rd

Degradation 371.01 20.31 339.83 27.37 412.20 28.17


36

Figure 8: DSC test for each untreated, water treated and urea treated samples Napier Grass Fiber

3.3 Digital Scanning Calorimetry (DSC) test

From the DSC Thermograms, the thermal transition were observed and presented at figure 8. The glass

transition, Tg for the untreated Napier Grass Fiber is at 78°C, while for the urea treated sample, is at 82°C

and for the highest one is water treated at 85°C of glass transition temperature. At this Tg, the Napier grass

fibers molecules have enough energy to overcome the intermolecular forces and have the degree of

freedom. At this time, the napier grass fiber now becomes softer and more flexible. The water treate has

highest Tg value because of the part of lignin and hemicelluloses is removed from the alkalization process. 15The urea affect as the other layer to delay the process of removal lignin and hemicelluloses as affected it

Tg value lower rather than the water treated sample. Thus it shows that the thermal stability of the water

treated with NaOH sample increases compared to the other samples. From the DSC analysis, it is showed

that the water treated sample has the highest thermal stability followed by the urea treated sample, then

untreated sample. This is because the sample become more hydrophobic when treated with alkali because

the lost of hemicelluloses and part of lignin where contains the moistures.16

4. CONCLUSIONS

The influence of fiber treatment by water retting process, urea retting process, together with the NaOH

soaking process on single fiber tensile test, thermal analysis and digital scanning calorimetry test were

analyzed. From the single fiber tensile test, it can be concluded that the urea treated with the NaOH soaking

sample has the highest tensile strength with 108 MPa. For the TGA analysis, the urea treated sample has

15 Kabir, M., Wang H ., Cardona and Aravinthan T. Effect of Chemical Treatment on the Mechanical and Thermal

Properties of Hemp Fiber Reinforced Thermoset Sandwich Composites. Incorporating Sustainable Practice in Mechanics and

Structures of Materials. 2010;439-44. 16 Joseph, P.v, K. Joseph, S. Thomas, C.k.s Pillai, V.s Prasad, G. Groeninckx, and Mariana Sarkissova. The Thermal and

Crystalisation Studies of Short Sisal Fiber Reinforced Polypropylene Composites. Composites Part A: Applied Science and

Manufacturing 34.4;2003:253-66.


37

the highest residual weight left at 412°C for 28.17% of sample left after that temperature. The data shows

that the urea retting process with NaOH treated sample has good impact on the thermal stability. The DSC

than shows the water retting process with NaOH treated sample has the highest value of glass transition,

Tg indicate it is more stable in the thermal stability rather than the urea treated, because of present of urea

that delay the lost of hemicelluloses and part of lignin in the fiber.

5. ACKNOWLEDGMENTS

The authors would like to thank to Universiti Kuala Lumpur, UniKL MICET especially the polymer unit,

biochemical unit and process unit, for providing the laboratory equipment and facilities to conduct this

research. Great appreciative to Mr Halim, who help a lot by providing the Napier grass for this research.

REFERENCES

Larbig H, Scherzer H, Dahlke B, Poltrock R. Natural fibre reinforced foams based on renewable resources

for automotive interior applications. Journal of Cellular Plastics 1998;34 (July/August):361-79

Semple K, Evans D. Adverse effects of heartwood on the mechanical properties of wood-wool cement

boards manufactured from radiate pinewood. Wood Fiber Sci 1999;32:37-43.

Brandt AM. Cement based composite: materials, mechanical properties and performance. London:E & FN

SPON; 1995. P. 90-1

M. Hameem JA,Abdul Majid M.S,Afendi M, Idris F, Alkaline treatment and thermal properties of napier

grass fibres, 2015 (August), 7-2.

Kabir,M., H. Wang, F. Cardona, and T. Aravinthan. “Effect of Chemical Treatment on the Mechanical

and Thermal Properties of Hemp Fiber Reinforced Thermoset Sandwich Composites.” Incorporating

Sustainable Practice in Mechanics and Structures of Materials (2010): 439-44.

Wong, K.j., S. Zahi, K.o Low, and C.c Lim. Fracture Characterisation of Short Bamboo Fiber Reinforced

Polyester Composites. Materials & Design 31.9;2010:4147-154.

Taha I, Steunage L, Ziegmann G. Optimization of the alkali treatment process of date palm fibres for

polymeric composites. Compos Interface 2007;14:669-84.

ZuhrI MYM, Sapuan SM, Ismail N. Tensile properties of single oil palm empty fruit bunch (OPEFB) fiber.

Sains Malaysiana 2009;38(4):525-9

Gu H. Tensile behaviors of the coir fiber and related composites after NaOH treatment. Mater Des

2009;30:3931-4

Al-Sulaiman FA.Mechanical properties of date palm fiber reinforced composites. Mater Design

2006;30:3931-4.

Okubo K, Fuji T, Yamamoto Y. Development of bamboo-based polymer composites and their mechanical

properties. Compos Part A: App Sci Manuf 2004;35:377-8


38

Arib RMN, Sapuan SM, Ahmad MMHM, Paridah MT, Khairul Zaman HMD.Mechanical properties of

pineapple leaf fiber reinforced polyporopylene composites. Mater Design 2006;27:391-96

Aziz SH,Ansell MP. The effect of alkalization and fiber aligment on the mechanical and thermal properties

of kenaf and hemp bast fiber composites; Part 1-polyester resin matrix. J Compos Sci Technol

2004;64:1219-30.

Joseph, P.v, K. Joseph, S. Thomas, C.k.s Pillai, V.s Prasad, G. Groeninckx, and Mariana Sarkissova. The

Thermal and Crystalisation Studies of Short Sisal Fiber Reinforced Polypropylene Composites.

Composites Part A: Applied Science and Manufacturing 34.4;2003:253-66.


39

DETERMINATION OF MECHANICAL PROPERTIES OF OIL PALM

FROND (OPF) FIBER CEMENT BOARD

Nor Azlina Ramlee1, Mohd Edyazuan Azni1 and Shaikh Abdul Karim Yamani2 1 Malaysian Institute of Chemical and Bioengineering Technology, Universiti Kuala Lumpur, Malaysia,

[email protected] and [email protected] 2 Faculty of Applied Sciences, Universiti Teknologi MARA, Malaysia, [email protected]

ABSTRACT

In recent years the development and application of lightweight and durable construction materials has been

of great interest. As a result, natural fiber cement bonded boards are widely used in building constructions

throughout the world as suitable candidate for construction materials. One of natural fiber that easily

produced is fiber from palm oil tree. This benefit Malaysia greatly as Malaysia is among the top most

important palm oil producers in the world. As this industry becomes bigger and wider, a substantial amount

of oil palm frond (OPF) wastes is generated and create the problem of biomass waste overload. The

agriculture residue especially oil palm fronds (OPF) produce waste and environmental pollution that cause

high carbon dioxide (CO2) in the air and also increase the carbon footprint. This research paper describes

the development of eco-friendly oil palm frond (OPF) fiber cement board from agricultures waste for

application in the housing or building industries and for sustainable infrastructure regeneration. Three

different ratio of OPF to cement; 1:3.50, 1:4.00 and 1:4.50 with same thickness 25mm and density 600

kg/m3 was produced and tested. The mechanical properties such as modulus of rupture (MOR), modulus

of elasticity (MOE), internal bonding strength (IB) were analysed in this project. The boards were evaluated

according to Malaysian Standard MS 934:1986. From the observation, the lower ratio with high particles

OPF fiber 1:3.50 performed a higher bending strength MOR & MOE of the cement board.

Keywords: Oil palm frond OPF, fiber, cement board, eco-friendly .

1. INTRODUCTION

The oil palm tree (Elais Guineesis Jaq) is a major agriculture crop in Malaysia, where is rich with

lignocellulose. It is a unique resourceful and sustainable in being not only economically valuable and

productive but also that the trunks, frond, and the empty fruit bunches all provide the most useful source

of raw material of a range wood based industries. Advance studies from Sudin (1996) shown that fiber

extracted from the fronds can be used as wood aggregate in the manufacture of wood fiber cement

composite. According to Malaysian Palm Oil Board (MPOB), it was reported that Malaysia is the world’s

second largest palm oil producer. In the year 2008, Malaysia has generated approximately 51 million tons

of OPF, accounting for 53% of the total palm biomass (Goh et al., 2010; MPOB, 2009). Thus, OPF is a

solid agro waste which is abundantly available on oil palm plantations (Goh et al., 2010).

Currently, the disposal of the OPF is by direct decaying in the natural environment or by burning on

site, with only a small amount being composted. These practices are creating environmental problems, and

alternative ways to utilize or dispose OPF are needed (Tan et al., 2011). Nowadays, the development of

natural fiber reinforced composite based products to substitute traditional engineering materials is





40

becoming a trend in engineering application. Despite the inherent advantages of low cost, low density,

competitive specific mechanical properties and sustainability (Coutts and Warden, 1990). Fiber-reinforced

cement based materials have been used in many aspects of construction. Previous research studies that

steel, polymers and cellulosic fibers are most commonly used to reinforce cement-based materials, which

may range from cement paste to mortar to concrete (Mohr, 2005). Otherwise, nowadays many cement

boards have been used as building partitions for over one century (Y.W.Liu 2010).

2. MATERIALS AND METHOD

2.1 Materials

The dried oil palm frond was obtained from a private plantation nearby to Universiti Kebangsaan Malaysia

(UKM) in Bangi. The oil palm fronds were selected from 15 to 20 years old trees. The selected of oil palm

fronds were then transported to Malaysian Palm Oil Board (MPOB) for subsequent processing. Leaflets

were removed from the fronds. Only the petiole part was used in this study. The collected dried oil palm

frond was crushed by using hammer mill as shown in figure 1 (a). The average lengths of the OPF fiber

were 2 cm to 3 cm as shown in figure 1 (b). And the moisture content of dry OPF fiber is 13%.

Figure 1: (a) Dried OPF fiber (b) length of OPF fiber

Dragon Eco-friendly Portland cement type was used in this study supplied by YTL cement

corporation. Two chemicals has been used as an additive during processing the cement board which are

aluminium sulphate, Al2 (SO)4 and sodium silicate Na2SiO3. The mixture of chemical additive/ binder was

mixed well in order to increase the bonding and hardness of fiber board.

(a) (b)


41

2.2 Mixture Proportions

The mixture proportions of oil palm frond (OPF) fiber cement board are shown in Table 1. Three different

ratio of OPF to cement; 1:3.50 (B1), 1:4.00 (B2) and 1:4.50 (B3) with targeted density 600 kg/m3 will

produce.

Table 1: Ratio mix proportion of OPF

to cement

Each material was calculated specifically and the Table 2 shows the quantity of the material required

for board formation.

Table 2: Weight of material

Board No. OPF (g) Cement (g) Al2 SO4 (g) Na2SiO3 (g) H2O(g)

B1 441.78 1368.35 205.28 410`51 214.31

B2 397.18 1405.95 210.89 421.79 204.21

B3 360.79 1436.78 215.51 431.04 195.92

2.3 Board Preparation and Testing

The method for manufacture OPF fiber cement board is conducted as follows:

i. Weigh the constituents shown in Table 2.

ii. Put the fiber into mixer machine. Turn on the mixer.

iii. Then pour slowly the mixture of 10% aluminium sulphate (Al2 (SO)4 ), sodium silicate

(Na2SiO3) and distilled water.

iv. Blend ten minutes by middle speed of the mixer.

v. Open the cover of mixer, add the Portland cement carefully until finished.

vi. Blend ten minute until the mixture mixed well.

vii. Then turn off the mixer and open the cover. Collect the mixture.

Each batch of materials was prepared for two replicate. Next, the mixture was uniformly distributed

in a mould with dimensions of, 340mm × 340mm × 25mm, which was then placed on a metal plate and

covered with plastic (this prevented the board from sticking to the plate). Another plate was placed on the

Board No. OPF Cement Al2 SO4 Na2SiO3

B1 1 3.50 1.5% 3.0%

B2 1 4.00 1.5% 3.0%

B3 1 4.50 1.5% 3.0%


42

top of the mat. The mat was cold-pressed using a hydraulic press, which applied 100 kg/cm2 pressure gauge

for three minutes.

For primary curing to occur, the board was placed in conditional chamber for 24 hours. The board

were then removed from the mould and placed in the tank at the room temperature and consistent relative

humidity for 14 days final curing of the boards. The cured boards were cut into the test pieces. Then, the

specimens were trimmed into various pieces of different sizes as précised in MS 934: 1986.


As mentioned earlier the focus of this paper was to determine the mechanical properties for manufacturing

of oil palm fronds (OPF) fiber cement board. The boards were manufactured around 600 kg/m3 density and

can be considered as a lightweight cement board. The photographs of samples of the various OPF fiber

cement board are shown in figure 2 below. The analysis of mechanical strength was done by using

INSTRON testing machine.

(a) 1:3.50 (b) 1:4.00 (c) 4.50

Figure 3: OPF fiber cement board with different ratio

3.1 Mechanical Properties of OPF Fiber Cement Boards

The average value of mechanical properties of modulus of rupture (MOE), modulus of elasticity

(MOR) ,internal bond (IB) after 14 days curing was summarized in table 3. The result show that the density

of board are accepted as targeted which is ±600 kg/m3

The bending strength modulus of rupture (MOR) of ratio 1:3.50 are greater 18.8 MPa compared to

board 1:4.00 and 1:4.50 which is 14.3MPa and 12.3 MPa respectively. This is probably due to the amount

of particle fiber. It can said that more particle of OPF fiber in manufacturing increase the strength of cement

board. These three boards can be consider to be acceptable board that satisfied the strength properties of

the Malaysian Standard MS 934. Because in MS 934 for board of density more than 1000 kg/m3 the

minimum bending strength is 9 MPa. However, this board has density 604.16 to 661.59 kg/m3 which is

less than 1000 kg/m3 but the bending strength in this study is more than 9MPa which definitely satisfied

the requirement of the MS 934.


43

In addition, similar trend was attained for modulus of elasticity (MOE) where OPF cement board

with ratio 1:3.50 indicates higher result 2569 MPa compared another two board 2431.7 and 2362.6 MPa as

shown in graph in figure 5. These result can be consider acceptable board that satisfied strength properties

of MS Standard specification which is minimum requirement is 3000 MPa for 1000 kg/m3. But in this

study, the board density is lower 600±60 kg/m3 and the analysis show the modulus of elasticity is

approximate 2569MPa near to achieve 3000 MPa.

The internal bond (IB) values of OPF fiber cement board increased with increased ratio and all the

boards meet the specification of the Malaysian Standard MS 934 where is should be more than 0.50 MPa.

Table 3: Mechanical properties of OPF fiber cement board

Board

no.

OPF cement ratio Density

(kg/m3)

MOR

(MPa)

MOE

(MPa)

Tensile

Strength (MPa)

B1 1:3.50 661.59 18.8 2569.0 0.52

B2 1:4.00 632.42 14.3 2431.7 0.57

B3 1:4.50 604.16 12.3 2362.6 0.63

Malaysian Standard MS

934 >1000 9.00 3000 >0.50

Figure 4 Modulus of rupture of OPF fiber cement board

0

2

4

6

8

10

12

14

16

18

20

B1 (1:3.50) B2 (1:4.00) B3 (1:4.50)

MO

R (

MP

a)

OPF cement board ratio

OPF fiber cement board ratio Vs MOR (MPa)


44

Figure 5 Modulus of elasticity of OPF fiber cement board

4. CONCLUSION

The purpose of this study is to determine the mechanical properties in the production of low density oil

palm frond (OPF) fiber cement board especially for the application in wall for building industries. Based

on the results of the study, the following conclusion can be reached.

i. The trend for the density value of the OPF fiber cement board is decrease but still in acceptable

range; 600±60 kg/m3.

ii. The bending strength or Modulus of Rupture (MOR) of 1:3.50 ratio OPF fiber cement board

have higher result 18.8 MPa compare to board with ratio 1:4.00 and 1:4.50.

iii. All three OPF fiber cement boards can be consider to be acceptable board that satisfied the

strength properties of the Malaysian Standard MS 934 because more than 9 MPa for MOR value

and near to 3000 MPa for MOE specification.

iv. All board are meet internal bond (IB) specification which is optimum requirement for MS 934

is 0.5 MPa. The amount of chemical additives give influence to the internal bond strength and

this indicates the higher internal bond is at board ratio 1:4.50.

It can be conclude that oil palm frond (OPF) agriculture waste has a potential to be used as a value

added and natural materials in bio-composite industry to produce wall and multipurpose cement board in

future.

2250.0

2300.0

2350.0

2400.0

2450.0

2500.0

2550.0

2600.0

B1 (1:3.50) B2 (1:4.00) B3 (1:4.50)

MO

E (

MP

a)

OPF cement board ratio

OPF fiber board Ratios Vs MOE (MPa)


45

5. ACKNOWLEDGEMENTS

The author of this work wish to gratefully acknowledge the financial support and experimental facilities

for this work to the Universiti Teknologi MARA (UiTM) Campus of Jengka Pahang and Universiti Kuala

Lumpur.

REFERENCES

Coutts RSP, Warden PG, 1990. Effect of compaction on the properties of air-cured wood fiber reinforced

cement. Cement Concrete Compos, 12:151-156.

Goh CS, Tan KT, Lee KT, Bhatia S (2010). Bio-ethanol from lignocelluloses: status, perspective and

challenges in Malaysia. Bioresour. Technol., 101: 4834-4841.

Sudin R. (1996) Development, properties and durability of oil palm fiber cement composites, PhD Thesis,

University of Sheffield.

Sudin R. Ibrahim W.A. (1990) Cement bonded particle from Acacia Mangium – A preliminary study J.

trop For Sci. 267-273

Mohr BJ, 2005. Durability of pulp fiber-cement composites. Ph.D. Thesis, Georgia Institute of Technology

Y.W. Liu, 2010 Properties of natural fiber cement boards for building partitions Department of Civil and

Water Resources Engineering, National Chiayi University, Chiayi, Taiwan

Website:

Web-1 http://www.mpob.gov.my/ consulted 18th October 2016

Web-2 http://www.mpoc.org.my/The_Oil_Palm_Tree.aspx consulted 23th October 2016

http://www.mpob.gov.my/

http://www.mpoc.org.my/The_Oil_Palm_Tree.aspx%20consulted%2023th%20October%202016


46

ANALYSIS OF TEMPERATURE CHANGING PATTERN IN

THAILAND USING LINEAR REGRESSION MODEL

Chaloemchon Wannathong 1 and Attachai Ueranantasun 2

1 Department of Mathematics and Computer Science, Faculty of Science and Technology,Prince of Songkla University,

Pattani Campus, 94000, Thailand.email: [email protected]

2 Department of Mathematics and Computer Science, Faculty of Science and Technology,Prince of Songkla University,

Pattani Campus, 94000, Thailand.email: [email protected]

ABSTRACT

Global warming has been one of the primary concerns for the world's environmental problems over the

recent years. Understanding of temperature patterns locally can be helpful to evaluate the warming

situations for a particular area, and can be further combined and assessed for the climate at the larger scale.

Hence, this study aims to investigate changing patterns of temperatures in Thailand. Using satellite photos

recorded by NASA satellite (MODIS) for the period of 15 years, from 2000-2014. Five locations in

Thailand are purposefully selected to have a roughly fair distribution of each region around the country,

both in-land and by-the-sea. The data structure of satellite data is divided into days and nights for modelling

separately. After managing data, the data are analysed using the linear regression model to extract the

trends. The results show mixed directions of temperature changing patterns for day and night of the selected

locations.

Key Words: Temperature Changing Pattern; Linear Regression Model; Thailand

1. INTRODUCTION

The situation of global warming and climate change throughout the world has been one of the main alarms

for the crisis in global environment. Global mean temperature has been warmer by 0.3 °C to 0.6 °C for the

past couple of centuries, and this has been coincided with the increasing levels of greenhouse gases,

including carbon dioxide, methane and nitrous oxide, induced by human activities (Houghton, 1996). The

increasing temperature on earth’s overall surface has been a possible cause for climate alterability and, in

turn, an effect on a variance in agricultural products. Dore et al. (2005) conclude that the precipitation

patterns around the world, likely related to global increasing temperature, evidently changed, for example,

higher precipitation in the Northern hemisphere and lower precipitation in China, Australia and some

Pacific islands. For crop yields, the study on temperatures and rice yields at the research farm in The

Philippines from 1979 to 2003 reveals that the annual mean of minimum temperature for the location

increased by 1.13 °C, and grain yields are found to be decreasing by 10% for each 1 °C drop of minimum

temperature in the growing season (Peng et al., 2004).

The studies on temperature changes have been conducted for many regions in the world using

different methods, especially with statistical analyses. Multiple linear regression analysis is used by Lean


47

et al. (2009) to decompose monthly mean surface temperature anomalies since 1980 into four components

on a global scale. Global and regional changes in the next two decades are then projected. From 2009 to

2014, the rises in anthropogenic influences and solar irradiance increase global surface temperatures by

0.15 ± 0.03 °C, while the average temperature in 2019 will be only 0.03 ± 0.01 °C warmer than in 2014.

Hughes et al. (2006) study the variations in the minimum and maximum temperatures of the Antarctic

region using a multiple regression model with non-Gaussian correlated errors, and linear autoregressive

moving average (ARMA) models with innovations. The innovations have an extreme value distribution.

This analysis shows an increase in the minimum monthly temperature of approximately 6.7 °C over 53

years, from 1951 to 2003, without a significant increase in the maximum temperatures. Earth surface

temperature change above latitude of 45 °N from 1973 to 2008 is investigated by Wanishsakpong et al.

(2014) using linear modelling and factor analysis to study the trends and patterns of temperature changes.

The study also shows that the North Pacific Ocean had high temperature increasing level, ranging from

0.200 °C to 0.320 °C. For Alaska and Eastern Siberia including North Canada, Greenland, Iceland, Norway,

Sweden and Finland, moderate temperature increasing level are found to span from 0.130 °C to 0.199 °C.

The north of Siberia and parts of the North Atlantic show minimally increasing level of temperatures from

0.090 °C to 0.129 °C. The temperature changes in Southeast Asia during 1973 to 2008 are examined by

Chooprateep et al. (2014). The data structure is monthly surface temperature patterns from grid boxes of

40 regions inside latitude 25 °S to 25 °N and longitudes 75 °E to 160 °E. Multivariate linear regression

models are then fitted to the data. Temperatures are found to increase in all regions of Southeast Asia from

0.091 °C to 0.240 °C per decade. Anisimov et al. (2007) investigate the changes in air temperature in

Russia over the periods of 1900-1949 and 1950-2004. The spatial homogeneity of air temperature

anomalies within each studied is assessed through coefficients of correlation between the regionally

averaged temperature time series and series at each station in each region. The result shows that the

minimum coefficient of multiple correlations was found to be 0.8.

In Thailand, Most of the studies cover overall climate situations including rising temperatures,

rising sea level and lower precipitation with impacts on socio-economics. Naruchaikusol (2016) indicate

that the climate changes have been worsened in Thailand, for example, more warm days and fewer cold

days are evident. The study also points out that these changes caused both droughts and flooding in both

urban and rural areas. ICEM (2014) shows the results from the study on the Thailand portion of Lower

Mekong Basin. The results include the projection of rising temperatures in the areas for the coming years

and the threat to vulnerable crops like lowland rice and rubber. However, a study focusing mainly on the

temperature changes with statistical analyses has not been extensively performed in Thailand. One of those

few studies is from Limsakul et al. (2009) which investigate the extreme temperature patterns from 65

meteorological stations across Thailand from 1970 to 2006 with linear regression model. The results show

that annual series and means of daily minimum, averaged and maximum temperatures increase roughly

0.25 °C per decade. The temperature extreme indices have the same direction of warmer temperatures as

the overall region, particularly for indices related to daily minimum temperature.

To understand more about temperature changes in Thailand, more studies are needed to be done.

Another aspect of temperature, such as separated day and night temperatures, can provide more information

for analysing and characterising. Moreover, data from sources other than ground meteorological stations

can be implemented as another reference. Satellite data, for instance, can provide more coverage for areas


48

that are not in proximity of a ground station with higher accuracy than ground measurement. Therefore,

this study is aimed to analyses temperature changing patterns in Thailand, both day and night separately,

using data collected from the satellite images. The analysing part is implemented using linear regression

on freely available software.

2 METHODOLOGY

2.1 Data Collection and Management

For this study, satellite data from MODIS (Moderate Resolution Imaging Spectroradiometer) are freely

downloaded from Web-1.

MODIS is a capturing device installed in NASA satellites, Terra and Aqua, for recording images

of locations on earth, except for the North Pole and the South Pole. With the satellites’ orbits, MODIS

records images of each location for every eight days and every 16 days, depending on the locations, and

have been providing them publicly since 2000. These images can be converted into earth’s surface data

including temperatures from their colour index. The smallest resolution for each MODIS image represents

1x1 km2.

In this study, the study area is Thailand located in the tropical zone near the equator and between

latitudes 5 37 N to 20 27 N and longitudes 97 22 E to 105 37 E, covering the peninsula area of

513,115 km2. Five locations in Thailand were based on their geographical locations across the country. The

locations are located at five provinces - Nakhon Sri Thammarat, Payao, Phetchaburi, Phetchabun and Sakon

Nakhon from Southern, Northern, Middern and North Eastern parts of Thailand. Furthermore, there are

two groups of locations regarding their distances to the sea. Payao, Phetchabun and Sakon Nakhon are in-

land province, while Nakhon Sri Thammarat and Phetchaburi are a province by the sea. These criteria are

designed to approximately cover aspects of geographical differences.

In this study, the downloaded data from MODIS website are chosen from March 2000 to March

2014 (15 years) form five aforementioned locations from Land Surface Temperature (LST) datasets. For

each location, the area of 9x9 km2 for each image is selected. MODIS takes images every eight days above

Thailand area. Therefore, there are a total of roughly 46 periods each year for overall 15 years, which

equaled to 675 observations in total. However, due to missing data from MODIS database, each dataset for

each selected location provides different total images ranging from 630 to 675. These numbers of data are

sufficient to investigate the trend of temperature changing per each location in Thailand.

After downloading all chosen data, the data are cleansed for possibly unreliable temperature due to

random factors such as cloud covering. These unreliable data points are marked as not available and thus

are not included in the analysis. Consequently, cleansed LST data are converted into C before analyzing,

because the default unit of downloaded temperatures from MODIS is K. All data managements are

implemented using programs written in R Statistical Package (Web-2).


49

2.2 Statistical Analysis

Upon completion of preparing all temperature data for selected locations, the temperature data are divided

into two groups, day and night temperatures, and analysed separately. For each group, the patterns and

trends of the temperatures in these locations from 2000 to 2014 are modelled using linear regression as

follows.

𝑦𝑖𝑗𝑘 = 𝛽𝑖𝑘𝑎𝑖𝑘 + 𝛾𝑗𝑘𝑏𝑗𝑘 + 𝑐𝑘 (1)

where 𝑖 was a study year equalling to 1, 2, …,15, 𝑗 was a period for each image taken in one year equalling

to 1, 2, …,46, and 𝑘 was a study location equalling to 1, 2,..,5. Therefore, 𝑦𝑖𝑗𝑘 denotes the temperature data

in C for the year 𝑖 and the period 𝑗 at the location 𝑘, 𝑎𝑖𝑘 is the year 𝑖 at the location 𝑘, 𝑏𝑗𝑘 is period 𝑗 at

the location 𝑘, and 𝑐𝑘 was a random error of regression at the location 𝑘. 𝛽𝑖𝑘 and 𝛾𝑗𝑘 are coefficients from

the linear model for variables 𝑎𝑖𝑘 and 𝑏𝑗𝑘, respectively.

The results from the model are used to fit the patterns of temperatures for each location. Additionally,

the effects from 46 periods in one year are considered a seasonal or periodic pattern and thus are removed,

when a trend of temperature for each location is calculated. The plots for both patterns and trends of

temperature changes for five locations are then created and presented for day and night temperatures. The

changing trends are displayed in the map of Thailand for a clearer view of changes, both days and nights,

for all locations. The analyses and plots are implemented using R Statistical Package, except for the map

which is modified from website of ThaiSAT From Web-3 using an image editor.

3 RESULTS AND DISCUSSIONS

For all five locations, the details for changing rate of each temperature trend are also shown in Table 1,

while the plots for patterns from the models, compared to real temperature data from MODIS, are shown

in Figure 1 for day temperatures and Figure 2 for night temperatures. In each panel, the black plots represent

real satellite data, while the red lines indicate the patterns from the linear models. Furthermore, the trends

are presented in terms of how the temperatures changed over 15 years with a positive figure for an

increasing trend and a negative figure for a decreasing trend. The details for locations including names,

latitudes and longitudes are also shown in respective panels.

The results show that, for day temperatures, there is an increasing trend in Payao and Sakon Nakhon,

while other provinces have a decreasing trend of temperature. For night temperatures, an increasing trend

is found in Payao, Nakhon Sri Thammarat and Phetchabun, whereas temperatures in the other two

provinces experience a decreasing trend. The day and night trends for all five locations are thus presented

in the map shown in Figure 3.


50

Table 1 The list of five study locations in Thailand with both latitude and longitude coordinates and

Universal Transverse Mercator (UTM)

Location Latitude

(oN)

Longitude

(oE) Province

Day

Temperature

Changing (C)

Night

Temperature

Changing (C)

1 19 100 Payao 0.087 0.470

2 13 100 Phetchaburi -0.288 -0.091

3 8 100 Nakhon Sri

Thammarat -0.046 0.495

4 16 101 Phetchabun -0.585 0.261

5 17 104 Sakon Nakhon 0.341 -0.029

Figure 1 Day Temperature changing 5 locations in Thailand by MODIS during 2000-2014.

Figure 2 Night Temperature changing 5 locations in Thailand by MODIS during 2000-2014.

From the results, it is shown that linear regression can be fitted to the data quite well. The red trend

lines represent the pattern of temperature means of temperatures over the years. The differences between

the measured and fitted values are due to seasonal fluctuation for each location.


51

Almost all patterns cannot indicate a cycle change or repeated pattern in days or nights, except for

Nakhon Sri Thammarat and Sakon Nakhon, where the day and night temperatures, respectively, are going

up and down in a cycle-like with the period of 2-3 years. However, this is inconclusive to suggest that there

is a well-defined cycle, because the respective night and day temperatures of these two provinces are not

seen with the same cycle. It is needed a longer dataset of temperatures to confirm whether the cycle is well

defined for the locations. The other feature that can be retrieved from the patterns of temperature is an

indication that in almost all locations, both days and nights, the temperatures are higher in 2010 compared

to other consecutive years. This coincides with one of the strongest depression in Gulf of Thailand and the

great flooding incident all over the country in the year after (Web-4). Even though, it is not yet conclusive

that these natural events were connected with these high levels of temperatures, a further study of this

association needs to be conveyed.

Figure 3 Trends of Day and Night Temperature changing from 5 locations in Thailand.

The plots of temperatures also show that there are smaller differences between the maximum and minimum

temperatures, for both days and nights, in Nakhon Sri Thammarat and Phetchaburi than in other provinces.


52

At first, it seems to be the effects of differences in latitudes with low latitude indicating smaller differences

in peak temperatures. However, it is not valid when comparing Petchabun and Payao, for example. The

first is located at the lower latitude but showing a greater swing in temperature patterns. These smaller

differences, in turn, are found to be connected with the other aspect of the locations for these two provinces.

Nakhon Sri Thammarat and Phetchaburi are the only two by-the-sea provinces selected in this study, while

the others are a representative for an in-land province. This interesting finding is rather distinctive from a

well-established fact that it is less different for diurnal temperatures, or temperatures between day and

night, for sea or nearby sea temperatures. However, the result in this study indicates that the levels of day

and night temperatures, when examined separately, are also less fluctuating over the year for by-the-sea

locations than in-land locations.

The comparison of temperature trends between days and nights for selected locations in this study

is found to be a random variation. It can be seen that, in Payao, both day and night temperature trends are

increasing for the study period, while both trends are both decreasing in Petchburi. The other three

provinces are found to have different trends for day and night temperatures. For Nakhon Sri Thammarat

and Petchabun, the day temperature trend is decreasing, while the nigh temperature trend is increasing.

This is opposite to the trends in Sakon Nakhon, in which the day temperature trend is increasing and the

night temperature trend is decreasing. The ranges of changing temperature trends are also found to be in a

random fashion. For example, Nakhon Sri Thammarat shows a higher increasing trend for the night

temperatures compared to a lower decreasing trend for the day temperatures, while Petchabun has a lower

increasing temperature trend during the night compared to a higher decreasing temperature trend during

the day. It can be seen that the locations, for this study in particular, does not have an effect on the trends

in temperature changes. It can be considered that the local temperatures are not following the trends of

warming temperatures for a bigger scale found in other studies.

The limitation of this study is the number of selected locations. Even though, this study provides a

useful demonstration for studying temperature patterns and trends with a simple statistical technique like a

linear regression and shows some interesting findings, five locations can be considered not enough to be

conclusive for investigating for the whole country or region. The further study with more locations to cover

the whole country should be implemented.

4 CONCLUSION

This study indicates that using linear regression can be effective in finding patterns and trends in

temperatures. The results show that the patterns and trends in Thailand can be varied by locations when

analysing temperatures locally. It is also initially suggested that the fluctuations of temperatures for days

and nights are found to be smaller in the sites close to the sea. Even though, this study needs more locations

in Thailand to confirm the findings, it is a good demonstration in using a simple statistical method for

environmental study and its further applications.


53

5. ACNOWLEDGEMENT

The authors are grateful to Prof. Emeritus Don McNeil, Department of Statistics, Macquarie University,

Australia, for his guidance and helpful suggestions. This study is supported by grant funds from Graduate

School, Prince of Songkla University, Thailand.

REFERENCES

Anisimov, O.A., Lobanov, V.A. and Reneva, S.A. (2007). Analysis of Changes in Air Temperature in

Russia and Empirical Forecast for The First Quarter of The 21st Century. Russian Meteorology and

Hydrology, 32(10), 620-626.

Chooprateep, S and McNeil, N. (2014). Temperature Changes in Southeast Asia: 1973-2008. CMU J.

Nat. Sci., 3(2), 105-116.

Dore, M.H. (2005). Climate Change and Changes in Global Precipitation Patterns: What Do We Know?

Environment international, 31(8), 1167-1181.

Griffiths, G.M., Chambers, L.E., Haylock, M.R., Manton, M.J., Nicholls, N., Baek, H.J. and Lata, R.

(2005). Change in Mean Temperature as A Predictor of Extreme Temperature Change in The Asia–

Pacific Region. International Journal of Climatology, 25(10), 1301-1330.

Houghton, J.T. (1996). Climate Change 1995: The Science of Climate Change: Contribution of Working

Group I to The Second Assessment Report of The Intergovernmental Panel on Climate Change (Vol.

2). New York, NY: Cambridge University Press.

Hughes, G.L., Rao, S.S. and Rao, T.S. (2006). Statistical Analysis and Time-Series Models for

Minimum/Maximum Temperatures in The Antarctic Peninsula. The Royal Society, 463(2077), 241-

259.

Lean, J.L. and Rind, D.H. (2009). How Will Earth’s Surface Temperature Change in Future Decades?

Geophysical Research Letters. 36(15), L15708.

Limsakul, A., Limjirakan, S. and Sriburi, T. (2009). Trends in Daily Temperature Extremes in Thailand.

in "Second National Conference on Natural Resources and Environment", Bangkok, Thailand,

September 14-16. 2009.

Naruchaikusol, S. (2016). Climate Change and Its Impact in Thailand: A Short Overview on Actual and

Potential Impacts of The Changing Climate in Southeast Asia. TransRe Fact Sheet, 2, 1-6.

Peng, S., Huang, J., Sheehy, J.E., Laza, R.C., Visperas, R.M., Zhong, X. and Cassman, K. G.

(2004). Rice Yields Decline with Higher Night Temperature from Global Warming. in "Proceedings

of the National Academy of Sciences of the United States of America", 101(27), 9971-9975.

ICEM (2014). USAID Mekong ARCC Climate Change Impact and Adaptation Study on Agriculture

Report, Prepared for the United States Agency for International Development by ICEM – International

Centre for Environmental Management, Bangkok.


54

Wanishsakpong, W., Luo, K. and Tongkumchum, P. (2014). Earth Surface Temperature Changes Above

Latitude 45 Degrees North from 1973 to 2008. Chiang Mai University Journal of Natural Sciences,

13(3), 247-257.

Web sites:

Web-1: http://daac.ornl.gov/cgibin/MODIS/GLBVIZ_1_Glb/modis_subset_order_global_

col5.pl., consulted 10 November 2014.

Web-2: http://www.R-project.org, consulted 12 December 2014.

Web-3: http://thaisat.co.th/, consulted 20 September 2015.

Web-4: http://www.tmd.go.th/index.php, consulted 2 October 2016.


55

PATTERNS OF SOLAR RADIATION ABSORPTION IN USA

USING STATISTICAL MODEL Jaruek Atthasongkhro 1,2 and Attachai Ueranantasun 3 1Department of Mathematics and Computer Science, Faculty of Science and

Technology, Prince of Songkla University, Pattani Campus, 94000, Thailand. email: [email protected]

2Centre of Excellence in Mathematics, Commission on Higher Education, Ratchathewi, Bangkok, 10400 Thailand.

3Department of Mathematics and Computer Science, Faculty of Science and Technology, Prince of Songkla University, Pattani Campus, 94000, Thailand. email:

[email protected]

ABSTRACT

The transitivity of solar radiation in the atmosphere depends on various factors and it varies

significantly with locations, times of day, earth-to-sun distances, solar rotations and other

activities. Apart from playing a major role on sustaining life on earth and determining terrestrial

climates, solar radiation is the most abundant of all energy sources with its direct application

including photovoltaic power for generating electricity. Knowledge of the spatial and temporal

variability of solar irradiance patterns is thus precarious for designing the appropriate energy-

conversion equipment and infrastructure, and generating an efficient management plan for both

urban and rural areas. This study is thus aimed to study solar energy patterns on the earth’s

surface via solar radiation absorption of cloud covers. Solar radiation data, between 1961 and

1990 in USA, are retrieved from the National Solar Radiation Database (NSRDB) and then

analyzed to determine patterns in solar radiation absorption. A statistical method used in this

study is a regression model with square root transformed and filtered to fit to the solar radiation

absorption in five-day averages periods in selected nine monitoring stations. The results show

that the mean cloud cover in each of periods over the 30 years is well estimated by this model.

The model is then tested to predict the amount of solar radiation absorbed for the further

periods.

Key Words: Solar Radiation; Statistical Model; USA

1. INTRODUCTION

Humans and other life forms rely greatly on solar radiation. Radiant energy is the source of

metabolism in ecosystem, starting from photosynthesis in plants, and then being transfer to

primary consumers and later consumers by consumption and respiration processes (Raven et

al., 2011). It also causes and influences natural cycles and weathers on the earth including wind

and rainfall. When radiation from the sun is reaching the earth surface it is in a form of

shortwave radiation, which covers the ranges of infrared, visible light and ultraviolet in the

electromagnetic spectrum band (Salby, 2012). The levels of solar radiation on the earth's

surface are influenced by many factors, ranging from location, elevation, season, time of day

and cloud cover. It is also absorbed, reflected and scattered by the earth's atmosphere (Wetzel,

2001). The resulting radiations at the surface are then divided into two types - direct radiation

for visible light and infrared wavelength and diffuse or indirect radiation for ultraviolet


56

wavelength, solar energy can be absorbed directly from the sun, called direct radiation, or from

light that has been scattered as it enters the atmosphere, called indirect radiation (Wenham et

al., 1994).

For the past decades, power from solar radiation has been also used as an energy source

to provide electricity and thermal energy, such as photovoltaic panels, which is increasingly

developed and used in many countries including the United States and Germany (Toshiyuki

and Mika, 2014; Matthew and Jan, 2010). Therefore, understanding of solar irradiance

characteristics is valuable for planning and designing the appropriate energyconversion

equipment and infrastructure, and generating an efficient energy management plan of the

facilities and areas. The most important aspect of solar energy design is the amount of solar

radiation at the ground. There have been studies about solar radiation models and calculations.

For instance, Maxwell (1998) use meteorological/statistical (METSTAT) solar radiation model

to compute direct normal, diffuse horizontal, and global horizontal solar radiations for an hour

period to compensate the missing observed data. Moreover, mathematical model like hidden

Markov process is used to find solar radiation as a hidden parameter from an observe parameter,

temperature (Hocao lu, 2011).

As mentioned before, cloud is one of the absorbing agents of solar radiation before

reaching the earth's surface. It can greatly affect the amount of local radiation on the ground in

a particular area. Cess et al. (1995) showed that solar radiation from the top of the atmosphere

can be absorbed by clouds for approximately 30 W/m2. This indicates the relationship between

solar radiation and a level of absorption by clouds. One study demonstrates that clouds can be

used as an input to simulate global solar radiation using stochastic model (Ehnberg and Bollen,

2005). Thus modeling of cloud absorption is beneficial for study a quantity of solar radiation

on earth. In Australia, Cheung et al. (2015) examine the available amount of data of solar

radiation to find the spatial and temporal patterns of solar absorption by clouds using a simple

statistical model like linear regression. It is found that the data are needed to be transformed

for latitude less than 30º and the model has to include a lag-1 term. The results from the study

shows that the model fitted to the measured data well for all study locations in Australia, located

in the southern hemisphere. Therefore, it is interesting for a research point of view whether

implementation of the same method for differently located site could yield the similar result,

and any appropriate adjustment is required.

Hence, this study is aimed to use linear regression model to analyze the solar absorption

by clouds using the database station observations of solar radiation in the United States, located

on the northern hemisphere, from 1961 to 1990. This study also further applies the method to

forecast the amount of solar absorption by clouds for the next two years after the period from

the model to prove feasibility of the model application for energy planning.


57

2. DATA AND METHODS

Solar radiation data used in this study are retrieved from the website of the National Solar

Radiation Database (NSRDB), USA (Web-1). There are totally 239 National Weather Service

(NSW) stations from the database, but only 133 are selected to be used in this study. The

reasons for omitting other 106 NSW stations are to remove stations with incomplete data sets,

and to remove stations in Alaska and Hawaii to reduce unbalanced geographical effects. These

data are collected over the years from 1961 to 1990 (30 years), and 133 station locations are

displayed in Figure 1. To demonstrate the investigation of method used in this study, only nine

locations are chosen to be shown as a sample based on the variation of latitudes, and displayed

in blue squares in the map, while the rests are shown in red dots. The locations of selected

stations are Seattle (WA), International Falls (MN), Caribou (ME), Sacramento (CA), Topeka

(KS), Baltimore (MD), San Diego (CA), Corpus.Christi (TX) and Daytona Beach (FL).

Figure 1 Locations of 133 stations where hourly radiation data are collected in the United

States from 1961-1990 with blue squares representing the demonstrated nine locations. The

axes are latitude and longitude.

Each station supplies hourly solar irradiation observed at the station or ground radiation

(RG) and at extra-terrestrial space (RE). After collecting the data from the source, the hourly

solar radiation data are converted into daily solar data to reduce the influence from hours of

exposing to daylight for different latitudes. In order to maintain an equivalent number of

observations for each year, we omitted one observation in each leap year, specifically the

observation on February 29. To compare recorded data from the stations to theoretically

calculated data, we computed extraterrestrial irradiation (RE) for each station by the formula

stated in Klein (1977).


58

(1)

In this formula, is the latitude angle, d is the day of the year, is the Earth’s declination, is the

sunset hour angle, and K is the solar constant.

The computed RE is then used to determine the possibly maximum solar on the ground.

It is widely known that solar energy absorbed and diffused by earth's upper atmosphere around

20-30% (Stine and Harrigan, 1986). To accommodate this loss, we reduce the level of solar

radiation by trial and error of absorbing and diffusing percentage. We found that 0.25 is the

most matching proportion to be adopted to fit the data. This means that 25% of extraterrestrial

radiation is absorbed and diffused by the upper atmosphere. Therefore, we can express solar

energy at the earth's surface on a totally clear day as 0.75RE. However, solar radiation is often

absorbed by clouds before reaching the ground. Therefore, when considering the effect of cloud

absorption on the radiation, we calculate the daily percentage solar radiation absorbed by

clouds as follows.

(2)

Where RC is the daily percentage of solar radiation absorbed by clouds, RE is the calculated

extraterrestrial radiation, and RG is the observed solar radiation at the stations. Afterwards the

RC values for each station are averaged for five days, and in turn, the number of radiation data

is reduced from 365 days to 73 periods in each year. These five-day averages are determined

to remove correlation from consecutive days.

For data analysis, we follow the method from Cheung et al. (2015), which propose that

linear regression model is fitted to the estimated solar radiation absorption from Australia by

transforming data and adding a lag-1 term into the model for data from the stations below

latitude of 30º. We prove this statement by firstly fitting linear model to five-day averaged data

with only years and periods as a determinant. The model is described as follows.


59

3. RESULTS AND DISCUSSIONS

For the purpose of demonstration, the results from only nine selected station are shown in this study. When fitting a linear model to the data with only years and periods, the resulting Q-Q plots, shown in the left panel Figure 2, point out that solar radiation from the stations below latitude of 40º did not follow the assumption of normality as the curves does not fit the normal lines and hence the data need to be transformed. The ACF plots also indicate that there is correlation for residual with the one lag term. This means that a lag-1 term is required to be added to the model. For the transformation, we apply square root to the data and a lag-1 term. Subsequently, the square-rooted values are multiplied by 10. The reason is to increase the transformed values by one magnitude to roughly level with the untransformed data. Therefore,

plots and ACF plots of the model with transformation and a lag-1 term are shown in Figure 3. The Q-Q curves of the stations below 40º become fitter to the diagonal lines, while ACF plots indicates that residuals are now independent. Thus, the model follows the assumption of linear model eventually.


60

Figure 2 Residual quantile–quantile (Q–Q) plots and residual auto-correlation (ACF) plots

for nine sample stations from the model with only years and periods

Figure 3 Residual quantile–quantile (Q–Q) and residual auto-correlation (ACF) plots for

nine sample stations from the model with transformation a lag 1 term

The fitted values from the model are then compared to the real data from 1961 to 1990 as shown

in Figure 4. It is clearly evident that, for all stations, the model can represent the real data very

well for all 30 years. Regarding a forecasting performance, the predictions from the model and

the real data from 1991 to 1992 are displayed in Figure 5. This result also indicates that the

model can forecast the trend of the future data fairly well. The differences of the real data from

the fitted lines from the model is considered a variations from other causes, that are not included

in the models such as non-seasonal winds and rains, and even severe weather conditions.


61

Figure 4 Plots of period solar radiation absorption from the real data (blue dots) and

from fitting linear regression model (red) for nine stations


62

Figure 5 The forecasted values (black) and real data for solar radiation absorption by cloud from 1991 to 1992

This study has confirmed that the method proposed by Cheung et al. (2015) can be used with

the data of solar radiation absorption by clouds in other locations rather than Australia and even

in the opposite hemisphere. However, determination of latitude for transforming data is varied

by locations and needs to be considered case by case. It is also interesting to further investigate

if the implementation of this method still holds true for the location above 30-40º for both north

and south, and for the locations below these sets of latitudes, for example, near the Equator.

This study also proves that the simple method like linear regression can be used as a tool to

forecast solar radiation absorption, and in turn, solar radiation.

4. CONCLUSION

This study has proven that the use of linear regression can be used to develop a model, which

can be used as a forecasting tool for solar radiation absorption. The transformation is

implemented to justify the model for statistical fashion, and is not difficult to follow for a user


63

without advanced statistical knowledge. Therefore, this method can be applied for energy

planning associated with solar power.

5. ACNOWLEDGEMENT

The authors are grateful to Prof. Emeritus Don McNeil, Department of Statistics, Macquarie

University, Australia, for his guidance and helpful suggestions. This study is supported by grant

funds from Graduate School, Prince of Songkla University, and also by the Centre of

Excellence in Mathematics, the Commission on Higher Education, Thailand.

REFERENCES

Cheung K.K., Chooprateep S. and Ma J. (2015). Spatial and Temporal Patterns of Solar

Absorption by Clouds in Australia as Revealed by Exploratory Factor Analysis. Solar

Energy, 111, 53-67.

Cess R.D., Zhang M.H., Minnis L. and Corsetti L. (1995). Absorption of Solar Radiation by

Clouds: Observations versus Models. Science, 267(5197), 496.

Ehnberg J.S. and Bollen M.H. (2005). Simulation of Global Solar Radiation Based on Cloud

Observations. Solar Energy, 78(2), 157-162.

Hocao lu F.O. (2011). Stochastic Approach for Daily Solar Radiation Modeling. Solar Energy,

85(2), 278-287.

Klein, S.A. (1977). Calculation of Monthly Average Insolation on Tilted Surfaces. Solar

Energy 19, 325-329.

Raven P., Berg L. and Hassenzahl D. (2011). Environment, 8th edition. Hoboken, NJ: Wiley.

Salby M.L. (2012). Physics of the Atmosphere and Climate. New York, NY: Cambridge

University Press.

Stine W.B. and Harrigan R.W. (1986). Solar Energy Systems Design. Hoboken, NJ: John

Wiley and Sons, Inc.

Wenham S.R., Green M.A. and Watt M.E. (1994). Applied Photovoltaics. Sydney, Australia:

University of New South Wales.

Wetzel R.G. (2001). Limnology: Lake and River Ecosystems, 3rd edition. San Diego, CA:

Academic Press.

Web sites:

Web-1: http://rredc.nrel.gov/solar/old_data/nsrdb, consulted15 November 2015. Web-2:

http://www.R-project.org, consulted 18 April 2015.


64

THERMO-PHYSICAL PROPERTIES OF NANOCARBON

PARTICLES IN ETHYLENE GLYCOL AND DEIONIZED

WATER

Syazwani Zainal Abidin1, Imran Syakir Mohamad1,2, Ahmad Yusairi Bani Hashim3, Norli Abdullah4, Tee

Boon Tuan1,2, Amirah Abdullah1 1 Faculty of Mechanical Engineering, Universiti Teknikal Malaysia Melaka,

Hang Tuah Jaya, 76100 Durian Tunggal, Melaka, Malaysia, [email protected] 2 Centre for Advanced Research on Energy, Universiti Teknikal Malaysia Melaka,

Hang Tuah Jaya, 76100 Durian Tunggal, Melaka, Malaysia, [email protected] 3 Faculty of Manufacturing Engineering, Universiti Teknikal Malaysia Melaka,

Hang Tuah Jaya, 76100 Durian Tunggal, Melaka, Malaysia, [email protected] 4 Department of Chemistry, Centre for Foundation Studies, Universiti Pertahanan Nasional Malaysia, Kem

Sungai Besi, 57000, Kuala Lumpur, Malaysia, [email protected]

ABSTRACT

Nanofluids are widely used as heat transfer media for numerous applications such as

microelectronics, pharmaceuticals, vehicle thermal management and others. The recent

research has demonstrated that nanofluids have provided significantly better thermo-physical

properties than the based fluids because of its novel properties. The nanofluids proved to have

a much higher heat transfer property and specific heat capacity at a very low particle

concentration than conventional heat transfer fluid. Generally, the available based fluid such

as ethylene glycol (EG) and deionized water (DI) has a limitation in terms of thermo-physical

properties like thermal conductivity and heat transfer. Demand for ultra-high performance

cooling in electronics has been increasing and conventional enhanced surface techniques have

reached their limit regarding improve heat transfer. An innovative way to overcome this

limitation is by adding nanoparticles in the based fluid to form nanofluid. In this paper, the

proposed objective is to formulate a stable nanofluid from HHT24 carbon nanofiber (CNF) and

–OH functionalized multiwalled carbon nanotubes (MWCNT-OH) in based fluid with the

presence of polyvinylpyrrolidone (PVP) as the stabilizer through two-step preparation process.

Then, the thermal conductivity and heat transfer was investigated at three different

temperatures (6ºC, 25ºC and 40ºC). Nanofluids tested for thermal conductivity and heat

transfer shows that all the samples achieved enhancement in EG and DI based nanofluids when

CNF HHT24 and MWCNT-OH particle was added. Overall, this studies shows that

nanocarbon material is a great alternative to be used in conjunction with ethylene glycol and

deionized water as a heat transfer media in cooling application.

Key Words: Thermal Conductivity; Heat Transfer; Nanofluids






65

1 INTRODUCTION

Nanofluids are widely used as heat transfer media for many applications such as

microelectronics, cooling process, heating process, thermal management (Kamel et al., 2016)

and others. However, nanofluids are commonly used as a coolant in heat transfer equipment

such as electronic cooling system. The recent research has demonstrated that nanofluids have

exhibited better heat transfer properties than the base fluids because of its novel properties

(Khanafer et al., 2013). The nanofluids proved to have a much higher and strongly temperature-

dependent thermal conductivity (Das et al., 2003) at very low particle concentrations than

conventional radiator coolants without the nanoparticles.

The amazing properties of nanocarbon such as carbon nanotube and carbon nanofiber

has gained attention among the researchers as the addition of the small number of suspending

nanoparticles has the potential to enhance the thermo-physical properties of the base fluid.

These nanoparticles which have high surface area and high thermal conductivity (Singh, 2008)

are potentially to be used as superior medium for a heat transfer media. This shows that

prospect of nanofluids as future coolants for industrial applications and the development of the

nanofluids should be widely enhanced in nanotechnologies area.

Nanocarbon materials for example CNT and CNF, has a nanometer sized diameter and

specifically molecularly smooth surfaces (Guo et al., 2013) which offers an interesting

framework for molecular transport in nanofluidic (Choi et al., 2011). Since the discovery of

the nanocarbon materials, CNT and CNF has received a considerable attention around the

world because of its amazing electronic properties which possess excellent mechanical and

thermal properties. Apart from the excellent thermal and mechanical properties that been

possess, nanocarbon materials proves to have physiochemical properties that makes them

suitable as a conventional heat transfer fluid in industrial cooling application. Thus, the first

aim of this present work is to formulate a stable nanofluids produced from the mixture of

nanocarbon particles (CNT and CNF), base fluids (EG and DI) and dispersing agent. Then, the

thermo-physical properties of the formulate nanofluids will be studied in terms of thermal

conductivity and heat transfer.

2 METHODOLOGY

2.1 Material Selection

The nanocarbon particles used in this study is multiwalled carbon nanotube (MWCNT-OH)

from the industrial grade multiwalled CNT that has been functionalized with –OH, purchased

from Nanostructured & Amorphous Materials, Inc. (Nanoamor). Meanwhile, CNF used in this

research is from Pyrograf III Carbon Nanofiber, High Heat Treated 24 (CNF HHT24) grade,

which have been treated to high heat treatment temperature up to 3000°C (Zainal Abidin et al.,

2016). In order to allow the easy dispersion of nanoparticles in nanofluids, the

polyvinylpyrrolidone (PVP) from Sigma-Aldrich Co. was chosen as a stabilizer in this

research. The addition of stabilizer will lower the surface tension, increases the particle

immersion and may prevent fast sedimentation in the mixture.

2.2 Nanofluids Sample Preparation

The preparation of nanofluids in this study is carried out using a two-step method preparation

process. This process involved the dry powder of nanoparticles that have been formed by

chemical or physical methods to be mixed together with the base fluids. The nanofluids were


66

synthesized with various mass fractions which the different masses of nanoparticles were added

to a 40ml of the base fluids EG and DI with the presence of polyvinylpyrrolidone (PVP) as the

surface activator. The use of ethylene glycol and deionized water as the base fluid is because

of their function as the main fluid base for convective heat transfer who was used in a car

radiator engines and liquid cool computers (Selvam et al., 2016). The experiment is conducted

by setting the variable of weight percentage of nanoparticles from 0.1wt% to 1.0wt% with the

addition of base fluid. The suspension was homogenized for five minutes by using Digital

Homogenizer LHG-15 at 10000 rpm rotational speed. The homogenization is important to

ensure the solid particles inside the suspension are uniformly dispersed. Then, the nanofluids

sample undergoes ultrasonication process at 25oC using ultrasonic for about 5 minutes at 60

kHz frequency. The nanofluid dispersion and stability is then be observed by Stability Test Rig

(STR) as to make sure the nanofluid is in the stable condition and well homogenized (Abdullah

et al., 2016).

2.3 Thermal Conductivity Test for Nanofluids

All the samples which achieved the stability then were tested for thermal conductivity test.

KD2-Pro Thermal Properties Analyser (Decagon Devices, Inc.) was used to measure the

thermal conductivity of nanofluids at three different temperatures which is 6°C, 25°C and

40°C. The best three samples of CNT and CNF in each based fluid which enhance the highest

thermal conductivity were chosen to undergo heat transfer test.

2.4 Heat Transfer Test for Nanofluids

The heat transfer test was conducted using a copper coil which was drenched inside the water

bath where the inlet was attached to water pump and the outlet will be flow out back into the

400ml beaker. The thermocouple wire was placed at the inlet and outlet of the copper coil to

measure the temperature differences of the nanofluid. The temperature difference can be

obtained by observing the inlet and outlet temperature. In this experiment, the thermocouples

were attached to the data logger and the result is directly shown in the PicoLog data acquisition

software. The beaker was filled with 400ml of nanofluid samples. The water pump was retained

inside the sample to pump up the nanofluid to the copper coil and flow back into the beaker.

The pump will ensure the constant flow of the nanofluid through the passage ways. The reading

will be taken at 6°C, 25°C and 40°C of water bath temperature in collectively five minutes after

the constant flow of nanofluids. Figure 1 shows the experimental set-up for heat transfer test.


67

Figure 2 Experimental set-up for heat transfer coefficient test

3 RESULT AND DISCUSSION

3.1 Thermal Conductivity of Nanofluids

The thermal conductivity test was conducted at three different temperatures which are 6°C,

25°C and 40°C to observe the temperature effect to the enhancement of thermal conductivity.

The zero percentage of CNF HHT24 and MWCNT-OH is the pure EG and DI that has been set

as a standard or datum to observe the enhancement of thermal conductivity at different

temperatures. The result of thermal conductivity is represented clearly in Figure 2, Figure 3,

Figure 4 and Figure 5 to identify the patterns of the heat effects on each sample.


68

Figure 3 Thermal conductivity of CNF HHT24 EG-based nanofluid

Figure 4 Thermal conductivity of MWCNT-OH EG-based nanofluids.

Referring to Figure 2, the results for thermal conductivity of CNF HHT24 EG-based nanofluid

are fluctuate at all temperatures but for most of the results the thermal conductivity increase

with the increment of nanoparticles percentage. The highest thermal conductivity at all

temperature was recorded at 0.6wt%, 0.8wt% and 1.0wt% concentration. For MWCNT-OH


69

EG-based nanofluid, Figure 3 shows that the thermal conductivity of most nanofluids is directly

increased with the increasing of weight percent of CNT. The highest thermal conductivity at

all temperature was noted at 0.8wt%, 0.9wt% and 1.0wt%. When comparing both CNF HHT24

and MWCNT-OH, the highest thermal conductivity was recorded by 1.0wt% of CNF HHT24

at temperature 25oC with 0.319W/m.K values. Meanwhile, the highest thermal conductivity

value for MWCNT-OH was observed at 1.0wt% with 0.256W/m.K values at 40oC.

Figure 5 Thermal conductivity of CNF HHT24 DI-based nanofluid.


70

Figure 6 Thermal conductivity of MWCNT-OH DI-based nanofluid

From the Figure 4, CNF HHT24 DI-based nanofluid recorded an increase in thermal

conductivity and the value is above the standard as the temperature increase from 6oC to 25oC.

However, there are few samples recorded a decrement of thermal conductivity as the

temperature increases to 40oC which are at concentration 0.1wt%, 0.2wt%, 0.3wt%, 0.4wt%

and 0.5wt%. While the other samples continuously perform an increment in thermal

conductivity as temperature increases to 40oC. The highest thermal conductivity at all

temperature was recorded at 0.8wt%, 0.9wt% and 1.0wt%.

The similar trend was also observed with MWCNT-OH DI-based nanofluid as shown

in Figure 5, where all the sample recorded an increase in thermal conductivity as the

temperature rises from 6oC to 25oC. However, there are few samples shows a decreased in

thermal conductivity after the temperature reaches to 40oC which include concentration of

0.3wt%, 0.6wt%, 0.7wt%, 0.8wt%, 0.9wt% and 1.0wt%. While the other samples continuously

perform an increment in thermal conductivity as temperature rises to 40oC. The highest thermal

conductivity at all temperature was recorded at concentration of 0.8wt%, 0.9wt% and 1.0wt%.

When comparing both CNF HHT24 and MWCNT-OH, the highest thermal conductivity is

0.723W/m.K for 0.4wt% of MWCNT-OH at temperature 40oC. Meanwhile, the highest

thermal conductivity value for CNF HHT24 is 0.686W/m.K for 1.0 wt% at 40oC.


71

The enhancement analysis is done to see the trend and was later compared to the fluid

standard. The enhancement can be calculated by using the formula in Eqs. 1. The enhancement

percentages of the nanofluids are shown in Table 1, Table 2, Table 3 and Table 4.


72


73

The results obtained in Table 1, Table 2, Table 3 and Table 4 was observed to be irregulars in term

of the enhancements at all temperature. At temperature 6°C, 25°C and 40°C, most of the sample

exceeds the standard samples in thermal conductivity enhancement excepting for NF11, NF12,

NF13, NF14, NF15, NT13, NT16, NT17, NT18, NT19 and NT20. The highest recorded

enhancement is at temperature 25°C by NF10.

In opposition to the enhancement of thermal conductivity, however a few samples show

decrement in thermal conductivity which below the value of standard suspension. The increase in

nanofluids concentration will also cause the viscosity of base fluid to increase and consequently

cause a reduction in thermal conductivity of nanofluids (Tsai et al., 2008). The viscosity of the base

fluid affects the brownian motion of nanoparticles and the thermal conductivity of the nanofluid

(Syed Idrus et al., 2015). The decreasing trend in thermal conductivity is also due to the increment

in bundling size and their constant parting from the base fluid (Kole and Dev, 2012).

As stated in many literature reviews, there are many factors which can affect the thermal

conductivity of the nanofluid. Some literature review stated that in conventional effective medium

theory, when the thermal conductivity of the base fluid decreases, the effective thermal

conductivity of a nanofluid will increases (Mohamad et al., 2012). Ethylene glycol is said to have

the highest thermal conductivity ratio when compared with water, engine oil and vacuum pump oil.

The weight ratio of CNT may cause irregular patterns in thermal conductivity reading as well as

give rise to the irregular behaviour of the nanofluid suspension (Mohamad et al., 2011). The

bundling of nanoparticles may give rise to the increment or decrement of the thermal conductivity

(Ravi Sankar et al., 2012). The fast heat transport between the nanoparticles will occur if a network

of nanoparticles is formed as a result of bundling. On the other hand, excessive bundling may result

in sedimentation, which decreases the effective particle volume fraction of the nanofluid. Similar

result was reported by the Hamilton-Crosser model (Esfe, 2014) which shows that the thermal

conductivity ratio increases nonlinearly with an increase in solid concentration. The results also

show that the increment rate of thermal conductivity at lower concentrations is much greater than

those that at higher concentrations. The reason is due to the increase in nanofluid viscosity that is

much higher than the enhancement in thermal conductivity at high solid concentrations.

3.2 Heat Transfer Coefficient of Nanofluids

A heat transfer test was conducted through heat convection as fluid is used as the medium. Three

selected samples for CNF HHT24 and MWCNT-OH from both base fluids which have the best

enhancement in thermal conductivity were tested for heat transfer test. In order to make the data

simpler for observation, the percentage enhancement is calculated and the results were shown in

Figure 6, Figure 7 and Figure 8.


74


75

From Figure 6, all the sample undergo enhancement at 6oC temperature and sample

NT08 experienced the highest enhancement which is 133.27% followed by sample NF06

(123.06%) and NT10 (122.35%). Meanwhile, from Figure 7, the similar pattern was also

recorded where all the sample undergo enhancement at 25oC temperature and sample NF08

experienced the highest enhancement which is 210.0% followed by sample NF06 (191.0%)

and NF10 (193.0%). Sample NT18 experienced only a slight increment with values of 3.0%.

The enhancement of heat transfer was also observed at 40oC (refer Figure 8) where the higher

enhancement was recorded at NF20 (234.94%). Based on the result obtain, almost the entire

percentage enhancement for the heat transfer properties for the selected sample met the

agreement with the theoretical facts where the nanofluid recorded the high heat transfer

properties than pure ethylene glycol and deionized water.

Regardless of the significantly scattered results, the presence of nanoparticles does

enhance some of the results for heat transfer test. From the result, CNF HHT24 and MWCNT-

OH nanofluid experienced enhancement in heat transfer as opposed to the standard solution of

ethylene glycol and deionized water. Conversely, the enhancement of nanofluids shows

irregularities reading whilst some results show enhancements and other results even shows

reduction in heat transfer capability when nanoparticles are added. This trend is similar with

the prior work done by other scientists (Mohamad et al., 2013) where the research shows an

insignificant enhancement and some reduction in heat transfer test. Favourably, nanofluids

sample mostly recorded the temperature difference above the standard temperature different

and this result shows that the heat transfer properties of formulated nanofluid are higher

compare to standard solution. The high temperature difference between inlet and outlet is due

to the properties of the fluid that can transfer heat proficiently. A previous study conducted by

some investigator reveals that a large surface area encourages high heat transfer from two

mediums (Chopkar et al., 2006). The reduction of particle size which is represented by the

nanoparticles affects the surface area. When particle size is decrease, the surface area per unit

volume will increases, thus the heat transfer that is related directly to the surface area will


76

increases, resulting in a good efficiency of nanoparticles to transfer heat to the base water

(Hussein et al., 2014).

A broader perspective has been adopted by Duangthongsuk and Wongwises (2010)

who investigated the effect of thermo-physical properties models on prediction of the heat

transfer coefficient and concluded that the heat transfer coefficient of nanofluid is slightly

greater than that of water. This statement had met an agreement with most of the result obtained

where the percentage of enhancement is positive. However, there are some results shows a

negative value of percentage. This result is because of several factors such as gravity, brownian

forces, friction between the fluid and solid particles, sedimentation and dispersion that may

presence in the main flow of a nanofluid.

4 CONCLUSION

The inclusion of CNF HHT24 and MWCNT-OH nanocarbon particles into a pure ethylene

glycol and deionized water as based fluid has proved to exhibit enhancements in terms of

thermo-physical properties as compared to the standard samples. In the meantime, all the tested

samples mostly exhibit enhancements above the standard samples at all three temperatures of

6°C, 25°C and 40°C. From the results and analysis of the thermo-physical properties test for

the formulated nanofluids, several improvements are seen in terms of enhancement percentages

by comparison to the standard mixture of ethylene glycol and deionized water as base fluid. In

thermal conductivity test, the highest value was recorded at 0.723W/m.K for 0.4wt% of

MWCNT-OH at temperature 40oC. Whilst, for heat transfer test, the best enhancement was

recorded by NF20 (234.94%) at 40oC. It was noted that there are several factors that plays an

important role in affecting the percentage enhancement of nanofluids in terms of thermo-

physical properties and has been discussed in result and discussion section. Therefore, the aim

of this research which is to formulate a stable nanofluid of CNT and CNF in ethylene glycol

and deionized water based and to investigate the thermo-physical properties of the nanofluids

is achieved.

5 ACKNOWLEDGEMENT

Authors would like to thank Universiti Teknikal Malaysia Melaka (UTeM), Universiti

Pertahanan Nasional Malaysia (UPNM) and the Ministry of Higher Education (MOHE) for

supporting this research under the grants of FRGS/2010/FKM/SG03/1-F0076,

FRGS/2/2013/ST05/UPNM/03/1 and FRGS/2/2013/SG02/FKP/02/2/F00176.

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Duangthongsuk W. and Wongwises S. (2010). An Experimental Study on the Heat Transfer

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79

EFFICIENT REMOVAL OF GRAPHENE OXIDE QUANTUM

DOTS (GOQDS) FROM NATURAL WATER BY PEI-

MODIFIED SILICA NANOCOMPOSITES

Shanaz Jahan1, Ismail Bin Yusoff1, Yatimah Binti Alias2,3, Ahmad Farid Bin Abu Bakar1

1 Department of Geology, Environmental and Earth Sciences, Faculty of Science, University

Malaya, Kuala Lumpur 50603, Malaysia 2 Department of Chemistry, Faculty of Science, University Malaya, Kuala Lumpur 50603, Malaysia

3 University Malaya Centre for Ionic Liquids (UMCiL), University of Malaya, Kuala Lumpur 50603,

Malaysia

Author e-mail: [email protected]

ABSTRACT

We report a protocol for the efficient removal of graphene oxide quantum dots (GOQDs) from

natural river water using polymer polyethylene imine (PEI) modified silica nanocomposites

(PMSNC). The nanocomposites were synthesized by one pot hydrothermal method (75

ºC/2hrs) with magnetic stirring at 1100 rpm. The synthesized nanocomposites have well-

ordered cubic structures with diameters of ~10 µm with a polymerized stable layer at the

surface. The synthesized PMSNC was applied to investigate the removal of GOQDs form

snatural river water dosimetry. Results revealed that PMSNC imparts great efficiency for the

entrapment and removal of GOQDs from the natural water environment. The PMSNC interacts

with the dispersed nanoparticles and removes them readily by making aggregated complex.

The complex then can easily be removed by centrifugation, filtration or simply decantation.

The maximum removal efficiency of PMSNC for GOQDs was 504 mg/g. The entrapment

efficiency of PMSNC was also examined under different solution pH and found that the

maximum adsorption occurred at a pH value 6. The kinetic study revealed that the adsorption

process can be described well with the pseudo-second-order kinetic model. The desorption and

recycling studies demonstrate that the as-synthesized PMSNC can be used effectively even

after 5 recycling processes.

Key Words: Silica nanocomposites, Adsorption, Graphene oxide quantum dots, Kinetics

1. INTRODUCTION

Carbon based materials particularly graphene oxide quantum dots (GOQDs) because of their

exciting electronic, mechanical and physicochemical properties excite the scientists and

engineers for decades (Baughman, Zakhidov and de Heer, 2002). Due to the unique structural

properties these materials have been attracting increasing interest in recent years and find great

potential towards industrial and biomedical applications. The tremendous applications of

graphene based materials increases the concern towards their possible adverse effects on the

environment and leading to potential damages to animals and the human body (Zhao and Liu,



80

2012, Sun, Bornhoft, Hungerbuhler and Nowack, 2016). After the extensive use and disposal,

these nanomaterials directly enters the natural water system and create toxicity to aquatic plants

(Zhao, Wang, Zhao, Rui and Wang, 2015) and animals (Cano, Maul, Saed, Shah, Green and

Canas-Carrell, 2016) after readily taken up by aquatic system.

In addition, due to the ultra-small sizes, the Brownian motion of the particles provide

sufficient energy to prevent aggregation thus making it more stable in natural water

environment (Peng, Gao, Gupta, Liu, Romero-Aburto, Ge, Song, Alemany, Zhan and Gao,

2012). The toxicity concern of GOQDs was studied by several research group in past though

there are only few reports on the removal or remediation techniques. Furthermore, previous

remediation techniques demonstrate the removal process in synthetic water. However, keeping

in mind the effects of co-existing anions and natural organic matter (NOM) that may affect the

remediation processes, there is still a need in determining the removal efficiency in natural

water system. Since natural water particularly rivers have played a significant role in providing

water resources for human and ecosystem survival and health.

In this research effort we demonstrate the efficient removal of GOQDs from natural water

dosimetery by polymer modified silica nanocomposites. Natural river water samples was

collected from Klang River-Malysia. Klang River is the main river which passes through the

city of Kuala Lumpur (Malaysia) and considered as most polluted water (Faridah Othman,

2012). The huge urbanization and industrialization at nearby area adds a high degree of water

pollution into the RW (Othman, ME and Mohamed, 2012). Therefore, it may act a better

candidate to investigate the remediation process under natural water environment. We also

studied the kinetics of removal process in order to gain better understanding of the mechanism

of remediation.


2.1 Materials & method

Column silica gel, Polyethylene imine (PEI) linear was purchased from Fluka AG, Ferric

chloride (FeCl2), Sucrose, Hydrochloric acid (HCl) and Sodium hydroxide (NaOH) were

purchased from Aldrich. PEI linear was purchased from Fluka AG. Ethanol (EtOH) and 2-

propanol were purchased from Fisher Scientific.

2.2 Synthesis of GOQDs

GOQDs were synthesized by hydrothermal pyrolysis of sucrose molecules (Tang, Ji, Cao, Lin,

Jiang, Li, Teng, Luk, Zeng and Hao, 2012) at 400 ºC for four hours. Typically, 6 g of sucrose

molecules were dissolved in 10 ml of deionized water and the pH of the solution was adjusted

to 9 by adding sodium hydroxide (1M). The resulting mixture was heated hydrothermally


81

producing a pale yellow solution of GOQDs. Subsequently, the solution is allowed to dry in an

oven at 100 ºC to remove the water molecule and the resulting product (as-synthesized

GOQDs) in powder form is stored at room temperature for further characterization and

remediation purposes.

2.3 Water Sampling & Preparation of Nano-dispersion

For the GOQDs removal studies, the natural river water (RW) sample was collected from Klang

River. The RW sample was stored at 28 ºC and physical & chemical parameter, i.e., dissolved

oxygen, pH, total suspended solid (TSS) and presence of certain anions and cations were

determined (Table 1) by ion chromatography and inductively coupled plasma mass

spectrometery. In the preparation of nano-dispersion, the amount of GOQDs (mg/L) was

dispersed in RW, ultrasonicated (POWERSONIC 405) at 20 ºC for 30 mins and centrifuged

(Thermo scientific heraeus megafuge-8 ultracentrifugation) at 3000 rpm for 15 mins to remove

undissolved fraction.

Table 1: The physical characteristics and ionic composition of natural RW

Anions/Cations Values (mg/L) pH DO (mg/L) TSS (mg/L)

Fluoride

Chloride

Carbonate

Bromide

Nitrate

Phosphate

Sulfate

Sodium

Potassium

Calcium

Magnesium

0.364

34.15

30.47

0.998

4.504

2.194

36.32

31.70

50.17

26.11

41.05

6.86 11.5 100

2.4 Synthesis of PMSNC


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In a typical synthesis of PMSNC, 0.2 g of silica gel was mixed with 100 µl of PEI (500 µl-5

ml diluted) in a 20 ml of deionized water. The resulting mixture was magnetically stirred at

1100 rpm at 75 ºC for 10 mins, and then 0.02 g of FeCl2 was added. The resulting reaction

mixture was heated and stirred for a further 2 hrs for the maximum synthesis of PMSNC. The

as-synthesized PMSNC were washed several times with ethanol followed by deionized water

and centrifuged at 4500 rpm in order to remove unreacted precursors.

2.5 GOQDs removal

For the GOQDs removal study (10-700 mg/L), batch experiments were performed on an orbital

shaker (Model: OS-200, ORBIT 20 mm) with a shaking speed of 120 rpm at 25 ºC at pH values

ranging from 4-9. For kinetic study, the solution of GOQDs (10 ml) was mixed with PMSNC

(10 mg) at optimum pH values. After a predetermined adsorption period, the fraction of the

GOQDs solution (2 ml) was taken and the removal of efficiency was determined by using

Shimadzu 3600-UV visible spectrophotometer at 280 nm and the % removal efficiency was

calculated by the following equation. (Zinchenko, Maeda, Pu and Murata, 2013).

% Removal efficiency = (1-A/Aº) x 100 (1)

Where Aº and A are the initial and final absorbance of the GOQDs solution before and after

adsorption period respectively. The maximum adsorption capacity (q) of PMSNC was

calculated on the basis of the following equation. (Ma, Wang, Fu, Si, Yu and Ding, 2015).

q (mg/g) = (Co – Ce) V/W (2)

Where, Co and Ce are the initial and equilibrium concentration of GOQDs in solution (mg/L),

V is the total volume of testing solution and W is the weight of adsorbent (PMSNC).

3. RESULTS & DISCUSSION

3.1 Characterization of GOQDs and PMSNC

Figure 1(a, b), representing the FESEM morphology and UV-Visible absorption spectra of as-

synthesized GOQDs. As can be seen the synthesized material are of spherical structure with

approximately 50 nm in diameter. The typical absorption spectra show peak maxima at 280 nm


83

which is the corresponding peak of carbonatious material (Tang, Ji, Cao, Lin, Jiang, Li, Teng,

Luk, Zeng and Hao, 2012).

Figure 1: FESEM image (a) at bright field mode and UV-Vis absorption spectra of GOQDs

The structural morphology of PMSNC was characterized by FESEM analysis (Figure 2a).

Figure 2: FESEM image of PMSNC at bright field microscopy (a) with its EDS elemental

loading (b)

As depicted by the figure, the nanocomposites are of cubical morphology with a diameter of

10 µm and modified by PEI at the surface. The EDS analysis (Figure 2b) revealed the elemental

composition of N, O, Si, Cl, and Fe at the surface of PMSNC.

Table 2: Main characteristics of investigated GQDs and PMSNC

Characteristics GQDs PMSNC

FESEM size (nm) 50 nm 10 µm

ξ-potential (mV) -24 +29


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Optimum pH 6 3-7

Time taken (min) 50 -

Removal efficiency (mg/g) 504 -

Table 2 summarizes the main characteristics of as-synthesized GOQDs and PMSNC. The zeta

potential analysis revealed that the surface of GOQDs is of negatively charged due to the

presence of –OH group of sucrose molecules. The PMSNC showed as positively charged

particles due the cationic PEI layer at the surface.

3.2 Adsorption Performance of PMSNC

3.2.1 Effect of pH

We studied the effect of pH on the removal efficiency of PMSNC. As can see from figure 3a,

the maximum removal of GOQDs in solution (40 mg/L) was occurred at pH value 6. The

decrease in removal efficiency at pH higher or lower than 6 was due the electrostatic repulsion

(Anatoly A Zinchenko, 2013) between the negatively charged GOQDs and added –OH ions

and between positively charged PMSNC and added H+ ions from acid. Therefore, pH 6 was

considered as a suitable pH for maximum removal of GOQDs from natural RW.

3.2.2 Adsorption Kinetics

Figure 3, represents the adsorption kinetics of GOQDs in RW. It can be seen that during the

first 50 min, GOQDs exhibit fast adsorption process and reached equilibrium within 50 mins.

It means that within 50 min all active adsorptive site of PMSNC was filled and saturated with

GOQDs. The maximum adsorption capacity of GOQDs was found to be 504 mg/g. The kinetics

of adsorption mechanism was also investigated by the linear forms of pseudo-first-order

(Nandi, Goswami and Purkait, 2009) and pseudo-second order (Liu, Xu, Cheng, Ho and Yu,

2015) model.

Here qt (mg g-1), and qe (mg g-1) represents adsorption capacity at time t, and at

equilibrium and k1 (min-1) and k2 (g mg-1 min-1) are the pseudo-first and second-order rate

constants respectively. The linear plots of log (qe-qt) and t/qt versus t are summarized in Table

log (qe – qt) = log qe – k1/2.303 × t (3)

t/qt = 1/k2q2e + t/qe (4)


85

3. The data obtained from the two empirical models suggested the adsorption mechanism fits

well with the pseudo-second-order model (Figure 3b).

Figure 3: Effect of pH on the removal efficiency of GOQDs of initial concentration of 40

mg/L, PMSNC dose 10 mg/ 10 ml of GOQDs solution, temperature (28 ± 2) at 50 min of

contact time (a) and the variation of adsorption amount with time (min), at GOQDs initial

concentration of 700 mg/L, PMSNC dose 10 mg/10 ml (b). The linear graph in the inset

represents modelled pseudo-second-order kinetics.

The obtained correlation coefficient (R2) value in the second-order kinetic model was higher

than pseudo-first-order kinetic model. Furthermore, the calculated qe value from the pseudo-

second-order model was in good agreement with the experimental qe value. This confirmed

that an empirical pseudo-second-order kinetic model fitted well for the description of GOQDs

adsorption on PMSNC.

Table 3: Pseudo-first-order and pseudo-second-order kinetic model constants

qe.exp

(mg/g)

Pseudo-first-order model Pseudo-second-order model

qe.cal

(mg/g)

k1

(x 10-2 min-1)

R2

qe.cal

(mg/g)

k2

(x 10-3 g mg-1 min-1)

R2

504 475 0.73 0.992 500 0.21 0.998

3.3 Recycling

After adsorption investigation of GOQDs in natural RW, the recycling ability of as-synthesized

PMSNC was investigated. The composites were washed several times with ethanol followed


86

by deionized water and adsorption capacity was determined. Figure 4 representing the

recycling ability of PMSNC. As can see from Figure 4, the adsorption capacity of PMSNC was

same even after five recycling steps.

Figure 4: The removal efficiency of PMSNC after 5 successive recycling

4. CONCLUSION

In summary, the PEI-modified silica nanocubes were successfully synthesized via facile one

pot hydrothermal method. The surface modification of silica nanocubes with cationic polymer

(PEI), making it a good candidate for the arrest and removal of negatively charged GOQDs in

natural river water. The maximum adsorption capacity (qe) was observed as 504 mg/g. The

kinetic study revealed that maximum adsorption occurred within 50 min realizing the complete

adsorption at all active sites of adsorbent PMSNC. The results from kinetic studies demonstrate

that the adsorption of GOQDs at the surface of PMSNC fits well with the pseudo-second-order

kinetic model. Desorption and recycling results suggested that even after five separation and

regeneration recycling, the PMSNC maintained high adsorption performance. These

experimental results imply that PMSNC are expected to have promising adsorption capacities

for negatively charged GOQDs from natural river water. Furthermore, the adsorption capacity

of PMSNC worked well in the presence of coexisting anions and cations present in the natural

river water.

5. ACKNOWLEDGEMENTS

The authors highly acknowledge the University of Malaya HIR grant-UM

C/625/1/HIR/MOHE/SC/04 for throughout funding and successful completion of this study.

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Zhan, X., and Gao, G. (2012). "Graphene quantum dots derived from carbon fibers." Nano

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J. (2012). "Deep ultraviolet photoluminescence of water-soluble self-passivated graphene

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332, 121-129.


88

EVALUATION OF LIGHT RARE EARTH ELEMENTS

(LREES) IN CASTOR OIL AND LILAC TASSEL FLOWER PLANT GROWN IN CONTAMINATED SOIL FROM

ABANDONED MINES IN PERAK, MALAYSIA

Aysha Masood Khan1, Ismail Yusoff1, Nor Kartini Abu Bakar2, Ahmad Farid Abu Bakar1 and Yatimah

Alias2, 3 1 Department of Geology, Faculty of Science, University of Malaya, 50603, Kuala Lumpur, Malaysia

([email protected]) ([email protected]) ([email protected]) 2 Department of Chemistry, Faculty of Science, University of Malaya, 50603, Kuala Lumpur, Malaysia

([email protected]) 3 University Malaya, Centre for Ionic Liquids (UMCiL), University of Malaya, 50603, Kuala Lumpur, Malaysia

([email protected])

Author email: [email protected]

ABSTRACT

Two plant species, Ricinus communis L. (castor oil plant) and Emilia sonchifolia (lilac tassel

flower) belonging to Euphorbiaceae (spurge family) and Astraceae were sampled along with

contaminated soil from Lahat Perak. Light rare earth elements (LREEs) (Sc, Y, La, Ce, Pr,

and Nd) were determined in the roots, stem and leaves by using microwave acid digestion

method involving time pressure system followed by inductively coupled plasma mass

spectrometry (ICP-MS) analysis. Among the LREEs, Ce and La were found in highest amount

in roots with 66 µɡ ɡ-1 and 35 µɡ ɡ-1 in castor oil and 41 µɡ ɡ-1 and 22 µɡ ɡ-1 in Emilia

Sonchifolia while less concentrations were found in stem and leaves of the plants. Transfer

factor (TF), bioconcentration factor (BCF) and bioaccumulation factors (BAF) calculated

showed accumulation for Y, La and Ce having values > 1. Such plants are considered good

enough to clean the contaminated soil from LREES by simple and cheap way to keep our

environment green and friendly.

Key Words: Light rare earth elements, ex-mine, castor oil, Emilia Sonchiofolia

1. INTRODUCTION

Rare earth elements (REEs) are not rare in true sense but largely distributed over the earth crust.

These form chemically uniform group of seventeen elements. Of all the REEs, cerium (Ce)

has been found in highest concentration in earth crust comparable to zinc (Zn) and copper (Cu).

Most of the REEs have been found beneficial to soil-plant system and now a days widely

applied in fertilizers specially in China and other countries of the world to enhance the yield of

fields and crops (G.Tyler, 2004, Xu, Zhu, Wang and Witkamp, 2002, Zhang and Shan, 2001).

Although biogeochemical behaviour of REEs in soil and plants has not been fully understood

yet. These days metal pollution and their environmental impacts has been of much concern for

the researchers. Mining has been one of the factor for the degradation of soil and land. Mining






89

waste by the processing companies has been dumped to specific areas but that waste contain

radioactive materials which is continuously deteriorating our environmental quality (González

and González-Chávez, 2006).

Reestablishment of mining land has been one of the encounters met to the world in

terms of environment (Mukta and Sreevalli, 2010). For the last forty years, many geologists

work to find out REEs origin and nominate them as good tracers (FengFu, Tasuku, Sadayo and

Masaya, 2001). Many methods have been applied to make mining land fertile and usable but

all found costly, hard to apply, involve complex instruments and very time consuming.

However in accordance to these aspects, one of the simple and cheap method used by researcher

is the phytoremediation that involves removal of hazardous materials from the contaminated

soil in very easy way (Stamatiadis, Memon, Vassilev, Caviezel and Vangronsveld, 2008).

Two plant species were studied for their uptake capacity of LREEs. Ricinus communis

L. (Castor bean) is a widely grown plant on mining land because of its high resistance towards

metal tolerance, belongs to family Euphorbiaceae. This plant has been used for

phytoremediation of metals (Olivares, Carrillo-González, González-Chávez and Hernández,

2013). Ricinus communis L. has the ability to withstand all types of weather and climatic

conditions. Many researchers also found this plant as source of bioenergy rather than as food

(Rajkumar and Freitas, 2008). Emilia sonchifolia is an annual herb belonging to Astraceae,

commonly known as lilac tassel flower and setumbak Merah in Malaysia. This plant has been

previously used as antioxidant, anticancerous and for medicinal purposes (Essien, Nwidu and

Nwafor, 2009).

2. MATERIAL AND METHODS

Ricinus communis L. (castor oil plant) and Emilia sonchifolia (lilac tassel flower) were

collected by digging the soil in December 2015. Samples were collected from an ex-mining

area in Lahat Perak and immediately pressed in paper bags. Soil samples were also collected

and stored in polyethylene plastic bags before being air dried and taken to the laboratory for

further analysis. Plant samples were first cleaned with distilled water in an ultrasonic water

bath to remove adhering particles and then with Milli-Q water. Samples were air dried for three

months and then all parts of plants were separated, measured and stored in clean plastic bags.

The soil samples were also air dried, sieved and stored until further analysis.

2.1 Analysis of soil samples

Air dried soil samples were sieved to get homogeneous particle size of 2 mm and then stored

in plastic bags. Physical characteristics like pH, EC, CEC, OM and soil texture were

determined. Soil pH was measured by using soil water solution (1:1 ratio), EC by conductivity

meter, CEC using sorption method, organic matter content by Walkley and Black method and


90

soil texture by electrical sieving technique. A total of 0.1 g of each soil sample was also

digested using acid digestion method. Samples were digested in 3 ml of nitric acid (HNO3 -

65%) and 2 ml of hydrogen peroxide (H2O2 - 35%) in Teflon tubes in microwave digester using

time pressure system. After digestion samples were taken out in 50 ml centrifuged tubes and

diluted. All the samples were sent to ICP-MS (Agilent 7500 series, USA) for REEs analysis.

Standard reference material (SRM-2586) runs together with samples.

2.2 Analysis of plant samples

Acid digestion method was used to determine REEs in each part of plant. About 0.1 g of each

plant sample was digested using 7 ml of nitric acid (HNO3 - 65%) and 2 ml of hydrogen

peroxide (H2O2 - 35%) in microwave digester (Perkin Elmer- Titan MPS) using time pressure

system. Two standard reference materials; one of spinach leaves (SRM 1570a) and other apple

leaves were used for quality control purpose in order to check the accuracy of the results. For

both soil and plants samples, REEs were analysed by using multi-element standard. Standards

for multi element analysis were prepared by appropriate dilution of a multi-elemental reference

standard (Agilent 8500-6944, USA) containing Ce, Dy, Er, Eu, Gd, Ho, La, Lu, Nd, Pr, Sc,

Sm, Tb, Tm, Y, and Yb. After digestion samples were analysed by ICP-MS with three

replications.

2.3 Translocation factor (TF)

Translocation factor for REEs in plants was described as a ratio of REEs in plant shoot to that

in plant root given in equation 1.

TF = C stem /C root (1)

Where Cstem and Croot present the concentrations (µg g-1) of REEs in the shoot and root of plant,

respectively. TF>1 represent that translocation of REEs effectively to the shoot from the root.

2.4 Bioconcentration Factor (BCF)

Bioconcentration factor (BCF) was calculated for all REEs in plant species by using the

following equation 2.

BCF = C leaves / C soil (2)


91

2.5 Bioaccumulation Factor (BAF)

For the determination of REEs in plant species, bioaccumulation factor (BAF) was calculated

using following equation 3.

BAF = Cplant / C soil (3)


Soil samples were analysed for their physical properties and light rare earth elements (LREEs)

and results are given in Table 1 below.

Table 1: Physical parameters of soil collected and analysed with light rare earth elements

Soil Parameters Ricinus Communis Emilia Sonchifolia

pH 6 5.3

EC(µS cm-1) 52.9 15.9

CEC(cmol kg1) 16 21

MC (%) 8 32

OM (%) 21 12

Sc 44.6 30.17

Y 15.5 35.26

La 62.88 55.69

Ce 74.58 76.27

Pr 24.75 20.65

Nd 92.6 80.36

*all REEs measured in units mg kg-1

The pH of the soil of Ricinus Communis L. was 6 whereas of Emilia Sonchifolia was less about

5.3. Electrical conductivity values for both the plants found were 52.9 (µS cm-1) and 15.9 (µS

cm-1). It was found that the soil where Ricinus Communis L. was grown contains more metal

ions than other plant species. Cation exchange capacity (CEC) was 16 cmol kg-1 and 21 cmol

kg-1 for both plant species analysed. Moisture content was found high for Emilia Sonchifolia


92

but organic matter content was found high in Ricinus Communis L. Among the LREEs Sc, La,

Pr and Nd were high in the soils of Ricinus Communis L whereas Y and Ce were abandoned in

Emilia Sonchifolia. Results were confirmed by using SRM values for reference which is shown

in Table 2 below.

Table 2: Analysed and certified values for standard reference materials for plant species with

their % recovery

Standard Reference Material for plants (Apple leaves-1515a)

Elements Analysed SRM

Value (ng g-1)(n=3)

Certified SRM

Value (ng g-1)

Recovery

(%)

1 Al 575 ± 0.05 572 ± 0.81 100.5

2 Gd 5.96 ± 0.25 6 ± 0.14 100

3 La 41.1 ± 0.45 40 ± 0.28 102.75

4 Ba 98.5 ± 0.15 98 ± 0.11 100.5

5 B 53.9 ± 0.75 54 ± 0.35 99.8

6 Ce 6.02 ± 0.18 6 ± 0.21 100.3

7 Eu 0.38 ± 0.39 0.4 ± 0.22 95

4 Nd 3.44 ± 0.15 3.4± 0.05 101.1

Standard Reference Material for plants (Spinach leaves-1570a)

1 Al 518 ± 0.55 620 ± 0.55 83.5

2 Sc 0.011 ± 0.24 0.01 ± 0.16 110

3 Eu 0.01 ± 0.15 0.01± 0.15 100

3.1 Determination of REEs in plants

Different parts of plants after being prepared were studied for LREEs. Their concentration

varies in different parts of same plants and also compared to other plant specie analysed.

Results obtained have been shown in Table 3 and Figure 1 below. For every plant grown in

any kind of soil, root play an important role for its growth and nutrition. Root of Ricinus

Communis L. absorb Sc 22.1 (µg g-1), Y 6.7 (µg g-1), La 36.5 (µg g-1), Ce 66.1 (µg g-1), Pr 11.4

(µg g-1) and Nd 35.1 (µg g-1). Leaves of this plant contain Ce (35.5 µg g-1) in highest

concentration. La was detected in 25.5 µg g-1 while Sc was 18.6 µg g-1.

Table 3: Showing concentrations of LREEs oil in different parts of plant species analysed


93

Elements

Ricinus Communis (Castor)

(µg g-1)

Emilia Sonchifolia (lilac tassel flower )

(µg g-1)

Root Stem Leaves Root Stem Leaves

Sc 22.1 15.5 18.6 6.5 2.5 19.5

Y 6.7 3.5 6.3 3.2 0.8 5.2

La 36.5 18.1 25.5 22.2 6.9 35.5

Ce 66.1 12.2 35.5 41 11.5 48.2

Pr 11.4 2.2 4.6 3.4 1.1 12.5

Nd 35.1 6.5 20 16.5 2.05 10.6

This plant is considered as high biomass and has the capability to take up metals from soil.

Previous studies show its high uptake capacity for certain metals. This plant is considered as

hyperaccumulator for heavy metals (de Abreu, Coscione, Pires and Paz-Ferreiro, 2012). In

this study it was found for light rare earth elements (LREEs). Roots of Ricinus Communis L.

were high in LREEs (Figure 1a).

Emilia Sonchifolia was also studied for its rare metal uptake capacity. This plant is a

fast growing specie among its family. Ce was high in leaves (48.2 µg g-1) (Figure 1b).

(a) (b)

Figure 1: The concentration of light rare earth elements (LREEs) in plants stem, root and

leaves of (a) Ricinus Communis L. root shows greater uptake capacity of LREEs from soil (b)

Emilia Sonchifolia leaves were found loaded with LREEs

3.2 TF, BCF and BAF Analysis

Sc Y La Ce Pr Nd

0

10

20

30

40

50

60

(Co

nc.

(u

g g-

1))

Ricinus communis (Accumulator)

Root

Stem

Leaves

Sc Y La Ce Pr Nd

0

5

10

15

20

25

30

35

40

45

50

ug

g-1

Emilia Sonchifolia (L.) (Accumulator)

Root

Stem

Leaves


94

The transfer factor (TF), bioconcentration factor (BCF) and bioaccumulation factor (BAF) of

light rare earth elements (LREEs) in these plants grown on the ex-mining soil were also

analysed (Fig. 2). Such factors have been widely applied for REEs for many years and

considered much important for evaluating their behaviour in soil-plant system (Ndeda and

Manohar, 2014). Transfer factor is mostly correlated to the mass fraction of metals in the soil

and physico-chemical properties.

In our study for Ricinus Communis L. TF factor was found less than 1 which shows

the lower transfer of LREEs from roots to the shoots. This is the reason that most of LREEs

were concentrated in the roots and acting as accumulator. BCF factor was also found less than

1. Lower BCF values may be due to increased potential of soil water, dilution of LREEs and

low precipitation that decrease the plant growth (Agyarko, Darteh and Berlinger, 2010). BAF

factor was > 1 for Y, La and Ce. For the removal of pollutants from the soil and keep it as

green it is good having BAF >1 meaning that such plants can be used for phytoremediation.

Emilia Sonchifolia (lilac tassel flower) show very low TF from roots to shoots. Most

of the LREEs were concentrated in the roots and very less were found in shoots. BCF was also

< 1 for all LREEs whereas BAF was > 1 for La and Ce. Comparing the uptake capacity and

accumulation behaviour we see that most of the REEs were mainly present in the roots while

both plants have the capability to accumulate these rare metals in them.

Figure 2: Transfer factor (TF), bioconcentration factor (BCF) and bioaccumulation factor (BAF) of

(a) Ricinus Communis L. and (b) Emilia Sonchifolia studied for REEs

4. CONCLUSION

Both plant species used in this study were found with considerable amounts of LREEs. Ce, La

and Y were mainly found in roots and leaves of the plants. Shoots were low in these rare

elements. BCF and BAF were > 1 for some elements indicating that these plants can be used

for phytoremediation of light rare earth elements (LREEs) from ex-mining soil.

Sc Y La Ce Pr Nd0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

1.1

1.2

1.3

1.4

1.5

1.6

TF

, B

CF

, B

AF

va

lue

s

Ricinus Communis(L.)

TF

BCF

BAF

Sc Y La Ce Pr Nd0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

TF,

BC

F, B

AF

Va

lue

s

Emilia Sonchifolia (L.)

TF

BCF

BAF


95

5. ACKNOWLEDGEMENTS

The work reported in this paper was carried out in High Impact Research Laboratory and

UMCiL, Department of Chemistry, and some of the facilities were utilized from Hydro-

Geological Laboratory, Department of Geology, University of Malaya, Kuala Lumpur,

Malaysia and was supported through UM Research Grant RG257-13AFR and IPPP grant

PG133-2014B.

REFERENCES

G.Tyler (2004). "Rare earth elements in soil and plant systems " Plant and Soil, 1 - 2(267),

191- 206.

Xu, X., Zhu, W., Wang, Z., and Witkamp, G.-J. (2002). "Distributions of rare earths and heavy

metals in field-grown maize after application of rare earth-containing fertilizer." Science of the

Total Environment, 293(1), 97-105.

Zhang, S. Z., and Shan, X. Q. (2001). "Speciation of rare earth elements in soil and

accumulation by wheat with rare earth fertilizer application." Environ pollut, 112(395-405).

González, R. C., and González-Chávez, M. (2006). "Metal accumulation in wild plants

surrounding mining wastes." Environmental Pollution, 144(1), 84-92.

Mukta, N., and Sreevalli, Y. (2010). "Propagation techniques, evaluation and improvement of

the biodiesel plant, Pongamia pinnata (L.) Pierre—a review." Industrial Crops and Products,

31(1), 1-12.

FengFu, F., Tasuku, A., Sadayo, Y., and Masaya, I. (2001). "The variation of REE (rare earth

elements) patterns in soil-grown plants: a new proxy for the source of rare earth elements and

silicon in plants." Plant and Soil, 235(1), 53-64.

Stamatiadis, S., Memon, A., Vassilev, A., Caviezel, M., and Vangronsveld, J. (2008).

"Bioenergy to save the world. Producing novel energy plants for growth on abandoned land."

Environ Sci Pollut Res, 15, 196204Schwartz.

Olivares, A. R., Carrillo-González, R., González-Chávez, M. d. C. A., and Hernández, R. M.

S. (2013). "Potential of castor bean (Ricinus communis L.) for phytoremediation of mine

tailings and oil production." Journal of environmental management, 114, 316-323.

Rajkumar, M., and Freitas, H. (2008). "Influence of metal resistant-plant growth-promoting

bacteria on the growth of Ricinus communis in soil contaminated with heavy metals."

Chemosphere, 71(5), 834-842.

Essien, G., Nwidu, L., and Nwafor, P. (2009). "Anti-inflammatory and analgesic potential of

methanolic extract of Emilia sonchifolia (Compositae) leaves in rodents." African Journal of

Biomedical Research, 12(3), 199-207.

[11] de Abreu, C. A., Coscione, A. R., Pires, A. M., and Paz-Ferreiro, J. (2012).

"Phytoremediation of a soil contaminated by heavy metals and boron using castor oil plants

and organic matter amendments." Journal of Geochemical Exploration, 123, 3-7.

[12] Ndeda, L., and Manohar, S. (2014). "Bio concentration factor and translocation ability of

heavy metals within different habitats of hydrophytes in Nairobi Dam, Kenya." J Environ Sci

Toxicol Food Technol, 8(5), 42-45.

[13] Agyarko, K., Darteh, E., and Berlinger, B. (2010). "Metal levels in some refuse dump soils

and plants in Ghana." Plant Soil Environ, 56(5), 244-251.


96

NOVEL MAGNETIC BIOCHAR FOR THE REMOVAL OF 6

OCPS FROM WASTEWATER

Samavia Batool1, Mohd Jamil Bin Maah2, Nor Kartini Binti Abu Bakar 2

Ahmad Farid Bin Abu Bakar1, Athar Ali Shah3

1 Department of Geology, Faculty of Science, University of Malaya, 50603 Kuala Lumpur,

Malaysia 2 Department of Chemistry, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia

3 Institute of Micro Engineering and Nano Electronics , National University of Malaysia

Author Email : [email protected], [email protected], [email protected], [email protected],

[email protected]

ABSTRACT

The novel zero-valent iron magnetic biochar composites (ZVI-MBOP) were synthesized by

novel method using oil palms leaf waste and applied for the simultaneous removal of 6 OCPs

(pp-DDT, op-DDT, endosulfan, aldrin, heptachlore, hexachlorobenzene) from wastewater.

Field emission scanning electron microscopy (FESEM) and energy dispersive spectroscopy

(EDS) indicated the Fe° nanoparticles. Wastewater samples were collected from drained out

water of old oil palm tree plantation, Shah Aalam, Malaysia. Batch experiments revealed that

as prepared ZVI-MBOP has removed 79.17-84.28 % of 6 OCPs within 150 minutes at pH 4.

Desorption analysis has confirmed the simultaneous adsorption and dechlorination of OCPs in

wastewater. In conclusion, the treatment of wastewater using as-prepared ZVI-MBOP revealed

a favorable option for simultaneous adsorption and reduction of OCPs in aquatic system.

Key Words: Oil palm, ZVI-MBOP, OCPs, Removal

1 . INTRODUCTION

Organo-chlorine pesticides (OCPs) have been widely used all over the world since 1940 to

control vector diseases in agriculture (WHO, 1979). These are known as highly toxic

contaminants for animal and human health because of their persistence in nature (Behrooz et

al., 2009). Although, application of these OCPs including hexachlorocyclobenzene, aldrin,

endosulfan, DDT (1,1,1-trichloro-2,2-bis(p chlorophenyl)ethane), and heptachlor restricted in

most developing countries, remaining of these toxic compounds are still present in our aquatic

environment. The contamination by theses OCPs in our aquatic system is a major issue for

environment and human health.

Many efforts have been made for the removal of these OCPs from the environment

including chemical precipitation, thermal treatment and biodegradation. Among these,

adsorption is found to be effective technology because of less cost and good performance.

However, powdered biochar




97

was not easy to be isolated from aqueous solution (Zhang et al., 2013; Devi and Saroha, 2014).

Nano zero valent iron supported biochar particles are not difficult to be isolated from aqueous

solution by using an exterior magnetic field. Another main advantage of combining nano zero

valent iron with biochar is availability of active sites for the simultaneous adsorption and

dechlorination of organochlorine compounds.

Several wastes have been used for the biochar production such as sludge, animal manure,

forestry waste, food waste and agricultural waste (Reddy et al., 2014). In the present study, we

have used oil palm leaf waste which is cost-effective and easily available in Malaysia. Owed

to its ease of availability, inexpensive and highly rich in fuctional groups that were required for

the synthesis of magnetic biochar composites, in this study we have selected oil palm leaf waste

as an originator for the production of ZVI-MBOP. The main objectives of present study include

(i) the synthesis and characterization of ZVI-MBOP by FESEM and EDS analysis; (ii)

determination of removal capacity of novel ZVI-MBOP for the OCPs from the effluent of the

old oil palm field; Desorption analysis.

2 . MATERIALS AND METHODS

2.1 Synthesis of ZVI-MBOP

Ferrous sulfate heptahydrate (FeSO4.7H2O) was purchased from Sigma Aldrich. All Pesticides

were obtained from Dr. Ehrenstorfer GmbH, Germany. Oil palm leaves were obtained from

local farm, Selangore, Malaysia. Deionized water was used in all experiments.

Oil palm leaf waste was washed thoroughly by distilled water air-dried. Then they were

converted into powder form using grinder. The leaf powder was pyrolyzed at 350 W and used

for preparation of ZVI-MBOP. In a typical method, biochar was dissolved in 0.054 M

FeSO4.7H2O solution and leaf extract was added drop wise for reduction of Fe+ to Fe0 under

vigorous stirring. The black residue was washed thoroughly with ethanol, vacuum dried at 60

°C overnight and stored in an air tight container.

2.2 ZVI-MBOP application experiment

In order to test the removal efficiency of ZVI-MBOP on real effluent, the wastewater samples

were collected from the water drained out from old oil palm plantation in Shah Alam, Malaysia

and stored in amber bottles at 4 °C until use. Physic-chemical characteristics of wastewater

were determined. Organochlorine pesticides were detected and quantified in wastewater. The

wastewater samples were spiked with 6 OCPs at an individual concentration of 2 mg/L and

treated with 10g/L dosage of adsorbent. The treatment times of 10-150 min was tested. Final

concentrations of OCPs in solution and amount of OCPs adsorbed on exhausted ZVI-MBOP

were determined using Agilent technologies 7890A GC system. Removal % and amount of

dechlorination (mg/L) was determined as below:

Removal % = ( )

Amount of dechlorinated (mg/L) = Total removal (mg/L) - Adsorption on exhausted adsorbent (mg/L) (2)

where is the initial c'oncentration and


98

2.3 Characterization

Morphological studies were done with FESEM images on Hitachi SU8220. Element analysis

of ZVI-MBOP was carried out with 51P1000 Aztec Energy standard element diffraction

spectrum (EDS).

3 . RESULTS AND DISCUSSION

3.1 Characterization of adsorbent

Figure 1: FESEM images of ZVI-MBOP

FSEM and EDS were used to analyze the surface morphology and chemical

composition of ZVI-MBOP. Figure 1 shows that nZVI particles were spherical in shape and

evenly immobilized on the surface of biochar with less agglomeration which is attributed to the

biological components in biochar (Chandraiah, 2016). EDS analysis confirms the formation of

Fe0 particles in figure 2. The C and O peaks were originated from C, O-containing compounds

in biochar (Kuang et al., 2013).

6 0 nm

Biocha r

0

Fe 0


99

Figure 2: EDS pattern of ZVI- MBOP

Table 1: Physico-chemical characteristics of real wastewater

Parameters Description

Coordinates 03°217421N 101°45530E

pH 5.2

Temperature (ºC) 26.2

Conductivity (µs/cm) 38.4

TDS (mg/L) 24.2

DO (mg/L) 11.59

TSS (mg/L) 7.2

pp-DDT (µg/L) 0.6

op-DDT (µg/L) 0.8

Endosulfan (µg/L) 2.976

Aldrin (µg/L) 1.02

Heptachlore (µg/L) 0.283

Hexachlorobenzene (µg/L) 2.576


100

3.2 Wastewater characteristics

Physic-chemical characteristics of wastewater are presented in table 1. The pH, conductivity,

TSS, TDS and DO Values were found less than water quality standards values for land

irrigation water which are 5.5-9, 2250 µs/cm, 200, 2500 and > 3 (mg/L) respectively.

Organochlorine pesticides (pp-DDT, op-DDT, endosulfan, aldrin, heptachlore,

hexachlorobenzene) were detected and quantified in range of 0.6-2.576 µg/L. Concentrations

of Endosulafan, Aldrin and hexachlorobenzene found higher than permissible limits (1 µg/L)

for wastewater (Fipps, 2015).

3.3 Removal of OCPs from wastewater and desorption analysis

In this study, pH 4 and 10 g/L dosage of adsorbent was found optimum for the maximum

removal of OCPs from wastewater. At high pH, OH- ions are responsible for the formation of

iron hydroxide layer on the surface of ZVI-MBOP, which blocks the exposure of active sites to

the target pollutants (Setini et al., 2013). Conversely, very low acidic condition destructs the

carbon structure and impairs the reducing ability of nZVI particles as well. Therefore, weak

acidic condition pH 4 was found best for maximum removal of OCPs from solution.

Figure 3: Removal efficiency of OCPs in the synthetic wasterwater ; Adsorbate: 2 mg/L

each, Adsorbent: 10 g, Agitation speed 150 rpm, 25±2 °C, pH: 4

Figure 3 shows that there was an abrupt increase in OCPs removal (42.82-50.29 %) by

ZVI-MBOP with the increase in time up to 30 min and thereafter gradual increase in OCPs

removal was obtained with 79.17-84.28 % removal within 150 min. The quite fast rate of

removal of OCPs at initial timing is because of obtainability of large number of adsorption sites

(Quan et al., 2014) which were later engaged by contaminants providing limited availability of

adsorption sites.

The initial concentration of each OCP in wastewater was 2 mg/L. The concentration of

OCPs adsorbed on exhausted ZVI-MBOP at 150 min was between 0.201 to 0.226 mg/L.

ZVIMBOP has removed 79.17 to 84.28 % of OCPs. It was concluded that 86.48 to 87.5 %


101

decholorination was occurred by ZVI-MBOP which shows its adsorption and reducing ability

simultaneously.

4 . CONCLUSION

This study demonstrates the successful synthesis and characterization of novel magnetic

biochar (ZVI-MBOP) using oil palm leaf waste. This ZVI-MBOP has efficiently adsorbed and

reduced the OCPs in wastewater. Out of overall maximum removal, 86.48 to 87.5 % was found

to be dechlorinated by nZVI particles. Consequently, the ZVI-MBOP will provide the advantage

of both adsorption and reduction of OCPs simultaneously.

5 . ACKNOWLEDGEMENTS

Financial support of the “University of Malaya IPPP research grants RP018C-14AFR” and

PG111-2015A are appreciatively acknowledged.

REFERENCES

Reddy D.H.K. and Lee S.M. (2014). Magnetic Biochar Composite: Facile Synthesis,

Characterization, and Application for Heavy Metal Removal, Colloids Surf. A: Physicochem.

Eng. Aspects, 454, 96–103.

Zhang M., Gao B. Varnoosfaderani S. Hebard A. Yao Y. and Inyang M. (2013).

Preparation and Characterization of a Novel Magnetic Biochar for Arsenic Removal,

Bioresource Technology, 130 (2013) 457– 462.

Devi P. and Saroha A.K. (2014). Synthesis of the Magnetic Biochar Composites for Use

as an Adsorbent for the Removal of Pentachlorophenol from the Effluent, Bioresource

Technology, 169, 525–531.

Hay A.G and Focht D.D. (2006). Transformation of 1,1-dichloro-2,2-(4 chlorophenyl)

ethane (DDD) by Ralstonia Eutropha Strain A5. FEMS Microbiolgy Ecology, 31, 249– 253.

WHO. (1979). World Health Organization. Environmental Health Criteria 9, DDT and

its Derivatives. World Health Organization, Geneva.

Behrooz R.D. Sari A.E. Bahramifar N. and Ghasempouri S.M. (2009). Organochlorine

Pesticide and Polychlorinated Biphenyl Residues in Human Milk from the

Southern Coast of Caspian Sea. Iran. Chemosphere, 74, 931–937.

Quan G., Sun W. Yan J. and Lan Y. (2014). Nanoscale Zero-Valent Iron Supported on

Biochar: Characterization and Reactivity for Degradation of Acid Orange 7 from Aqueous

Solution. J. Water Air Soil Pollution, 225-2195.

Seteni B., Ngila J.C. Sikhwivhilu K. Moutloali R.M. and Mamba B. (2013).

Dechlorination of 3,30,4,40-tetrachlorobiphenyl (PCB77) in Water, by Nickel/iron

Nanoparticles Immobilized on L-lysine/PAA/PVDF Membrane. J. Physics and Chemistry of

Earth, 60-67.


102

Smuleac V., Varma R. Sikdar S. and Bhattacharyya D. (2011). Green Synthesis of Fe and

Fe/Pd Bimetallic Nanoparticles in Membranes for Reductive Degradation of

Chlorinated Organics. J. Membrane Science, 379, 131-137.

Kuang Y., Wang Q. Chen Z. Megharaj M. and Naidu R. (2013). Heterogeneous

Fentonlike Oxidation of Monochlorobenzene Using Green Synthesis of Iron Nanoparticles. J.

Colloidal Interface Science, 410, 67-73.

Chandraiah M.R. (2016). Facile Synthesis of Zero Valent Iron Magnetic Biochar

Composites for Pb(II) Removal from the Aqueous Medium. J. Alexandria Engineering, 55,

619– 625.

Fipps G. (2015). Irrigation Water Quality Standard and Salinity Management Strategies.

Agri life extention Texas A & M system.


103

STUDY OF AMD AND HEAVY METAL CONTAMINATION

IN ACTIVE AND ABANDONED IRON MINING IN PAHANG

Rizwana Naureen 1, Prof. Dr. Ismail Bin Yusoff 1 and Dr. Ahmad Farid Bin Abu Bakar 1

1Dept. of Geology, Faculty Science, University Malaya, 50603, Kuala Lumpur, Malaysia, [email protected]

ABSTRACT

Heavy metal contamination resulting from mining activities involves complex biogeochemical

interaction where dissolution of minerals from tailings cause acid mine drainage. Mining

operations in Pahang date back to 1960s and continue today for iron extraction. Many sites are

still under heavy mining activities while some have been abandoned along the way with

improper closure practices. A study was made to investigate the heavy metal content in surface

soil and water samples of Bukit Ibam which is an old active mining site located at eastern ridge

of Pahang mineral belt. Lab quality parameters such as pH, EC, salinity, DO and ammonium

concentrations were measured. Samples were also analysed for anions and heavy metal content.

The study revealed the acidic trend in water with pH as low as 2.56 and EC of 2183 µS/cm.

The study also showed high level of sulphates which is a typical character of mine tailings.

Heavy metal content was analysed by ICP-OES with high concentrations of Cu, Fe, Mn and

Zn. An investigation was also made into possible biological treatment method using RBC for

soil and water reclamation. The study concludes that there is a need to adopt better mining

practices with proper closure protocols as not only the environment in general but also the local

biodiversity suffers from adverse effects.

Key Words: Metal contamination, Acid Mine Drainage, Rotating Biological Contactor

1 .INTRODUCTION

Mining operations for the extraction of mineral resources have always been a part of human

civilization. Mining activities generate toxic substances with serious implications to ecological

systems and human health and also lead to adversity for social and economic setup of the area.

As per studies of 20th century, approximately 19,300 Km of streams and rivers along with

72,000 ha of reservoirs have been damaged by mine-effluents (Johnson & Hallberg, 2005).

Major source of AMD formation is the oxidation of iron pyrite and other minerals when

exposed to oxygen and water, which is accelerated by mining operations (eq.1) (Simate &

Ndlovu, 2014).

4FeS2 +15O2 +14H2O 4Fe (OH)3 + 8SO2-4 +16H+ -------------------------- (Eq. 1)

Acid mine drainage is the result of iron disulfide oxidation on exposure to air during or after

mining, however the extent of Acid Mine Drainage (AMD) varies from site to site making it a

challenge to develop a standardized protocol for predicting the potential of AMD. Heavy metal

contamination resulting from mining activities involves complex biogeochemical interaction


104

where dissolution of minerals from tailings cause acid mine drainage. Treatment and/or

remediation methods to control this contamination combine the exposure to water and oxygen

through flooding of underground mines, land-based sealing or storage, application of anionic

surfactants and packed bed oxidizing bioreactors. The efficient removal and treatment of metals

and neutralization of AMD and soil requires millions of dollars and years of time with latest

technology. The damage restoration costs only for USA were assessed to be 2-5 billion dollars

where its already spending around 1 million dollar each day for acid effluent treatment

(Kalyoncu Ergüler, 2015).

Mining operations in Pahang date back to 1960s and continue today for iron extraction.

Many sites are still under heavy mining activities while some have been abandoned along the

way with improper closure practices.

2 .MATERIALS AND METHODS

2.1 Study area and field sampling

The main problems caused by mining are namely formation of wasteland, damage to natural

drainage, pollution and the destruction of natural habitats. Sampling was undertaken in Bukit

Ibam, located in Rompin District of Pahang. Iron ore mining in Bukit Ibam started in 1962

being one of the largest mine in south-east Asia at that time being the largest individual iron

ore deposit located in the centre of eastern ridge of mineral belt in Pahang. The sungai Tepesuk

flowing out from bukit Ibam towards south is a part of 3939 Km2 of Sungai Rompin Basin. All

the tributaries in the basin originate from mountain ranges running parallel to coast line and

merging before finally draining into South China Sea.

Sampling was carried out to assess the water and soil contamination over time as area

has been under mining for about six decades now. The area has a lot of big lakes and small

ponds that are interconnected by earth drains. All soil and water sampling locations were

marked using GPS. A total of eight sampling locations were investigated for both water and

surface soil in both active (S4, S5, S6, S7, S8) and abandoned mining area including the

residential dwellings (S1,


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Water samples were taken in triplicate for anion and dissolved metal concentration using HDPE

bottles and 1% nitric acid was added in one triplicate set for heavy metal analysis.

Physiochemical parameters were analysed by portable (Temperature, pH, Total Dissolved

Solids, Ammonium ion, Dissolved Oxygen, Conductivity, Salinity) meters on-site. The surface

soil samples were extracted using stainless steel auger upto 20cm and stored in plastic bags.

All samples were stored in ice-box and transferred to lab for further analysis.

2.2 Laboratory analysis

Dissolved anion samples were filtered through 0.2 μm filters before analysis by Ion

Chromatography while for quantitative heavy metal estimation, ICP-OES was utilized after

filtering the acidified samples through 0.45 μm membrane filters. Soil samples comprising of

top 20cm layer stored in polythene bags were later air-dried and sieved (0.5mm). Solutions

through shaker in ratio of 1:5 were prepared for basic physiochemical parameters such as pH,

electrical conductivity and anion content. The metal content was analysed by ICP-OES after

the samples were digested using wet acid digestion.

3 .RESULTS AND DISCUSSION

3.1 Physico-chemical Parameters Study

The results as presented in Figure 2, show a relatively higher pH for water samples as compared

to surface soil in all active and abandoned sites. The water pH ranges from 2.68-5.97 in the

active iron-ore mining area while its between 5.28-7.48 in abandoned sites. The low pH at

active sites is a characteristic of mineral exposure leading to acidic environment and leaching

as a result of excavation. On the other hand, the pH at abandoned sites still ranges from low

S2, S3) .

Figure 1: Study area (Bukit Ibam), location in Pahang state, Malaysia


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acidic to neutral range suggesting the presence of alkaline compounds acting as buffer but still

acid character is prevalent at some sites. The soil samples exhibit a pH range of 4.68-6.75 at

abandoned sites in comparison to pH of 3.75-5.04 at active sites.

Figure 2: pH variation in water and soil samples in Bukit Ibam

Results for water samples analyses show a variation in water quality at different sampling

stations. Water quality parameters for sampling station SW4 are; pH 2.68, temperature 35.2°C,

conductivity 2183 µS/cm, salinity 1.166 psu, dissolved oxygen 5.9 mg/L, total dissolved solids

1 mg/L, ammonium ion 0.8mg/L showing typical AMD characters. While at SW2 (Residential

area) water quality parameters are; temperature 31.8°C, pH 7.48, conductivity 1168 µS/cm,

salinity 0.631 psu, dissolved oxygen 6.1 mg/L, total dissolved solids 573 mg/L. This shows the

variation between the AMD in abandoned tailings with low pH and also the neutral pH of water

in residential area, although the level of TDS is high. Similarly, the sulphate concentration in

mining area is a characteristic of AMD associated with low pH as given in Figure 3.

Figure 3: The relationship between sulphate concentration and conductivity in water


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The significance between sulphate concentration and conductivity in water samples indicates

the level of contamination at all sites. It is evident from the Figure 3 that all active sites have

high levels of dissolved sulphate concentration confirming the presence of AMD in field.

3.2 Heavy Metal Analysis

The concentration of heavy metals in the water samples of mining area was not as significant

as their presence in soil samples. In the active mining area, the concentration for iron and

manganese was 5.10 m/L and 3.65 mg/L, respectively in water sample while for soil sample of

the same location, it was 6180 mg/Kg and 3.94 mg/Kg. The heavy metal content in water

samples was as high as 0.2 ppm, 3.65 ppm, 0.33 ppm and 5.10 ppm for Pb, Mn, Zn and Fe,

respectively. Figure 4 and Figure 5 show the concentration of heavy metals in both water and

surface sediment.

There is almost a linear relationship between Mn and Fe concentration in soil samples

as both tend to increase or decrease with same trend. This can be attributed to pH changes

which alter the solubility of Fe and Mn thus accumulating them in the sediment. Highest

contamination for Pb was 21.69 ppm for 0.5g of sample to as low as 0.32 ppm. Mn

concentration ranged from 263.3 ppm to 0.45 ppm while Cu was 109.8 ppm to 0.33ppm. Zn,

As, Cr, Si and Ni were also present in the soil samples. The results show that there is presence

of heavy metals in the soil both in active mining area as well as in the surrounding residential

area including the samples from playground, school and community centre. Figure 6 and Figure

7 show the relationship between Fe and Mn concentration in soil samples with regard to

changes in water pH showing strong dependence of Fe towards pH change.

Figure 4: Heavy metals in water


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Figure 5: Heavy metal concentration in surface soil

Figure 6: Concentration of Fe in water and soil samples, with pH

Figure 7: Concentration of Mn in water and soil samples, with pH


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3.3 Biological Solutions

The heavy metal mineralization in soil and water results in acidic metal rich mine-water (pH

from Table 1) (Whitehead & Prior, 2005). The treatment methods include hydroxide

precipitation, the use of sulphate reducing bacteria (Bratkova, Koumanova, & Beschkov,

2013), aerobic wetlands, permeable reactive barriers or oxidizing bioreactors (Johnson &

Hallberg, 2005). One aspect of bioreactor treatment for mining wastewater includes Rotating

Biological Contactor whereby the immobilised microorganisms in the biofilm remove heavy

metals through bioaccumulation, biosorption and biomineralisation. Several studies have

shown the successful removal of heavy metals from mining wastewater using RBC. It provides

as a sustainable and environment friendly treatment method with low operational costs,

minimal maintenance and simple process control (Costley & Wallis). The process can be

utilized as an effective method for mining wastewater treatment using indigenous

microorganisms at mining sites (Orandi & Lewis, 2013).

4 .CONCLUSION

The water and soil analysis show heavy metal contamination and AMD presence in Bukit Ibam

evident from lab analysis where pH value of flowing water is as low as 2.68. The use of

biological technologies such as RBC is a sustainable way to treat heavy metals in natural

environments with proper management practices.

5 .ACKNOWLEDGEMENTS

The authors are thankful to Institut Pengurusan Dan Pemantauan Penyelidikan, (IPPP)

University of Malaya for the provision of research grants (FRGS-FP046-2013A and PG

0082013B) to carry out the research.

REFERENCES

Bratkova, S., Koumanova, B., & Beschkov, V. (2013). Biological treatment of mining

wastewaters by fixed-bed bioreactors at high organic loading. Bioresource Technology,

137, 409-413. doi: http://dx.doi.org/10.1016/j.biortech.2013.03.177

Costley, S. C., & Wallis, F. M. Treatment of heavy metal-polluted wastewaters using the

biofilms of a multistage rotating biological contactor. World Journal of Microbiology

and Biotechnology, 17(1), 71-78. doi: 10.1023/a:101662150847

Johnson, D. B., & Hallberg, K. B. (2005). Acid mine drainage remediation options: a review.

Science of The Total Environment, 338(1–2), 3-14. doi:

http://dx.doi.org/10.1016/j.scitotenv.2004.09.002

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Kalyoncu Ergüler, G. (2015). Investigation the applicability of eggshell for the treatment of a

contaminated mining site. Minerals Engineering, 76, 10-19. doi:

http://dx.doi.org/10.1016/j.mineng.2015.02.002

Orandi, S., & Lewis, D. M. (2013). Biosorption of heavy metals in a photo-rotating biological

contactor--a batch process study. Appl Microbiol Biotechnol, 97(11), 5113-5123. doi:

10.1007/s00253-012-4316-5

Simate, G. S., & Ndlovu, S. (2014). Acid mine drainage: Challenges and opportunities. Journal

of Environmental Chemical Engineering, 2(3), 1785-1803. doi:

http://dx.doi.org/10.1016/j.jece.2014.07.021

Whitehead, P. G., & Prior, H. (2005). Bioremediation of acid mine drainage: an introduction

to the Wheal Jane wetlands project. Science of The Total Environment, 338(1–2), 15-

21. doi: http://dx.doi.org/10.1016/j.scitotenv.2004.09.016








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THEORETICAL REVIEW ON SUCCESS FACTOR

AFFECTING COMPETENCIES OF CIVIL ENGINEER

Hassan Ismail, Zainal Abidin Akasah & Sasitharan Nagapan Faculty of Civil and Environmental Engineering, Universiti Tun Hussien Onn Malaysia, Parit Raja, Johor

Email : [email protected]

ABSTRACT

Critical success factors (CSFs) are inputs to project management practice which can lead directly or indirectly to project success. It encompasses many elements, which have to be synchronized to ensure the project delivered on time. Competencies are important in all fields of human endeavor. Features of the construction process and construction project render competencies even more essential. Therefore the choosing a civil engineer for a construction project, particularly is a critical project decision. The selection process involves different criteria and should be in accordance with company policies and project specifications. Traditionally, potential candidates are interviewed and most qualified are selected in compliance with company priorities and project conditions. This paper aims to reveal a conceptual, critical success factor affecting competencies of civil engineer for construction project in Malaysia. Hopefully the result can be used as a guidance to measure the level of competency of civil engineer.

Keywords: Critical Success Factor (CSFs), Competencies, Construction, Civil Engineer.

1. INTRODUCTION

Generally construction industry is one of the most significant sectors in the Malaysian

economic. The industry is critical to rational wealth creation as it acts as a substance for and

has multiplies effects to the economy, which enables other industries such as manufacturing,

professional services, financial services and education (CIDB, 2012). According to Myer

(2013) stated many studies have emphasized the significant contribution of the construction

industry to development of national economic. It also increases the quality of life by providing

the necessary infrastructure such as highways, universities, housing and other basic and

improved facilities. Therefore, it is basically crucial to ensure the construction projects

completed successfully within the time scheduled, budget allocated, good quality and

productivity. Nevertheless, being a complex, fragmented and schedule driven industry it

always facing chronic problems such lack of competencies, low quality and productivity non-

achievement, lack of communication between project team, time overrun, waste of construction

and others. Furthermore, Lapiņa & Ščeulovs (2014), Omar & Fayek, (2016) stated the

competencies are a severe problem because it effects the overall development of any country.

Success of the construction project importantly depends on how the project has been planned,

managed and organized by a qualified project team besides support and commitment by the top

management itself. The critical success factors (CSFs) are more helpful in decision-making

support; more player-based research studies should be conducted. Several factors determine

the progress of the Malaysia construction industry. These include the availability of labour,


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financial resources, building materials, and machinery. In construction industry, the manpower

plays a pivotal role particularly. The wide ranges of construction personnel from project

managers, executives, civil engineers, employees at different levels, and general workers. The

overall outcome of the project in one way or another are affected from the performance of each

individual involved in a project. Engineers, particularly civil engineers, are crucial in

construction projects. Before a project is realized, they have to study and assess its feasibility;

once the project was approved, civil engineers need to plan, design and monitor every stage of

the construction. To ensure that the project goals are reached, before construction work at the

site starts, civil engineers need to coordinate with the owners, project advisors, consultants,

main contractors, subcontractors, and suppliers appropriately. Hereafter, civil engineers need

to have adequate on-site experiences. Frequently, they are also entrusted with high levels of

managerial level and administrative responsibilities. At that time, organisations owning such

as directors, general managers and project managers the project should monitor the

performance of their engineers to ensure that their projects are successfully executed.

2. DEFINITION OF COMPETENCIES

Competencies are beneficial concepts that try to describe why certain people accomplish better

than other (Vries, 2001;Boyatzis,1982; Boyatzis, 2008; Hopkins, 2008; McClelland, 2008;

Liikamaa, 2015).

Competency is an individual‟s fundamental characteristic that is causally related to in

effect performance in a job or situation and job tasks. A person needs competencies, which are

abilities to use knowledge and to make happen. The reveal what a person is capable of doing

and why he or she acts in a certain way. According to PMI (2000) stated the competencies have

been grouped in the International Competence Baseline into three categories: behavioural,

technical and contextual competencies. Table 1 revealed the definitions of competencies from

1993 until present.

Table 1 : Definition of competencies

Authors Definition of Competencies

Spencer & Spencer

(1993)

Competency is fundamental characteristic of the individual

that is causally related to a standard of effectiveness and /or

to a superior performance in a job or situation.

Glader (2001) Competence is used to achieve something. It includes

knowledge in all their shapes, but it also includes

personality traits and abilities, such as persistence, stress

tolerance ,social competence and so on

Markus (2005) Competencies is a generic body of knowledge, motives,

traits, selfimages and social roles and skill that are casually

related to superior or effective performance in the job.

Caupin et al., (2006) ;

Muller & Turner (2010)

Competencies are a combination set of an individual‟s

knowledge, personal characteristics and abilities used to

execute a particular activity or task.


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Crawford (2005) Competency in term of skill, knowledge & behavior

Serpell & Ferrada

(2007)

Basic competencies as entry attributes this are the

knowledge, attitudes and abilities of people upon joining an

organisation.

Brozova & Subrt (2008) Competencies are a standardised requirement for an

individual to properly perform a particular job and it

includes a combined set of knowledge, skills and behavior

utilised to develop performance”.

Buntat et al., (2013) Competency is required to guide implementers of

competency – based initiatives

Liikamaa (2015) Competencies are as a ability or capability; it consists of a

set of alternate behaviors organized around an underlying

construct.

3. SUCCESS CRITERIA FOR CONSTRUCTION PROJECTS.

According to Chan & Chan (2004), Alzahrani & Emsley (2013) stated success are defines as

the grade to which project objectives and expectation are encountered. In addition, Alias et al.,

(2014) stated Project success means that certain expectation for given member were met, either,

owner or client, consultant, main contractor etc.

For example, Frodell (2008) has drawn a list of success criteria in construction through

reviewing 16 articles. His empirical study has originated success measures, as success on a

project means different things to different people (Chan and Chan, 2004; Freeman and Beale,

1992; Liu and walker, 1998). Delivered on time,within budget and meeting the preset quality

measures are the main criteria to success on a project for construction project, while, safety and

environment are also addition criteria that contribute to success on a project nowadays. Table

2 summaries and discusses the potential factors selected from previous literature.

Table 2 Project Success Factors For Construction Projects.

Factors Sources Discussion

Company‟s

technical

capacity

Alzahrani &

Emsley

(2013)

successful project based on having the right planning, goals,

capacity at the right time, knowing and targeting the related

customers, cost effective supply and then constant

innovation.

Planning

Efforts

Doloi et al.,

(2012), Jha &

Iyer (2007)

Successful project implies the use of advanced planning

methods that allow to determine the feasible sequences of

activities and to finish a project within budget and delivered

on time.

Adequate

project

management

techniques

Gudiene et al.,

(2014), Chan

& Chan

(2004)

Implementation of Project management techniques such as

planning and control of time, cost and quality have been

widely recognised to project success. Besides, success of

one project are depend on having such as realistic and

definite goal, client satisfaction, competition and etc.


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Effective site

management

Doloi et

al.,(2012)

Effective site management requires competent such as civil

engineer, Project manager to allocate work in line with the

workers skill, ability and knowledge they have. Then,

evaluate workers when they do jobs efficiently.

Team

motivation

Kog & Loh

(2012),

Tabish

& Jha (2012)

All personnel such as civil engineer, project manager and

workers in the worksite must be motivated to achieve their

target and planning, carry out their job responsibilities

safely. Hopefully, the possibilities of achievement and

recognition will give an opportunity for rewards,additional

responsibilities and personal development

4. CRITICAL SUCCESS FACTORS AFFECTING THE CIVIL ENGINEER

COMPETENCIES

From the perspective of Project Management, critical success factors (CSFs) are conditions and

characteristics on variables that can have a major impact on project success when properly

managed, sustained and maintained. (Patanakul & Milosevic, 2009; Stevenson & Starkweather,

2010). Some studies have identified a some different critical success factors and also lack of

opinion among researchers on the criteria and factors that influences project success. (Fortune

& White, 2006). Whilst, numerous studies on critical success factors have observed the impact

of context on which factors are considered most critical as well as whether certain on critical

success factors indeed related to success. In some construction companies, management

activities in construction project can be a better understanding by exploring the critical success

factors for improving the performance in their building projects. There are various factors that

are currently being perceived to be critical for successful that affecting civil engineer

competencies. While, there are some discussions given by various authors.

1st CSFs is support and commitment by top management to the project

The need for support and commitment by management to the project is highlighted by most

authors such as Kog,Loh (2012), Doloi et al., (2012), Yang et al., (2011), Zou et al., (2014).

According to Aziz et al.,(2016) stated a good management always be aware of demand for

change. The ability to plan an asset shows skill in managing the organisation’s leaders. Among

the commitments that need to be highlighted is to renew and update main elements of the

organisations, preparation for the new job specification, make structural changes in the

organisation, resolving conflicts to be faced, make sure the involvement of members and create

an effective plan to improve the administration of an organisation. Whilst, management should

provide the employees with sufficient resources like technical, financial and physical in order

for them to perform their work effectively and improve their competencies. The appointment

of a coordinator is also needed to managed and coordinate all related activities in daily

operations and translate what the management expectations so that the people at the lower

levels of the organization can understand and able to carry-out their job efficiently and

effectively (Mohammad et al., 2007; Zutshi & Sohal, 2005).


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2nd CSFs is Appropriate training and education

Appropriate training and education are essential to acquire involvement of management and

employees‟. Management and employees especially civil engineer have to be trained to ensure

that they are aware and improve the level of competencies. Good management should

demonstrate that they are prepared to learn and arrange for learning opportunities for all

employees in organisations. Tabish & Jha, (2012, Zutshi & Sohal, (2005) stated that all

employees should have well founded knowledge about internal company procedures and some

of the employees are trained for interpretation of the management systems standard. Whilst,

the organisation should regularly review the training planning and modules to ensure it is

relevant and sufficient for successful affecting the civil engineer competencies (Mohammad et

al., 2007). According Salas et al., (2006), training is a process of enhancement in the

competencies, skills, capabilities, knowledge and intelligence of employees. Ability involves

the ability of worker‟s task are entrusted with by their own experiences. In the meantime

competence and skill is the ability to complete a task because of continuous training,

knowledge is stored in the mind and the ways in which it is understood and used.

3rd CSFs in Team members related factor

The appropriate selection of team members also influences the success of a construction

projects. A good coordination between all parties in management factors plays the main role

(Ismail et al., 2012). This group includes such factors as decision making effectiveness,

competence, experience, motivation, technical capability, personnel issues.

4rd CSFs is Communication

Basically, the briefing processes is an act of communication. Effective communications are

needed between all parties to identify, clarify and represent the client requirement. In the

previous research written by some author's,the most important in critical success factor are

briefing process. (Yu et al., 2008). According (Barret and Stanley, 1999 ; Yu & Shen, 2015)

suggested that communicating with all the tools that are available is a key area for successful

briefing. Active listening should be encouraged in the briefing exercise to allow a free and

complete flow of communication.

5th CSFs is Employee Involvement

Employee involvement is a process for empowering to participate in managerial decision-

making and enhancement activities suitable to their levels in the organisation. According to

Lawler (1995),”Employee involvement”, if well implemented, changes the fundamental

relationship between individuals and the organisation they work for”. It really builds employees

in as a business partner, so they know more and they do more to make the organisation

successful, particularly in industries where the human component is important most knowledge

work, high-tech and kinds of service industries.

6th CSFs is Contractor related factor

Contractor‟s performance and expertise play a important role in delivery of a project succesful

(Doloi et al., 2011).They start their main duties when a project reaches the construction or

execution stage where the actual work of the project is accomplished (Alzahrani, 2013). The

group includes these factors : company characteristics, technical and professional capability


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and competencies, experience, economic and financial situation, quality issues, health and

safety conditions, work conditions.

7th CSFs is Stakeholders

A stakeholder is a group of people who have a conferred in the project success and the

environment within which the project operates. There are many stakeholders participating in

the implementation process of construction projects: clients, designers, planners, main

contractor, project manager and financial institutions. An important issue for a project

management team is to recognise those stakeholders who can affect the project and manage

their differing demands through good communication in the early stages of a project (Gudienė

et al., 2013). Hence, effective communications between stakeholders are very significant to

ensure the successful of construction projects.

8th CSFs is Decision Making

Briefing involves a lot of decision making by individuals and by groups. Effective decision

making processes are the backbone of an effective strategy. Knowing when and what kinds of

decisions must be made are crucial to the success of any project (Blyth and Worthington, 2001).

A good briefing team should not limit itself to just one decision making method and should

operate in contingency fashion by changing decision methods to best fit the problem and

situation at hand. Therefore, effective decision making are related from clarity of the project

mission, effective scheduling, clear project briefing and others by project manager or civil

engineer in construction project. There are supports by most authors such as (Gudience et

al.,2014 ; Jha & Iyer, 2007; Kog & Loh, 2012 ; Tabish & Jha, 2012).

5. DATA COLLECTION

In this study, data collection will be categories into two phases. Result of data collection will

be analysed through statistical software which SPSS version 21 and Smart Partial Least Square

(PLS)

a) Questionnaire: The development of the questionnaire will be conducted (based

on literature) and will be distributed to respondents. The development of the

questionnaire will be based on Malaysia contractor environment (culture, social-

economic and politics). The questionnaire will consist of respondents demographic,

critical success factors and suggestions that contributes to the competencies of

construction personnel in project management practice.

b) Interview: Interview is a more qualitative approach. Individual and group

interview will be deployed among the experience and competence of construction

personnel in project management practice in Malaysia,

6. RESEARCH VALIDATION

After analysing result thorough SPSS and Smart PLS software, the validation of the result will

be conducted through a group interview among the expert of construction personnel in

Malaysia. Then, the development of critical success factors model in construction industry will

take place.


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7. CONCLUSION

At the end of this research, a critical success factors affecting the competencies of civil

engineer.are been identified. It will be develop and validate by the experts. Hopefully this

significance model will provide a new knowledge to be used for the management practice.

8. ACKNOWLEDGEMENT

The authors would like to acknowledge Associate Professor Dr. Zainal Abidin Akasah and Dr.

Sasitharan Nagapan for all the encouragement and help to complete this research works.

Special thanks to University Tun Hussien Onn Malaysia for the support on the ongoing PhD

research works.

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122

SUPERCRITICAL CO2 EXTRACTION OF NEEM

SEED OIL: A COST COMPARISON STUDY WITH

SOXHLET EXTRACTION AT LAB SCALE

Sheela Subramanian1, Md. Sohrab Hossain1 and Robert Thomas Bachmann1

1 Malaysian Institute of Chemical and Bioengineering Technology, Universiti Kuala Lumpur, 78000 Alor

Gajah, Melaka, Malaysia

Author Email : [email protected], [email protected], [email protected]

ABSTRACT

Azadiractha indica is mahogany tree species whose seeds contain oil that has been used for

more than 4000 years due to its medicinal and insect repellent properties. The neem seed oil

may be obtained through numerous techniques including Soxhlet extraction (SE) and

supercritical fluid extraction (SFE). SE requires organic solvent such as hexane which may still

be present in defatted neem seed oil thus lowering its quality and potential destruction of

valuable substances. SFE typically uses CO2 as solvent which does not leave undesirable traces

in defatted seeds while yielding oil of superior quality that does not require further treatment.

Optimum SC-CO2 extraction time for lab-scale and similar oil yields is 0.5 hours compared to

6 hours required by SE. Oil separation from solvent is achieved during SFE process, while SE

requires an addition distillation step. This paper therefore aims to determine cost of oil

extraction and separation at lab-scale using SE and SC-CO2. The expected life span of

equipment for both SE and SFE was assumed to be 10 years. Loss of solvent for hexane is

expected to be 20% and 50 % per run, while all CO2 is lost to the atmosphere for SFE.

Operational costs comprise of electricity for both technologies and cooling water for SE.

Annual maintenance cost of each equipment was set to 10 % of the investment cost, while

labour time and hence cost for SE were assumed to be higher than SFE due to lengthy extraction

process and subsequently required distillation process. Preliminary results show that

production cost for neem seed oil by SE with and without chiller is MYR 14,665/kg and MYR

13,672/kg while MYR 2,503/kg for SFE. Based on the economical performance and higher

neem seed oil quality, it is suggested to use SFE instead of SE.

Key Words: Neem seed oil, Soxhlet extraction, Supercritical CO2 extraction, Cost assessment.

1.INTRODUCTION

The neem tree (Azadirachta indica) is a tropical plant commonly found in Asia especially India.

The ripe neem fruits are oval shaped and have light - coloured seeds inside the fruit (Puri,

1999). The greatest oil content is found in the seeds (Hussain et al., 2008), which has been used





123

for more than 4000 years due to its ability to treat birth control, mosquito repellent, wood

preservative (Hall and Menen, 2009). Over the past few decades’ compounds within neem oil

were shown to successfully treat diabetes, cancer, heart disease and AIDS (Pankaj et al., 2011).

Neem seed oil is also used in agriculture as pesticide, insecticide, and fungicide due to its

natural insect repellent properties (Hall and Menen, 2009). In addition, Neem seed oil has its

importance in the personal care sector such as shower, acne care, and shampoo (Hussain et al.,

2008).

Neem seed oil comprises of (palmitic acid, stearic acid, oleic acid and linoleic acid )

and contains quercetin, a polyphenolic flavonoid used as supplement in beverages and food

(Kaur and Kapoor, 2001), azadirachtin, nimbosterol as well as a number of liminoids such as

nimbin and its derivatives (Radha and Manikandan, 2011). Azadirachtin, a flavonoid occurring

in fruits and vegetables, has proven beneficial effects for health (Kaur and Kapoor, 2001), and

is also known for its antibacterial and antifungal properties (Harborne and Williams, 2010).

The quality of raw neem seed oil depends on the type of extraction process used

(Morgan et al., 2007) such as cold mechanical pressing (Burt, 2004), hot mechanical pressing

(Bale and Shinde, 2013), conventional solvent extraction (Camel, 2010; Caviedes, 2006) or

super critical fluid extraction (Mamata, 2008). Soxhlet extraction (SE) is liquid-solid process

in which a liquid substance present in a solid phase is preferentially dissolved into another

liquid of compatible solubility. Organic solvents such as ethanol and hexane are frequently

used for oil extraction (Caviedes, 2006). SE overcomes the downsides of distillation but has

major drawbacks in terms of solvent residue in the defatted material as well as a lengthy

extraction time (Sadeghi et al., 2011). A few criteria have to be considered when selecting a

solvent such as its selectivity, solvent recovery potential, corrosivity and toxicity (Gamse,

2010).

Supercritical fluid extraction (SFE) is process of separating one component from solid

matrix using supercritical fluids such as nitrogen and carbon dioxide (CO2) that above their

critical point can act as solvent (Figure 1). Supercritical carbon dioxide (SC-CO2) has a critical

temperature and pressure of 304.1 K and 7.3 MPa, respectively (Mamata, 2008). The

application of CO2 as a supercritical fluid has been extensively studied due to its low critical

temperature, non-toxicity, non-flammability, ease of removal and low cost. The final products

obtained by SC-CO2 extraction retain their quality, and stability of thermally labile natural

components is assured without changing the bioactivity of natural molecules. Due to the

absence of oxygen, SC-CO2 has less oxidation reaction while extraction occurs (Gracia et al.,

2009). The main drawbacks of SC-CO2 are the need for adequate contact time for penetration

of CO2 to enhance equilibrium flow rate for solubility (Gracia et al., 2009).


124

Figure 1: Supercritical fluid properties of CO2(Source : Mamata, 2008)

Essentially every manufacturing process has a manufacturing cost sheet to accumulate the costs

of manufacturing a product. The manufacturing costs comprise of variable costs (raw

materials), utilities and energy and fixed costs (labour, benefits, depreciation, and overhead).

Maintenance costs are usually viewed as fixed costs with components of labour salaries,

materials and overhead. Maintenance categories into scheduled maintenance and preventative

maintenance comprehensive of general and monitoring maintenance. Scheduled maintenance

required for all equipment with parts that have reduction rates with performance degradations

that can be practically identified. Thus, the Performance Verification and Safety Testing are

considered important for certain critical equipment sometimes required to be monitored. The

preventive maintenance is idea of keeping equipment well maintained to extend its expected

life and avoid future repair costs as more concerned focused on saving money and obtaining

optimum value from the investments on equipment (Sullivan & Les Meyer, 2005).

The main aim of this paper is to clarify whether SE is more expensive as claimed by

Hawthorne at al. (2000), Sapkale et al. (2010), Bimakr et al. (2011), Nobre et al. (2012) and

Kőszegi et al. (2015), or SC-CO2 as claimed by Guan et al. (2007), Halim et al. (2011) and

Pragya et al. (2013). The specific oil production cost (OPC) will be determined using a

theoretical cost analysis approach at lab-scale for neem seed oil. For SE n-hexane is chosen as

most prominent solvent (Liauw et al., 2008), while also exploring the cost-effectiveness of a

circulating water bath for improved solvent recovery.


125

2. METHODOLOGY

2.1 Assumed operational conditions for SE and SC-CO2

The operation conditions for SE and SC-CO2 are summarised in Table 1.

Table 1: The independent variables for neem seed oil extraction by SE and SC-CO2

Parameter SE SC-CO2 Reference

Temperature [K] 343 313 - 333 Tonthubthimthong et al.

(2001), Kumoroa and Masitah

(2007), Hossain et al. (2016) Pressure [MPa] 0.1 20 - 40

Flow rate [min/mL] - 1 - 5

Time [hr] 4 - 8 0.5 Morgan et al. (2007), Liauw

et al. (2008), Gamse (2010),

Saxena et al. (2011), Awolu et

al. (2013)

Particle size [mm] 0.20 - 0.85 0.425 - 0.700

Solid to solvent ratio

[g/mL]

1:5 - 1:25 -

We assume that SE and SC-CO2 operate 9 hr per day, 5 days per week for 52 weeks per year.

For SE and SC-CO2 40 g of neem seeds are used per extraction run. In SE one extraction run

can be accomplished per day while for SC-CO2 seven extraction runs per day are assumed,

which is equivalent to 260 runs per year for SE and 2340 runs per year for SC-CO2.

The oil yield for SE and SC-CO2 was assumed to be 46 wt.% (Awolu et al., 2013) and 45 wt.%

(Kumoroa and Masitah, 2007) under optimized conditions.

2.2 Consumables

During oil extraction numerous consumables such as solvent, coolant and electricity are

required as summarised in Table 2.

Table 2: List of consumables used for neem seed oil extraction by SE and SC-CO2

Process Solvent

[mL/run]

Coolant

[L/run]

Electricity

[kWhel/run]

Reference

SE

- Soxhlet 600 60 3 Refer to the

quotations

column

demonstrated in

Table 3 below

- Distillation

- Circulating water bath

- Fume hood

- Digital hot plate stirrer

1000

-

-

600

90

-

-

-

1.7

0.85

0.3

0.5

SC-CO2 100 - 11

3


126

2.3 Scenarios

Two scenarios for SE are investigated, conventional (S1) and improved (S2) oil production. In

conventional SE oil production, tap water is used as coolant for Soxhlet and distillation

condenser. The loss of hexane into the laboratory environment is assumed to be 50 % which

may pose a health and safety hazard and thus requires the use of a fume hood, both of which

incur additional operation and investment cost. For improved SE, a circulating water bath is

used which is assumed to reduce the fugitive emissions to 20 % due to improved condenser

efficiency without the need to operate under a fume hood. However, the electricity

consumption is higher while an additional 0.5 hr are required to disconnect and connect the

chiller from the Soxhlet and distillation unit, respectively.

2.4 Cost Analysis

2.4.1 Investment cost

The investment cost of equipment for SE and SC-CO2 are summarised in Table 3. The lifespan tlife of

all equipment was assumed to be 10 years.

Table 3: The investment cost of equipment for SE and SC-CO2 inclusive 6% of GST

Equipment Cost of

Investment (RM) Brand and Model Quotation

Supercritical fluid

extractor 210,405 SFT-110-1X1 SFE MyLab Scientific Sdn. Bhd.

Fume hood 22,790 Ross Edamix

GP1800 Impian Z Enterprise (Ref 2)

Digital hot plate

stirrer 3,604 Daihan Impian Z Enterprise (Ref 1)

Soxhlet extractor 136,634 Buchi Extraction

System B-811 Impian Z Enterprise (Ref 3)

Rotary evaporator 20,352 Buchi Rotavapor R-

100 Impian Z Enterprise (Ref 4)

Circulating water

bath 15,900

Buchi Recirculating

Chiller F-105 Buchi Malaysia Sdn. Bhd.

The annuitized investment cost AIC were calculated using following formula:

life

i

t

EAIC

(1)


127

where Ei is investment cost (RM) of the ith equipment used for respective oil production

process. It is assumed that the laboratory is not equipped with a fume hood hence an investment

for scenario S1 is required to minimise the exposure of laboratory users to fugitive emissions

of n-hexane.

2.4.2 Annual maintenance cost

The annual equipment maintenance cost MC for SE and SC-CO2 are summarised in Table 4.

The annual maintenance cost reported in literature for lab-scale equipment ranges from 8 to 12

% of the investment cost (Singleton & Stikeleather, 1999; Sullivan & Les Meyer, 2005). In this

study an average maintenance cost of 10% for SE and SC-CO2 was assumed.

Table 4: The equipment maintenance cost inclusive of 6% of GST for SE and SC-CO2

Equipment SE (RM/yr) SC-CO2

(RM/yr) S1 S2

Supercritical fluid extractor 21,040

Fume hood

Hot plate magnetic stirrer 360

Soxhlet extractor

13,663

Rotary evaporator 2,035

Circulating water bath 1,590

Total 18,338 17,648 21,040

Annual maintenance of equipment has classified into general and monitoring maintenance

besides spare part replacement after several tentative years in 10 years of equipment life span

cycle. General maintenance of SE include cleaning the all glass condenser from the sampling

process, cleaning the all tubing hose link with main unit, remove the condenser from the main

unit besides check programmer and electrical parts with monitoring maintenance of hose tubing

and thimble holder filtering. General maintenance of rotary evaporator inclusive of cleaning

all glass sampling, check wiring and motor system, depart all connector glass part besides

graham condenser and mother board parts replacement tentatively on period of 8 years. The

circulating water bath has general maintenance of cleaning filter system, cleaning water

circulating, cleaning the coil from the plug debris, cleaning compressor, check gas system,

check piping and remove the old water. Its assumed some of spare parts that may replace

tentatively on every 6 years are cooling compressor, motor pump, coil circulate water, copper


128

tubing and refill gas. Digital hot plate stirrer general maintenance such as cleaning all debris

from the equipment (outside and inside) and check the sensor temperature and wiring system.

Finally, general maintenance of fume hood are check air flow system (from fume hood to

motor), check vibration motor, check water tank system, wiring system and sensor where

DOSH certification issued for 2 years to inspect on motor blower and hose ducting (Singleton

& Stikeleather, 1999).

2.4.3 Annual operational cost

The annual operational cost (OC) of neem seed oil was calculated using Equation 2 for SC-

CO2 and S2 as well as equation 3 for S1 inclusive of 6% GST.

OC = A + B + C + D (2)

OC = A + B + C + D + E (3)

where, A (RM/yr) represents annual cost of neem seeds; B (RM/yr) represents annual cost of

solvent; C (RM/yr) represents annual cost of labour; D (RM/yr) represents annual cost of

electricity and E (RM/yr) represents annual cost of water.

The water tariff is RM 1.80/m3 based on Syarikat Air Melaka Berhad scheduled on 1st January

2016. The electricity tariff is assumed to be RM 0.365/kWh under tariff code of C1: Medium

Voltage General Commercial Tariff of Malaysia electricity tariff scheduled on 1st January 2014

by Tenaga Nasional Berhad. The solvent price for n-hexane (Merck, ACS grade) is assumed

to be RM 180 per 2.5L bottle (Impian Z Enterprise) while liquefied CO2 solvent cost is RM350

per 25L cylinder (4.5 – 6.5 MPa) (MyLAb Scientific Sdn. Bhd.). According to Malaysia

Employment & Labour Law 2016, the minimum labour cost for bachelor degree holder

working 5 days a week, 9 hours a day is RM 1800 per month. The price of neem seeds is

assumed to be RM 330 per kg after drying, peeling and roasting (Maragatham Flour Mill &

Groceries).

2.4.4 Oil production cost

The OPC (RM/kgoil) were calculated as illustrated in equation 4

H

OCMCAICOPC

(4)

where H (kgoil/yr) represents annual oil production.


129


The annual production cost of neem seed oil was determined for SE and SC-CO2 and are

summarised in Table 5.

Table 5: The annual cost and oil production cost for neem seed oil extraction process

Parameter SE

SC-CO2 S1 S2

Oil yield (wt%) 46 47 45

Oil yield (g/run) 18.4 18.8 18

Time (hr/run) 8.5 9 1

Start-up 0.92 1.17 0.25

Process 6.75 6.75 0.5

Shut down 0.83 1,08 0.25

Number of runs [runs/yr] 260 260 2,340

Mass of neem seeds [g/run] 40 40 40

Cost of neem seeds [RM/run] 13.17 13.17 13.17

Cost of neem seeds (RM/yr) 3,423 3,423 30,810

Solvent (mL/run) 600 600 100

Solvent loss (%) 50 20 100

Cost of Solvent (RM/run) 21.60 8.64 1.75

Cost of Solvent (RM/yr) 5,616 2,246 4,095

Cost of Electricity (RM/run) 8.22 9.47 2.16

Supercritical fluid extractor

(11kW) 2.16

Fume hood (0.3kW) 0.77

Hot plate magnetic stirrer (0.5kW) 0.05 0.05

Soxhlet extractor (3kW) 7.07 7.07

Rotary evaporator (1.7kW) 0.33 0.33

Circulating water bath (0.85kW) 2.02

Cost of Electricity (RM/yr) 2,137 2,463 5,055


130

Cost of Water (RM/run) 0.79 - -

Soxhlet extractor (60L/hr) 0.70 - -

Rotary evaporator (90L/hr) 0.09 - -

Cost of Water (RM/yr) 205.40 - -

Cost of Labour (RM/run) 85 90 10

Cost of Labour (RM/yr) 22,100 23,400 23,400

Cost of Investment (RM/yr) 18,338 17,649 21,040

Cost of Maintenance (RM/yr) 18,338 17,649 21,040

Annual cost [RM/yr] 70,158 66,830 105,440

Oil production cost [RM/kg] 14,665 13,672 2,503

From Table 5 it is shown that OPC using SC-CO2 are approximately five times lower

than for SE, which supports the claims made by Hawthorne at al. (2000), Sapkale et al. (2010),

Bimakr et al. (2011), Nobre et al. (2012) and Kőszegi et al. (2015). The lower production cost

for SC-CO2 are mainly due to a seven times higher throughput. The annual electricity

consumption is 1.6 to 1.8 times higher for SC-CO2 compared to SE, while solvent cost are 1.8

times lower for SC-CO2 compared to SE scenario S1. However, for scenario S2, SC-CO2

solvent cost are 1.4 times higher due to improved solvent recovery.

For scenarios S1 and S2, a circulating water bath was found to help reduce the fugitive

emissions of n-hexane and thus the cost of solvent and fume hood. The annual savings attained

in scenario S2 when using a circulating water bath are MYR 3575 inclusive of zero water and

2.5 times lower solvent cost. The annual electricity cost in S2 scenario is 15 % higher than S1

scenario whereas the annual investment and maintenance cost of a circulating water bath save

up to 30.26 % compared to S1 scenario. Therefore, the payback time for a circulating water

bath assumed to be 4.5 years as investment and maintenance cost of a circulating water bath is

very low-cost compared a fume hood although a circulating water bath power consumption is

superior by 0.55 kW.

4. CONCLUSION

Theoretical cost of oil production by SC-CO2 was found to be five times lower compared to

SE thus supporting the claims made by proponents of the SC-CO2 technology. Fugitive

emission of n-hexane are assumed to be reduced by 60 % in SE using a circulating water bath

resulting in 6.8 % or MYR 993/kg lower oil production cost. Based on the economical


131

performance, simpler production line and reported higher oil quality it is suggested to use SC-

CO2 instead of SE. It is recommended to verify the findings using experimentally derived data.

5. ACKNOWLEDGEMENTS

This work was supported by Mr. Kathirvel, Tamil Nadu, India, who help for purchasing fo

neem seeds besides Impian Z Enterprise company’s supplier Mr. Azrim, MyLab Scientific Sdn.

Bhd. company’s supplier Mr. Abrahim and Buchi Malaysia Sdn. Bhd. company’s supplier Mrs.

Lee who help providing quotations and technical information for equipment.

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POTENTIAL ROLES OF BIOCHAR IN ANAEROBIC

DIGESTION OF PALM OIL MILL EFFLUENT Ishak, D.1, Bachmann, R.T.1

1Universiti Kuala Lumpur, Malaysian Institute of Chemical and Bioengineering Technology

Lot 1988, Taboh Naning 78000 Alor Gajah, Malacca, Malaysia

[email protected]

ABSTRACT

Biochar is a carbon-rich residue which produced by pyrolyzing (thermal decomposition) a

biomass (manure, agriculture waste, and organic wastes) without oxygen. The primary

concerns for biochar are its cost effectiveness, and its mechanism when implementing in

wastewater management or soil are poorly understood. Recent studies about biochar in

anaerobic digestion (AD) have shown a promising outcome in enhancing the biogas production

and quality and also improve the digested waste. Biogas harnessing is an eco-friendly solution

that could bring revenues besides reducing the carbon footprint. Malaysia as one of the largest

producer of crude oil palm (CPO) produced a vast amount palm oil mill effluent (POME) over

the year. The conventional method of POME treatment is a ponding system; freely released

CH4 to the environment which contributes to global warming. By integrating a biochar into an

anaerobic digester treating POME, it may not just improve the energy conversion efficiency

but also the digested waste can be used as a fertilizer for the oil palm plantation. There is

literally the small body of published studies that is related to this issue. Thus, this paper review

is dedicated to investigates the influence of biochar towards AD which can be used to optimize

the technology and also solve several challenges in AD. It is acknowledged that biochar acts

as a support for anaerobic microorganisms, especially methane-forming bacteria, sorbent for

known inhibitors and also reactant for biogas upgrading. The biochar-amended biodigester

gave different outcomes when seeded with different types of wastewater, biochar and different

concentration of biochar.

Key Words: biochar, palm oil mill effluent, anaerobic digestion, palm kernel shell.

1.INTRODUCTION

Biochar is produced from biomass and considered a stable carbon compound that can be kept

in the soil for a long time. It is typically produced by the incomplete combustion of biomass

such as wood, MF, and PKS, sawdust or manure, while bio-oil and syngas may also be

produced and collected (Lehmann & Joseph 2009; Ahmad et. al., 2014; Parmar et. al, 2014).

Pyrolysis processes can be categorized into slow pyrolysis and fast pyrolysis, where slow

pyrolysis can produce a high yield of biochar (about 35 %) with 30 % of bio-oil and 35 %

syngas while fast pyrolysis gives a low biochar (15 %), high bio-oil (70 %) and low syngas

yield (Kong et. al., 2014). Different processes and biomass types can also affect the

characteristic and usability of the biochar. Abas & Nasir Ani (2014) have shown that

fundamental composition of biochar included carbon (> 60 %), N, H, O and some nutrient

elements such as K, Ca, Na, Mg, and Si. These elements, if bioavailable, are essential for plant

growth. Biochar was found to adsorb ammonium, phosphate, potassium and nitrogen (Gai et.


136

al., 2014; Bolan et. al., 2004; Ghezzehei et. al., 2014). In recent years, biochar has frequently

been prescribed as soil modifier that can solve numerous environmental issues such as

improving soil fertility (van Zwieten et. al., 2010; Southavong 2012; Insam et. al., 2009),

drainage (Ayodele et. al., 2009), water holding capacity and pH (Southavong et. al., 2012), and

efficiently sequester carbon thus mitigating global warming. Charcoal is different from biochar,

as biochar is intentionally created for soil amendment while charcoal is used as fuel for heat

and power generation, as a filter in water treatment, as a reductant in iron-making or as a

coloring agent in industry or art (Lehmann & Joseph 2009). Activated carbon is best for

contaminants removal from water but costly. Generally, it is made from biomass or coal,

activated chemically or physically (Mohan et. al., 2014; Azargohar & Dalai 2006). On the other

hand, biochar is likely the new, lower cost and efficient absorbent since the feedstock is

abundantly available from agricultural solid waste and biomass. Many organic wastes can

contribute to GHG emission during disposal or decomposition. Agricultural waste from palm

oil industry, papermaking, and many other industrial activities can lead to GHG emissions such

as CH4 and N2O release from the improper disposal. Pyrolysis of biowaste can be used as part

of an alternative waste management strategy (Lehmann & Joseph 2009). Peter (2009) used a

pyrolysis-gasification process to convert biomass to syngas with a combined cycle gas turbine

technology and observed an increase in the conversion efficiency to 35 – 40 %, compared to

25 – 30 % achieved for direct combustion of biomass to electricity. In another, an ongoing

project between Felda Global Ventures (FGV) and Tenaga Nasional Berhad, FTJ Bio Power

Sdn. Bhd. is using pyrolysis to obtain bio-oil from EFB which can be used as bio-fuel (Jamin

2014).

2. PALM OIL MILL EFFLUENT (POME)

Malaysia is known as the 2nd largest producer of crude palm oil (CPO) in the world, accounting

for 20 million metric CPO produced in 2013 (Chuen & Yusoff 2015). This high productivity

is partially due to Malaysia’s tropical and damp weather throughout the year that encourages

the growth of oil palm, Elaeis Guineensis. The oil palm plantation area, as well as the palm oil

processing industry continues to expand and play a significant role in Malaysia’s economy. In

2014, the oil palm plantation area reached 5.39 million hectares, 3.1 % higher than the previous

year, with 442 palm oil mills in Malaysia currently processing fresh fruit bunch (FFB) (MPOB

2014; Rasidi 2014). The growing amount of processed palm oil also increases the amount of

palm waste generated, which consist of palm oil mill effluent (POME), empty fruit bunch

(EFB), decanter cakes, oil palm fronds (OPF), mesocarp fibers (MF) and palm kernel shells

(PKS). MF and PKS are usually utilized as in-house fuel to produce steam for electricity

generation and palm oil mill’s requirement (Subramaniam et al. 2008). CPO extraction

generates enormous quantities of POME because its operation requires a significant amount of

water for clarification and steam sterilization. On average, 3 tons of POME are generated for

every ton of CPO produced (Suprihatin et. al., 2014). It contains soluble substances including

methane (CH4), lignocellulosic wastes, high level of organic loads (COD values greater than

80,000 mg/L) and solids, some of which are harmful to the environment if the concentrations

are above prescribed threshold limits (Nwoko et. al., 2010; Bala et. al., 2014). It is, therefore,

essential for POME to be treated before releasing it to the environment. Most conventional

methods of POME treatment comprise of watercourse treatment, biological ponding system for

pre-treatment process, anaerobic and aerobic ponding (Aziz et. al., 2014; Rupani & Singh

2010).


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During the watercourse treatment, the anaerobic stage main products are biogas and

digestate. Biogas consists of 55 - 70% CH4 and 30 - 40% of CO2 and trace amounts of H2S and

NH3 (Loh et. al., 2014). The calorific value of the biogas is directly related to CH4 content

since CO2 has zero heating value. As shown in Figure 1, more than 90 % of palm oil mills

choose to use some form of watercourse treatment and disposal solely because of their

particularly low cost compared to other methods. However, such practice requires a large area

of land, longer hydraulic retention times (HRT) for degradation, while it is also challenging

regarding collecting and utilizing CH4 gas. CH4 is a greenhouse gas (GHG) that has a global

warming potential 20 times greater than CO2.

3. ANAEROBIC DIGESTION (AD)

AD is a biochemical process that converts organic matter to biogas by anaerobic bacteria in the

absence of oxygen (Rajagopal et. al., 2013). The process is a cost-effective and

environmentally friendly method to reduce organic pollution from the liquid waste from

residential, industry and agriculture while at the same time minimizing the use of fossil fuels

(Chen et. al., 2008). In general, when the effluent or wastewater is kept in an anaerobic

environment, various groups of anaerobic bacteria will use the sludge as a source of carbon

and energy for fermentative metabolic processes which main products are CH4, CO2, and water.

The overall process of the conversion of organic matter into CH4 and CO2 can be distinguished

in four stages occurring concurrently: hydrolysis, acidogenesis, acetogenesis and

methanogenesis (Figure 2). The metabolic activity is primarily affected by a diverse group of

bacteria which are mostly anaerobic, therefore, it is essential to have favourable environmental

conditions such as temperature, pH, the absence of toxic substances and the availability of

macro- and micronutrients (O’Flaherty et. al., 2010; Deublein & Steinhauser 2010) (Table 1).

Comparing the C:N:P ratio of POME (420:21:5) with the recommended range in Table 1

46%

23%

20%

6%3%

1% 1%Watercourse

Watercourse (Land

Irrigation)

Land Disposal

Watercourse & Land

Disposal

Compost

Watercourse (Land

irrigation) & Compost

Watercourse (Land

Irrigation) & Land Disposal

Figure 7 Method of POME disposal in Malaysia (Rasidi 2014)


138

(500:15:5) it can be hypothesized that macronutrients in POME are more or less balanced with

carbon slightly growth limiting and while N is present in excess. The digestion can be disturbed

or inhibited by the presence of inhibitors such as NH3, high volatile fatty acid concentration

(triggering a drop in pH which inhibited methanogenesis), and heavy metals (Cu, Zn, Pb, Hg,

Cr, Fe, Ni, Co and Mo) (Bala et. al., 2014; Mumme et. al., 2014; Chen et. al., 2014; Chen et.

al., 2008; Ohimain et. al., 2012). Optimal pH conditions for methanogens is 6.8 to 7.2, and it

is important to maintain to prevent overgrowth of acidogenic bacteria that may lead to

accumulation of organic acids, the inhibition of methanogenesis and process failure

(O’Flaherty et. al., 2010).

Table 1 Environmental requirements for microbial activities (Deublein & Steinhauser 2010;

O’Flaherty et al. 2010)

Parameter Hydrolysis/acidogenesis Methane formation

Temperature 25 – 35 °C Mesophilic: 32 – 42 °C

Thermophilic: 50 – 58 °C

pH value 5.2 – 6.3 6.8 – 7.2

DM content < 40 % DM < 30 % DM

Redox potential + 400 to -300 mV < -250 mV

Required C:N:P:S ratio 500: 15: 5: 3 600: 15: 5: 3

Trace elements No special requirements Essential: Ni, Co, Fe, Zn, Mn

Figure 8 Schematic representation of the decomposition of organic compound by AD (van

Haandel & Van Der Lubbe 2007)

There have been some studies involving biochar incorporation in AD process reported its

ability to mitigate inhibition by NH3 and other toxicants available in AD and also improving

the biogas production (Reza et. al., 2015). According to Kumar et al. (1987), a 17% and 34.7%


139

increase in biogas in the bath and semi-continuous biodigester, respectively, also of

commercial charcoal Darco G-60. The use of commercial charcoal was found to have the same

effect on the biogas production with the locally produced charcoal. Adeyanju (2008) studied

the effect of biogas production using pig waste and cassava peels with seeding wood ash. The

wood ash-seeded digester produced the highest volume of biogas, 170% compared to other

digesters despite the maceration of cassava peels resulting in a reduced biogas volume.

However, the author didn’t clarify the concentration, and the composition of the wood ash used.

Fagbohungbe et al. (2016) carried out an investigation on the effect of several types of biochar

on the AD of citrus peel. The coconut shell biochar (CSB) achieved the highest methane

conversion efficiency, 93.43% compared with rice husk biochar (CHB) and wood biochar

(WB). They also highlighted that a greater amount of biochar would lower the lag phase of

methanogenesis and maintained the stability of AD process. They suggested that adsorption

capability of biochar attributed to the reduction of the limonene which is an inhibitor in citrus

peel waste digestion. Mumme et al. (2014) studied the behavior of pyrochar and hydrochar in

AD. The methane yield increased 31% with the addition of hydrochar to the inoculum while

there is no significant difference with the addition of pyrochar, but it still possesses the ability

to mitigate the ammonia inhibition and support the growth of archaeal and methanogens

bacteria. The authors point out that the biochars were not optimized to be used in AD.

Inthapanya et al. (2012) observed a 31% biogas increased by adding 1% of rice husk biochar

in a biodigester with cattle manure as substrate and further increased the concentration of

biochar did not increase the biogas production anymore.

Luo et al. (2015) found that a smaller particle size enhanced the biogas and methane

yield much more to compare with bigger particle size. A 75 µm biochar increased the methane

yield by 70.6% while 0.5-1.0 mm biochar only increased 21.4% at 6 g/L glucose loading.

However, Lü et al. on 2016 studied the effect of particle size to mitigate the ammonium (NH4-)

inhibition reported that the higher methane yield was obtained for 2-5 mm biochar to compare

with 0.5-1.0 mm and 75 µm biochar, which is 47.1%, 23.5%, and 44.1% respectively. Both

studies have shown that microbial lag phase shortened when the particle size of biochar

reduced. While Luo et al. (2015) focus on to relieve the acid stress, Lü et al. (2016) are more

concerned with ammonium mitigation in AD by enriching Methanosaeta and Methosarcina by

integrating a biochar. Selective functional microbes are required for every stage of

degradation. Therefore, an optimization of the particle size depending on the digester condition

and the feedstock. Methanosaeta (rods shape, 0.8-1.3 by 2-7 µm in size with long filament),

Methanobacterium (0.2-1.0 µm with length varies in range 1.2-120 µm in diameter) and

Methanosarcina (spherical, 1-2 µm or macro-cyst 100 µm diameter) are some of the crucial

and dominant methane-forming bacteria and most abundant methanogens can be found in

anaerobic digesters (Shrestha et al. 2014; Gerardi 2003; Lü et al. 2016). The size of the

methanogens may relate its accessibility to biochar macro- (>50 µm), meso- (2-50 µm) and

micropores (< 2 µm) (Downie et al. 2009). The porosity of biochar could be a carrier and a

natural biofilm to accommodates a broad range of bacteria. Xu et al. (2015) examine the extent

which incorporation of biochar in AD allows higher organic loading rates without upsetting

the biodigester. They found that powdered activated carbon (PAC) was favorable for specific

bacteria, such as syntrophic VFAs-oxidizing bacteria and Methanosarcina which explains the

ability of the microbes to adapt during organic shock loading.


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4. CONCLUSION

The effects of biochar integration in anaerobic digestion are highlighted in previous studies

suggests that it can be applied in anaerobic digester treating POME and serve as reliable

microbial supports especially methane-forming bacteria which helps enhanced the biogas

production. However, the optimal condition for biochar needs to be investigated due to the

characteristics of POME is unlike other substrates used in previous research.

5. ACKNOWLEDGEMENT

We are grateful to Universiti Kuala Lumpur for providing a financial support with the research

grant (STRG15157).

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EFFECT OF SOLVENT AND LEAVES CONDITION ON THE

CONCENTRATION OF QUERCETIN EXTRACTED FROM

MURRAYA KOENGII BY USING SOXHLET EXTRACTION

METHOD.

Nor Aini Burok1*, Nur Farthiah Mohd Adanan1, Khairul Nadiah Ibrahim1, Nurzat ShairaRoslan1,

Siti Nurhidayana Md Lajis1

1Universiti Kuala Lumpur Malaysian Institute of Chemical & Bioengineering Technology

78000 Alor Gajah, Melaka, MALAYSIA.

*Corresponding author: Nor Aini Burok,

Section of Chemical Engineering Technology,

Universiti Kuala Lumpur Malaysian Institute of Chemical & Bioengineering Technology

78000 Alor Gajah, Melaka, MALAYSIA

Email: [email protected]

ABSTRACT

Alzheimer's diseases (AD) was categorized as dementia which is lost mind work that influences

memory; considering dialect, judgment and conduct in conjunction with different

nonreversible contaminations and sicknesses. Alzheimer Disease International report, this

disease will increase to 0.126% in 2020. Among the list of medicinal plants, Murraya Koenigii

extract contain flavonoid (polyphenolic compound) which possess antioxidant and anti-

dementia properties that inhibit acetylcholinesterase activity by breaking down acetylcholine

in the brain. Thus this study conducted to extract quercetin (family of flavonoid) from Murraya

Koenigii leaves by conventional extraction method which is Soxhlet extraction. Murraya

Koenigii leaves in powder form and non-powder form was used to study the effect of surface

area towards extraction process. Acetone, ethanol, methanol and petroleum ether used as a

solvent to compare the yield of quercetin obtained from the extraction of Murraya Koenigii .

The presence of quercetin was analyzed by using ultraviolet visible spectrophotometer (UV-

VIS) at wavelength 382 nm. Ethanol showed the highest concentration of quercetin obtained

in powder form which is 883.783 ppm since ethanol has been known as a high polarity solvent

for polyphenolic active compound extraction. Murraya Koenigii leaves in powder form give

higher concentration of quercetin compared with non-powder due to its large contact surface

area between solvent and the leaves.

Key words: Murraya Koengii, quercetin, bioactive compound, soxhlet extraction.

1. INTRODUCTION

Murraya Koenigii its common name is curry leaf belongs to citrus family, Rutaceae. Curry leaf

trees are distributed throughout the India and spread to the asia including Malaysia (Suman,

P.K, & Mohan, 2014). Nowadays, Murraya Koenigii plants were found in many states of

Malaysia as it is easily to grow. Four major bioactive flavonoids profile was analyze from



145

Murraya koenigii leaves was rutin, quercetin, myricetin and kaempferol (Ashokkumar,

Selvaraj, & M., 2013). Quercetin was classified as flavonols that most common flavonoids in

foods and natural sources.

Flavonoids are represent one of the polyphenols group which are mostly found in the

leaves, fruits, vegetables and grains. The structure of flavonoids consists of two aromatic ring

linked with hydroxylated phenolic substances occur at a C6 to C3 unit. It is divided into six

classes which are flavonols, flavones, isoflavones, flavanones, antho-cyanidins and flavanols

variying in their structural characteristic around the heterocyclic oxygen ring as shown in

Figure 1 (Manach, Scalbert, Morand, Rémésy, & Jime´nez, 2004).

Figure 1 Structure of flavonols (Manach, Scalbert, Morand, Rémésy, & Jime´nez, 2004)

Quercetin from Murraya Koenigii leaves has anti-dementia properties specifically in

Alzheimer’s disease. It was found to inhibit acetylcholinesterase activity (Vasudevan, Aliya,

Kalavathy, Siong Meng, & Abu Bakar, 2015) by breaking down acetylcholine in the brain.

Thus increase the concentration of acetylcholine. Acetylcholine is organic chemical function

in human brain as neurotransmitter that helps to send messages between certain nerve cells

(McShane, 2014).

There are two techniques to extract these bioactive compounds from plant which are

conventional and non-conventional method. Conventional method often extract in small

quantities, requirement costly and time consuming purification procedures (Lam, 2007), while

non-conventional extraction improve the production, detection, separation and characterization

of extraction. However, extraction yield was not only depend on the method, but also on the

type of solvent used. Soxhlet extraction method with polar solvent acetone, ethanol, methanol

and petroleum ether at 40oC-60oC used to extract polyphenol compound.

2. MATERIALS AND METHOD

2.1 Sample Collection and Preparation

Freshly Murraya Koenigii leaves collected in Lubok China, Alor Gajah, Melaka. The leaves

were stripped off from the stem, rinse under tap water and dried under ambient temperature for

24 hours. Then, half of the leaves were grinded using electric blender into the fine powder.

Meanwhile, the other half were maintain in non-powder form.


146

2.2 Sample Extraction

Fine powdered of 15 grams of Murraya Koenigii leaves placed in a thimble then the beaker

was filled with 150 mL solvent. The thimble was put in distillation flask and the beaker was

place on the heating mantle under the distillation flask. Condenser tube was connected on the

top of the distillation flask then soxhlet extractor was programmed with heating lower and

extraction period program according to type of solvent. Murraya Koenigii was extracted with

acetone, ethanol, methanol and petroleum ether 40oC-60oC (three times each) for 3 hours. This

extraction repeated with non-powdered Murraya Koenigii leaves.

2.3 Sample Analysis

Concentration of quercetin in Murraya Koenigii extract was analysed by Perkin-Elmer

Ultraviolet Vissible (UV-Vis) Spectrophotometer model Lambda EZ210. A standard solution

of quercetin hydrate was prepared from 20 ppm to 1000 ppm. Wavelength scan obtained for

quercetin hydrate was 382 nm, bandwidth was 2 nm and sampling interval was 1.00 nm.

3. RESULT AND DISCUSSION

Concentration of quercetin in each Murraya Koenigi extract was determined by using UV-Vis

Spectrophotometer with the wavelength of quercetin hydrate standard 382 nm. All extracts

obtained from extraction for powder Murraya Koenigii leaves were observed as a dark green.

However, extraction for non-powder leaves produced a yellowish-green colour. Table 1 shows

the concentration of quercetin detect by UV-Vis.

Table 2 Table of mean concentration and standard deviations extraction of Murraya Koenigii

Type of solvent Leaves

Conditions

Mean Concentration

(ppm)

Standard

Deviation

Acetone Powder 710.178 10.874

Non-powder 420.177 2.241

Ethanol Powder 883.783 28.255

Non-powder 582.889 8.058

Methanol Powder 760.528 26.598

Non-powder 532.821 33.057

Petroleum

Ether

Powder 629.286 18.065

Non-powder 256.053 9.811

Powder Murraya Koenigii leaves give higher concentration compare to non-powder

(Figure 2). This is because powders Murraya Koenigii provide a greater surface area for solvent

to extract quercetin thus increase the extraction process. Among the type of solvent, ethanol

shows the highest mean concentration where 883.783 ppm for powder and 582.889 ppm for

non-powder concentration. The lowest mean concentration of quercetin was petroleum ether

powder 629.286 ppm and non-powder 256.053 ppm.


147

Figure 2 Concentration of quercetin with different type of solvents and leaves conditions

Although the ethanol powder extracts give better yield of quercetin, the standard

deviation of the acetone non-powder extracts (2.241) is more significant as the standard

deviation is more nearer to the mean. The standard deviation for ethanol powder is wider and

far from the mean. The lower the standard deviation, the more the significant the extraction

method. This shows the highest accuracy for the concentration of the extract samples.

Extraction of quercetin from Murraya Koenigii extract depends on the polarity of the

solvent. Table 2 shows the polarity index of the solvent. The highest polarity index was pure

methanol which is 6.6, ethanol 5.2, acetone 5.4 and the lowest polarity was petroleum ether

0.1. Polar organic solvent containing hydroxyl group (hydrophilic) which able to attract

hydrogen from quercetin, Petroleum ether observed has low concentration yields which is

629.286 ppm for powder and 256.053 ppm for non-powder when the extraction was done

because it is a non-polar organic solvent (Kumoroa, Hasan, & Singh, 2008).

Table 3 Table of polarity index (Source: (Kumoroa, Hasan, & Singh, 2008)

However, in this study ethanol shows highest concentration yield compare to methanol

even though polarity of the methanol was higher. According to Do, et al. (2014), it is found

710.178

883.783

760.528

629.286

420.177

582.889532.821

256.053

0

100

200

300

400

500

600

700

800

900

1000

Acetone Ethanol Methanol Petroleum Ether

Co

nce

ntr

atio

ns

(pp

m)

Solvent

Concentration of Quercetin with different type of solvents and leaves conditions

PowderNon-…


148

that ethanol is a good solvent for polyphenol extraction, methanol more efficient to low

molecular weight of polyphenol and acetone extract higher molecular weight of flavanols.

These findings is in agreement with previous research (Chandrappa, et al., 2014) that shows

quercetin was extracted by ethanol solvent from Carmona Retusa and the quercetin is detected

by using High Performance Liquid Chromatography (HPLC).

4. CONCLUSIONS

Bioactive compound extract from Murraya Koenigii leaves by using soxhlet extraction method

was quercetin. The quercetin extract obtained was analyzed by using Ultraviolet-visible

Spectrophotometer with the wavelength scan obtained was 382 nm. This extraction method

was also varies in type of solvent to determine the effectiveness of the solvent to extract the

quercetin and leaves condition whether in powder or non-powder form. The highest

concentration of quercetin obtained was 883.783 ppm for powder Murraya Koenigii.

Concentration in powder form was higher than non-powder form of Murayya Koenigii leaves

due to its large suface area. Therefore, it is recommended using ethanol to extract quercetin

since it is more effective towards polyphenol compound in powder form.

5. ACKNOWLEDGEMENTS

Upon completion of this project, I would like to express my gratitude to my supervisor, Madam

Nor Aini binti Burok, my parents and all of the laboratory staffs for their help in completing

this study.

REFERENCES

Ashokkumar, K., Selvaraj, K., & M., S. D. (2013). Reverse phase-high performance liquid

chromatography-diode array detector (RP-HPLC-DAD) analysis of flavonoids profile from

curry leaf (Murraya Koenigii). Journal of Medicinal Plants Research, 3393-3399.

Chandrappa, C., Govindappa, M., Anil Kumar, N., Channabasava, R., Chandrasekar, N.,

Umashankar, T., & Mahabaleshwara, K. (2014). Identification and separation of quercetin

from ethanol extract of carmona retusa by TLC and HPLC with diode array detection. World

Journal of Pharmacy and Pharmaceutical Sciences, 2020-2029.

Cowan, M. M. (1999). Plant Products as Antimicrobial Agents. Clinical Microbiology Review,

564–582.

Do, Q. D., Angkawijaya, A. E., Tran-Nguyen, P. L., Huynh, L. H., Soetaredjo, F. E., Ismadji,

S., & Ju, Y.-H. (2014). Effect of extraction solvent on total phenol content,total flavonoid

content, and antioxidant activity of Limnophila aromatica. Journal of Food and Drug

Analysis, 296-3 0 2.

Kumoroa, A. C., Hasan, M., & Singh, H. (2008). Effects of solvent properties on the Soxhlet

extraction of diterpenoid lactones from Andrographis paniculata leaves. Science Asia, 306–

309.


149

Lam, K. (2007). New aspect of natural products in drug discovery. Trends Microbiol 15(6),

279-89.

Manach, C., Scalbert, A., Morand, C., Rémésy, C., & Jime´nez, L. (2004). Polyphenols: food

sources and bioavailability. The American Journal of Clinical Nutritions, 79:727–47.

McShane, R. (2014, December). Drug treatments for Alzheimer's Diseases. Alzheimer's

Society.

Suman, S., P.K, O., & Mohan, S. M. (2014). CURRY LEAVES (Murraya koenigii Linn.

Sprengal)- A MIRCALE PLANT. Indian Journal Science Research, 3.

Tembhurne, S., & Sakarkar, D. (2010). Beneficial Effects of Ethanolic Extract of Murraya

Koenigii (Linn) Leaves in Cognitive Deficit Aged Mice Involving Possible

Anticholinesterase and Cholesterol Lowering Mechanism. International Journal of

PharmTech Research, 181.

Vasudevan, M., Aliya, A., Kalavathy, R., Siong Meng, L., & Abu Bakar, A. M. (2015).

Murraya koenigii Leaves and Their Used in Dementia. Selangor Darul Ehsan: Elsevier.


150

LIQUID FUEL PRODUCTION FROM PYROLYSIS OF

PLASTIC WASTES AS PROMISING FUTURE

ALTERNATIVE ENERGY RESOURCES

Shafferina Dayana Anuar Sharuddin1, Faisal Abnisa1, Wan Mohd Ashri Wan

Daud1 and Mohamed Kheireddine Aroua1

1 Department of Chemical Engineering, Faculty of Engineering, University of Malaya, 50603, Kuala

Lumpur, Malaysia

[email protected] (S.D. Anuar Sharuddin)

[email protected] (F.Abnisa)

[email protected] (W.M.A. Wan Daud)

[email protected] (M.K. Aroua)

ABSTRACT

The worldwide plastic generation expanded over years because of the variety applications of

plastics in numerous sectors. The persistent interest of plastics caused the accumulation of

plastic wastes in the landfill which utilized a huge amount of spaces that added to the ecological

issue. The growing of plastics demand definitely affected the petroleum resources availability

as non-renewable fossil fuel since plastics were the petroleum-based material. A few options

that have been considered for plastic waste management were recycling and energy recovery

technique. Nevertheless, there were a few disadvantages of the recycling technique such as the

needs of sorting process that was labour intensive and caused water pollution that lessened the

process sustainability. These problems have led the researchers to focus more on other

alternative such as the energy recovery method to overcome the continuous demand of energy.

As a result, the plastic waste conversion into energy was developed through innovation

advancement and extensive research. Since plastics were part of petroleum, the oil produced

through the pyrolysis process was said to have high calorific value that could be used as an

alternative fuel. This paper reviewed the thermal and catalytic degradation of plastics through

pyrolysis process and the key factors that affected the final end product, for instance, oil,

gaseous and char. Additionally, the liquid fuel properties and a discussion on several

perspectives regarding the optimization of the liquid oil yield for every plastic were also

included in this paper.

Key Words: Pyrolysis, plastic wastes, energy recovery, fuel






151

1. INTRODUCTION

Plastic plays an important role in improving our lifestyles in numerous sectors such as

healthcare, construction, packaging, electronic, automotive and many more. The rise of the

world population has caused the demand of commodity plastics to further increase. According

to statistic, the global production of plastic has reached about 299 million tons in 2013 and has

increased by 4% over 2012 (Association of Plastic Manufacturers Europe, 2015). Since most

of the plastics were thrown out after single use, the amount of plastic waste accumulated in the

environment each year was at alarming level. In Europe, 25 million tons of plastic ended up in

waste stream during the year of 2012 (Association of Plastic Manufacturers Europe, 2015).

Based on the statistic, about 38% of the plastic waste still went to the landfill, 26% were

recycled while 36% were utilized for energy recovery (Association of Plastic Manufacturers

Europe, 2015). This signifies that the percentage of plastic waste dumped in the landfill was

high and it was occupying a large space. Besides, the degradation of plastics may take up

billions of years, thus the continuous disposal of plastic in the landfill would definitely impact

the environment negatively.

In order to overcome the challenges faced for recycling such as the needs of sorting that

is labour intensive, a much more reliable method was established. Nowadays, converting the

waste into valuable energy resource has been a brilliant way to fully utilize the waste in order

to meet the increased energy demand. Plastic wastes can be turned into valuable energy since

they are derived from petrochemical source which having significant calorific value. The

conversion can be made possible through pyrolysis process as one of the routes to waste

minimization.

Pyrolysis is the process of thermally degrading long chain polymer molecules into

smaller, less complex molecules through heat. The process requires intense heat with shorter

duration and in absence of oxygen. The three major products that are produced during pyrolysis

are oil, gas and char which are valuable for industries especially production and refineries.

Pyrolysis was chosen by many researchers since the process able to produce high amount of

liquid oil up to 80 wt% at moderate temperature around 500⁰C (Fakhrhoseini & Dastanian,

2013). In addition, pyrolysis is also very flexible since the process parameters can be

manipulated to optimize the product yield based on preferences. The liquid oil produced can

be used in multiple applications such as furnaces, boilers, turbines and diesel engines without

the needs of upgrading or treatment (Bridgwater, 2012). Unlike recycling, pyrolysis is

considered as green technology when even the pyrolysis by-product which is gaseous has

substantial calorific value that it can be reused to compensate the overall energy requirement

of the pyrolysis plant (Abnisa & Wan Daud, 2014). The process handling is also much easier

and flexible than the common recycling method since it does not need an intense sorting

process, thus less labour intensive.

Several research papers have been published regarding the potential of different types of

plastics in pyrolysis processes for liquid production. It has to be noted that the product yield

and quality mainly relies upon the set up parameters. Therefore, this paper reviewed the

potential of thermal degradation of plastic with the important parameters in pyrolysis process

that need to be considered to obtain an optimal liquid oil production and improve the oil quality.

Selective catalysts and their influences to the product yield were briefly discussed.

Additionally, some relevant discussion regarding the optimization of liquid oil yield and the

potential fuel quality were also presented in this paper.


152

2. PROCESS PARAMETERS INFLUENCE ON PRODUCT YIELD

Parameters play major role in optimizing the product yield and composition in pyrolysis. There

are several parameters that influence liquid oil production in pyrolysis such as temperature,

type of reactors, pressure, residence time, type and rate of fluidizing gas, and catalyst selection.

In thermal degradation of plastics, temperature is one of the most significant operating

parameters in pyrolysis since it controls the cracking reaction of the polymer chain. Different

plastics have different degradation temperature depending on the chemical structure. For

common plastics such as PET, HDPE, LDPE, PP and PS, the thermal degradation temperature

started at 350⁰C except for PVC which the degradation started at lower temperature of 220⁰C.

Additionally, the operating temperature required relies strongly on the product preference. If

gaseous or char product was preferred, higher temperature more than 500⁰C was suggested. If

liquid was preferred instead, lower temperature in the range of 300-500⁰C was recommended

and this condition is applicable for all plastics (Anuar Sharuddin et al., 2016).

Besides temperature, right reactor selection for the process also crucial to increase

efficiency of the reaction towards achieving the final desired product. Most plastic pyrolysis in

the lab scale were performed in batch, semi-batch or continuous-flow reactors such as fluidized

bed, fixed-bed reactor and conical spouted bed reactor (CSBR). Each reactor may have its own

advantages and disadvantages depending on the application. Batch or semi-batch reactors were

likely used in thermal pyrolysis since the parameters could be easily controlled. Nevertheless,

these reactors might not be suitable for catalytic pyrolysis because of the potential of coke

formation on the catalyst outer surface when they were mixed together with the plastics. The

coke formation would reduce the efficiency of the catalyst that would affect the overall product

yield. In addition, batch operation was not suitable for large scale production since it required

high operating cost for feedstock recharging and thus, it was more appropriate for laboratory

experiment. Fluidized bed reactor is concluded to be the best reactor to perform catalytic plastic

pyrolysis since the catalyst can be reused many times without the need of discharging,

considering catalyst is a very expensive substance in the industry. Besides, it is more flexible

than the batch reactor since frequent feedstock charging can be avoided for continuous process

and the process does not need to resume often. Hence, fluidized bed reactor would be the most

suitable reactor for large scale operation in terms of economic point of view. On the other hand,

CSBR also provides good mixing with the ability to handle large particle size distribution and

low bed segregation than the bubbling fluidized bed as claimed by Olazar et al. (2009).

However, a variety of technical challenges during operation of this reactor have been

encountered such as catalyst feeding, catalyst entrainment and product (solid and liquid)

collection that make it less favourable (Fogler, 2010). Additionally, its complicated design that

requires many pumps to be used in the system makes it unfavourable due to the high operating

cost involved.

Furthermore, pressure and residence time also governed the performance of pyrolysis

process. Pressure and residence time are both temperature dependence factors that may have

potential influence on product distribution of the plastic pyrolysis at lower temperature. Higher

pressure increased the gaseous product yield and affected the molecular weight distribution for

both liquid and gaseous products but only apparent at high temperatures. Based on the

literature, most researchers conducted their plastic pyrolysis studies at atmospheric pressure

and focused more on the temperature factor. The residence time was not brought up to attention

while carrying out the experiment since the effect would become less apparent at higher

temperatures. Moreover, in terms of economic viewpoint, additional units such as compressor

and pressure transmitter need to be added into the overall system, thus increase the operation


153

cost if the factor of pressure is considered. However, it should be noted that these two factors

should be put under consideration based on the product distribution preference especially when

running at temperature below 450⁰C.

Apart from that, type and rate of fluidizing gas used during pyrolysis also influenced the

pyrolysis product. Fluidizing gas is an inert gas (also known as carrier gas) which only engaged

in transportation of vaporized products without taking part in the pyrolysis. There are many

type of fluidizing gas that can be used for the plastic pyrolysis such as nitrogen, helium, argon,

ethylene, propylene and hydrogen. Each type of fluidizing gas has different reactivity based on

its molecular weight as reported by Abbas-Abadi et al. (2014). Nevertheless, of all those gases,

nitrogen was commonly used by most researchers as fluidizing gas in plastic pyrolysis since it

was easier and safer to handle than the high reactivity gas like hydrogen and propylene due to

their flammability hazard. In terms of fluidizing gas flow rate, Lin and Yen (2005) found that

the rate of degradation dropped instantly at the lowest fluidizing flow rate of 300 ml/min. The

contact time for primary product is high at lower flow rate, causing the formation of coke

precursor (BTX) to increase with the secondary product obtained even though the overall

degradation rate is slower (Lin & Yang, 2007). This was indicated by the high residue left when

lower fludizing flow rate was applied. At the highest flow rate of 900 ml/min, the gasoline and

hydrocarbon gases fraction were maximized. This clearly shows that the flow rate of fluidizing

gas also affected the final product distribution.

As for the catalytic degradation, catalyst is used in the thermal process to speed up

chemical reaction and improves the hydrocarbon distribution in order to obtain pyrolysis liquid

that had similar properties to the conventional fuel such as gasoline and diesel. The three types

of catalysts that are widely used in plastic pyrolysis are zeolites, fluid cracking catalyst (FCC)

and silica-alumina catalysts. The usage of zeolite catalyst in pyrolysis of real municipal plastic

waste may also help to reduce the impurities in the oil produced and this was proven in the

study conducted by Miskolczi et al. (Miskolczi et al., 2009). SEM and EDAX analysis showed

that elements of impurities from the plastic wastes such as trace of sulfur, nitrogen and

phosphorus attached on the catalyst surface. In fact, the catalyst obtained from the waste plastic

pyrolysis could be re-used since the pore diameter was found to be similar with the fresh

catalyst (Miskolczi et al., 2009). In terms of liquid oil properties, the sulfur content in HDPE

waste pyrolysis reduced tremendously from 75 mg/kg to 37 mg/kg with the usage of HZSM-5

catalyst. Besides zeolite, the usage of spent FCC catalyst could also improve the plastic

conversion in pyrolysis. According to Kyong et al. (2003), the amount of solid residue left

reduced drastically from 4.5 to 0.9 wt% and this indicates that the conversion was maximized.

They also observed that the HDPE degradation temperature was lowered down to 350⁰C with

the presence of FCC catalyst in comparison to thermal pyrolysis which required higher

temperature of 430⁰C. This proves that the usage of catalyst may help in saving energy as heat

is one of the most expensive costs in industry. Other than these two catalysts, some researchers

also chose to use silica-alumina catalyst which is an amorphous acid type. The acid

concentration of silica alumina catalyst is determined by the mole ratio of SiO2/Al2O3. Different

strength of acidity in catalyst has great influence in the final end product of plastic pyrolysis.

Sakata et al. (1997) explored the effect of catalysts acidity (SA-1, SA-2, ZSM-5) on the product

distribution of HDPE pyrolysis. It was observed that SA-2 catalyst with lower acidity produced

higher amount of liquid oil (74.3 wt%), followed by SA-1 (67.8 wt%) and ZSM-5 (49.8 wt%).

ZSM-5 possessed strong acid sites, thus produced more gaseous products than the other two

acid catalysts but very less liquid yield. Therefore, it is worth noting that that the usage of

zeolite catalyst in plastic pyrolysis only maximized the production of volatile hydrocarbon

while FCC and silica-alumina maximized the liquid oil production. However, for higher


154

efficiency and longer cycle time usage, HZSM was recommended since the deactivation rate

of the catalyst was extremely low and thus, more efficient for regeneration.

3. LIQUID FUEL PROPERTIES FROM PYROLYSIS OF PLASTICS

Table 1 summarized the fuel properties of the liquid oil produced in pyrolysis process. The

experimental calorific value of HDPE, PP and LDPE are all above 40 MJ/kg and were

considered high for energy utilization. The calorific value of PS was commonly lower than the

polyolefin plastic due to the existence of the aromatic ring in the chemical structure which had

lesser combustion energy than the aliphatic hydrocarbon (Onwudili et al., 2009). Overall, PET

and PVC had the lowest calorific value below 30 MJ/kg due to the presence of benzoic acid in

PET and chlorine compound in PVC that deteriorated the fuel quality. Benzoic acid also

consisted of aromatic ring that explained the low calorific value in PET. Overall, Table 1

clearly depicted that the physical properties of plastics pyrolysis oil were very close to the

properties of commercial gasoline and diesel. Therefore, plastic pyrolysis oil has very high

potential to be used as new energy resources.

Table 1: Fuel Properties of Plastic Pyrolysis Oil

Physical

Properties

Type of Plastics (Experimental typical value) Commercial Standard

Value (ASTM 1979)

PET

(Cepeliog

ullar &

E.Putun,

2013),(Sa

rker et al.,

2011)

HDPE

(Ahma

d et al.,

2014)

PVC

(Cepeliog

ullar &

E.Putun,

2013),(M

anickaraj

a &

Tamilkol

undu,

2014)

LDPE

(B.Desa

i &

K.Gala

ge,

2015)

PP

(Ahma

d et

al.,

2014)

PS

(Pinto

et al.,

1998),

(Blazso,

2006)

Gasoline

(Ahmad et

al., 2014)

Diesel

(Ahmad

et al.,

2014)

Calorific value

(MJ/kg)

28.2 40.5 21.1 39.5 40.8 43.0 42.5 43.0

API gravity @

60⁰F

n.a 27.48 38.98 47.75 33.03 n.a 55 38

Viscosity (mm2/s) n.a 5.08a 6.36b 5.56c 4.09a 1.4d 1.17 1.9-4.1

Density @ 15⁰C

(g/cm3)

0.90 0.89 0.84 0.78 0.86 0.85 0.780 0.807

Ash (wt%) n.a 0.00 n.a 0.02 0.00 0.006 - 0.01

Octane number

MON (min)

n.a 85.3 n.a n.a 87.6 n.a 81-85 -

Octane number

RON (min)

n.a 95.3 n.a n.a 97.8 90-98 91-95 -

Pour point (⁰C) n.a -5 n.a n.a -9 -67 - 6

Flash point (⁰C) n.a 48 40 41 30 26.1 42 52

Aniline point (⁰C) n.a 45 n.a n.a 40 n.a 71 77.5

Diesel index n.a 31.05 n.a n.a 34.35 n.a - 40

*n.a., not available in the literature a Viscosity at 40⁰C b Viscosity at 30⁰C c Viscosity at 25⁰C d Viscosity at 50⁰C


155

4. DISCUSSON ON PLASTIC PYROLYSIS SCENARIOS

Table 2 summarized the optimum temperature required to optimize liquid oil yield in thermal

and catalytic pyrolysis at different conditions. Other affected parameters include the type of

reactors, pressure, heating rate and pyrolysis duration for each type of plastics. All experiments

carried out were using nitrogen gas as the fluidizing medium. Based on Table 2, PET and PVC

are two plastics that produced very low yield of liquid oil in comparison with other plastic

types, which made these plastics infrequently explored by researchers. It also should be noted

that not all plastic types are recommended for pyrolysis. PVC was not preferred in pyrolysis

since it produced the major product of harmful hydrochloric acid and very low Table 2 Summary of Studies on Plastic Pyrolysis

(Kyon g et al., 2002)

HDPE Semibatch 400 1 atm 7 - 82 16 2 Stirring rate 200 RPM, FCC catalyst 10 wt%

(Misko lczi et al., 2004)

HDPE Batch 450 - - 60 74.5 5.8 19.7

(Abbas -

Abadi et

al.,

2013)

HDPE Semibatch 450 1 atm 25 - 91.2 4.1 4.7 Stirring rate

50 RPM, FCC

catalyst 20

wt%

(Luo et al., 2000)

HDPE Fluidize d

bed

500 - - 60 85 10 5 Silica alumina

catalyst

(Marcil la et al., 2009)

HDPE Batch 550 - 5 - 84.7 16.3 0

(Mastr al et al., 2001)

HDPE Fluidize d

bed

650 - - 20-25 68.5 31.5 0

(Cepeli ogullar & E.Putu n, 2013)

PVC Fixed bed 500 - 10 - 12.3 87.7 0

(Miran da et al., 1998)

PVC Vacuum batch

520 2 kPa 10 - 12.79 0.34 28.13 Also yield

HCl=58.2 wt%

(Onwu dili et al., 2009)

LDPE Pressuriz

ed batch

425 0.8-4.3 Mpa

10 60 89.5 10 0.5

Reference Type of

plastic

Reactor Process parameters Yield Others


156

(Uddin et

al.,

1996)

LDPE Batch 430 - 3 - 75.6 8.2 7.5 Also yield

wax= 8.7 wt%

(Fakhr hoseini & Dastan ian, 2013)

LDPE - 500 1 atm 6 - 80.41 19.43 0.16

(Bagri & T. Willia ms,

2001)

LDPE Fixed bed 500 - 10 20 95 5 0

(Marcil la et

LDPE Batch 550 - 5 - 93.1 14.6 0

al., 2009)

(T. Wiliia ms & A.Will iams,

1998)

LDPE Fluidize d

bed

600 1 atm - - 51.0 24.2 0 Also yield

wax=24.8 wt%

(Ahma d et al., 2014)

PP Horizont al steel

300 - 20 30 69.82 28.84 1.34

(Sakata et al., 1999)

PP Batch 380 1 atm 3 - 80.1 6.6 13.3


PP Semi-

batch

400 1 atm 7 - 85 13 2 Stirring rate 200 RPM,

used FCC

catalyst 10

wt%

(Abbas -

Abadi et

al.,

2014)

PP Semibatch 450 1 atm 25 - 92.3 4.1 3.6 Stirring rate 50 RPM, used FCC catalyst 10 wt%

(Fakhr hoseini & Dastan ian, 2013)

PP - 500 1 atm 6 - 82.12 17.76 0.12

(Demir bas, 2004)

PP Batch 740 - - - 48.8 49.6 1.6


157


PS Semibatch 400 1 atm 7 - 90 6 4 Stirring rate 200 RPM, used FCC catalyst, cat/poly=10

w/w

(Onwu dili et al., 2009)

PS Pressuriz

ed batch

425 0.31-1.6 MPa

10 60 97 2.50 0.5

(Adnan et

al.,

2014)

PS Batch 500 - - 150 96.73 3.27 0 Used Zn catalyst, Cat/poly=5

w/w

(Demir bas,

2004)

PS Batch 581 - - - 89.5 9.9 0.6 64.9 wt% of liquid comprised

of

styrene *All experiments used nitrogen gas as fluidizing medium.

5. CONCLUSION

Pyrolysis process was chosen by most researchers because of its potential to convert the most

energy from plastic waste to valuable liquid oil, gaseous and char. Therefore, it is the best

alternative for plastic waste conversion and also economical in terms of operation. The

flexibility that it provides in terms of product preference could be achieved by adjusting the

parameters accordingly. The pyrolysis could be done in both thermal and catalytic process.

However, the catalytic process provided lower operating temperature with greater yield of

liquid oil for most plastics with the right catalyst selection. The sustainability of the process is

unquestionable since the amount of plastic wastes available in every country is reaching

millions of tons. With the pyrolysis method, the waste management becomes more efficient,

less capacity of landfill needed, less pollution and also cost effective. Moreover, with the

existence of pyrolysis method to decompose plastic into valuable energy fuel, the dependence

on fossil fuel as the non-renewable energy can be reduced and this solves the rise in energy

demand.

6. ACKNOWLEDGEMENTS

The authors would like to thank the University of Malaya for fully funding the work

described in this publication.

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STUDY THE PROPERTIES OF CONCRETE AS RADIATION

SHIELDING

Siti Amira Othman1 and Kamarizan Kidam2 1Department Science, Faculty Science, Technology and Human Development, Universiti Tun Hussein

Onn Malaysia, [email protected] 2Faculty of Chemical and Energy Engineering, Universiti Teknologi Malaysia,

[email protected]

ABSTRACT

Ionizing radiation is widely used in industry and medicine and can present a significant health hazard. It causes microscopic damage to living tissue which can result in skin burns and radiation sickness at high exposures. There are three factors that control the amount or dose of radiation received from a source which is time, distance and shielding. Different types of ionizing radiation interact in different ways with shielding material. This study intends to see the suitability of concrete as radiation shielding by taking factors such as concrete and technique of composition, properties of concrete and intensity of radiation towards concrete composition, Based on this study, concrete shows promise as a shielding material particularly for nuclear application.

Key Words: Properties, Concrete, Radiation, Shielding.

1. INTRODUCTION

Radiation takes place when the atomic nucleus of an unstable atom decays and starts releasing ionizing particles, known as ionizing radiation. When these particles come into contact with

organic material, such as human tissue, they will damage them if levels are high enough, causing burns and cancer. Ionizing radiation can be fatal for humans. Since photons, gamma and X- ray widely used in radiation therapy and medical imaging, the problem of flux deposition in the body and their biological effects is very important in shielding analysis. When exposed to high levels of radiation all at once, damaged cells are unable to sufficiently repair themselves, and this has effects on health. Exposure of the entire body has greater health effects than exposure of part of the body at the same level of radiation. Standards for protection from radiation are based on the concept that the best course is to prepare safety and minimize exposure as much as possible.

Radiation shielding is based on the principle of attenuation, which is the ability to reduce a wave’s or ray’s effect by blocking or bouncing particles through a barrier material. Charged particles may be attenuated by losing energy to reactions with electrons in the barrier, while x-ray and gamma radiation are attenuated through photoemission, scattering, or pair production. Neutrons can be made less harmful through a combination of elastic and inelastic scattering, and most neutron barriers are constructed with materials that encourage these processes. There are several factors that influence the selection and use of radioactive shielding


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materials. Considerations such as attenuation effectiveness, strength, resistance to damage, thermal properties, and cost efficiency can affect radiation protection in numerous ways.

Theoretically, all materials could be used for radiation shielding if employed in a thickness sufficient to attenuate the radiation to safe limits. However, due to certain characteristics, magnetite and concrete are among the most commonly used materials. The choice of the shield material is dependent upon many varied factors such as: final desired attenuated radiation levels, ease of heat dissipation, resistance to radiation damage, required thickness and weight, multiple use considerations (e.g., shield and/or structural), uniformity of shielding capability, permanence of shielding and availability.

Concrete has been widely used as a radiation shielding material due to its extremely low cost and considered the best materials, as they are easily available, economical, and have good structural strength. This is a material, which is used to protect buildings at a large extent. This is because of the thickness that the walls will have in the same. Today, most concrete mixtures contain supplementary cementitious materials that make up a portion of the cementitious component in concrete. For use in concrete, supplementary cementitious materials, sometimes referred to as mineral additives, need to meet the requirements of established standards and can be used for improved concrete performance in both its fresh and hardened state (Yilmaz et al. 2011).

1.1 Concrete Composition

Concrete is the world’s most broadly used man-made material. More specifically, it is employed in the construction of complicated infrastructure (dams, nuclear reactors, high-rise buildings and etc). Recently there has been interest in specialty concrete for radiation shielding applications. The composition of concrete can be modified using additives and different forms of aggregates, making it an ideal material to be tailored toward specific uses (Mohsen et al. 2015). A computational study on various compositions of concrete for gamma attenuation, has shown that adding magnetite (Fe3O4) and lead oxide (PbO) in specific concentrations to standard concrete increases attenuation and greatly reduces exposure rate outside the spent fuel cask.

Concrete shielding walls and structural parts around pressure vessels of light water reactors become low radio-active wastes. The cost of recovery of these wastes is 100– 3000 times more than that of deal with non- radioactive wastes. Nowadays,the standards used for selection of concrete radiation shields aggregates don't take into consideration the effect of the potential neutron activation on the size of the resulted radioactive wastes in these shields. Most of the requirements of these standards concentrate on mechanical and shielding effectiveness of the resulting concrete (Daria et al. 2015).

Concrete is strong in compression, as the aggregate efficiently carries the compression load. However, it is weak in tension as the cement holding the aggregate in place can crack, allowing the structure to fail. Reinforced concrete adds either steel reinforcing bars, steel fibers, glass fibers, or plastic fibers to carry tensile loads. Increasing the volume of sand in the aggregate in the range from 35 to 55% tends to reduce the yield stress (increasing the propagation of fresh concrete) with a simultaneous increase of the plastic viscosity (rising time of propagation). While further enhancing the sand point from 50% to 60% causes reducing the


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diameter of the propagation of about 10 cm (reduction of one class of selfcompacting) and increasing propagation time of about 1 s.

The current research on concrete technology in terms of rheological properties of fresh concrete provided general knowledge about influence of composition and technological factors on the SelfCompacting Concrete (SCC) workability. Unfortunately, in case of High Performance Self-Compacting Concrete (HPSCC) that issue is not well recognized yet. It was

only observed that designing of SCC is similar to designing HPSCC (Aleksandra et al. 2016). HPSCC has to meet high requirements of workability, self-compacting, strength and durability. In the latter case, it is very often required, that the fresh concrete should remain self compacting at least for 60 min. Because of that it is important to recognize composition influence on the rheological properties of HPSCC. Influence of aggregate the type and particle size on the rheological properties of concrete mixture was the subject of numerous studies by authors

1.2 Properties of Concrete

Radiation shielding concrete is used in nuclear research facilities, health care facilities, storage/transport casks for radioactive waste, nuclear power plants, and conducting radiation therapy. In radiation shielding concrete mixtures, light atomic aggregates, such as materials containing hydrogen, are used to absorb neutrons. The content of crystal water or bound water in shielding concrete is one of the important factors affecting the shielding performance of concrete, because hydrogen occupies a large proportion in water (Mugahed et al. 2015). Thus, water proportions will affect the characteristics of radiation shielding mixture.

Aggregate size and content play a critical role in the successful development of radiation shielding concrete mixtures. As with any concrete mixture, aggregate size must be limited to that which will pass through rebar openings. In radiation shielding concrete,the maximum size is often 10–20 mm. Also,the coarse aggregate content is usually smaller in a radiation shielding concrete mixture compared to normal-vibrated concrete (NVC) to reduce the effect of blocking and friction between aggregate particles (Krystian et al. 2015). Concrete is recognized for its low cement content, high flowability, excellent thermal insulation and low aggregate usage. Furthermore, the concrete is considered as an economical solution in fabrication of large scale lightweight construction materials and components such as partitions, structural members, road embankment infills and filling grades due to its easy production process from manufacturing plants to final position of the applications (Hassan et al. 2015)

Concrete is a porous and highly heterogeneous composite material containing aggregate, cement paste and interfacial transition zone between them. It is thought that concrete is the second most consumed material after water in the world. Cement is known as a key

ingredient of concrete that binds the aggregates together through hydration. Portland cement is the most commonly used cementitious material in concrete, the production of which consumes more energy and natural resources. It is predicted that the service life of Portland cement concrete exposed to weathering is approximately 50–100 years (Sun et al., 2010). Under the circumstance of resource shortage and environmental protection, more and more eco-materials are required for preparation of concrete with excellent durability.


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Conglomerate can be viewed as a natural concrete, the appearance of which is similar to that of cement concrete (Feng et al. 2007). Conglomerate is a sedimentary clastic rock in which clasts with particle size larger than 2 mm are cemented together by dissolved silicate minerals. Mealy sand, clay and chemical sediments are generally filled between gravels in the conglomerate. It is the superfine particles of silicate minerals that play an important cementing role in the conglomerate. These silicate minerals possess characteristics of secondary enlargement, dissolution and recrystallization. In the diagenetic process of sedimentary rock,

the superfine silicate minerals were dissolved under the effect of rock forming liquid, and then re-crystallized with overgrowth and cemented the large particles together. All the micropores in the sediments were filled by the new formed silicate minerals, and thereby loose sediments were bond together into a hard natural rock. It illustrates that the rock forming liquid has a strong dissolution ability on the silicate minerals. Although the macrostructure of conglomerate and cement concrete is very similar, their microstructure is different. In the conglomerate, gravels and sands are firmly welded together by the fine silicate minerals relying on Si–O covalent bonding and chemical bonding between grain boundaries. While in the traditional cement concrete, stones and sands are cemented together by C-S-H gels relying on Van der Waals’ force (Ni et al. 2005).

1.3 Lead as Shielding Material

Lead is generally used as gamma radiation shield but due to its high density and cost, it is not possible to use it on large scale. So in the past, different authors have studied various other construction materials for shielding of gamma radiations by evaluating their radiation parameters. One such material investigated commonly by researchers is concrete. El-Sayed et al. (2015) investigated radiation properties of different types of concretes and good agreement

between the calculated and measured values was reported. Besides that, he also studied building materials as shielding materials for gamma radiations both theoretically as well as practically concretes. Michael A. F. (2016) studied shielding characteristics of concretes using barites and natural local materials by evaluating half value layer and tenth value layer. Ioannis S.F. have computed electron density of different materials above 1 keV. To have desired compressive strength, cement intake is high in concretes, which leads to terrible effect on the human health and environment. So besides trying for various admixtures in the preparation of concretes as a gamma shielding material by narrow beam geometry technique, much importance has always been on checking of attenuation in concretes incorporating different cement substituents (Othman et al. 2011)

The shielding properties of concrete may vary depending on the composite of the concrete. Aggregates occupy the largest proportion of concrete (about 70–80% of the sum weight of normal concrete). The most common natural aggregates used in radiation shielding

concrete are extracted from ores of high-density minerals, such as limonite, hematite, ilmenite, magnetite, and barite (Mugahed et al. 2015). For neutron ray shielding, the content of crystal water in the aggregate is generally required to be higher than 10% (ASTM C637–09) and the aggregate itself should possess thermal stability.

Due to the overwhelming concern about release of radionuclides from various sources, as well as the increasing use of gamma ray-emitting isotopes in industry, medicine, and


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agriculture, it has become necessary to study the shielding properties of new and improved materials. There is always a need to develop new materials that can be used under the potentially harsh conditions of radiation exposure and act as shielding materials for extended periods of time (El-Sayed et al. 2016). The most conventional material used for the purpose of radiation shielding for nuclear reactors and nuclear waste storage is concrete with various aggregates. It is a mixture of light nuclei (primarily hydrogen) and heavy nuclei, giving it the ability to be an effective shield against neutron and gamma radiation. Concrete is relatively

inexpensive and easy to cast in many shapes and sizes, in addition to being strong and structurally sturdy. However, prolonged exposure to nuclear radiation results in heating of the concrete, which causes a decrease in density and a possible loss of cooling water and/or gas.

The recent research orientations in radiation shielding is to develop denser concrete by adding suitable percentage of additives. As an example, minerals such as magnetite, hematite, goethite and limonite were incorporated with concrete and their effects have been evaluated. Effects of barite and lead additives in concrete have been separately investigated. Similarly, the effect of lime/silica ratio of concrete specimens on gamma absorption and variation of

attenuation coefficient for cement specimens have been verified. The relation between compressive strength of heavy concrete and the attenuation of γrays were also considered in special study on high performance concrete which was found to be linear. It should be mentioned that there is no available study that deals with the size of additive materials on the concrete γ-ray attenuation.

Today the design and construction of radiation shielding to protect people, equipment

and structures from the harmful effects of radiation is one of the most important problems in nuclear engineering. It has been shown that concrete, is a robust, effective, and economical material for the construction of radiation shielding. It has been used for many purposes and particularly for large, permanent installations such as nuclear power plants, research reactors, particle accelerators, and highlevel radioactive research laboratories (Kaplan, 1989). In radiation shielding concrete (RSC) mixtures, a large variety of materials may be used to attenuate gamma rays. The most common aggregates are produced from natural ores of high density minerals such as hematite, limonite, magnetite, and barite (Demir et al., 2010). From an environmental point of view, substitution of these natural aggregate with industrial by-products and wastes materials can be done in RSC production.

1.4 Composition techniques

Under high temperature, chemical composition, physical structure and moisture content of concrete change and the thermal properties of concrete are modified. These changes are observed in the cement paste and in the aggregates and at the paste–aggregate interface. Heating up to high temperatures causes the dehydration and decomposition of C–S–H gels (150–300 oC), Portlandite (450 oC) and calcium carbonate (700oC) of the hardened cement paste. Aggregates also lose their evaporable water and hydrous aggregates dehydrate at high temperatures (e.g. goethite dehydrate from 250oC), and undergo crystalline transformations accompanied by a significant volume expansion (e.g. quartz a–b transformation). These changes will affect the thermal properties of concretes and allow large amounts of energy consumption (Othman et al. 2011).


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Hassan et al. (2015) reported an experiment according to the local standards of building materials that doped by different percentages of PbO and PbTiO3 nano powders using co-precipitation and oxalate precursor techniques, respectively. In addition, commercial PbO2 powder additive was used to check the effect of particle size on concrete attenuation properties. The phase composition and particle size of all the lead-oxide additives were confirmed by XRD and TEM imaging. The γ-rays attenuation coefficients were measured as a function of the additive percentage of lead compounds for γ-ray energies of 662, 1173 and 1332 keV using 137Cs and 60Co sources. The microstructure changes occurred in the concrete samples doped with Pb compounds additives were probed using the positron annihilation spectroscopy (PAS) and the results were compared with that for normal concrete. The obtained data revealed that the overall defect density of the investigated samples, as seen by the positrons, decreases with increasing the nanoPbO contents which is in agreement with the determined values of the samples apparent densities. It was found that the γ-ray attenuation coefficient of concrete doped by nano-PbO is improved. The results are explained in the view of the fine structure enhanced modification and its impact on the γ-ray interaction probability at different energies.

There are many types of concrete available, created by varying the proportions of the main ingredients below. In this way or by substitution for the cementitious and aggregate phases, the finished product can be tailored to its application with varying strength, density, or chemical and thermal resistance properties. Aggregate consists of large chunks of material in a concrete mix, generally a coarse gravel or crushed rocks such as limestone, or granite, along

with finer materials such as sand.

1.5 Intensity of Radiation Towards Concrete Composition

Nowadays, as the application areas of nuclear technology increases, protection from radiation has become even more important. Especially, the importance of radiation-shielding is important for the environment and employees which are in close proximity. Berk (2002) reported that in nature,there are no living cells immune to radiation and there hardly exists a radiation free place. Each person living on earth is exposed to radiation originating from cosmic rays, radio active sources or artifical sources of daily life. 78% of the public doze is caused by the natural sources, 20.7% by medical irradiators and therest is caused by occupational irradiators and artificial sources.

The dose of radiation received is directly proportional to duration of the exposure, and inversely proportional to the square of the distance from the source. Additionally, the most important and effective way of preventing the radiation hazard is shielding. Placing a barrier between the radiation source and the employee provides a reduction in radiation intensity. In this process, radiation attenuation property of the substances is utilized so that the working

duration around the source can be extended. Shielding can be in various shapes and thicknesses depending on the radiation type and energy. α rays can be stopped by a paper or body skin, whereas β rays require 2.5cm thickness and γ rays require large amounts of lead or concrete (Kowalsky et al. 1987)

Hassan et al (2015) reported that, the recent research orientations in intensity of radiation shielding is to develop denser concrete by adding suitable percentage of additives. As


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an example, minerals such as magnetite, hematite, goethite and limonite were incorporated with concrete and their effects have been evaluated. Effects of barite and lead additives in concrete have been separately investigated. Similarly, the effect of lime/silica ratio of concrete specimens on gamma absorption and variation of attenuation coefficient for cement specimens have been verified. The relation between compressive strength of heavy concrete and the attenuation of γ-rays were also considered in special study on high performance concrete which was found to be linear.

When gamma radiation interacts with matter,its intensity will decreaseas it travels through matter. The decrease inintensity of radiation i sdependent mainly on the type of target material and its thickness in its path. The attenuation properties of radiation for a particular target material are required to determine the amount of shielding necessary and how much dosage one would receive if that particular target material is used for the shielding. Concrete remains to be the first practical choice for radiation shielding for several reasons.

Mehta and Monteiro(2006) asserted that concrete is used in abundance particularly for shielding purposes due to its good mechanical and radiation shielding properties. The determination of accurate values of interaction parameters is necessary before their usage in the field of industry, medicine, agriculture, tomography, etc.Mass attenuation coefficient is the basic parameter for studying gamma ray interactions with matter. Half value layer (HVL)and the effective atomic number are the two other important parameters for understanding the interaction with matter.

1.6 Current Technology in Shielding Material

The information regarding thickness and density of material can be obtained by gamma ray back scattering technique. This technique is based on detecting gamma backscattering from the interior of an object surface when gamma made to strike on the target material. The gamma backscattering method is very useful for estimating the thickness of hot objects, unclean and corroded surfaces when ultrasonic method fail to use. The gamma backscattering technique is useful in investigating historical objects. The gamma-backscattering peak is useful technique in determining density, thickness, and composition of backscattering material. The distribution of gamma rays from a point source is modified when the source is placed on semi infinite and homogeneous medium. Accurate knowledge of the angular distribution of the number and energy albedos of the backscatter photons from different materials is important in desiging reactor shields and other shield calculation in nuclear installations.

Many researchers have used various oxides on the nanoscale (such as nano-SiO2, nano-TiO,nano FeO2) to improve the chemical and physical properties of the concrete.T he use of these small grains helps to improve the shielding properties of concrete (Hanus et al. 2013). A particular area of interest for NonDestructive Testing and Evaluation (NDT, NDE) techniques is detection of defects in concrete structures. Moreover, NDE techniques are useful for condition assessment of concrete structures. The most common defects present in concrete are internal cracks, voids, shallow delamination, honeycombing and surface opening cracks. The main NDT techniques used to inspect concrete structures are ultrasonic, ground penetrating radar, impact echo, electromagnetic techniques and radiography. In the case of reinforced


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concrete structures, these techniques are expected to provide information about thickness variations as well as the inclusions such as the reinforcing bars, cracks, voids and delamination, deteriorated zones and moisture (Buyukozturk, 1998).

Multi-functional structures (MFS) technology is a concept that incorporates various functions such as electronics, thermal man-agement, radiation-shielding and load-bearing into a composite structure, thereby offering the possibility to achieve large mass and volume savings

in spacecraft. In conventional technology, an electronic housing has been widely used to support and protect the electronics, while MFS concept does not require bulky alu-minum housing any more due to direct integration of electronics into structures; thus they can provide the considerable reduction in spacecraft mass and volume by elimination of housing. Previous studies on MFS implementation can be classified into two major approaches according to the way in which the elec-tric/electronic function is incorporated with structure: (1) mount-ing electronics onto honeycomb core sandwich panel and (2) embedding electronics into honeycomb core sandwich panel (Jang et al. 2016).

Kim et al. (2014) has constructed a lattice-based MCNP model to simulate the relationship between tungsten particle size and gamma-energy-dependent attenuation. They observed the size effect increases as the gamma energy decreases, while it decreases and disappears all energies higher than ~1 MeV. They also verified this concept experimentally by measuring the gamma attenuation using three different energies (~0.3 MeV to ~1.2 MeV) for both nano and micro systems. More importantly, they developed a simple but efficient preparation method for such materials. In-situ pulverization of microtungsten powder with polyethylene powder using high energy ball milling produced nano tungsten powder, the surface of which is encapsulated.. Based on this method, a nano-

tungsten/polyethylene dispersed polymer nanocomposite was prepared using a conventional polymer extruding process, which is readily applicable to mass production. The researchers believe that their nano tungsten containing products for shielding X-ray and gamma radiation including a full body apron and a thyroid guard are the first commercially available.

2. CONCLUSION

It was found that, effective concrete can be achieved by studying the different properties of concrete. Besides that, level of radiation intensity towards concrete composition can be

identified. As a result enhances the shielding material efficiency against gamma ray.

3. ACKNOWLEDGEMENTS

The authors would like to thank the Universiti Tun Hussein Onn Malaysia and Universiti

Teknologi Malaysia for facilities provided and gratefully acknowledged the financial support a research grant (U138) that make the research possible.


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STUDY ON ACID PRE-TREATMENT OF SAGO PITH

WASTE FOR GLUCOSE PRODUCTION

Wong Teck Soon1, Lennevey Kinidi2 and Shanti Faridah Salleh3

1Faculty of Engineering,Universiti Malaysia Sarawak, Kota Samarahan, Sarawak. Department of Chemical Engineering and Energy Sustainability. [email protected]



ABSTRACT

Sago Pith waste is one of the waste which is produced in the processing sago starch flour in the

sago mill. The current waste management of the sago pith waste is just by placing the waste at

large area and let it undergo decomposition. If this current practice of Sago Pith Waste

management continues, it will pose threats to the environment. However, many researches were

done to sago hampas to maximize the use of Sago Pith Waste by converting it to added-valued

product. In the acid pre-treatment which is also known as acid hydrolysis is crucial for chemical

modification of the Sago Pith Waste which leads to the production of glucose. The purpose of

this study was to study the acid pre-treatment on the physical changes of the Sago Pith Waste

and amount of glucose produced with regards to different acid concentration, temperature and

time. In this study, the time taken for the Sago pith wastes to convert into a gel-like substance

during acid pre-treatment was shorter with increasing concentration and temperature. The

concentration of acid used had a less significance on the amount of glucose production. At a

higher temperature, the time for glucose production was shorter. It was also founded that at

temperature of 100oC the glucose production was 3.361 g/L. This study shows that temperature

did have a significant effect on acid hydrolysis of Sago Pith Waste and physical change of the

sago pith waste was faster when the temperature is higher.

Key Words: Sago Pith Waste, Waste Management, Acid Pre-treatment, Acid Hydrolysis.

1. INTRODUCTION

Sago Pith Waste is a type of agricultural waste which is produced in the processing sago starch

flour in the sago mill. Agricultural waste can be defined as the waste that is generated by

agricultural activities. The lignocellulosic-biomass materials from agricultural wastes offered

a renewable, economical and abundant feedstock. For every tonnes of sago starch flour

produced, around 3 tonnes of Sago Pith Waste is generated (Karim et al., 2008). This is

equivalent to more than 120,000 tonnes/yr sago hampas generation, making it an important

byproduct in sago industry (Department of Agriculture Sarawak, 2009b). These lignocellulosic

wastes can be used to produce biofuels (Slade et al, 2009) bio-sorbent (Kadirvelu et al, 2004),

particle-board production (Phang et al, 2000) and degradable plastic composites (Cheong, ).

According to Mtui and Nakamura (2005), Lignocellulosic wastes are comprised of

glucose, hemi-cellulose and lignin (Mtui & Nakamura, 2005). However, these cellulose and


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hemicellulose with lignin are enclosed in the plant cell wall, pre-treatment is crucial in order to

obtain these carbohydrates (Radeva et al, 2012). The pre-treatment break down the lignin

structure and disrupt the crystalline structure of cellulose in order for the acids or enzymes can

readily hydrolyze the cellulose into monomers (Harmsen et al,2010). Some structural and

compositional properties were found to have an effect on the biodegradability of lignocellulosic

biomass. Hence, the main objective for pre-treatment is to modify such properties to enhance

biomass amenity and enzymes and microbes (Zheng et al, 2014). According to Zheng et al

(2014), different pretreatment methods have different effects on the properties of the

lignocellulosic biomass (Zheng et al, 2014) . The types of pre-treatment can be divided into

several categories, including physical, physic-chemical, chemical, biological, electrical or a

combination of this (Zheng et al, 2014). Among all the pre-treatment methods, chemical

treatment is one of the most favorable methods to enhance he biodegradability of cellulose

(Mtui & Nakamura, 2009). In the acid pretreatment process, the most important criteria are to

improve the formation of sugars, avoiding the degradation, avoiding the formation of

byproducts, and be cost-effective (Talebnia, 2012). The formation of sugar is important because

if the formation is low, it will render the pretreatment process meaningless. If both the

formation of sugar and the degradation is high, which means that the formed sugar are degraded

and the sugar left is low so it is important to avoid degradation. Another thing to be avoided is

production of byproduct. Formation of byproduct will also decrease the fermented sugar. And

the final product will also decrease and made the pretreatment process become worthless

(Talebnia, 2012). In the acid pre-treatment which is also known as acid hydrolysis is crucial

for chemical modification which can lead to modification of the structural and functional

properties of the Sago Pith waste. A deep understanding of the effect of acid hydrolysis on the

structure of the lignocellulosic biomass wastes and functionality posed a great significance for

the scientific research and its industrial applications.

Therefore, the objective of this article is to report the effect of different acid pretreatment

condition on the amount of glucose produced from the acid hydrolysis of sago pith waste and

also the properties of the sago pith waste after the acid pre-treatment at different temperature.


2.1 Materials

Sago hampas was collected from Soon Ngeang sago mill, Dalat. The samples collected were

placed inside a foam box. This was done to reduce the chance for the sample to be oxidized.

Wet sago hampas used in this study was shown in Figure 1. The wet sago hampas was dried

under sun light for 1-2 days. Finally, it was placed inside the oven to remove residual moisture

until it reaches a constant weight.


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Figure 1 Wet Sago Hampas

2.2 The Effect of Temperature and Acid Concentrations on the Amount of Glucose

Production

5 g dried sago hampas sample was weighed and placed into beaker. Then, 200 mL of 2%

H2SO4 was added into the beaker. The sago hampas was fully submerged by the H2SO4. After

that, the beaker was placed on the hot plate. The sago hampas with sulfuric acid was stirred and

the temperature was set to room temperature at 30oC. 2 mL sample was taken out from the

beaker after 10 minutes heating time, and stored in a sampling tube. These steps were repeated

for 20, 30, 40 and 50 and 60 minutes of heating time. The experiment was repeated under

different temperature (60oC and 100oC). The experiment was continued by changing the

concentration of H2SO4 to 4% H2SO4 and 6% H2SO4. The pretreated sago hampas were

tested using UV-visible spectroscopy at 340nm the wavelength for glucose detection to

determine amount of glucose produced.


3.1 The Effect of Temperature And Acid Concentrations on the Physical Changes of the

Sago

3.1.1 Acid Hydrolysis for 2%H2SO4

For 2% sulfuric acid 100oC, only 10 minutes heating time makes the sago hampas change

color to red. For 2% sulfuric acid 60oC, only 15 minutes heating time make the sago hampas

change color to red. For 2% sulfuric acid at 30oC, 20 minutes heating time make the sago

hampas change color to red.

3.1.2 Acid hydrolysis for 4% H2SO4

For 4% sulfuric acid 100oC, only 5 minutes heating time makes the sago hampas change color

to red. For 4% sulfuric acid 60oC, only 10 minutes heating time make the sago hampas change


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color to red. For 4% sulfuric acid at 30oC, 10 minutes time needed to make the sago hampas

change color to red.

3.1.3 Acid Hydrolysis for 6%H2SO4

For 6% sulfuric acid heating under 100oC, only 5 minutes heating time makes the sago hampas

change color to red. For 6% sulfuric acid heating at 60oC, only 5 minutes heating time make

the sago hampas change color to red. For 6% sulfuric acid heating at 30oC, 10 minutes heating

time make the sago hampas change color to red.

Figure 2 Pretreatment under 4% H2SO4 100oC at (a) 10 mins, (b) 30 mins and (c) 60 mins

Figure 3: Pretreatment under (a) 2%, (b) 4% and (c) 6% H2SO4 100oC at 50 mins

As the sago Pith Waste undergone pretreatment under sulfuric acid with different temperature,

it changed the color to red because of oxidation-reduction reaction. The time for pretreatment

sago Pith waste with 6% sulfuric acid was the shortest for sago Pith waste changing color to

red followed by 4% sulfuric acid and 2% sulfuric acid. It means that the concentration of acid

also affect the time of experiment. High concentration will bring the high reaction rate. For the

temperature, 100oC gives fastest result and followed by 60oC and 30oC. It means that high

reaction rate in high temperature. High temperature will provide high energy and the reaction

will fast. From the experiment above, at 60oC and 30oC, for 60 minutes heating time, it was

still considered to be safe. Hence, the heating time for this study was set at 60 minutes for other

experiments in this research.


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For the temperature and reaction time, this study was different from the previous work. Alfi et

al (2010) used high temperature which was 115oC and the heating time only took 15 minutes.

At higher temperature, the energy provided will be high also and the reaction time will be short

(Alfi et al, 2010). This study use 30oC and 60oC as the heating temperature and the maximum

heating time was 60 minutes.

3.2 Amount of Glucose Produced for Acid Hydrolysis

Table 1 Evaluation of amount of glucose under different condition

H2SO4

Conc. used

Temp (oC) Heating time (min)

10

20

30

40 50

60

Amount of glucose produced

(g/L)

2%

30 0.944 0.905 1.183 1.352 1.078 0.966

60 1.554 1.695 1.764

1.839 1.972 2.182

100 1.570 2.018 2.488 2.944 2.874 2.763

4% 30 0.955 1.269 1.741 1.435 1.272 1.152

60 1.157 1.525 1.895 2.360 2.877 2.954

100 2.322 3.015 3.128 3.232 3.361 3.097

6% 30 1.244 1.323 1.622 1.574 1.445 1.187

60 1.314 1.440 1.604 1.812 1.899 1.936

100 1.675 1.979 2.264 2.456 2.730 2.813


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3.2.1 Highest Amount of Glucose Produced

Figure 4 Highest Amount of Glucose With Respect To Acid Concentration at Different

Temperature Using Hotplate

Figure 4 shows the highest amount of glucose produced for different concentration with

different heating temperature using hotplate. Sago Pith waste submerged inside 4% H2SO4

heating at 100oC gave the best result which the highest amount of glucose produced as

compared to other concentration and heating temperature. The heating temperature of 60oC and

100oC gave same pattern of result which was the highest glucose produced was by 4% H2SO4

followed by 2% H2SO4 and the lowest is 6% H2SO4. For 30oC, the highest still the 4% H2SO4,

but the lowest was 2% H2SO4 not the 6% H2SO4. Acid hydrolysis at low temperature with low

concentration of acid didn’t bring much effect to the sago hampas because the energy provided

was low at low temperature and the molarity of ion H+ was low at low concentration of acid.

3.2.2 Effect of Concentration

i. Acid Hydrolysis at 30oC

For acid hydrolysis at low temperature, the highest amount of glucose can be achieved was

1.741 g/L which subjected under 4% sulfuric acid at 30 minutes heating time. But the overall

pretreatment with 6% sulfuric acid will give better result than 2% and 4% sulfuric acid. It means

that at high concentration will cause more lignin breaks thus more glucose can be produced.

When a maximum value of glucose was obtained, it will drop because the glucose degraded to

levulinic acid which is secondary product of glucose. Figure 4.6 shows the general pathways

of cellulose to levulinic acid (Grethlein, 1978).


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Figure 3 Amount of Glucose With Respect To Acid Concentration at 300C

Cell Gluc

Figure 4: General Pathway of Cellulose To Levulinic Acid (Grethlein, 1978)

ii. Acid Hydrolysis at 60oC

Figure 5 Amount of Glucose With Respect To Acid Concentration at 60oC

During the first 20 minutes, pretreatment with 2% sulfuric acid shows the best result but

when heating time proceeds more than 30 minutes, pretreatment with 4% sulfuric acid

overtakes to give the best result if compare to the others. The highest amount of glucose can be

achieved was 2.954 g/L by 4% sulfuric acid at 60 minutes. The result obtained by 6% sulfuric

Gluc

Levulinic


179

acid was lower than 2% sulfuric acid. It was due to the both high temperature and concentration

will cause the glucose easily degraded to secondary product (Grethlein, 1978) compared to low

concentration.

iii. Acid Hydrolysis at 100oC

The best result obtained was by 4% sulfuric acid followed by 2% sulfuric acid and finally 6%

sulfuric acid. The highest amount of glucose can be achieved at 100oC was 3.361 g/L which

obtained at 50 minutes heating time. The results of 2% sulfuric acid and 6% sulfuric acid were

similar and not much of a difference.

The overall effects of concentrations were analyzed using Statistical Package for the

Social Sciences (SPSS) software. Sig. value obtained for hotplate with different concentration

was 0.411 and this value is greater than 0.05 so the result obtained are non-significant

difference which means that the concentration of acid doesn’t much affect the production of

glucose.

Figure 6 Amount of Glucose With Respect To Acid Concentration at 100oC

For comparison between 2% and 4% of acid used, the sig. value was 0.395 which was

greater than 0.05 and this means that the glucose obtained from hydrolysis at 2% and 4% acid

were non-significant difference. The sig. value for comparison between 2% and 6% was 0.914

also greater than 0.05. There were also non-significant difference between 2% acid and 6%

acid. For the 4% and 6% acid, there were non-significant differences also with the sig. value

0.635. It can be concluded that the concentration doesn’t much affect the production of glucose.

Although there has a little bit increase of amount of glucose when concentration of acid

increase, but the hypothesis still be accepted.


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3.2.3 Effect of Temperature

i. Acid Hydrolysis Using 2% H2SO4

Figure 7 Effect of Temperature on Amount of Glucose for 2% Sulfuric Acid

ii. Acid Hydrolysis Using 4% H2SO4


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iii. Acid Hydrolysis Using 6% H2SO4

High temperature (100oC) will easily break more lignin if compare to low temperature

(30oC and 60oC) for all 2%, 4%, 6% sulfuric acid. Pretreatment at 30oC after 30 minutes, the

amount of glucose starts drop for all 2%, 4%, 6% sulfuric acid. But for the high temperature

it continue to increase after 30 minutes for all 2%, 4%, 6% sulfuric acid. At high temperature,

the highest amount of the glucose can be obtained is 2.813 g/L.

The result obtained were also undergone SPSS analysis to study the effect of the temperature.

The computation of one-way ANOVA at 0.05 significant levels was used to test for significant

difference between temperature 30oC, and 60oC to the amount of glucose produced. The result

were presented appendix. The sig. value obtained is 0.000 which was lower than 0.05 which

means that the glucose produced at temperature 30oC and 60oC are significant difference.

Hence, the temperature gave significant effect to the production of glucose during pretreatment.

Therefore, the hypothesis stated about temperature is accepted.

3.3 Observation under SEM

Sago Pith waste, the solid waste produced after starch extraction, contains a significant

proportion of starch granule material and fiber (Figure 4.28). According to Awg-Adeni et al,

2013, microscopic examination revealed a large number of starch granules to be trapped within

the lignocellulosic matrix of sago Pith waste (Awg-Adeni et al, 2013). The sago starch granules

were either pear or cigar shaped and had a generally smooth outer surface with some shallow

indentations (Wang et al., 1996).


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Figure 10 Scanning electron microscope photograph of untreated sago Pith waste.

Figure 11 Enlarged Image of Starch of Untreated Sago Hampas

Figure 12 Scanning electron microscope photograph of treated sago Pith waste with

4% Sulphuric acid heating at 60oC


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All values except starch are comparable to those reported previously (Vickineswary et al,

1996). In this study, high amount of starch in sago hampas was observed due to the quality of

the extraction process practiced by sago mill as it greatly depended on the sophistication of the

methods employed (Siti Mazlina. et al, 2007). Moreover, sago industry is still under

development, and therefore every year the factory owners will try to improve their processing

to minimize the starch content in sago Pith waste. According to one owner of factory, most of

the factory that achieves food grade for their starch production will have more starch in the

sago Pith waste compared to the factory that produces industrial grade starch. This was due to

the reduced recycling process which was carried out during the starch extraction stage, to

ensure the starch whiteness.

4. CONCLUSION

It can be concluded that the concentration of acid is does not affect the amount of glucose so

much when the concentration of acid used incerased. Although there is increase a little bit in

amount of glucose, but when the concentration of acid used is high, it will increase the cost.

Hence, it is not suggested to use high concentration of acid. For the temperature, it is clear that

when temperature increases the amount of glucose increases too. When high temperature is

used, the time for the experiment will be short. It is not only save time but also the energy.

From this research, it was found that using hotplate for temperature of 100oC gave a positive

result with yeild of 3.361 g/L compare to the experiments using hotplate for temperature of

60oC with yeild of 2.729 g/L. This shows that temperature does have a significant effect on

acid hydrolysis of sago hampas. Temperature does have a significant effect on acid hydrolysis

of sago hampas. The pretreated sago hampas under optimum condition was scanned via SEM.

It was done to observe morphological changes of sago hampas. From the SEM photographs, it

showed that the starch components in the sago hampas presented by sphere like objects was

reduced after sago hampas undergoes the acid hydrolysis.

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enzyme hydrolysis of steam-exploded wheat straw. Cellul Chem Technol 2012; 46:61–7.

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185

DESIGN FORWARD: BIOMIMICRY APPROACH IN

SUSTAINABLE LANDSCAPE ECOLOGY

I. Nur-Afikah1, M.Y.M. Yunos1* and N.A. Ismail1 1 Department of Landscape Architecture, Faculty of Design and Architecture, Universiti Putra Malaysia,

43400 Serdang, Selangor.

[email protected]*, [email protected]

ABSTRACT

The density of human population in an urban area of this era increases strongly. Its at risk as

the capacity continues critically at the alarming rate even though the city nowadays is in

unsustainable behaviour challenge of majority come from landscape ecology. This scenario is

mostly cases of the implementation sustainability-oriented contemporary urban planning and

relationship between landscape ecological design practices. The most difficult problem is in

enhancing the urban ecological area in various perspectives of developing future patterns and

theories although it relevant for socio-economic issues, environmental concerns and context of

planning. However, this paper examines the application of biomimicry in sustainable landscape

ecology and obtains the lesson beyond the formalistic characteristic design to more responsive

understanding nature. Besides, it generates significant to explore sustainable and relevant

solution towards design form and approach for successful landscape ecology. Biomimicry is

an expression of imitation of the life process in nature reveals the unsustainable behaviour as

the design field seen to imitate nature. Therefore, a qualitative method research is involved by

having comprehensive content analysis throughout different task of ideas to strengthen the

design context and interpreted the existing design instead of new design. Nevertheless, within

the design context strikingly identify the biomimicry approach and develop multi-disciplinary

design framework by having nature as inspiration to the future design field. The expected added

value of integrating biomimicry approach into sustainable landscape ecology may be improved

on social life behaviour which is more responsive towards natural environmental setting,

economic, political issues and most importantly changing urban thought and understanding the

fundamental approach of biomimicry that leads the globe objectives for enhancing the

sustainable landscape ecology development. Thus, this study highlight that biomimicry

approach as the emerging trends and opportunities areas by moving ahead of the transfer and

sharing knowledge between the designers and biologist.

Key Words: Biomimicry, Sustainable, Landscape, Ecology

1. INTRODUCTION

In recent years, there has been an increasing concern about the sustainability in landscape

ecology with raising of the human population as the effect from expeditious of urbanization. A

key aspect of landscape ecology is a dominant threat to the practice of sustainability-aligned

contemporary urban planning and environmental implementation. The issue of landscape

ecology has received considerable critical attention. However, the sustainable landscape

ecology purpose essentially to save the environment and accomplish the human well-fixed with

minimum conceivable financial. Very little is known about sustainable landscape ecology

context of planning and future pattern and theories aspect. Thus, there are some element that

should be included in solving the sustainability discourse which is the application of

biomimicry.


186

Central to the entire discipline of biomimicry is the concept through nature. Extensive

research has shown that nature portrays an interminable source of guidance for researcher and

designers from the multi-disciplinary field of involvement (El-Zeiny, 2012). Interestingly,

most of the organism is altered to the environment with own uniqueness. Considering this

indigence and relevant design toward exploration of sustainable landscape ecology, nature

develops and expand. A great extension for latest generation to face the circumstances for

surviving the future generation’s think and practice (Badarnah, 2009).

. Biomimicry can be broadly being defined as stimulating or captivating inspiration from

nature’s form either flora or fauna and refine to resolve human’s problem (Benyus, 1997).

Biomimicry is greater extent than just imitating a natural object or system and there is a degree

of uncertainty around the terminology in biomimicry simply considered as green or sustainable

(El-Zeiny, 2012). Besides, biomimicry is not a new-fangled where the circuitous

interconnection of livelihood, either human and nonhuman related, has enlarged prepared to

inspire inquisitivieness, drive responsiveness and escort personal ingenuity (Goldstein and

Johnson, 2015). Nevertheless, biomimicry may have played a vital role in bringing about a

future application inherent to design ideas that scrutiny of an organism or ecosystem.

The study of the concept of biomimicry by (Benyus, 2008), founder and president of the

Biomimcry Institute examined that “Nature is imaginative by necessity, and has already solved

many problems we are grappling with today”. Therefore, nature evolves in period and solutions

well-rounded as biomimicry is a new task to challenge the design pattern throughout the

comprehensive study and application of the natural solution that more responsive.

2. SIGNIFICANT OF BIOMIMICRY

The advantages of the new approach of biomimicry can be implemented in several sectors. The

far-flung and virtual application of biomimicry as design process endures yet mostly evasive.

Whereas most researchers and professionals in the field of sustainable architecture finding

diverse forms of biomimicry or bio-inspired design (Reed, 2006 and Berkebile, 2007) yet

largely the practical application still unknown, as established by just a few built case studies

related to biomimicry in architectural design method (Faludi, 2005). Therefore, the finding has

been far more useful and source of potential new innovation in landscape ecology by

supporting more sustainable built environment.

Generally, the designer says that a design is determined by nature, largely touched about

the appearance likely organic shape. In this regard, nature is the beneficial teacher but mocking

or being inspired by natural-looking forms, textures, and colours entirely are not biomimetic

(El-Zeiny, 2012). According to Dr. Julian Vincent, hold the view that “Biomimetic has to have

biology in it”. Since this difference perspective has not been found elsewhere it is probably

not due to the only appearance of biomimetic but the design should be a compliment and

integrated with nature’s science.

Extensive research has shown that varieties form of biomimicry has been developed and

investigation toward the application biomimicry in designer scopes. The theory of biomimicry

provides a useful account of how smart materials in landscape ecology are formulated.

Biomimicry from biological process gives the ability to establish the significant responses to

some key stimuli whether in the physical context, social behaviour and the environment.

Besides, biomimicry develop ‘nature’ in different practice which is become a part of a universal


187

progression approaching the conceptualization and improvement of bio economy (Goldstein

and Johnson, 2015). The biological structural is pleasing phenomena in nature where sustain

the ability of the system to embrace a certain structural arrangement, pattern without external

influences (Lurie-Luke, 2014). Thus, research into the structures has assisted the designer and

scientist to evolve and capable of mimicking the product in landscape ecology to be more

responsive to relevant property.

Transportation

One major theoretical issue that has dominated the field for many years concerns about

the transportation. Commonly, animal present a range of devotion to the others and

comprehensive behaviour which may be altered for the human system (Lurie-Lake, 2014). For

example, the ant's army yield inspiration for better transportation strategies by the lay out

systematic behaviour and self-organization. Ant often moving in opposite direction even in the

range of 200,000 colonies of the army. The behavioural different between ants with or without

food is major regulation in ant’s army. Successful ants travel with food are less divert path

while ants return without food with move aside from the pheromone trail of ants’ path. Thus,

the ant in the middle lane carrying food back and two lanes unload ants moving in the different

direction. Moreover, an anchor of biologist, naturalists, financers, educators and ecologically

responsible designers have conjugated Benyus to guide and practice in a global biomimicry

movement (Harvet, 2009 and Johbson, 2010). The evidence presented thus far supports the

idea that behavioural difference between burdened and unburdened ants decrease throughout

computer modelling showed the impact to the efficiency of the three-lane systems declines

(Couzin and Franks, 2003). The exposure to biomimicry has been shown to be more related

with landscape ecology to adverse the effect in the transport system.

Environmental Friendly

Moving on now to consider about the environmentally friendly process by mimicking

the range of organism produce compounds from materials in prompt of the environment (Ball,

2001). In this case, the processes inspired a series of the manufactured system in the industry.

Coral is one of example that incorporate carbon dioxide in immediate surrounding into multi-

layers of stable mineral (Lurie-Lake, 2014, Arinah et at, 2015). Recent year, the amount of

carbon dioxide give significant in naturally absorbed by the oceans and transferred in sustain

of landscape ecology.

In support of environmentally friendly, biomimicry has been shown to induce

biomimicry in several cases (Smith et al., 2001). Now, future technology has been established

that can sustain these processes. Mostly eco design instruments have emanated to adherent for

green invention shift by assimilate environmental attention into product expansion (Karlsson

and Luttropp, 2006). The importance of this is the formation of novel, metastable calcium and

magnesium carbonate, and bicarbonates same as finding in corals and the skeletons in several

of marine organism. Besides, this technology seems possible to enhance new building materials

in an environmentally sustainable behaviour in landscape ecology. According to one of R&D

manager execute this modification pull the business increasingly discovering that innovation

driven by environmental sustainability attempt advantages to gain competing opportunities,

create business market and build up prospect kinship (Metz et al., 2016). However, the people


188

around opt natural environments overbuilt environment potential to regenerate and assist in

improving well-being that found from the nature (Appleton, 1975; Ulrich, 1983; Kaplan, 1987;

Rohde and Kendle, 1994). Therefore, natural environment confirms enhancing the sustainable

landscape ecology encompassing biomimicry system integrating with nature behavioural.

Energy Production

In addition, it is important ways for bioenergy also known as green energy production in

the quest for sustainable landscape ecology and efficient power energy. Potentially, the plant

is generating a cheaper alternative to silicon-based photovoltaics rather than inspired by solar

cell energy (Lurie-Lake, 2014). With respect to biomimicry, the formalistic design of solar

panel captivates and employ the light energy in a wide scope of purified material that create

large energy inputs and several of toxic solvent. While dye-sensitive solar cells from plant

photosynthetic compound potential to be better flexible and more integrated into existing

buildings and into window panes, building paints and textiles (Service, 2011). Biomimicry

boost integral thinking which is emotional impression by reason of biological structure drift to

influence various operation in design (Baumeister 2014). Furthermore, a correlation between

the mindful action of biomimicry and spawning of green invention approach makes instinctive

feel, given that natural option compliment with biological system capable for life on earth over

the long lading (Kennedy and Marting, 2016). Thus, the key to understanding the function

approach of biomimicry in landscape ecology with reducing the energy production give a

positive impact in a viable manner to economic and environment.

3. METHODOLOGY

The paper observed the interdisciplinary approach by having comprehensive content

analysis with different ideology interpreted the existing design into the new design. The paper

explored the concept and the application of biomimicry for future design approaching

sustainable landscape ecology. Thus, biomimicry highly placed in development for future

design within the contemporary context of sustainability cries in the landscape ecology.

4. DISCUSSION

Now, biomimicry becomes infancy in the landscape ecology. The trend of biomimicry

application highly growing the number of bio-inspired developments and enhancing the

friendly environment potential for industrial. Prior to commencing the study, biomimicry

focuses on the discovering the ability of sense by the organism and react to the environment

that can be used in the development of daylighting, energy consumption and ecological

footprint of new facilities. It is expected that biomimicry approach will retain with successful

and widely applied in the designer field in the future especially as a tool for sustainable design.

Moreover, to improve the landscape ecology, biomimicry approach provides a source of

inspiration for several of technology development. The design field is coherence enough to

establish innovation approaches and future technologies to spread expeditiously with the clear

profit. Therefore, by using biomimicry to solve the idea development problem can help to

produce a fresh sustainable standard for landscape ecology, buildings, interior spaces,

communities, and cities worldwide.


189

5. CONCLUSION

Biomimicry offers the experiences of many years of evaluations as the reference of guidance

whereas biomimicry becomes the main product development starts with beginning concept

defining the objective performance benefits. Instead, biomimicry research not only

concentrates to materials utilized by organisms but also on sensing, movement, behaviour and

process.

Biomimicry has discovered new opportunities to change the urban thought and lead the

global objectives for enhancing sustainable landscape ecological development. The

development of biomimicry exploiting the multi-disciplinary offer in nature introduce the

unique opportunity to employ the environment to be responsive toward the physical setting,

balance socio-community, and stable economic properties.

Therefore, expansion of biomimetic is the significant role in giving the education to the

community. It is important for better understanding the fundamental approach to the designer

and researcher to ensure the biomimicry approach is being aware. Thus, the transfer and sharing

knowledge among designer and researcher can build more sustainable landscape ecology.

6. ACKNOWLEDGEMENT

The authors would like to thank and express deepest appreciation for those from Universiti

Putra Malaysia, Faculty of Design and Architecture and WARIS research group as the funding

bodies of this research, under Fundamental Research Grant Scheme (FRGS).

REFERENCES

Appleton, J. (1975). Experience of landscape.

Arinah, R., Yunos, M. Y. M., Md Azree, O. M., Isa, N.K.M., Noor Fazamimah M, A.,

Nor Atiah, I. (2015). Building The Safe City Planning Concept : An Analysis Of

Preceding Studies, Jurnal Teknologi, 75(9), 95–100

Badarnah, L. (2009). Bio-mimic to realize: biomimicry for innovation in architecture. The

Architecture Annual 2007-2008, Delft University of Technology, eds. L. Calabrese, A.

Doeschate, A. Geenen, D. Hauptmann, and U. Knaack, 010 Publishers: Rotterdam, pp. 54-

59, 2009.

Ball P. (2001). Life’s lessons in design. Nature 2001; 401:413-6.

Baumeister, D. (2014). Biomimicry Resource Handbook: A Seed Band of Best practices.

Missoula, Montana: Biomimicry 3.8.

Benyus, J. (1997). Biomimicry – Innovation Inspired by Nature. New York, Harper Collins

Publisher.

Benyus, J.M. (2009). Biomimicry in action. Presentation given at TEDGlobal, Oxford,

England, July. http://www.ted.com/talks/

Janine_benyus_biomimicry_in_action?language=en


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Benyus, J.M. (2013). A biomimicry primer. In Biomimicry Resource Handbook: A Seed Bank

Best Practices. Biomimicry 3.8. http:// biomimicry. Net /b38files/ A_ Biomimicry_

Primer_ Janine_ Benyus.pdf

Biomimicry 3.8 Institute. (2013). Biomimicry taxonomy. http:// static. Biomimicry. Org/

asknature/biomimicry_taxonomy-v6.0.pdf

Bekebile, B. (2007). Master Speaker Address. Proceeding of Living Future Conference. Settle,

WA.

Couzin I., Franks N. (2003). Self-organized lane formation and optimized traffic flow army

ants. Proc R Soc 2003: B 270: 139-46.

El-Zeiny R.M.A. (2012). Biomimicry as a Problem-Solving Methodology in Interior

Architecture. Proceeding- Social and Behavioral Sciences 50 (2012): 502-512.

Faludi J. (2005). Biomimicry for Green Design (A How To). Wold Changing.

Goldstein, J., and Johnson, E. (2015). Biomimicry: New Natures, New Enclosures. Theory,

Culture & Society. Vol. 32(1): 61-81.

Harvey, N. (2009). What’s good for life wins: The biomimicry scientific revolution. Bioneers

radio Series Podcast. Available at: http://www.bioneers.org/radio/series-archives/2009-

series/episode-1-mirroring -nature (accessed 22 July 2011).

Johnson, E. (2010). Reinventiong biological life, reinventing ‘the human’. Ephemera: theory

and Politics in Organization 10(2):177-193.

Karlsson, R. and Luttropp, C. (2006). EcoDesign: What’s happening? Journal Cleaner

Production 14:1291-1298.

Kennedy, E.B., and Marting, T.A., (2016). Biomimicry: Streamlining the Front End of

Innovation for Environmentally Sustainable Products. Research-Technology Management

59:4, 40-48.

Lurie-Luke, E. (2014). Product and technology innovation: What can biomimicry inspire?

Biotechnology Advances 32 (2014) 1494-1505.

Metz, P., Burek, S., Hultgren, T.R., Kogan, S., and Schwartz, L. (2016). The path to

sustainability-drive innovation. Research-Technology Management 59(3): 50-60.

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332(6025): 25.

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in idea generation. Design Studies 31(2): 169-186.


191

ACCUMULATION OF METAL (CD, CR, CU, NI AND PB)

CONTAMINATED WATER USING BACOPA MONNIERI,

LILAEOPSIS BRASILIENSIS, HEMIANTHUS

CALLITRICHOIDES AND GLOSSOSTIGMA ELATINOIDES

Rashidi Othman and Anis Fatihah Abu Yazid 1 Department of Landscape Architecture, KAED, International Islamic University Malaysia Kuala Lumpur,

53100, Malaysia. Email: [email protected]

ABSTRACT

The pollution of aquatic ecosystems in Malaysia has emerged as a major ecological problem

coinciding with rapid industrialization and urbanization. The contamination often contributed

by industries bearing heavy metals, such as Cd, Cr, Cu, Ni, and Pb can cause significant

ecological and environmental problems. Due to their high solubility in water environment, they

can easily enter food chain, thus making it a serious health hazards for human and other

organisms. Presently, the study on phytoremediation by using macrophytes are still on-going

and appears to be one of prospective alternative and innovative technology that can be applied

at contaminated aquatic environments. However, it is noted that careful evaluation of its

applicability and effectiveness will be required. Cd, Cr, Cu, Ni, and Pb remediation in water

was assessed through selected aquatic plant species, which are Bacopa monnieri, Lilaeopsis

brasiliensis, Hemianthus callitrichoides and Glossostigma elatinoides via in-vitro model

system. Based on the bioconcentration factor (BCF), the capability of the plant species to

remediate Cd, Cr, Cu, Ni, and Pb can be assessed and it was concluded that all of the plants

have different capabilities of heavy metals uptake and shown vary signs of stress and symptoms

of toxic poisoning.

Key Words: Aquatic ecosystems, Heavy metals, Phytoremediation, Macrophytes

INTRODUCTION

The overwhelming increase of aquatic ecosystems pollution either inorganic or organic

becomes an increasingly evident worldwide (Schwarzenbach, Escher et al. 2006). The threat

of heavy metals contamination in particular usually coincides with rapid industrialization and

urbanization contributed by mobile contaminants resultant from open dumps, industrial

discharges, urban-storm water runoff, and agricultural drainage (pesticides and herbicides)

(Onwughara, Umeobika et al. 2011). Unfortunately, Malaysia is not exempted from these

threats where reports have shown a deteriorating water quality year by year especially in urban

areas (Afroz, Masud et al. 2014). Aquatic organisms such as fishes, shellfish, shrimps and

plants can bioconcentrate and biomagnify the heavy metals in their tissues and systems,

subsequently compromising human health that consume them (Karim and Shah 2015).

Phytotechnology is currently among widely discussed effective and affordable technological

solution used to trace environmental imbalance, immobilize, accumulate and degrade metal


192

pollutants from contaminated water. This ecological technology not only beneficial to our

environment but also cost effective (Ismail and Beddri 2009) by capitalizing naturally

occurring relationships among plants, microorganism and environment. Presently, due to

arising concerns on metal contamination and its possible accumulation in food chain, there are

many studies on new aquatic plants (macrophytes) that have been discussed to unravel their

tolerance towards toxic environment and their potential in phytoremediation or

phytostabilization (Bazihizina, Redwan et al. 2015). So far, the use of macrophytes to treat

water body contamination has shown positive outcomes mostly contributed by the strategic use

of the natural and inherent traits of plants. Proper selection of plant species is important in order

to achieve a successful phytoremediation (Subhashini and Swamy 2014).


The four aquatic species selected were obtained and sub-cultured in a controlled environment

where they are free from external contamination of heavy metals that could interfere with the

model systems settings. The medium used for the plants propagation is Murashige and Skoog

(MS). Matured sub-cultured plants were then selected for treatment. Only uniform size and

healthy seedlings was selected and transferred into treatment tubes. The heavy metals

treatments will be introduced in the form of water for this model system to recreate somewhat

similar conditions of contaminated water bodies settings in a controlled environment.

Analytical grade salts were used (PbCl2, CuSO4, NiCl2, CrCl2, and CdCl2) to recreate the

occurrence of heavy metals contaminations in the model system. The treatment waters were

prepared at three different concentrations (1ppb, 2ppb, and 5ppb) and filled into the tubes

containing the plants . The treatments tubes were then placed inside an incubator room under

24/27-hour photoperiod with a lighting system of Philips fluorescent tubes TL-D-36W/54-

765.3.5.3 with a temperature of 24°C. The treatments were left for there for four periods of

time, which were 1 week, 2 weeks, 3 weeks and 4 weeks. Then the treatments were harvested

after they reached the end of the treatment period. Harvested samples were prepared

accordingly with appropriate procedures (water/US EPA 3015, media/agar, aquatic plants) as

suggested by ETHOS microwave digester. The prepared samples were subjected to acid

digestion according to procedure prescribed by ETHOS microwave digester. Lastly, sample

were analysed by using ICP-MS and results were recorded.

3 RESULT AND DISCUSSION

The ability of the four plants to accumulate metals from water treatment can be estimated using

BCF value, which is the ratio of metals detected in the plant biomass to that in the aqueous

environment. According to Subhashini and Swamy (2014), plants exhibited more than 1 BCF

value, in which the plants can take up more than half the amount of metals from its surrounding

can be considered as suitable as bio-accumulator.

3.1 Bioconcentration factor (BCF)

3.1.1 Accumulation of Cr in Bacopa monnieri, Lilaeopsis brasiliensis,

Hemianthus callitrichoides and Glossostigma elatinoides


193

As presented in table 1 and 2, Bacopa monnieri Cr bioconcentration factor (BCF) for 1ppb and

2ppb concentrations is more than one throughout 4 weeks of exposure. Whereas, for 5ppb the

BCF exhibited is less than one throughout the whole 4 weeks of exposure, in which Cr

accumulated in the plant biomass is less than the amount Cr left in the water treatment. This

indicates that Bacopa monnieri is not an efficient bio-accumulator agent for Cr in higher

concentration. As for Lilaeopsis brasiliensis, Cr bioconcentration factor (BCF) for 1ppb, 2ppb

and 5ppb concentrations is less than one. This indicates that Lilaeopsis brasiliensis is not an

efficient bio-accumulator agent for Cr. Meanwhile for Hemianthus callitrichoides, the amount

of Cr accumulated in plant biomass for 1ppb and 2 ppb is more than the amount of Cr detected

in water treatment except for 2ppb at 2 weeks of exposure. For 5ppb the BCF exhibited is less

than one throughout the whole 4 weeks of exposure, in which Cr accumulated in the plant

biomass is less than the amount Cr left in the water treatment. This indicates that Hemianthus

callitrichoides are not an efficient bio-accumulator agent for Cr in higher concentration. Lastly,

for Glossostigma elatinoides, at 5ppb exposure, the BCF exhibited is less than 1 throughout

the whole 4 weeks of exposure, in which Cr accumulated in the plant biomass is less than the

amount Cr left in the water treatment. This indicates that Glossostigma elatinoides are not an

efficient bio-accumulator agent for Cr in higher concentration.

3.1.2 Accumulation of Ni in Bacopa monnieri, Lilaeopsis brasiliensis,


BCF value of Ni by Bacopa monnieri reach at least 1.74, which is the least BCF estimated on

the first week of exposure towards 5ppb concentration. The highest BCF value estimated for

Ni accumulation by Bacopa monnieri is in 5ppb concentration at 4 weeks of exposure, which

was 3.26. This shows that Bacopa monieri can accumulate Ni efficiently even at higher

concentration. Since the amount of Ni accumulated in plant biomass for 1ppb, 2 ppb and 5ppb

throughout four weeks of exposure is more than the amount of Ni detected in water treatment;

this easily shows that Bacopa monnieri is a suitable bio-accumulator agent for Ni. Ni

bioconcentration factor (BCF) for 1ppb, 2ppb and 5ppb concentrations is less than one. This

indicates that Lilaeopsis brasiliensis is not an efficient bio-accumulator agent for Ni in general.

Hemianthus callitrichoides bioconcentration factor (BCF) for Ni at 1ppb and 2ppb throughout

the whole 4 weeks of exposure is less than one. Meanwhile at 5ppb concentration, the

effectiveness of Hemianthus callitrichoides to accumulate Ni only proven from 2 weeks up

until 4 weeks of exposure. This indicates that Hemianthus callitrichoides are a potential bio-

accumulator agent for Ni only at higher concentration. The highest BCF value estimated is in

5ppb concentration at 4 weeks of exposure, which is 1.32. Meanwhile, for Glossostigma

elatinoides Ni bioconcentration factor (BCF) in 1ppb concentration only achieves more than

one at 4 weeks of exposure, whereas for 2ppb concentration the BCF reached more than one

only 2 weeks and onwards. However at 5ppb concentration, the effectiveness of Glossostigma

elatinoides to accumulate Ni already been proven from the first week up until 4 weeks of

exposure. This indicates that Glossostigma elatinoides are a potential bio-accumulator agent

for Ni at higher concentrations. The highest BCF value estimated is in 5ppb concentration at 4

weeks of exposure, which is 1.72.

3.1.3 Accumulation of Cu in Bacopa monnieri, Lilaeopsis brasiliensis, Hemianthus

callitrichoides and Glossostigma elatinoides


194

The highest Cu BCF for Bacopa monnieri estimated is in 2ppb concentration at 4 weeks of

exposure, which was 6.28. Cu BCF value estimated for 1ppb, 2 ppb and 5ppb was more than 1

throughout four weeks of exposure. This shows that Bacopa monnieri is a suitable bio-

accumulator agent for Cu. value estimated only for 1ppb throughout four weeks of exposure is

more than one. Lilaeopsis brasiliensis exhibited greater accumulation of Cu in lower

concentrations in which, the highest Cd BCF value estimated is in 1ppb concentration at 4

weeks of exposure, which was 1.49. This shows that Lilaeopsis brasiliensis is only suitable to

bioaccumulate Cu from the contaminated environment in lower concentrations. Hemianthus

callitrichoides exhibited more than 1 BCF value in 1ppb and 5ppb concentration. Meanwhile

at 2ppb concentration, accumulation by Hemianthus callitrichoides only proven to be effective

when the time of exposure reaches 4 weeks. The highest Cu BCF value estimated is in 1ppb

concentration at 4 weeks of exposure that is 4.62. Glossostigma elatinoides exhibited more

than 1 BCF value in 1ppb and 2ppb concentration only at 1 week up until 2 weeks of exposure.

Its capability to accumulate Cu in lower concentration decreases as time progresses.

Meanwhile, at 5ppb concentration, BCF value exhibited is more than one throughout the whole

4 weeks of exposure. The highest Cu BCF value estimated is in 2ppb concentration at 2 weeks

of exposure that is 1.56. This shows that Glossostigma elatinoides and Hemianthus

callitrichoides have different accumulation capability of Cu in relation to the concentrations to

which it was exposed.

3.1.4 Accumulation of Cd in Bacopa monnieri, Lilaeopsis brasiliensis,


Bacopa monnieri Cd BCF value estimated for 1ppb, 2 ppb and 5ppb throughout four weeks of

exposure is more than one. This clearly shows that Bacopa monnieri is a suitable bio-

accumulator agent for Cd. Lilaeopsis brasiliensis Cd bioconcentration factor (BCF) for 1ppb

and 2ppb concentrations only shows positive result starting from 2 weeks up until 4 weeks of

exposure. Whereas, for 5ppb the BCF exhibited is more than one throughout the whole 4 weeks

of exposure. Hemianthus callitrichoides exhibited more than 1 BCF value in 1ppb, 2ppb and

5ppb concentration. The highest Cd BCF value estimated is in 2ppb concentration at 4 weeks

of exposure that is 8.65. Hemianthus callitrichoides are identified easily as a very prospective

bioaccumulator of Cd. Glossostigma elatinoides exhibited more than 1 BCF value in 1ppb,

2ppb and 5ppb concentration. The highest Cd BCF value estimated is in 1ppb concentration at

4 weeks of exposure, which is 48.60. Glossostigma elatinoides are also identified easily as a

very prospective bio-accumulator of Cd.

3.1.5 Accumulation of Pb in Bacopa monnieri, Lilaeopsis brasiliensis,


Bacopa monnieri Pb BCF value estimated for 1ppb, 2 ppb and 5ppb throughout four weeks of

exposure is more than one. Bacopa monnieri exhibited greater accumulation of Pb in lower

concentrations in which the highest Cd BCF value estimated is in 1ppb concentration at 4

weeks of exposure, which was 10.21. The lowest BCF value estimated was 1.26, which is in

5ppb at 4 weeks of exposure. This clearly shows that Bacopa monnieri is suitable to bio-

accumulate Pb from the contaminated environment. Lilaeopsis brasiliensis Pb

bioconcentration factors (BCF) at 5ppb exhibited more than one throughout the whole 4 weeks

of exposure. Whereas, for 2ppb and 5ppb concentrations only shows positive result starting


195

from 2 weeks up until 4 weeks of exposure. The highest BCF value estimated is in 1ppb

concentration at 4 weeks of exposure, which is 2.15. The BCF value shows increasing pattern

as time progresses, thus indicating that Lilaeopsis brasiliensis is a potential Pb bio-

accumulator. Hemianthus callitrichoides exhibited more than 1 BCF value in 1ppb, 2ppb and

5ppb concentration throughout the whole 4 weeks of exposure. The highest BCF value

estimated is in 1ppb concentration at 1 week of exposure, which is 38.77. The BCF value shows

a decreasing pattern as time progresses, but still significantly more than 1 BCF value which

indicates that Hemianthus callitrichoides as a promising bio-accumulator agent for Pb.

Glossostigma elatinoides exhibited more than 1 BCF value in 1ppb, 2ppb and 5ppb

concentration throughout the whole 4 weeks of exposure. The highest BCF value estimated is

in 2ppb concentration at 4 week of exposure, which is 36.00. Glossostigma elatinoides are

identified easily as a promising bio-accumulator agent for Pb. Table 1 Accumulation of

Chromium, Nickel, Copper, Cadmium and Plumbum (ppb) in Bacopa monnieri, Lilaeopsis

brasiliensis, Hemianthus callitrichoides and Glossostigma elatinoides within 1ppb exposure

during the experimental period Table 2 Accumulation of Chromium, Nickel, Copper, Cadmium

and Plumbum (ppb) in Bacopa monnieri, Lilaeopsis brasiliensis, Hemianthus callitrichoides

and Glossostigma elatinoides within 2ppb exposure during the experimental period.

Table 4 Accumulation of Chromium, Nickel, Copper, Cadmium and Plumbum (ppb) in Bacopa

monnieri, Lilaeopsis brasiliensis, Hemianthus callitrichoides and Glossostigma elatinoides

within 1ppb exposure during the experimental period


196

Table 5 Accumulation of Chromium, Nickel, Copper, Cadmium and Plumbum (ppb) in

Bacopa monnieri, Lilaeopsis brasiliensis, Hemianthus callitrichoides and Glossostigma

elatinoides within 2ppb exposure during the experimental period

Table 6 Accumulation of Chromium, Nickel, Copper, Cadmium and Plumbum (ppb) in

Bacopa monnieri, Lilaeopsis brasiliensis, Hemianthus callitrichoides and Glossostigma

elatinoides within 5ppb exposure during the experimental period


197

4 CONCLUSION

This study suggest that the practicality of aquatic plant species as phytoremediators for heavy

metals in unhealthy aquatic environment is promising for greener, sustainable, effective and

cost-efficient treatment alternative compared to conventional cleanup technologies. With a

proper selection of plant species, phytoremediation also have a potential to rehabilitate

unhealthy contaminated sites since the results obtained from this experiment showed the

potential of aquatic plant expanded in relation to the time and concentrations of metals it was

exposed to. The potential of metal uptakes by certain plant species increases as the

concentrations and time of exposure increases for specific heavy metals.

5 ACKNOWLEDGEMENTS

The author would like to thank Mdm Nurhanizan Sahidan from Fisheries Research Institute

Glama Lemi, Jelebu, Negeri Sembilan, Malaysia for providing the in-vitro plant sub cultures

for the purpose of this research.

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highnickel concentration." Journal of plant physiology 174: 137-146.

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metals from petroleum refinery effluents." Water, air, and soil pollution 199(1-4): 57-65.

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Contaminated Soils Using Canna Indica." Current World Environment 9(3): 780.


199

Effect of Water Quenching on Physico-Chemical

Properties of Durian wood-derived Biochar produced with

the Kon-Tiki Earth Cone Kiln

Thilagam Krishnan1,2†, Syarifah Adawiyah Syed Idrus1,Tan Sue Sian2, Benson Khoo2,

Trevor Richards3, Robert Thomas Bachmann*1

1 Universiti Kuala Lumpur, Malaysian Institute of Chemical and Bioengineering Technology, Lot 1988, 78000

Alor Gajah, Malaysia.

2 Top Fruits Sdn. Bhd.

3 Environmental engineering consultant, Kuala Lumpur]

Author Email : [email protected], [email protected]

ABSTRACT

Durian fruits are commercially produced in South East Asia. Extraction of valuable

substances from by-products such as Durian shell and seed have been reported, while there is

a lack of knowledge about value-added use of orchard pruning waste and wood scraps. Kon-

Tiki earth cone kiln, a new low-cost and low emission biochar production technology, was

tested for its ability to convert Durian wood to biochar. Biochar was produced at 600-700°C.

The biochar yield was found to be 12.7 – 14 wt.% with a volatile matter content of < 17 wt.%,

while the biochar pH was alkaline. No functional groups where present on the biochar surface,

a typical feature of high-temperature biochars. Ash content determined by ASTM 1762-84 as

well as SEM-EDX agreed reasonably well. The Oorg/C ratio of all biochars as determined by

SEM-EDX was found to be well below the prescribed ratio of 0.4. Top quenching biochar,

DWB1-1 and DWB1-2 resulted two to five times greater BET (N2) surface area (263 and

102.73 m2/g) compared to bottom-quenched biochar. The average BJH pore diameter was

found to be > 50 nm suggesting the biochar to be macroporous and suitable for adsorption of

larger molecules such as humic acid. Potassium, calcium, magnesium, aluminium, silicon and

phosphorous were the main mineral constituents of the Durian wood biochars. It is

recommended to produce biochar with quenching from top to bottom for field trial

experiments. Future EDX analysis should include elements Na, Fe and Mn for a more complete

characterization of the ash composition.

Keywords: Kon-Tiki earth cone kiln, Durian wood biochar, FTIR, SEM-EDX, BET (N2)

surface are

1 INTRODUCTION

Durian (Durio zibethinus) is a fruit tree commercially grown in South East Asia. Total

production of Durian fruits in Malaysia was reported to be 376,273 metric tons in 2008

(Chowdhury, Karim, et al. 2016), and 686,478 metric tons in Thailand (Prakongkep et al. 2014)

Byproducts of Durian fruit production include Durian shells and tree pruning biowaste.

Penjumras, Rahman, Talib, & Abdan (2014) reported that only one third of the Durian fruit is

edible, while shell (~ 44 wt.%) and seed (~23 wt.%) are by-products. Prakongkep et al. (2014)

has shown that Durian shell can be converted to biochar at ~ 350°C using a traditional fixed-

bed allothermal kiln, while Penjumras et al. (2014) successfully isolated cellulose from Durian




200

shell for potential application in composite material. Durian seeds were found to contain

hydrocolloids that can be used as dietary fiber, texture modifiers, gelling agents, thickeners,

stabilizers as well as emulsifiers, coating agents, and packaging films (Amid & Mirhosseini

2012). The durian wood itself is classified as softwood, which typically contains 40 – 45 %

cellulose, 25 – 30 % hemicellulose and 25 – 35 % lignin (Brodin 2009; Morton 1987). The

wood is coarse, lightweight and sometimes used for making light furniture and clogs (Morton

1987). No publicly accessible reports are available about the use of pruning waste and other

low-value wood scraps from Durian orchards.

These low-value Durian wood wastes are converted into a useful product by produce

biochar via pyrolysis. Several technologies exist but most result in excessive production cost

(Meyer et al. 2011; Maroušek 2014; Brown et al. 2011). Cornelissen et al. (2016) stated that

the Kon-Tiki earth cone kiln an encouraging technique to existing technology because it is a

very low-cost yet environmentally friendly process suitable for farmer-scale biochar

production. The Kon-Tiki earth cone kiln was first reported by Schmidt, Taylor, Eglise, &

Arbaz (2014) who were inspired by observations of archaeologists noticing that black soil

deposits are often found in soil profiles as clearly demarcated cone pits with a upper diameter

of about 2 m and a depth of 1.5. The charring process involves the construction of a wood log

tower in the center of the kiln with ignition at the top. Once the ignited wood tower forms a

higher-energy fuel bed at the bottom of the Kon-Tiki kiln, biomass is added layer by layer until

reaching 10 cm from the top edge. In a last step water is added to quench the process. The

authors suggested to add water at the bottom to allow steam to form that will activate the char

by reacting with condensates from the pores of the biochar. The BET surface area measurement

(289 m2/g) reported by the authors was for a top-quenched biochar.

The main objectives of this study were therefore to investigate the yield and physico-

chemical properties of Durian wood derived biochar and test whether bottom-quenching results

in an even greater BET surface area for Durian-wood derived biochar.


2.1 Description of the Study Area.

The study was carried out at Top Fruits Sdn.Bhd. orchard located at Kangkar Senangar, Parit

Sulong, Batu Pahat, Johor, Malaysia.

2.2 Biochar production.

Durian wood logs for biochar production were collected from Top Fruits Sdn. Bhd. (TF)

orchard. The wood feedstock has been stored under shelter for a few weeks prior to use. The

wood were chopped into logs of 5 to 10 cm in thickness and 30-40 cm length without removing

the bark. The Kon-Tiki earth cone kiln was constructed as follows. The upper diameter of the

kiln is 1.5 m with a depth of 0.9 m and a wall inclination of 63o (Schmidt et al. 2014). A

modification of the original design was the inclusion of a metal grid 30? cm from the kiln

bottom. The large wood resting on the metal grid during the burning process will drop through

the grid when the char starts to break up. Another modification was the use of a concrete wall

to help partially reflect and partially store the process heat resulting in a more uniform


201

temperature distribution and ensuring more homogeneous charring conditions and biochar

quality. Four trials of biochar production were perform. For first trial, Durian wood biochar

was quenched from top to bottom (DWB1-1) while in the second and third trial biochar was

quenched from bottom to top (DWB2-1 and DWB2-2) and the last one was again quenched

from top to bottom (DWB1-2). The operation of Kon-Tiki cone kiln is shown in Figure 1. A

chimney with Durian wood scraps was built in the middle of the pit to ¾ of the height of the

cone kiln. The fire was started with cardboard on top of chimney to create updraft conditions

and minimize smoke. The first layer of Durian wood was added after about 15 min. Additional

Durian wood logs were added when the charred wood was covered with a white layer of ash.

The pyrolysis temperature was measured using an infrared thermometer (TECMAN, TM900)

and found to range from 600 - 700oC. Towards the end of the process, drain water was pumped

into cone kiln to quench the fire. The biochar was collected and sun-dried for few days, weighed

and stored. The quench water was collected after 12 hours of soaking and analysed for pH.

Figure 1: Operation of Kon-Tiki earth cone kiln

2.3 Soil sampling and analysis.

The soil used in this study was a sandy loam collected from Top Fruits Sdn.Bhd, Batu

Pahat Malaysia, at a depth of 0 to 15 cm. The soil was air dried, ground and passed through a

2 mm sieve for further analysis (pH and CEC) (Ahmed et al. 2012). The pH of soil was

determined in a 1:2.5 (soil: 1 M KCl) suspension using a digital pH meter (Ahmed et al. 2012).

The cation exchange capacity (CEC) of the soil was determined at the Malaysian Agriculture

Research and Development Institute (MARDI) using the leaching method (Ahmed et al. 2012).

Kon-Tiki ciln Built chimmey Ignited on top

Up-draft combustion ar creted within wood

chimmey.blaze for the first charring layer

FIrst layer added after 15min

Wood covered with white layer ash

Second layer added

FInal layer (last flames)Quenched with water

(Bottom to Top)After quenched


202

2.4 Physico-chemical characterization.

The moisture, volatile matter and ash content of Durian wood and char was determined

according to D1762-84. The pH value was determined by soaking 10 g of biochar samples in

10 mL of 0.01 M CaCl2 solution for 2 hours prior to measurement of pH (Yargicoglu et al.

2015). Ground biochar was analysed in a FTIR spectrometer (Perkin Elmer, Spectrum RX)

with a 4 cm-1 resolution and 100 scans between wavenumbers of 4000 and 400 cm-1. Sample

preparation for FESEM/EDX (FEI, Quanta 400) analysis consisted of drying and grinding the

biochar with a ceramic mortar and pestle. The samples were placed directly onto double sided

sticky carbon tape attached to aluminium stubs without any coating. The elemental composition

in terms of C, O, Mg, Al, Si, P, S, K and Ca was determined by EDX (Oxford-Instruments

INCA 400 with X-Max Detector). In order to calculate the O/C ratio the inorganic carbon

content was subtracted from the total carbon. The inorganic carbon content was estimated from

oxygen associations with ash minerals by assuming that mineral elements such as Ca and K

formed CaO and K2O, respectively (Vassilev et al. 2010). Similarly, the ash content was also

estimated using the same assumptions. Adsorption characteristics were determined by nitrogen

adsorption at -196°C with a surface area and porosimeter (Micromeritics, ASAP-2020). The

specific surface area and pore volume of the chars was determined from the Brunauer, Emmett

and Teller (BET) multipoint method, and the pore size distribution was obtained using the

Barret, Joyner, and Halenda (BJH) method (Gregg & Sing 1982). Prior to the analysis, samples

were degassed at 90°C for 1 hour, followed by 200°C for 2 hours to remove physisorbed water.


3.1 Biochar yield from Durian wood scraps

Durian wood was converted to char using the Kon-Tiki earth cone kiln. Experimental

conditions as well as results of the proximate analysis of Durian wood and char are summarized

in Table 1. The biochar yields for 1st, 2nd, 3rd and 4th trial were similar ranging from 12.7 to

13.7 wt.% suggesting that mode of quenching had no noticeable effect on the yield. The

observed biochar yield at 600-700°C is consistent with the trend reported by Chowdhury et al.

(2016) (Table 3.1). As the pyrolysis temperature increases thermal decomposition of

lignocellulosic materials occurs starting with hemicellulose (210-320°C), followed by cellulose

(310-390°C) and lignin (200-550°C) (Wu et al. 2009; Brebu & Vasile 2010). The yield depends

upon various operating parameters but generally low temperature and high residence time favor

high char yields (Tripathi et al. 2016).

3.2 Proximate analysis

According to Table 1, proximate analysis of Durian wood reveals a low volatile matter

as well as a high ash and fixed carbon content, which agrees reasonably well with literature

(Chowdhury et al. 2016). Variations between observed and reported values may be due to

different age and growth conditions of the Durian trees, presence of dirt of varying degree on

methods deployed. The volatile matter in Durian biochar was found to be consistently greater

than reported by Chowdhury et al. (2016) despite the use of higher temperatures. The increased

ash content in Durian biochar is a result of devolatilization during pyrolysis (Claoston et al.

2014) as well as presence of soil matter in quench water. However, the ash content can expected

to be even higher since leaching of water-soluble minerals into the quench solution occurred.


203

3.3 pH analysis

The pH is an important property of the soil, which influences the types of plants and

microbes to thrive, and the availability of nutrients to be absorbed. Neutralizing acidic soils by

applying biochar can improve soil quality and increase productivity of crops (Lee et al. 2013).

All four DWB samples as well as quench water were found to be alkaline (Table 1). The quench

water hasvery high pH due to leaching of ash minerals from the DWB. This quench water is

reported to be excellent for pouring on fruit and vegetable plants. It discourages snails and

fungus, acts as tonic to plants (Schmidt et al. 2014). In contrast, pH of soil at Durian farm was

pH 4.41 ± 0.01, which is one to two orders of magnitude lower than the recommended pH of

5.0 and 6.5 for Durian (Chung 2011). The alkaline biochar and quench water can therefore be

used to increase the soil pH, which is conventionally done by liming (Kong et al. 2014).

Table 1: Proximate analysis of Durian wood and Durian wood biochar

3.4 Surface area and pore diameter

According to Schmidt et al. (2014) quenching the charring process from the bottom to

top generates steam that rises upwards, reacting with condensates from the pores of the biochar

resulting in increased pore volumes as well as surfaces area. Table 2 shows that the DWB1-1

and DWB1-2 had a 2-5 times greater surface area (263 and 102.73 m2/g) than bottom-quenched

DWB2-1 and DWB2-2. While the surface area of DWB1-1 and DWB1-2 agrees well with the

Sample Temp

[0C]

Time

[min]

Yield

[%]

MC

[%]

VM

[%]

AC

[%]

FC

[%]

pH

DWS (Chowdhury,

Ashraf, et al. 2016)

- - - 8.07 78.9 9.67 3.38 -

DWBC

(Chowdhury,

Ashraf, et al. 2016)

350

450

550

180

180

180

66.6

41.2

24.5

4.58

3.05

1.57

45.9

22.8

6.77

12.7

18.3

20.8

36.9

55.9

70.9

6.1

6.4

6.8

DWS - - - 4.15 ±

0.02

75.85

±

0.02

14.7±

0.3

9.4±

0.3

-

DWB1-1 600-700 120 12.7 6.8±1.0 15.53

±1.02

11.07

±0.32

73.40

±1.33

8.37 ±

0.01

DWB1-2 600-700 120 13.2 6.00±0 16.0±

0.2

13.33

±0.7

70.67

±0.8

8.56±

0.01

DWB2-1 600-700 100 13.6 8.4±0.7 15.91

±0.75

12.53

±0.85

71.56

±0.97

8.87 ±

0.01

DWB2-2 600-700 90 13.7 8.8±0.9 16.82

±0.7

12.64

±1.0

70.55

±1.6

9.15 ±

0.02

QW1-1 - - - - - - - 12.36±

0.02

QW1-2 12.42±

0.07

QW2-1 - - - - - - - 12.30±

0.03

QW2-2 - - - - - - - 12.26±

0.01

SoilTopFruits - - - - - - - 4.41±

0.01


204

surface area of 289 m2/g reported by Schmidt et al. (2014) the lower values for DWB2-1 and

DWB2-2 are unexpected. More research is required to establish the optimum water flowrate

into the bottom of the Kon-Tiki earth cone kiln which is expected to play a role in the steam

formation process. The BJH pore diameter for DWB1-2 was found to be three times smaller

than DWB1-1, DWB2-1 and DWB2-2 (Table 2) suggesting that structural ordering, pore

widening and/or the coalescence of neighboring pores (Angın 2013) predominate in DWB2.

The average BJH pore diameter classifies DWB as macroporous carbon (> 50 nm) which

makes it suitable for the adsorption of larger molecules such as humic acid (Han et al. 2003).

Table 2: Surface properties of Durian wood and durian wood-derived biochar

Sample BET surface

area

[m2/g]

BJH adsorption

cumulative pore

volume (17 - 3,000 Å)

[cm³/g]

BJH adsorption

average pore

diameter

[Å]

DWS 0.4751 0.429 0.7952

DWB1-1 263 0.0834 65.9

DWB1-2 102.73 0.0543 73.19

DWB2-1 54.2 0.1008 171

DWB2-2 53.0 0.0950 181

3.5 FTIR analysis

This analysis carried out on Durian wood feedstock and biochar samples (Figure 1).

The band assignments for feedstock are summarized in Table 3. The raw feedstock showed 6

strong peaks; a peak at 3351 cm-1 corresponding to different O-H stretch modes commonly

found in phenolics present in lignin (Poletto et al. 2014); a peak at 2923 cm-1 indicative of

conjugated C-H stretch (alkanes); a peak at 1235 cm-1 corresponding to C–N stretch (aliphatic

amines); a peak at 1109 cm-1 corresponding to C–N stretch (aliphatic amines); a peak at 1032

cm-1 indicating the presence of C-O and C-N stretch; a peak at 539 cm-1 corresponded to C-Br

stretch (alkyl halides). No noticeable peaks observed for all three Duran biochars, phenomenon

typically encountered for high-temperature chars (Claoston et al. 2014).

Figure 1: FTIR spectrum of the original durian feedstock and durian wood-derived biochar


205

Table 3: Functional Group of DWB detected by FTIR

3.6 FESEM-EDX analysis of DWS and DWB

The Figure 2 shows representative SEM images of each DWS and all the DWB. These images

proof that the exoskeleton of the woody biomass such as tracheids was still preserved.

Tracheids are the major cell type and provide most of the structural support in softwoods. Their

high surface to volume ratio helps to hold water against gravity, a useful feature of woody

biochar in periods of draught. The exoskeleton texture is also useful for developing the soil

quality by providing habitats for symbiotic microbes and access to root hair of plants.

Figure 2: FESEM images of DWS, DWB1-1, DWB1-2, DWB2-1 and DWB2-2

Wavenumber [cm-1] Bond Functional group

539 C-Br stretch Alkyl halides

1032 C–O stretch

C–N stretch

Alcohols, carboxylic

acids, esters, ethers

Aliphatic amines

1109 C–N stretch Aliphatic amines

1235 C–N stretch Aliphatic amines

C–C stretch (in–ring) Aromatics

2923 C–H stretch Alkanes

3352 N–H stretch

O–H stretch, H–bonded

1˚, 2˚ amines, amides

Alcohols, phenols

DWS DWB1-1 DWB1-2

DWB2-1 DWB2-2


206

The elemental composition of Durian biochar is summarized in Table 4. EDX analysis

revealed that elements C and O predominate followed by Ca, K, Mg, Si, Al, P and S. The

normalized chemical composition of DWB ash is summarized in Table 5, which agrees

reasonably well with the order (CaO > SiO2 > K2O > MgO > Al2O3 > P2O5) and range reported

by Vassilev et al. (2010). Wood and woody fuels commonly show lower values of ash, Cl, K,

N, S, and Si and higher concentrations of C and Ca in comparison with other biomass varieties

(Vassilev et al. 2010). Some metals in the carbon lattice can start to volatilize at ~400°C such

as K (Joseph et al. 2010; Thy et al. 2006). In case of DWB2-1 the K concentration was lowest

of all suggesting that temperature was greatest followed by DWB1 and DWB2-2. This is further

supported by the Oorg/C ratio which is also lowest for DWB2-1 followed by DWB1 and DWB

2-2. The estimated ash content of DWB based on EDX data was 19 % (DWB1-1) to 140 %

(DWB2-1) lower than determined by ASTM D1762-84 (Table 3.1). Based on Thy et al. (2006),

elements such as Na, Fe and Mn are expected to be present in wood but where not measured in

this study. Their oxides often less abundant than Al2O3 (Al2O3 > MnO > Fe2O3 > Na2O) (Thy

et al. 2006) but are of sufficient abundancy to at least partially explain the observed differences.

The presence of Al, Si and O may suggest that clay material from quench water has

attached to the surface of the char which is expected to contribute to improved cation exchange

capacity once the char is placed in the soil. The presence of non-essential aluminium in Durian

wood char may also be attributed to enhanced uptake of this element from soil which has a pH

of 4.41. An increase in the soil pH through addition of biochar or liming can therefore be

expected to result in a decrease in dissolved aluminium in soil pore water as well as Durian

wood. The molar Oorg/C ratio of DWB ranged from 0.09 to 0.18. The low Oorg/C ratios are

further evidence of successful biomass conversion to biochar indicating a greater degree of

aromaticity and stability (Kumar et al. 2013). The DWB also complies with the European

Biochar Certificate V4.8, which prescribes a maximum molar O/C ratio of 0.4.

Table 4: Elemental composition of Durian wood biochar produced in Kon-Tiki earth kiln as

determined by FESEM-EDX

Element DWB1-1

[%-mol]

DWB1-2

[%-mol]

DWB2-1

[%-mol]

DWB2-2

[%-mol]

C 86 ± 6 92.6±0.2 90 ± 2 81 ± 4

O 12 ± 5 6.25±0.20 8.9 ± 1.6 15 ± 1

K 0.41 ± 0.27 0.18±0.02 0.33 ± 0.17 0.57 ± 0.31

Ca 0.60 ± 0.44 0.61±0.08 0.21 ± 0.06 2.0 ± 1.4

Mg 0.29 ± 0.26 0.08 0.15 ±0.05 0.29 ± 0.12

Al 0.17 ± 0.21 - 0.14 0.33 ± 0.19

Si 0.28 ± 0.11 - 0.13 ± 0.01 0.57 ± 0.56

P 0.18 ± 0.08 - 0.11 ± 0.01 0.21 ± 0.11

S 0.09 - BDL 0.07 ± 0.04

Oorg 9.5 ± 3.6 5.37±0.26 7.9 ± 1.3 14.6 ± 1.3

Oorg/C ratio 0.12 ± 0.05 0.06±0.00 0.09 ± 0.02 0.18 ± 0.02

Ash [wt.%] 10 ± 2 3.90±0.5 4.6 ± 1.2 11.6 ± 8.5


207

Table 5: Chemical ash composition normalized to 100 % (wt. %)

3.7 CEC analysis

The CEC properties decreased with successive increase of temperature. The reduction

of CEC value may be reduction of oxygen containing functional group (Chowdhury, Ashraf,

et al. 2016). Top quenched biochar CEC was 2.4-9.3 times greater than from other two trials.

The soil appears to be of low fertility comparable to. Adding top quenched biochar to

this soil will theoretically enhance its fertility by at least 0.8-4.6%. Higher CEC value can be

formed by two mechanisms; by a higher charge density per unit surface area which means a

higher degree of oxidation of SOM and by a higher surface area for cation adsorption sites, or

a combined effect of both. Black carbon enrichment assumed to be the main contributor to the

higher CEC (Liang et al. 2006).

The CEC value of DWB1-2 in Table 6 showed highest values compared to other trials,

24.11meq/100g.The reduction of CEC values as observed for DWB2 may be due to reduction

of oxygen containing functional groups (Chowdhury, Ashraf, et al. 2016). With increasing

pyrolysis temperature, the CEC values and O/C and H/C ratios were decreasing (Chowdhury,

Ashraf, et al. 2016).

Table 6: Cation exchange capacity of Durian wood charcoal and soil

S.I System: meq/100g=10mmolc kg-1

4 CONCLUSION

The Kon-Tiki earth kiln was able to convert Durian wood to biochar with a yield of 12 –

14 wt. %. The pH of the biochar was alkaline with a volatile matter content of < 17 wt. %

suggesting long-term stability in soil. No functional groups where present on the biochar

surface as evidenced by FTIR, a typical feature of high-temperature biochars. The Oorg/C ratio

of all biochars was found to be well below the value of 0.4 recommended in the EU biochar

guidelines. Quenching of biochar with water from the top resulted in a biochar with a 2-5 times

DWB1-1 DWB1-2 DWB2-1 DWB2_2 DWS

K2O 17.8% 10.1% 20.4% 5.6% 16.5%

CaO 42.4% 68.7% 25% 40.6% 30.7%

MgO 9.8% 2.8% 20.50% 6.1% 0.00%

Al2O3 7.8% 18.5% 4.96% 9.4% 52.8%

SiO2 12.5% 0.0% 14.2% 19.4% 0.00%

P2O5 9.70% 0.0% 14.99% 18.8% 0.00%

Sample/Trial Unit:

meq/100g

Unit:

mmolc kg-1

DWB1-1 11.31 113.1

DWB1-2 24.11 241.1

DWB2-1 1.21 12.1

DWB2-2 4.70 47.0

Soil 5.88 58.8


208

greater BET (N2) surface area of 263(DWB1-1) and 102.73(DWB1-2) m2/g than bottom-

quenching. The average BJH pore diameter was found to be > 50 nm suggesting the biochar to

be macroporous. Potassium, calcium, magnesium, aluminium, silicon and phosphorous were

the main constituents of the biochars. It is recommended to test the effect of quench water

flowrate on the activation of Durian wood biochar. Future EDX analysis should include Na, Fe

and Mn for a more complete characterization of the ash composition.

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DO DURIAN WOOD BIOCHAR AND LIQUID FISH

FERTILIZER AFFECT DURIAN PLANT GROWTH

(DURIO ZIBETHINUS L.) IN PEAT MOSS? - A

HORTICULTURAL NURSERY STUDY

Sharifah Adawiyah1, Thilagam Krishnan1,2, Benson Khoo2, Tan Sue Sian2, Trevor

Richards3, Robert Thomas Bachmann1*

1 Universiti Kuala Lumpur, Malaysian Institute of Chemical and Bioengineering Technology, Lot 1988, 78000

Alor Gajah, Malaysia. 2 Top Fruits Sdn. Bhd.

3 Environmental engineering consultant, Kuala Lumpur

Author Email : [email protected]

ABSTRACT

Durian fruits are commercially grown in Southeast Asia. After 80 - 150 years the trees are cut

and replanted with seedlings from nurseries. Instead of loamy sandy soils some nurseries start

to use peat moss due to its superior water holding capacity, light weight and possibility to

export the seedlings. Research has also shown positive effects of biochar addition to

mineral nursery soil on plant growth while also acting as carbon sink to mitigate global

warming. This project seeks to clarify whether Durian wood biochar (DWB) as well as liquid

fish fertilizer (LFF) have a beneficial effect on Durian plant growth in peat moss, and

also identify the best plant growth monitoring parameter. Biochar was produced from Durian

wood logs in a top-quenched Kon-tiki earth kiln, crushed and mixed with peat moss at dosages

of 0, 1, 2.5 and 5 wt-%. The plant height, steam diameter, pH, moisture content, number of

branches and leaves as well as leaf colour were monitored weekly. Data were inspected for

outliers and omitted if justified. Results show that plant height increased at a linear rate ranging

from 2.8 ± 0.6 (2.5 % biochar + LFF) to 6.2 ± 1.5 mm / d (1 % DWB + LFF) (R2 > 0.96) for

the first 11 to 41 days. Similarly, stem diameter grew linearly for the first 9 to 48 days at a rate

ranging from 88 ± 39 (1 % DWB) to 303 ± 119 m/d (2.5 % DWB) (R2 > 0.789). No

statistically significant effect of biochar and/or fertilizer was found compared to control

(p<0.05). pH of peat moss varied between 6.2-6.5. Number of leaves and branches increased

but no statistically significant difference between treatments and control was observed

(p<0.05). No statistically significant difference in plant health was found between control and

biochar and/or LFF treatment. Results suggest that peat moss provides a conducive

environment for Durian plant growth in terms of nutrients, water holding capacity, pH and

porosity. The use of biochar and LFF in peat moss therefore appears to be redundant at the

early nursery stage. According to the correlation coefficient plant height is the more accurate

monitoring parameter. It is recommended to compare the growth of Durian seedlings in loamy

soil to peat moss with and without biochar, as well as the number of times the potting medium

can be reused to help cut nursery cost.

Keywords: Durian wood biochar, peat moss, organic fertilizer, seedling growth


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1 INTRODUCTION

The durian fruit is widely known in Southeast Asia as the “king of fruits”. It is unique for its

large size, odour and formidable thorn-covered husk (Gunasekera, 2006). The lifespan of

Durian trees is about 80 to 150 years even though they appear to be inherently capable of living

for centuries. It takes the Durian fruit about 110-120 days from flowering to harvest, while the

yield decreases in very old trees though the fruit quality tends to noticeably increase with age

(Gunasekera, 2006). Durian trees can be propagated by seeds (Gunasekera, 2006) or bud-

grafted onto 1 year old rootstocks of the same species (Council, 2002). Durian trees grown

from seeds begin to bear fruits after 8-10 years, while grafted trees begin to produce fruits 4

years earlier (Morton, 1987). Morton (1987) reported that best growth is achieved on deep

alluvial or loamy soil. Effect of soil modifiers such as zeolite or biochar on durian plant growth,

health and yield have not been explored so far.

Biochar, a carbonised form of biomass, has received increased attention in the past

decade due to its positive effects on low fertility agricultural soils as it may increase water-

holding capacity, reduce the bulk density and provides additional cation exchange sites (Matt,

2015) while also locking up carbon to help mitigate global warming (Woolf, Amonette, Street-

Perrott, Lehmann, & Joseph, 2010). Biochar amended soils have reported positive interactions

between biochar and application of N and P fertilizer on plant growth, which were attributed

to reduced leaching and hence more efficient use of applied nutrients (Conversa, Bonasia,

Lazzizera, & Elia, 2015). Biochar also affects soil pH which may immobilise or enhance the

solubility of beneficial ions depending on the pH (Matt, 2015).

The durian seeds loose their viability quickly (Council, 2002), although Morton (1987)

reported that they have been successfully shipped to tropical America when packed in a barely

moist mixture of coconut husk fiber and charcoal. Selection of proper media components is

critical to the successful growth of plants at the horticultural stage and is largely dependent on

the chemical and physical properties of the potting media (Robbins, 2013). A suitable potting

medium should be free of weeds and diseases, dense enough to avoid frequent tipping over and

light enough to ease handling and shipping. Other parameters to consider include cost, the

availability, consistency between batches and stability in the media over time (Robbins, 2013).

In nursery and greenhouse mixes, the usage of peat is common. Peat included in a soil mix

helps to increase the water-holding capacity and/or decreases the weight. Peats used in

horticulture are usually classified into three types: peat moss, reed-sedge and peat humus

(Robbins, 2013). Peat moss is the most common form used and is derived mostly from

sphagnum moss. It is the least decomposed form of the peat types, typically light tan to brown

in colour, lightweight (104 kg/m3), high in moisture-holding capacity and acidic (pH 3.8 to 4.3)

(Robbins, 2013). Usage of soil is still occasionally encountered in a container mix primarily

because it is locally available or to add weight to a predominantly organic-based mix. Some

outdoor nurseries strip the topsoil in preparation for installing container beds, stockpile the soil

and then use it over time as a minor component (e.g. 10 %) in the mix. Major considerations

when using soil would be the amount of weed seed and presence of residual chemicals

(Robbins, 2013).

For fertilization of young grafted plants, Morton (1987) recommended monthly

feedings of about 5 g of a 6-6-6 fertilizer formula. However, no systematic studies are available

in scientific literature seeking to establish the best type and composition of fertilizer for durian

plant cultivation in horticulture nurseries. At Top Fruits Sdn Bhd, an in-house liquid fish


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fertilizer (LFF) has been developed and used for horticultural purposes in durian nurseries with

mineral soil, but its effect on plant growth has not been quantified while its performance in

peat is unknown.

In an attempt to cut cost, Conversa et al. (2015) investigated the effect of partial

substitution of peat with biochar on Pelargonium growth. The biochar was produced from

Abies alba wood in a pyro-gasifier at 1000-1100°C, and found to be alkaline (pH 10.7) with a

carbon content of 79 wt.-% and a cation exchange capacity of 32.4 cmol / kg. For the peat :

biochar ratio of 70:30 (v/v) in combination with a fertilizer, the authors observed that the

nitrogen and chlorophyll leaf concentrations, as well as leaf and flower numbers were enhanced

possibly due to improved fertilizer retention. In another study Graber et al. (2010) examined

the impact of 1–5 wt.-% additions of a nutrient-poor, wood-derived biochar on pepper

(Capsicum annuum L.) and tomato (Lycopersicum esculentum Mill.) plant development and

productivity in a coconut fiber : tuff potting mix under optimal fertigation conditions. Biochar

was found to increase plant height and leaf size for both plants, whereas only fruit yield for

pepper was positively enhanced. The improved plant performance under biochar treatment was

proposed to be due to either (i) biochar induced shifts in microbial populations towards

beneficial plant growth promoting rhizobacteria or fungi; or (ii) stimulation of hormesis due to

low doses of biochar chemicals, many of which are biocidal or phytotoxic at elevated

concentrations. Major et al. (2010) investigated the effect of a wood biochar addition to

isohyperthermic kaolinitic Typic Haplustox soil on maize grain yield over a four year period

and observed a gradual increase with time with no increase in first cropping season. While the

authors did not explain the reason behind the first year indifference in yield it may be

hypothesized that addition of fresh biochar not only retained the applied fertilizer more

effectively but also immobilised a fraction similar in magnitude to the quantity otherwise lost

due to leaching. Over time the surface of the biochar becomes colonised with soil microbiota,

coated with humic acid and clay colloids as well as chemically oxidised, all of which may

contribute to greater retention of bioavailable nutrients and hence improved plant growth.

For durian horticulture, little is known about the effect of biochar and LFF in peat moss

potting medium on Durian seedling growth. In this research we therefore seek to establish

whether addition of Durian wood biochar (DWB) produced in a top-quenched Kon-tiki earth

kiln and LFF provides additional benefits to plant growth and health at nursery level. In

addition we aim to identify whether plant height, stem diameter, number of branches or leaves

is the best growth indicator for Durian plants.


2.1 Durian wood biochar production

Durian wood biochar was produced in a Kon-tiki earth kiln at Top Fruits Sdn Bhd build

according to Schmidt et al. (2014) with following modifications. The side wall of the kiln was

coated with concrete, while a metal grid was installed about 30 cm above the kiln bottom to

allow char particles to drop down. Durian wood logs of 5 to 10 cm in thickness and 30 to 40

cm in length without removing the bark were stacked and ignited as recommended by Schmidt

et al. (2014). Towards the end of the process the DWB was quenched with 250 L of tap water

from the top. After soaking for 12 hrs the DWB was collected and air dried for 3 days. Prior to

use in nursery trials DWB was crushed.


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2.2 Characterisation of DWB

Proximate analysis was carried out in accordance with ASTM D1762-84 for moisture content,

volatile matter and ash content. All analyses were performed in triplicate and the mean value

and standard deviation calculated. Cation exchange capacity (CEC) was identified at MARDI

(Malaysia) using the leaching method (Ahmed et al., 2012). BET (N2) surface area was

determined with a Micromeritics ASAP2020 at Quantum Skynet Sdn Bhd (Malaysia) using

low-temperature N2 physisorption isotherms.

2.3 Durian seedling preparation and germination

Durian seedlings of the Kampong variety were collected from Top Fruits Sdn. Bhd. (Malaysia),

washed with clean water to remove the sugar that may otherwise increase the chances of fungi

attacking the seeds. Seeds that were floating on the wash solution were rejected. They were

then soaked for 15 min in a 2 wt-% chitosan suspension (Leili Marine Bioindustry Inc.) to

prevent the seeds from fungal, bacterial and viral infection and air-dried for 1 day. The air-

dried seeds were placed in perforated plastic trays containing peat moss (Free Peat B. V.) and

positioned in a rainshelter at UniKL MICET under shading. Peat moss was watered twice a

day with tap water to prevent the seed skin from drying out which can affect germination. After

6 weeks the germinated seeds were transplanted to individual polybags filled with peat moss

only (PM only), peat moss plus liquid fish fertilizer (PM + LFF), as well as various DWB

applications (1, 2.5 and 5 wt.-%) with (PM + 1 / 2.5 / 5 % DWB + LFF) and without LFF (PM

+ 1 / 2.5 / 5 % DWB). Plants were watered twice a day and 100 mL liquid fish fertilizer (Top

Fruits Sdn. Bhd.) added to selected treatments once a week as recommended by Top Fruits Sdn

Bhd. Experiments were carried out with four replicates per treatment.

2.4 Plant growth monitoring

Plant growth was monitored on a weekly basis in terms of plant height (Figure 1a), stem

diameter (Figure 1b), number of branches and leaves, and leaf colour. Peat moss pH and

moisture were determined using a DM15 Soil Tester (Takemura Soil pH & Moisture Meter

DM15). A 9 colour chart developed at Top Fruits Sdn Bhd was used to determine the colour

of 3 leaves per plant with green indicating healthy growth to brown indicating a dead plant.

Plant height and stem diameter growth were determined by plotting the height or diameter over

time in a spreadsheet and extracting the slope from the linear trendline equation.

(a)

(b)

Figure 9: Height (a) stem diameter (b) Durian plant grown in polybag measurement


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2.5 Statistical analysis

Continuous data from height and stem diameter monitoring were analysed for effect of

treatment using one way ANOVA and post hoc Tukey’s test using Excel. Ordinal data (number

of leaves, branches and leaf colour) were examined for treatment effects using the Kruskal-

Wallis test followed by Nemenyij’s post hoc test if results were found to be statistically

significantly different at the p<0.05 level.


3.1 Biochar characteristics

The physico-chemical characteristics of DWB are summarised in Table 1. Volatile matter was

low as expected for biochars produced at high temperatures. The pH of DWB was alkaline

while the BET (N2) surface area was found to be 295 m2/g which, combined with a CEC of

17.7 meq/100 g, is considered to be promising soil modifier.

Table 1: Process conditions and Durian wood & DWB physico-chemical properties

Samples DWS DWB

Temp [0C] - 600 – 700 Time [min] - 120 Yield [%] - 12.9 ± 0.2 MC [%] 4.15 ± 0.02 7.7 ± 1.7 VM [%] AC [%] FC [%]

pH BET (N2) [m2/g]

75.85 ± 0.02 14.7 ± 0.3 9.4 ± 0.3

N/A 0.48

13.5 ± 2.5 12.8 ± 0.5

65 ± 5 8.37 ± 0.01

295 ± 31 CEC [meg/100g] N/A 17.7 ± 7

3.2 Soil pH and moisture

The initial potting media pH was found to vary between pH 6.1 to 6.5. The application

of LFF in week 1 slightly reduced the peat moss pH from pH 6.2 ± 0.0 to pH 6.1 ± 0.0 (p>0.05)

whereas addition of alkaline DWB to PM was found to increase the pH from pH 6.2 to pH 6.5

(p<0.05). The pH of PM supplemented with DWB and LFF showed a pH of 6.3 which was not

statistically significantly different to PM. However, after 7 weeks no differences in pH between

treatments was observed (p>0.05) probably due to exhaustion of the liming capacity of DWB.

Peat moss moisture varied between 2.5 and 3.0 indicating that the potting media was

sufficiently and equally moist.

3.3 Effect of treatment on plant height growth

Plant height was found to increase linearly at two stages with stage one growth taking

place for the first 11 to 41 days at a rate of 2.79 to 6.15 mm / d (Figure 2, Table 2). No

statistically significant effect of DWB and LFF alone and in combination compared to control

(peat moss only) was found, while a statistically significant difference between 2.5 % DWB +

LFF and 1 % DWB + LFF as well as 5 % DWB + LFF and 1 % DWB + LFF was observed (p

< 0.05). However, these latter differences may be explained by the initial conditions of the trial


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were plant height between these treatments was also statistically significantly different (Table

2, Figure 2). In future nursery trials it is recommended to use plants of similar height for all

treatments to help identify genuine treatment effects.

Figure 2: Effect of DWB and LFF on plant growth in meat moss in horticultural nursery trials

Table 2: Effect of LFF and DWB on Durian plant growth at nursery stage

Treatment

Initial height [cm]

Final height (45d) [cm]

Height growth [mm/d]

Linear growth duration (stage

1) [d] R2 [/]

PM only 32±2a 45±4a 4.95±1.33 24±10 0.992 PM + LFF 40±3bcde 51±5bcde 3.90±0.74 24 ± 6 0.984 PM+ 1 % DWB 33±5f 48±5fk 4.29±0.93 32 ± 9 0.981 PM+ 2.5 % DWB 25±3bg 38±5bg 3.89±0.77 30±11 0.986 PM+ 5 % DWB 25±3ch 37±6ch 3.92±1.63 32 ± 9 0.988 PM+ 1 % DWB +LFF 37±2ghij 52±2ghij 6.15±1.52ab 20 ± 9 0.980 PM+ 2.5% DWB +LFF 27±7di 35±5dik 2.79±0.57a 30±11 0.958 PM+ 5% DWB+LFF 19±1aefj 28±5aefj 3.57±0.05b 25±14 0.991

3.4 Effect of treatment on increase of stem diameter

Stem diameter increased linearly (R2 > 0.79) for the first 15 to 40 days at a rate of 88

to 303 µm / d (Table 3). A statistically significant difference was found between ‘2.5 % DWB’

and ‘LFF’ treatment, ‘2.5 % DWB’ and ‘1 % DWB’ as well as ‘1 % DWB + LFF’ and ‘LFF’

or ‘1 % DWB’. In contrast to initial plant height, initial stem diameters did not vary between

treatments on a statistical level (Table 3). However, comparing the stem diameter after 45 days

of growth in polybags with stem diameter growth different trends were found. This may

partially be due to goodness of fit of data to the linear growth model. It is therefore

recommended to discontinue using stem diameter monitoring in future nursery trials.

15

25

35

45

55

0 20 40 60

Pla

nt h

eig

ht [c

m]

Time [d]

PM only

PM + LFF

PM +1% DWB

PM +2.5% DWB

PM +5% DWB

PM +1% DWB + LFF

PM +2.5% DWB + LFF

PM +5% DWB + LFF


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Table 3: Effect of LFF and DWB on steam diameter of Durian in nursery trials

Treatment

Initial stem

diameter

[mm]

Final stem

diameter

(45d) [mm]

Stem diameter

growth

[µm/d]

Linear

growth

[d]

R2

[/]

PM only 3.5±0.6 7.0±0.8a 165±64 25±16 0.962

PM + LFF 4.0±0.8 8.8±1.7 120±34ab 40±11 0.887

PM+BC 1% 3.8±1.0 8.3±1.9 88±39cd 29±19 0.789

PM+BC 2.5% 2.5±0.6 8.5±1.3 303±119ad 15±4 0.979

PM+BC 5% 2.8±0.5 7.0±1.8b 147±76 29±11 0.911

PM+BC 1%+LFF 3.8±1.0 11.0±1.6abc 285±41bc 20±7 0.932

PM+BC 2.5%+LFF 3.5±1.0 9.5±0.6 240±64 23±9 0.925

PM+BC 5%+LFF 2.8±0.5 7.3±1.3c 199±91 23±16 0.911

3.5 Effect of treatment on number of branches, leaves and plant health

Number of branches and leaves increased over time but in an irregular pattern. No

statistically significant differences after 45 days of growth were observed between treatments

(p < 0.05) (Table 4). Leaf health monitoring revealed that treatment had no significant effect

compared to control. However, addition of 1 % DWB appeared to have a detrimental effect on

plant health compared to ‘LFF’ and ‘5 % DWB + LFF’ treatment (Table 4). This effect could

not be replicated at higher DWB dosages. Additional experiments with more replicates are

therefore required to verify the observation reported here.

Table 4: Effect of LFF and DWB on number of branches, leaves and leaf colour of Durian

plants grown at nursery level

Treatment

Sum of ranks

for nbranch

(45d)

Sum of ranks for

nleaves (45d)

Sum of ranks for

leaf colour (45d)

PM only 82.5 85 47

PM + LFF 58 54 29.5a

PM+BC 1% 93.5 87 112ab

PM+BC 2.5% 76.5 96.5 101

PM+BC 5% 60.5 48.5 70

PM+BC 1%+LFF 87 79 56

PM+BC 2.5%+LFF 36.5 53.5 80

PM+BC 5%+LFF 29 23.5 32.5b

4 CONCLUSION

DWB produced in Kon-tiki earth kiln is an alkaline, high surface area, low volatile matter

biochar which can be expected to possess long term stability in soil. The pH and moisture of

peat moss for durian plant growth was stable and within the recommended range for durian


217

plant. Furthermore, peat moss appeared to provide a conducive environment for durian plant

growth. The plant height and stem diameter increased linearly for the first 11 to 41 as well as

9 to 48 days, respectively. However, no statistically significant effect of biochar and fertilizer

compared to control was found suggesting that DWB needs to undergo additional aging

process. The number of leaves and branches increased with time but showed no statistically

significant difference between treatments and control. The comparison between treatment and

control for leaves health also shows no significant effect, while the 1 % DWB revealed an

apparent detrimental effect on plant health compared to ‘LFF’ and ‘5 % DWB + LFF’

treatment. However this difference may be due to the use of plants of non-standardised height

at start of the trial. It is therefore recommended to use plants of similar height for all treatments

at the start of experiment to identify genuine treatment effects.

REFERENCES

Ahmed, O.H., Rosliza, S., Susilawati, K., Nik Muhamad, A.M. and Jalloh, M.B. (2012). Effect

of N, P and K Humates on Dry Matter of Zea mays and Soil pH, Exchangeable Ammonium

and Available Nitrate. African Journal of Biotechnology,11(40): 1684-5315.

Conversa, G., Bonasia, A., Lazzizera, C., & Elia, A. (2015). Influence of biochar,

mycorrhizal inoculation, and fertilizer rate on growth and flowering of Pelargonium

(Pelargonium zonale L.) plants. Frontiers in Plant Science, 6(June), 429.

http://doi.org/10.3389/fpls.2015.00429

Council, N. R. (2002). Underexploited tropical plants with promising economic value. New

York: The Minerva Group.

Graber, E. R., Meller Harel, Y., Kolton, M., Cytryn, E., Silber, A., Rav David, D., … Elad,

Y. (2010). Biochar impact on development and productivity of pepper and tomato grown in

fertigated soilless media. Plant and Soil, 337(1–2), 481–496. http://doi.org/10.1007/s11104-

010-0544-6

Gunasekera, D. L. (2006). Durian -The King Of Fruits In Southeast Asia.

Major, J., Rondon, M., Molina, D., Riha, S. J., & Lehmann, J. (2010). Maize yield and

nutrition during 4 years after biochar application to a Colombian savanna oxisol. Plant and

Soil, 333, 117–128. http://doi.org/10.1007/s11104-010-0327-0

Matt, C. P. (2015). an Assessment of Biochar Amended Soilless Growing Media for the

Nursery Propagation of Rocky Mountain Native Plants.


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Morton, J. F. (1987). Durio zibethinus L. In J. F. Morton (Ed.), Fruits of Warm Climates. (pp.

287–291). Miami, FL. Retrieved from

https://www.hort.purdue.edu/newcrop/morton/durian_ars.html

Robbins, J. ; (2013). Growing Media for Container Production in a Greenhouse or Nursery.

Schmidt, H., Taylor, P., Eglise, A., & Arbaz, C.-. (2014). Kon-Tiki flame curtain pyrolysis

for the democratization of biochar production. The Biochar Journal, 14–24. Retrieved from

http://www.biochar-journal.org/itjo/media/doc/1437139451142.pdf

Woolf, D., Amonette, J. E., Street-Perrott, F. A., Lehmann, J., & Joseph, S. (2010).

Sustainable biochar to mitigate global climate change. Nature Communications, 1(5), 56.

http://doi.org/10.1038/ncomms1053


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BIODIESEL PRODUCTION FROM USED COOKING OIL

(UCO): THE IDENTIFICATION OF POTENTIAL

ENVIRONMENTAL IMPACT

Khairul Nadiah Ibrahim1, Zaida Rahayu Yet2, Nor Aini Burok2, and Sivanesan

Krishnan2

1Section of Environmental Engineering Technology, Universiti Kuala Lumpur Malaysian Institute of Chemical

& Bioengineering Technology 78000 Alor Gajah, Melaka, MALAYSIA. Email: [email protected] 2Section of Chemical Engineering Technology,Universiti Kuala Lumpur Malaysian Institute of Chemical &

Bioengineering Technology 78000 Alor Gajah, Melaka, MALAYSIA.Email: [email protected],

[email protected], [email protected]

ABSTRACT

Increasing uncertainty about global energy production and supply, environmental concerns due to the use of fossil fuels, and the high price of petroleum products are the major reasons to

search for alternatives to petrodiesel. In this perspective, considerable attention has been given towards the production of biodiesel as a diesel substitute. Biodiesel fuel has become more

attractive because of its environmental benefits due to the fact that plants and vegetable oils and animal fats are renewable biomass sources. Nevertheless, the selection of appropriate

technology for production of biodiesel calls for careful selection of processing steps, catalyst

and downstream process integration. The life cycle analysis of biodiesel production from used cooking oil (UCO) in this study involves 5 stages. They are namely; preparation of UCO,

pretreatment of UCO, blending, washing, and filtration. The production process consists of several different approaches. An investigation was conducted on the environmental

performance of the chemically catalyzed process by using life cycle analysis (LCA). Transesterification method in the production of biodiesel was seen to potentially contributing

to all environmental impacts under damage assessment categories, which are human health, ecosystem quality and also natural resources. Electricity among others is found to be the input

significantly contributing to the environmental impacts. Other inputs that are also seen to

potentially contribute an adverse impact to the environment including methanol, glycerin, and sodium hydroxide solution, which are used in biodiesel production. Suggestions were included

in the study towards biodiesel production of less environmentally damaging impact.

Key Words: Biodiesel; Life Cycle Analysis (LCA); Transesterification, Damage assessment.

1. INTRODUCTION

Extreme weather changes due to global warming and declining crude oil deposits have

prompted the exploration of environment-friendly and renewable fuel source. These renewable fuel sources can possible be alternatives to petroleum based fuels include alcohol, biogas,

biodiesel and vegetable oil. The potential environmental benefits that can be obtained from replacing these petroleum fuels with biofuels and bioenergy derived from renewable biomass

sources are the main driving forces for promoting the production and use of biofuels and bioenergy. It is blended with diesel fuel derived from crude oil to reduce the proportion of CO2




220

attributed to the fossilfuel when the mixture is burnt. Biodiesel can also decrease other

emissions characteristic of normal diesel fuel, such as particulates and SOx (Harding et.al, 2007). Pogaku (2012) reported that biodiesel reduces net carbon dioxide emissions by 78% and

it has also been shown to have dramatic improvements on engine exhaust emissions.

Combustion of neat biodiesel decreases carbon monoxide (CO) emissions by 46.7%,

particulate matter emissions by 66.7% and unburned hydrocarbons by 45.2%. It is also identified from a study of biodiesel from used cooking oil (UCO) as an alternative fossil diesel,

in Australia. Where the advantages are substantial especially in the area of energy security, waste, recycling and greenhouse gas control (Wang, 2013). UCO was also reported to be able

to reduce the cost of biodiesel production (Canakci, 2007). Nevertheless, despite all proven

advantages of biodiesel, a vital requirement for biofuels to be a sustainable alternative fuels is that, it should be produced from renewable feed stock with a lower negative environmental

impact and preferably inexpensive (Connemann et. al, 1998). Consequently a study is needed in order to infer whether above requirements are met. Since the assessment of environmental

impacts is quite subjective. Therefore, one of the tools that can be employed to help answer this issue is life cycle analysis (LCA).

There is a broad agreement in the scientific community that LCA is one of the best

methodologies for the evaluation of the environmental burdens associated with biofuel production, by identifying energy and materials used as well as waste and emissions released

to the environment; moreover it also allows an identification of opportunities for environmental improvement (Consoli et. al, 1993, Lindfors et. al, 1995). LCA method has

been found to be suitable for evaluating the environmental impact of biodiesel produced from vegetable oils by Tan et. al, 2004. It is a wellknown tool for performing the evaluation of a

product environmental impacts throughout its life cycle, from a cradle-to-grave approach.

The purpose of this study is to determine the potential environmental impact for

biodiesel production, using used palm oil as raw material. Using LCA, this study aims to

quantify the interactions with the environment across all stages of the life cycle of palm based used cooking oil, in terms of inputs of energy and natural resources. The study has been carried

out in accordance with the ISO 14040 series on LCA (ISO-14040, 2006; ISO-14044, 2006). This analysis includes assessing energy inputs, greenhouse gas emissions, acidification

potential and land use change environmental impacts.

2 . CONCEPTIAL FORMAT OF LCA

According to the ISO 14000 series (14041-43), the technical framework for the LCA

methodology as it is defined in ISO 14040 consists of four phases: (1) goal and scope definition; (2) inventory analysis; (3) impact analysis; and (4) interpretation (ISO, 2006).

Defining the goal and scope involves defining purpose, audiences and system boundaries. Secondly, the life cycle inventory involves collecting data for each unit process regarding all

relevant inputs and outputs of energy and mass flow, as well as data on emissions to air, water and land. This phase includes calculating both the material and the energy input and output of

a building system. Thirdly, the life cycle impact analysis phase evaluates potential

environmental impacts and estimates the resources used in the modelled system. This phase consists of three mandatory elements: selection of impact categories, assignment of life cycle

inventory results (classifications) and modelling category indicators (characterization).


221

Classification of the life cycle inventory results involves assigning the emissions, wastes

and resources used to the impact categories chosen. The converted life cycle inventory results are aggregated into an indicator result, which is the final result of the mandatory part of a life

cycle impact analysis. Normalization, grouping, weighting and additional life cycle impact analysis data quality analysis are excluded, since they are optional elements and according to

the objective of the study, they would not provide any extra useful information (Harding et. al, 2007, Jeganathan et.al, 2010).

Finally, the last stage of ISO 14040 is the interpretation. This stage identifies significant issues, evaluates findings to reach conclusions and formulate recommendations. The final

report is the last element to complete the phases of LCA according to ISO 14040. Regarding

methodology, various LCA tools have been developed and made available for use in environmental assessment.

2.1 Goal and scope definition

The first phase of LCA is to define goal and scope, which are equivalent to objective and the

boundary of work to be performed. The objectives of this study are to analyze the different processes that comprise biofuel production suitable for consumption; determine the flow of

matter and energy; and establish and quantify the environmental impacts caused by different

inputs throughout the production process. In this study we have established that the LCA is done from the sample preparation until biodiesel is obtained.

2.2 Functional unit (FU)

The functional LCA unit chosen is 200ml of biofuel.

2.3 System boundary

The system has been divided into 6 phases, which are those that make the process of producing

200ml of biofuel. In this study, the system boundary is shown as Figure 1. Various substances, materials and energy become part in each of these processes which are detailed below in the

inventory analysis. As for the boundaries of the system it has been considered that biofuel production from the sample preparation until biodiesel is ready for use.

Figure 1: System boundary for biodiesel production.

System

boundary

Sample handling ( UCO collection and

storage )

Sample preparation

Biodiesel production Biodiesel use


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2.4 Life cycle inventory analysis

Life cycle inventory includes input data for the production phases of each principal process

for the production of biodiesel. The input and output inventory of biodiesel production from used cooking oil is shown in Figure 2.

Table 1 shows the material and energy obtained when performing the inventories for the production of biodiesel using the different processes. LCI was obtained from the data which

has been recorded from the inputs for the transesterification process of used cooking oil to synthesize biodiesel. Primary inputs which have been identified used cooking oil, electricity,

ethanol, sodium hydroxide (NaOH), glassware, filter paper, tap water, and gloves.


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Table 1 Material and energy inventory data for biodiesel from UCO

Type of nanoparticles Quantity

Used cooking oil 300 ml

Electricity 2.957 kWh

Methanol 50 ml

Sodium Hydroxide Pellets

(NaOH)

12 g

Filter Paper 10.37 g

Tissue Paper 43.45 g

Glove (22 pairs) 148.06 g

Water 20 L

2.4.1 Preparation of used cooking oil

Used cooking oil or waste oil collected from the household or restaurants is another raw

material which is an effective way to reduce the raw material cost for biodiesel production. It is reported that approximately 70-95% of total biodiesel production cost arises from the cost

of raw material; that is, vegetable oil or animal fats (Conneman et. al, 1998). Using used cooking oil as a raw material is estimated that the raw material cost can be reduced about half

the price of vegetable oil (Supple et. al, 1999). Furthermore, it could also solve the problem

of waste oil disposal. In this study palm oil based-used cooking oil was collected from the household. Palm based oil was chosen because Malaysia produced more than 90% of world’s

export (Tarmizi et. al, 2007). The oil was re-used for 3 times to fry chicken. The collected oil was brought to the lab and filtered to remove any unwanted residue and solid precipitate that

will affect the smoothness of blending method. UCO was dried by using microwave oven at 60oC for 10 minutes. This process was done to eliminate moisture in the UCO because

moisture content will affect the yield of biodiesel.

2.4.2 Titration method

Titration method was done in order to determine the required amount of catalyst to neutralize

the acid. The titration method starts with preparation of the reagent by using the sodium

hydroxide (NaOH) with 0.1N, phenolphthalein as an indicator, 1.0% neutralize of isopropanol. The preparation of neutralized isopropanol is by placing 50ml of isopropanol in

a beaker with 5g of UCO and boiled on a hot plate set at 40oC. Solution was shaken and added with 0.5ml of phenolphthalein and neutralized by dropwise addition of 0.1N NaOH till a faint

permanent pink colour was obtained and let set for 30 seconds. Amount of NaOH used was then recorded.

2.4.3 Blending method

Palm oil was weighted and heated to temperature 80oC on the hot plate. Ethanol was mixed

well into NaOH to produce sodium ethoxide. Sodium ethoxide was poured into the heated oil. Then the mixture was then stirred and heated for 20 minutes until the colour of the mixture

changed.


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2.4.4 Separation method

Mixture was placed in the separation funnel to allow it to settle for several hours. Density factor resulted two different phases, heavier glycerol at the bottom and lighter biodiesel float

on top of the glycerol.

2.4.5 Washing method

Washing method was done to wash the heterogeneous mixtures, which are ester, and glycerol

by using distilled water with the same amount of oil. The purpose of this step is to remove soap presented in the mixture as well as excess catalyst or alcohol since sodium hydroxide

and ethanol are soluble in water and not in oil (William, 2004). Water was added drop by drop

and stirred slowly to prevent soap formation. When layer was apparent, the byproduct was released out by opening the separation funnel valve for a few minutes until only biodiesel left

in the separation funnel.

2.4.6 Filtration method

This method was conducted in order to get the pure biodiesel from the transesterification

process. The unwanted glycerol was trapped onto the filter paper and removed. Biodiesel was then collected as a filtrate.

3. RESULTS

3.1 Life Cycle Impact Assessment

SimaPro v8 software program developed by PRé Consultant from Netherlands is used to

create the model of Life Cycle Impact Assessment for alkali catalyzed biodiesel production. Eco-indicator 99(E) methodology which includes the impact categories into three types of

damage: “Damage to human health, which includes the following categories of impacts: carcinogenesis, organic respiratory effects, inorganic respiratory effects, climate change,

ionizing radiation, and reduction of the ozone layer. Damage to ecosystem quality: ecotoxicity, acidification/eutrophication, and land use. Resource damage, including: minerals

and fossil fuels. More specifically, the environmental impacts of cultivation and harvesting,

drying and extraction procedure were evaluated.

The unit used for carcinogens, respiratory organics,climate change, radiation, ozone layer is DALY (Disability Adjusted Life Years); for ecotoxicity, acidification/eutrophication,

land use is PDF (Potentially Disappeared Fraction of Plant Species); for minerals and fossil fuel is MJ (Mega Joule, surplus energy requirement to compensate lower future ore grade).

For Eco-indicator 99 method,“E” refers to the weighting set belonging to the egalitarian perspective. Egalitarian is preferred due to the long term perspective of the assessment and

the valuation of all substances and impact categories are equal. Of all the steps defined by the

impact assessment phase in the LCA methodology, only the classification and characterization stages are considered. Normalization and evaluation are excluded, since they are optional

elements and according to the objective of the study, they would not provide any extra useful information (Harding et. al, 2007, Jeganathan et.al, 2010).


225

3.1.1 Classification and Characterization

First inventory data are classified by the impact categories described above. The

characterization enables to see what percentage gives each biofuels production processes to the total of each of the impacts studied depending on the methodology followed (Figure 3)

and the results are tabulated as shown in Table 2.

Figure 3 Impact assessment of 200ml of biodiesel

Among all the inputs we first note that glycerin, pentaerythritol in NaOH solution and

methanol has an impact to all categories. Specifically, glycerin impact land use the most,

NaOH solution impacts ozone layer and methanol on carcinogens and minerals. On one study comparing the environmental impacts between enzyme catalyzed process with alkali

catalyzed process, the impact on the respiratory organics is much higher for enzyme catalyzed process compared to the alkali catalyzed process. The methanol released to the air if inhaled,

will cause headache, dizziness and nausea. Methanol is the agent that causes respiratory organics (Pogaku et.al, 2012). Goedkoop et.al (2001) also mentioned that the environmental

sources that lead to the destruction of human health are such as infectious diseases, cardiovascular and respiratory which caused by climate change; cancer which caused by

ionizing radiation; cancer and eye damage which caused by ozone layer depletion and

respiratory disease and cancer which caused by the toxic chemicals contained in air, water and food.


226

Table 2 Characterization Results for the Production of 200ml of Biodiesel from

Waste Cooking Oil.

Impact

Category

Glycerin Methanol NaOH Electricity Unit

Carcinogen 1.22624E-08 7.17840E-08 1.1596E-08 6.83995E-12 DALY

Respiratory

organic

5.00729E-11 6.37591E-11 5.56045E-11 3.0022E-10 DALY

Respiratory

inorganic

2.95868E-08 2.61899E-08 2.39186E-08 1.16147E-06 DALY

Climate

change

8.02400E-08 6.05606E-09 6.04135E-09 4.55494E-07 DALY

Radiation 2.58305E-10 4.88979E-11 8.93355E-11 0 DALY

Ozone 4.19245E-12 3.07830E-21 9.65300E-21 0 DALY

Ecotoxicity 0.008353E-03 0.00440E-03 0.01052E-04 6.27963E-07 PAF*m2yr

Acidification/

Eutrophication

0.000692E-03

0.00063E-04 0.00057E-03 0.04384E-04 PDF*m2yr

Land use 0.000547E-03 0.000183E-03 2.18096E-05 0 PDF*m2yr

Minerals 0.001425E-03 0.000908E-03 0.001555E-03 0 MJ Surplus

Fossil fuel 0.173574E-03 0.230351E-03 0.0082316E-03 3.323707E-03 MJ Surplus

Electricity however impact rather significantly, even though not to all categories, to

respiratory organics, respiratory inorganics, acidification and fossil fuels. In electricity production, involves extracting, refining, and transporting natural gas and these activities are

environmentally destructive. Extracting natural gas through drilling causes severe land and ocean destruction and contamination and also releases some greenhouse gases and other air

pollutants (EcoSpark, 2011). As mentioned earlier, electricity also contribute significant

impacts to acidification and eutrophication because acidifying and eutrophying pollutants originate primarily from anthropogenic emissions of sulphur dioxide, nitrogen oxides and

ammonia. Most of sulphur and nitrogen oxides are emitted to the atmosphere under the combustion of fossil fuel in electricity generating power stations (EMEP, 2009).

3.1.2 Assessment of damage

With the assessment of damage we get the percentage that each process will impact on each

category (Figure 4). The difference is that in this case the data refer to the categories of harm and not impact, as in the characterization. In the category of human health emphasizes the

impact produced by electricity. In this category the impact is mainly due to electricity consumption (92%). The contributing factors linked to acidification during electricity

consumption of biodiesel production (Konstantina et.al, 2015). Glycerin produced was found to contribute the second highest to human health category. After glycerin, NaOH and methanol

also found to significantly contribute to the same category.


227

At 90%, electricity was also identified as the highest contributor for ecosystem quality

category. In David Suzuki Foundation (2014) report, it was stated that natural gas-fired power plants do emit lower levels of sulphur dioxide and nitrogen oxides than coal-fired plants, but

these emissions still contribute ground-level ozone or commonly called smog. Additionally, this smog does cause a range of respiratory illnesses and recently, ground-level ozone

contributes to the asthma illness among children which is also the "most common chronic

disease" among children. Other

Figure 4 Evaluation of damage of the production of biodiesel

than that, the electricity usage contributes to human health because from the generation of

electricity from natural gas emits fine particulates which can pass through human respiratory

filters and end up in deep in the lungs. Inputs that were identified to also can significantly impact the environment in the same category, in decreasing order are, glycerin, sodium

hydroxide solution, and methanol.

Results for resources show that again, electricity consumption contributes the highest

environmental impact for damage assessment category (88%). On the other hand at 5%, methanol was seamed to be next highest environmental stressor. Glycerin, followed by NaOH

were also found to impact the environment in this category. Table 3 shows the damage

assessment results for the production of biodiesel using the different processes.


228

Table 3 Damage assessment results

Impact

Category

Glycerin Methanol NaOH Electricity Unit

Human

health

5.018574E-16

3.954015E-16 4.171050E- 16

0.000002E-13 DALY

Ecosystem

quality

0.002075E- 11

0.000893E-12 0.001654E- 11

0.043844E-10

PAF*m2

yr

Resources 0.175000E- 09

0.231259E- 09

0.083872E- 10

3.323707E-04

MJ

Surplus

4. CONCLUSION

The use of biodiesel as fuel has shown promising potential in the world. First it can contribute

to the reduction of environmental impacts, and, second as a strategic source of renewable energy to replace diesel and other petroleum products. However, in order for biofuels to be a

sustainable alternative fuels, it should be produced from renewable feed stock with a lower negative environmental impact and preferably inexpensive. Since the assessment of

environmental impacts is quite subjective, LCA is one of the tools that can be employed in order to infer whether above requirements are met. From the assessment of biodiesel

production processes from used cooking oil, glycerin which was produced as the by-product, pentaerythritol in NaOH solution and methanol were found to impact all 11 categories, which

are carcinogen, respiratory organics and inorganics, climate change, ozone, eco-toxicity,

acidification/eutrophication, land use, minerals and fossil fuel. Electricity consumption on the other hand, impacted significantly 5 out of 11 impact categories, which are respiratory

organics and inorganics, climate change, acidification/eutrophication, and fossil fuel. When considering categories of damage, the electricity consumption have the greatest impacts on

the 3 damage categories; human health, ecosystem quality and resources. Other inputs that are also resulting impacts of all category in damage assessment include NaOH, glycerin and

methanol.

In general, producing biodiesel from UCO is one of recycling options. Even though utilising waste cooking oil helps solving the environmental problems that associated with the

disposal of waste cooking oil, it is important to study the environmental assessment of biodiesel production since a biodiesel plant utilizes heat, electricity, and materials during

production. Certainly, the complete sustainability of biodiesel production from used cooking oil can be addressed as regards the value of environmental potential in many impact

categories. Researches can be continually done in order to further reduce these direct and indirect impacts of biodiesel production towards the environment.


229

5. ACKNOWLEDGEMENTS

This research was supported by the following: Section of Environmental Engineering

Technology, Malaysian Institute of Chemical and Bioengineering Technology, Universiti of Kuala Lumpur, Malaysia.

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Konstantina K., Sofia P., Magdalini K. (2015). Life cycle analysis of b-carotene extraction

techniques. Journal of Food Engineering 167 (2015) 51–58.

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(1995). Nordic Guidelines on Life-Cycle Assessment, Nordic Council of Ministers, Copenhagen.

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treating waste cooking oil on the yield of methyl ester. Journal of the American Oil Chemists Society, 79 (2), pp.175-178.

Tarmizi, A.H.A., Lin, S.W., and Kuntom, A. (2007). Palm Oil Standard Reference Materials

for Determination of Solid Fat Content. MPOB Information series. 375.


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William, H.K (2004). Biodiesel Basic & Beyond-A Comprehensive Guide to Production and

Use for the Home and Farm. Aztext Press.

Web sites:

Web-1: http://davidsuzuki.org/issues/climate-change/science/energy/natural-gas, consulted 6

May 2016.

Web-2: http:// www.emep.int/acidify.html, consulted 11 May 2015.

Web-2: http://www.ecospark.ca/wattwize/students/gas, consulted 6 May 2016.


231

DESIGN OF EXPERIMENTAL TEST-RIG TO INVESTIGATE

TURBULENCE IN OSCILLATORY FLOW USED IN

THERMOACOUSTICS.

Mustaffa, S. H. A., 1, Mohd Saat, F. A. Z., 2 and Mat Tokit, E.3 1 Universiti Teknikal Malaysia Melaka, Faculty of Mechanical Engineering, [email protected]

2 Center of Advanced Research on Energy (CARE), Universiti Teknikal Malaysia Melaka,

[email protected] 3 Center of Advanced Research on Energy (CARE), Universiti Teknikal Malaysia Melaka, [email protected]

ABSTRACT

Thermoacoustic technologies are clean and sustainable technologies that provide alternative

ways of producing energy or cooling effect using proper interaction between pressure,

temperature and density. In thermoacoustics, turbulence behaviours are difficult to understand.

This paper provides a review about turbulence characteristics in oscillatory flow (the flow

commonly appeared in thermoacoustics). The use of several dimensionless numbers are

discussed. A research work about characteristics of turbulence is currently conducted at

Universiti Teknikal Malaysia Melaka. Hence, the design and fabrication of a standing wave

thermoacoustic rig for specific purpose of investigating turbulence in oscillatory flow is

reported. The rig is designed following quarter wavelength criteria. Details descriptions of the

design of various components of the rig including the internal structure that is to be investigated

is given with emphasise on the size of the internal structure and the resonator length. The

experiment is to be conducted with different drive ratios (defined as maximum pressure over

mean pressure) up to 3%. Two values of frequency, 13.1 Hz and 23.1 Hz, are considered in

the design in order to study the effect of frequency on turbulence. Future activities with regards

to the studies are also discussed.

Key Words: Thermoacoustics; Oscillatory flow; Turbulence.

1. INTRODUCTION

Thermoacoustics technology is one of the clean and sustainable technologies that offer

alternative ways for a variety of commercial, military and industrial applications (Garrett,

Adeff, & Hofler, 1993). Recent breakthrough of thermoacoustic technology is reported by

Qnergy (Web-1). Qnergy is an established company that develop and manufacture Stirling-

based engines and systems. The most recent invention is a solar thermoacoustic power

generation using acoustic waves in order to produce 1 kW of electrical power at the company’s

test facility in Ogden, Utah. The basis of this technology is the principle of sound wave inside

a pressurized environment which at the correct setting would produce either power (heat

engine) or cooling effect (refrigerator). The advantages of thermoacoustic technology are no

moving parts involve in the devices and environmentally friendly working medium. The type

of flow related to thermoacoustics is oscillatory flow. The thermoacoustic system can work

either in standing or travelling waves.





232

In standing wave thermoacoustic refrigerator, Zolpakar et al., (2016) provided a review

about past works conducted by various researchers on methods to analyze the performances of

the system. In order to achieve the best performances of the thermoacoustic refrigerator system,

optimization work has been done and genetic algorithm approach are introduced. There are

several factors affecting the thermoacoustic system performances mostly at high-amplitude

oscillation. Swift (2002) reported that the factors that affect the performances of the

thermoacoustic systems maybe related to tortuous porous media, mass streaming, entrance

effects, turbulence, harmonics and shocks.

In thermoacoustics, the behaviors of turbulence is very difficult to understand. Most

studies are based on steady incompressible flow in a circular pipe. However, based on previous

study by Saat et al., (2013), there is discovery of turbulence inside thermoacoustic flow but the

details regarding behavior of turbulence are still left unanswered. Thus, a research work about

characteristics of turbulence is currently conducted at Universiti Teknikal Malaysia Melaka

(UTeM). The objective of this paper is to provide an insight about the study of turbulence

characteristics and to report the details of the design and fabrication of a standing wave

thermoacoustic rig at UTeM.

2. REVIEW ON CONVENTIONAL AND OSCILLATORY FLOW

Turbulence in Conventional Flow

Fluid flow maybe classified as a single-phase flow and multi-phase flow. Multi-phase flow is

a flow related to more than one phases of liquid. Many recent studies reported the behaviour of

turbulent flow in the area of multi-phase flow either in simulations (Colombo et al., 2015) or

experiment (Penteado et al., 2016). Colombo et al., (2015) studied a two-fluid Eulerian-

Eulerian computational multi-phase fluid dynamic model in order to predict bubbly air-water

flows. According to the predictions of turbulence models, Colombo and co-workers inspected

an increase in the drag velocity profiles in the near-wall region. In thermal and fluid science

area, Penteado et al., (2016) used an Eulerian-Langrangian point-particle approach, to analyse

the transport of grains of a granular bed sheared by a turbulent liquid flow. However, the

multiphase flow is not the focus of current study.

This research is related to single-phase flow. Single-phase flow is defined as a flow with

fluid that exist in one-phase only. The flow can be divided into two groups. The first group

involves the effect of density of fluid. The second group is related to the effect of fluid’s

viscosity. In the perspective of density, fluid maybe categorized as either incompressible or

compressible. Generally, compressible fluids have density that changes over time. The density

of incompressible fluids normally is constant with time. Most fluid flow is also greatly affected

by the effect of viscosity. This kind of flow is commonly known as viscous flow. If the effect

of viscosity on flow is insignificant, the flow maybe categorized as inviscid flow. All fluids

(compressible, incompressible, viscous and inviscid) may experience either laminar, transition

or turbulent flow.

In classical physics, the behaviour of turbulent in flowing fluids still remains one of the

most challenging topics even to the scientists and engineers in understanding the turbulence


233

phenomenon. In flow, turbulence happen when laminar flow experience even the tiniest

disturbances which will make the flow goes through the transition phase to a turbulent flow

(Babu, 2010). As part of the branch of studies on turbulent flow, Taler (2016) presented a new

heat transfer correlation using the least-square and Levenberg-Marquardt technique. This

correlation was developed for Nusselt number, Nu, in terms of the friction factor, ξ

Investigations of turbulence in the area of thermoacoustics are scarce. Flow inside

thermoacoustic system is oscillatory in nature. Oscillatory flow is a bi-directional type of flow.

Flow changes directions with respect to time. The speed of change depends on frequency.

Figure 1 shows the illustration of conventional flow and oscillatory flow.

Figure 1 Illustration of (a) conventional flow (b) oscillatory flow.

Most experimental design of thermoacoustic systems rely on the understanding of turbulence

for oscillatory flow in pipes. As for the transition-to-turbulence, the studies by Merkli &

Thomann (1975) and followed by Ohmi & Iguchi (1982) showed great contribution in

describing the turbulence characteristics at this stage. Merkli & Thomann (1975) from their

experiment, for a wide range of Reynolds numbers, discovered the critical Reynolds number

where the transition to turbulence occurred in a Stokes layer.

𝐴𝑐 =2��𝑚𝑎𝑥

(𝒱𝜔)12

The term, is equal to Ac ≈ 400, where ��𝑚𝑎𝑥, 𝒱 and 𝜔 representing axial velocity amplitude,

kinematic viscosity and frequency respectively. Ohmi & Iguchi (1982) examined

experimentally the transition to turbulence using a hot wire anemometer for Reynolds numbers

between in an oscillating pipe flow. They classified the flow as laminar, transitional or

turbulent based on the velocity waveform. They discovered that the transition to turbulence

occurred at Reynolds number ranging from 1,000 until 10,000 at dimensionless frequency,

600 ≤ 𝑅𝑒 ≤ 65000. From the observation of velocity distribution, they concluded that when

Reynolds number, Re is larger than the critical Reynolds number, Recrit, a turbulence appears

most of the time except the early stage of accelerating phase and latest stage of decelerating

phase. Figure 2 shows the turbulence waveform at different dimensionless radius,

numbers, Reynolds Re number, Prandtl also and , Pr, Reynolds Prandtl and of ranges where

numbers are and r espectively. Equation 1 shows the new

correlation which is wall uniform and flux heat wall uniform for used be to also suitable temperature boundary conditions .

2.2 Turbulence in Oscillatory Flow

(1)


234

Figure 2 Turbulence waveform at difference dimensionless radius, . (Ohmi and Iguchi,

1982)

Ramaprian & Tu (1980) developed the oscillatory pipe flow facilities to study the effects of

the oscillation frequency and the thickness of the viscous and Stokes sublayer at the transitional

Reynolds number. Ramaprian and co-workers defined the critical Reynolds numbers as 2100

based on a time-mean cross-sectional average velocity, . They concluded that the

transitional flow may be laminarized even when the oscillatory flow is fully turbulent. Its

periodic, however, is still similar to that of oscillatory laminar flow. In 1991, Akhavan et al.,

performed both experimental and simulation works for flow in a circular pipe to measure the

axial and radial velocity components simultaneously in order to investigate the transition to

turbulence in oscillatory Stokes flows. At critical Reynolds numbers, turbulence suddenly

appeared towards the end of the acceleration phase of the cycle and was maintained along the

deceleration phase. In Stirling engine heat exchanger, Ahn et al., (1992) investigated

numerically both laminar and turbulent oscillating pipe flow for different maximum Reynolds

number ( by using a high Reynolds number turbulence model in order to identify

the oscillating flow regime with critical Reynolds numbers. They concluded that for a fully

turbulent regime or a quasi-steady turbulent regime, k turbulence model is suitable to predict

the oscillating flow at critical Reynolds numbers.

For flow visualization, Mao et al., (2010) used particle image velocimetry measurement

techniques to study the turbulence characteristics of oscillatory flows around parallel-plate

structures in thermoacoustic devices. Mao and co-worker suggested that the turbulence

characteristics which is “turbulence intensity” should be associated with the small scale vortex

structures that lead to the production of turbulence. After some time, Saat et al., (2013)

performed numerical modelling by solving the relevant transport equations that govern the flow

within parallel-plate heat exchangers of thermoacoustic systems. The solver selection for

turbulence model is Reynolds Averaged Navier-Stokes (RANS) equation. They reported that

in thermoacoustic system, turbulence may occurred at a very low Reynolds number particularly

in the area near structures such as heat exchanger.


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3. DIMENSIONLESS NUMBER

Dimensionless numbers are a set of dimensionless quantities that plays an important role in

describing the behavior of fluids. Examples of dimensionless number are Reynolds number,

Re, Mach number, Ma, Prandtl number, Pr, Strouhal number, St, Froude number, Fr, and

Nusselt number, Nu. For the study of turbulence, the most important dimensionless number

used in the representation of flow is the Reynolds number. Evidently, Reynolds number used

in oscillatory flow have many definitions. It is important that a standard formula should be

introduced to help generalized the data. Although Reynolds number is usually defined as ρvD/

µ (where ρ = density of the fluid, v = mean velocity of the fluid, D = diameter of the pipe and

µ = dynamic viscosity of the fluid), but many authors give different definitions of Reynolds

numbers based on the condition of their experimental environment.

Merkli and Thomann (1975) obtained the critical Reynolds number by introducing a non-

dimensional value,

𝐴𝑐 =2��𝑚𝑎𝑥

(𝒱𝜔)12

as a characteristic parameter that define the Reynolds number based on the boundary layer

thickness where is kinematic viscosity, is radian frequency and is axial velocity amplitude.

The characteristic parameter mentioned here described the transition to turbulence in an

oscillating pipe flow. Jensen et al (1989) conducted studies about turbulent oscillatory

boundary-layer flows over both smooth and rough beds. They defined the Reynolds number as

. The term, , is the maximum value of the freestream velocity and is the

amplitude of the free-stream motion. The term, , equal to , if the free-stream velocity

varies sinusoidally with time. While, term, , is the kinematic viscosity. They also included the

parameters, , to study the effect of parameter on boundary layer at higher Reynolds

number at rough bed boundary layer. The terms, , is the Nikuradse’s equivalent sand roughness

and is the amplitude of the free-stream motion.

Eckmann and Grotberg (1991) studied transition-to-turbulence flow in a straight

circular tube experiment. They defined Reynolds numbers, Re = based on Stokes-layer

thickness, .The term, , is a Womersley parameter and is an amplitude of stroke distance

over tube radius. While, Akhavan et al., (1991) defined the Reynolds numbers, to study the

turbulent oscillatory flow. The terms, , is equal to the amplitude of cross-sectional mean

velocity and is Stokes layer thickness. The term Stokes parameter,

(where = radius of the pipe), is to study the effect of Stokes parameter on the flow during the

turbulent portion of the cycle. They also identified the existence of a logarithmic layer

whenever the similarity parameters, ( and ) are separated.


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4. DESIGN OF EXPERIMENT

At Universiti Teknikal Malaysia Melaka (UTeM), a study about turbulence in thermoacoustic

is underway. Experimental rig is being set up for a standing wave thermoacoustic condition.

The standing wave thermoacoustic rig (Figure 3) consist of the loudspeaker as an acoustic

driver, constant square hollow cross-section resonator and the test section (stack). The test

section consist of parallel-plates configuration known as stack. From the experimental point of

view, standing wave rig is interesting for detailed analysis of core components such as stack,

due to its simplicity. An important parameter in thermoacoustics is the drive ratio, , defined

as the ratio of the maximum acoustic pressure amplitude, in the resonator to the mean

pressure, in the resonator. The rig is designed for studies of drive ratio range up to 3% which

is related to maximum acoustic pressure amplitude, , of 3000Pa.

The rig has been designed for use with ideal gas (air) at atmospheric pressure and room

temperature. The resonator is based on the quarter-wavelength criteria resulting to a

length of 6.60 m, corresponding to the frequency of 13.1 Hz (Shi et al., 2010). In addition, there

is another frequency, which is 23.1 Hz. At this frequency, the length of the rig will be reduced

to 3.80 m.

Figure 3: Schematic diagram of standing wave thermoacoustic rig.

Acoustic Driver and Resonator

In the standing wave rig, the loudspeaker is used as an acoustic driver to oscillate the air inside

the resonator to create the thermoacoustic effects. The specification of the loudspeaker and

other instruments are not reported here. This paper focused on the mechanical design of the rig.

The instrumentation perspective is to be reported in a different paper. The material for resonator

is mild steel. Resonator is a hollow square duct with cross-sectional area of 152.4 mm x 152.4

mm and the thickness of the wall is 4 mm. For the ease of experiment, the total length of the

resonator is divided into six sections and connected by gasket. The gasket is accompanied by

rubber sheet in-between to prevent the sound wave from leaking outside the resonator. Equation

(2) is used to calculate of the total length of the resonator equivalent to the wavelength of the

air,


237

is wavelength of the air, is speed of sound and is frequency of oscillations.

Test Section Design

The test section includes both the housing and the stack, as illustrated in Figure 4(a) and Figure

4(b). The housing of the stack is part of the resonator. The test section is where the turbulence

will be measured in this experiment. The stack is made from aluminium plates. Aluminium was

chosen due to the low thermal conductivity and high specific heat capacity. The stack consists

of 16 parallel-plates, each has thickness of 3 mm, length of 200 mm and the width of 142.4

mm. It is located at the position m measured from the closed end of the resonator. The

location of is as shown in Figure 3. The choice of this position is based on best judgement

of a high and large range of gas displacement amplitudes. The specific features of the test

section includes built-in flexibility and Particle Image Velocimetry (PIV) friendly usage.

The test section in Figure 4(a) is in tolerable size for ease of installation and re-assemble.

This accounts for the need to place different size of stacks and the spacing between each plates

in the test section without the need to re-fabricate the whole rig when changing the flow

frequency. Apart from that, every components of test section is connected with bolts and nuts

in order to prevent the components from loose. For ease of Particle Image Velocimetry (PIV)

measurements an opening is located at the side of the test section with width of 149.2 mm and

height of 101.6 mm. This is based on for the size of PIV’s interrogation window in order to be

able to capture the image of flow field features by Particle Image Velocimetry (PIV)

measurement.

if the frequency, f , is 13.1 Hz.

W here,


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Figure 4 (a) Exploded view of the test section (b) the configuration of the stack

(parallelplates)

5. CONCLUSIONS

This paper presents design of the experimental rig to investigate turbulence characteristics in

thermoacoustic’s related flow. The total length of the experimental rig, 6.60 m is based on

frequency, 13.1 Hz, corresponding to the quarter-wavelength criteria. The design of the internal

structures known as stack is to accommodate the nature of test section that needs to be

assembled and dissembled at the test site. In addition, this paper also provide review about

behavior of turbulence in conventional and oscillatory flows. In future, the studies aim to

conduct an experiment on investigating the turbulence characteristics and also simulation

works will be done to assist the analysis of the data obtained from the experiment.

6. ACKNOWLEDGEMENTS

S.H.A. Mustaffa would like to gratefully acknowledge the support and technical contributions

from Dr Fatimah Al-Zahrah binti Mohd Sa’at at Universiti Teknikal Malaysia Melaka (UTeM)

and also financial support from Ministry of Education Malaysia under research grant,

FRGS/1/2015/TK03/FKM/03/F00274.

REFERENCES

Ahn, K. H., & Ibrahim, M. B. (1992). Laminar/turbulent oscillating flow in circular pipes. International journal of heat and fluid flow, 13(4), 340-346.

Akhavan, R., Kammz, R. D., & Shapiro, A. H. (1991). An investigation of transition to

turbulence in bounded oscillatory Stokes flows Part 1. Experiment. Journal of Fluid

Mechanics, 225, 395-422.

Babu, V. (2010). Fundamentals of incompressible fluid flow. Ane Books Pvt Limited.


239

Colombo, M., & Fairweather, M. (2015). Multiphase turbulence in bubbly flows: RANS simulations. International Journal of Multiphase Flow, 77, 222-243.

Eckmann, D. M., & Grotberg, J. B. (1991). Experiments on transition to turbulence in

oscillatory pipe flow. Journal of Fluid Mechanics, 222, 329-350.

Garrett, S. L., Adeff, J. A., & Hofler, T. J. (1993). Thermoacoustic Refrigerator for Space

Applications. Journal of Thermophysics and Heat Transfer, 7(4), 595–599.

Jensen, B. L., Sumer, B. M., & Fredsoe, J. (1989). Turbulent oscillatory boundary layers at

high Reynolds numbers. Journal of Fluid Mechanics, 206, 265–297.

Mao, X., & Jaworski, A. J. (2010). Application of particle image velocimetry measurement

techniques to study turbulence characteristics of oscillatory flows around parallel-plate structures in thermoacoustic devices. Measurement Science and Technology, 21(3), 035403.

Merkli, P., & Thomann, H. (1975). Transition to turbulence in oscillating pipe flow. Journal of

Fluid Mechanics, 68(03), 567.

Ohmi, M., & Iguchi, M. (1982). Critical Reynolds Number in an Oscillating Pipe Flow. Bulletin

of the JSME, 25(200), 165–172.

Penteado, M. R. M., & de Moraes Franklin, E. (2016). Velocity fields of a bed-load layer under

a turbulent liquid flow. Experimental Thermal and Fluid Science, 78, 220-228.

Ramaprian, B. R., & Tu, S. W. (1980). An experimental study of oscillatory pipe flow at

transitional Reynolds numbers. Journal of Fluid Mechanics, 100(03), 513-544.

Saat, F. A. M., & Jaworski, A. J. (2013). Oscillatory flow and heat transfer within parallel-plate

heat exchangers of thermoacoustic systems. In Proceedings of the World Congress on Engineering 2013. Lecture Notes in Engineering and Computer Science (Vol. 3, pp. 16991704). Newswood Limited.

Shi, L., Yu, Z., & Jaworski, A. J. (2010). Vortex shedding flow patterns and their transitions in

oscillatory flows past parallel-plate thermoacoustic stacks. Experimental Thermal and Fluid Science, 34(7), 954-965.

Swift, G. W. (2002). Thermoacoustics: a unifying prespective for some engines and

refrigerators. Melville, NY: Acoustical Society of America through the American

Institute of Physics.

Taler, D. (2016). A new heat transfer correlation for transition and turbulent fluid flow in tubes.

International Journal of Thermal Sciences, 108, 108-122. Zolpakar, N. A., Mohd-Ghazali, N., & El-Fawal, M. H. (2016). Performance analysis of the

standing wave thermoacoustic refrigerator: A review. Renewable and Sustainable Energy Reviews, 54, 626-634.

Web-1: http://www.ireachcontent.com/news-releases/qnergy-captures-world-record-for-

solarthermoacoustic-power-generation-257497171.html?%3F%24G1Ref=, consulted 12

October 2013


240

INSTRUMENTATION FOR STUDYING THE TURBULENCE

CHARACTERISTIC IN OSCILLATORY FLOW USED IN

THERMOACOUSTICS: A REVIEW

D. Johari 1, E. Mat Tokit2 , F.A.Z. Mohd Saat3

1 Faculty of Mechanical Engineering, Universiti Teknikal Malaysia Melaka, [email protected]

2 Centre of Advanced Research on Energy (CARE), Universiti Teknikal Malaysia Melaka,

[email protected]

3 Centre of Advanced Research on Energy (CARE), Universiti Teknikal Malaysia Melaka,

[email protected]

ABSTRACT

This paper summarizes instruments that are being used in previous research when investigating

the turbulence characteristics in oscillatory flow across internal structures that are commonly

used in thermoacoustics. An overview of the thermoacoustic measuring equipment such as

loudspeaker, hot wire, pressure sensor, data logger, band pass filter, function generator, power

amplifier and Particle Image Velocimetry (PIV) are presented. These instruments are used to

examine the fascinating turbulence flow phenomena that can be observed within the internal

structures investigated. Each of these instruments has its own output range that will be

discussed later in this paper. The arranged studies for the future activities on the instruments

are also reported.

Keywords: Instrumentation, Turbulent, Oscillatory flow, Thermoacoustics.

1. INTRODUCTION

Recently, the field of thermoacoustic received high attention as renewable energy. The

thermoacoustic defines the thermoacoustic system which is based on the acoustic sources that

can causes changes of the temperature in a resonator (Zolpakar et al., 2016). Thermoacoustic

studies have been continued for years since 1777 by Byron Higgins and still being developed

until now. The theoretical basis for thermoacoustic phenomena was only established in 1969

through 1980 in a series of papers presented by Rott and his researchers (Rott, 1980).

In the resonator, the flow is the oscillatory flow. Due to the presence of the stacks and

solid structures, the flow tends to become chaotic and turbulence which will might changes the

performances in the thermoacoustic system. Turbulence flow is a complex, non-linear multi

scale phenomena, which inherit some of the most difficult and fundamental problems in

classical physics. In this review, the system is set up to be quarter-wavelength design with the

fundamental frequency of 13.1 Hz. Each instrument that had been reviewed in this study are

described in the paper which include the loudspeaker, amplifier, hotwire, pressure sensor, data

logger, function generator and PIV. These instruments are significant in observing the

turbulence characteristic flow as to enhance the performance of the thermoacoustic system.

2. EQUIPMENT SET UP AND APPARATUS

To study the turbulence characteristic in oscillatory flow, a common type of test rig is chosen

which consist of a driver, a hollow tube made of mild steel that acts as the “resonance tube’ or


241

“resonator”, while aluminum stack acts as a medium to allow thermoacoustic energy through

thermodynamic cycle. Loudspeaker is used as the driver and 6600 mm long resonator is used

as a medium for the wave to travel out the frequency of 13.1 Hz and 23.1 Hz. A perspex

resonator is used in at the test section region for the flow visualization using the Particle Image

Velocimetry (PIV). The schematic diagram of the experimental set up is shown as in Figure 1.

Figure 1. Schematic diagram of the experimental set-up

2.1 Loudspeaker

Generally, thermoacoustic engine can be classified into two groups which are ‘heat engines’

which converts heat into thermoacoustic and ‘heat pumps’ which converts acoustic power and

transport into heat (Zoontjens et al., 2005). It can be used in various ways and diverse

application (Chen et al., 2015). Most of the time, flexure bearing-upheld straight alternators

are a great arrangement because of their high quality and effectiveness (Chen et al., 2015;

Kamsanam et al., 2013). The alternators are highly expensive and it limits the usage for the

thermoacoustic devices instead, the normal audio loudspeaker is being used because it has the

same working principle as the linear alternators. The loudspeaker supplies the sound wave in

the resonators. In this study, the loudspeaker is used to supply 13.1 Hz and 23.1 Hz frequency

and using the quarter wavelength design. As this range is below the normal hearing of a normal

person, so the infrasound loudspeaker is used. The design of this loudspeaker used 2000 W

subwoofer Model PDW21250 with 21 inch diameter and it is connected to the rectangular

shaped box with dimension of 30” x 30” x 70” to generate an acoustic standing waves. Previous

researchers, are using 18” diameter loudspeaker (Model PD1850 rated 600w) (Jaworski et al.,

2009; Shi et al., 2010b) and using an electrodynamics AP130M0 loudspeaker using 0.27 m x

0.27 m x 0.27 m loudspeaker box (Jerbi et al., 2013).

2.2 Amplifier

An amplifier is an electronic gadget that expands the voltage, current, or power of a signal.

Amplifiers are utilized as a part of remote correspondences and broadcasting, and in sound

hardware of assorted types (Web-1). Amplifiers can be grouped as either feeble sign


242

intensifiers or force speakers. Nowadays, the yearning for more intense and profound bass has

brought about extraordinarily outlined amplifier to enhance low frequency yield of the speaker

frameworks. These incorporate using an enhanced high power speaker with consideration to

the force supply and enhanced damping variables. A professional amplifier 1000 W power is

used in this research which appropriate with 2000 W loudspeaker. Another work used an audio

amplifier made by Vid acoustic model network 4 (Shi et al., 2010a), a Canford power amplifier

(Jerbi et al., 2013) and a power amplifier (B-Audio MARCH-503K) (Pan et al., 2013).

2.3 Hot wire

Hot wire anemometry is the most widely recognized technique used to measure instantaneous

fluid velocity. The technique depends on the convective heat loss to the surrounding fluid from

an electrically heated sensing element or probe. In the last few years, both Laser Doppler

Anemometry (LDA) and Particle Image Velocimetry (PIV) are being widely used (Bailliet et

al., 2000; Berson et al., 2008; Mao et al., 2007; Thompson et al., 2005; Valiere et al., 2000)

but a few of researchers used the hot wire probe in investigating the flow velocity of the system

(Jerbi et al., 2013). The hot wire calibration is based on the determination of the acoustic

velocity references value through an acoustic pressure measurement. Their relationship is by

using a linear acoustic model. It is realized that the hot-wire anemometry is broadly utilized for

estimations of flow velocity and turbulence flow since it gives an exact and compact

anemometer for low velocity. There are a few advances have been made on the hot wire

anemometry but not many of them are applicable with the oscillatory flow (Davis, 1978; Lečić,

2009; Özahi et al., 2010). Dantec 55P11 probe was used by Jerbi et al. in measuring the acoustic

velocity measurements in the resonators (Jerbi et al., 2013).

2.4 Pressure sensor

A pressure sensor is a device equipped with a pressure-sensitive element that measures

the pressure of a gas against a diaphragm made of stainless steel or silicon and converts the

measured value into an electrical signal as an output. By using this pressure sensor, the drive

ratio is manipulated in order to have the required drive ratio. From other work (Marx et al.,

2006), the sensor used was piezoresistive pressure transducer Endevco 8510-B2 and the range

of the pressure was 0-2 psi.

2.5 Data logger

Data acquisition (DAQ) is an equipment to measure an electrical or physical wonder, for

example, voltage, current, temperature, pressure, or sound with a computer (Web-2).

Contrasted with conventional estimation frameworks, PC-based DAQ frameworks misuse the

preparing power, efficiency, showcase, and availability capacities of industry-standard PCs

giving more capable, adaptable, and financially savvy estimation arrangement. Instruments

without this option must remain tethered to a PC’s USB or Ethernet port during data acquisition

and use the PC’s own program and memory to store acquired data


243

2.6 Function generator

A function generator is a piece of electronic test equipment or software used to generate

different types of electrical waveforms over a wide range of frequencies. Some of the most

common waveforms produced by the function generator are the sine, square, triangular and

saw tooth shapes. In this study, the frequencies used are 13.1 Hz and 23.1 Hz using sine waves.

The function generator is connected to the power supply to control the gain and the frequency

of the loudspeaker in order to produce output of the required frequencies. By changing the

amplitude of this signal, the acoustic excitation and the drive ration can be manipulated. The

function generator is connected to the amplifier and filtered the frequencies. From the previous

researcher, the loudspeaker is powered by using Agilent 33120 A (Jerbi et al., 2013) and TTi-

TG1010A (Shi et al., 2010a).

2.7 Particle Image Velocimetry (PIV)

Particle Image Velocimetry (PIV) technique is the newest entrant to the field of fluid flow

measurements and provides instantaneous velocity fields over global domains. PIV records the

position over time of small techniques that have been practised for several decades (Jahanmiri,

2011). It measures of velocity measurement, which depends on the displacement of the particle

captured by two images, also known as time separation (Mao et al., 2010). Applications of PIV

for flow visualization or velocity measurement in acoustic systems were reported by Hann and

Greated (Hann et al., 1997a, 1997b) The oscillatory flow fields in standing-wave

thermoacoustic devices with and without adding stacks are visualized by Particle Image

Velocimetry (PIV) has been recorded before (Zhang et al., 2013). PIV consist of some

instruments such as camera, laser and a computer to generate the image captured by the camera.

The laser beam from a Nd:YAG pulsed laser (BigSky Laser) is also used in the study of

thermoacouostic (Mao et al., 2010)

3. CONCLUSIONS

In term of thermoacoustic aspect, all of this power equipment is significant to induce the flow

and assist in the study of turbulence characteristic in the resonator. This is also a general study

of reviewing the measuring equipment that is needed in this turbulence study. It is concluded

that the loudspeaker is utilised to control the level of excitation of the working fluid and hot

wire is used to measure velocity of the flow in the resonator. The pressure sensor is used to

measure the pressure within the required range of that is needed. This is important to ensure

the setting of the drive ratio as it is reported to have as low as 0.3 up to 3% with the fundamental

frequency 13.1 Hz. The PIV is a quantitative flow measurement technique by which two or

three components of velocities of the flow in a plane or even a volume can be measured at a

time. The function generator is used to generate electrical waveform and also discriminates

against signals at other frequency. These instruments are used as measuring equipment in

understanding the turbulence flow for the different parameters in the future study of

thermoacoustic system.


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ACKNOWLEDGEMENT

The author wish to thank the University Teknikal Malaysia Melaka for the research under

FRGS grant project no FRGS/1/2015/TK03/FKM/03/F00274 throughout the course of this

research.

REFERENCES

Bailliet, H., Lotton, P., Bruneau, M., Gusev, V., Valière, J.-C., & Gazengel, B. (2000). Acoustic

power flow measurement in a thermoacoustic resonator by means of laser Doppler

anemometry (LDA) and microphonic measurement. Applied acoustics, 60(1), 1-11.

Berson, A., Michard, M., & Blanc-Benon, P. (2008). Measurement of acoustic velocity in the

stack of a thermoacoustic refrigerator using particle image velocimetry. Heat and Mass

Transfer, 44(8), 1015-1023.

Chen, B., Jiang, R., Ho, K., Abakr, A., & Riley, P. (2015). Investigation of the Use of

Loudspeaker as a Liner Alternator for Thermoacoustic Application.

Davis, M. (1978). Hot wire anemometer response in a flow with acoustic disturbances. Journal

of sound and vibration, 56(4), 565-570.

Hann, D., & Greated, C. (1997a). The measurement of flow velocity and acoustic particle

velocity using particle-image velocimetry. Measurement Science and Technology, 8(12),

1517.

Hann, D., & Greated, C. (1997b). Particle image velocimetry for the measurement of mean and

acoustic particle velocities. Measurement Science and Technology, 8(6), 656.

Jahanmiri, M. (2011). Particle image velocimetry: Fundamentals and its applications:

Chalmers University of Technology.

Jaworski, A. J., Mao, X., Mao, X., & Yu, Z. (2009). Entrance effects in the channels of the

parallel plate stack in oscillatory flow conditions. Experimental Thermal and Fluid Science,

33(3), 495-502.

Jerbi, F. J., Huelsz, G., & Kouidri, S. (2013). Acoustic velocity measurements in resonators of

thermoacoustic systems using hot-wire anemometry. Flow Measurement and

Instrumentation, 32, 41-50.

Kamsanam, W., Mao, X., & Jaworski, A. J. (2013). Experimental investigation of heat transfer

effectiveness on finned-tube thermoacoustic heat exchanger. Lecture Notes in Engineering

and Computer Science, 3, 1979-1984.

Lečić, M. R. (2009). A new experimental approach to the calibration of hot-wire probes. Flow

Measurement and Instrumentation, 20(3), 136-140.


245

Mao, X., & Jaworski, A. J. (2010). Application of particle image velocimetry measurement

techniques to study turbulence characteristics of oscillatory flows around parallel-plate

structures in thermoacoustic devices. Measurement Science and Technology, 21(3), 035403.

Mao, X., Marx, D., & Jaworski, A. J. (2007). PIV measurement of coherent structures and

turbulence created by an oscillating flow at the end of a thermoacoustic stack Progress in

Turbulence II (pp. 99-102): Springer.

Marx, D., Mao, X., & Jaworski, A. J. (2006). Acoustic coupling between the loudspeaker and

the resonator in a standing-wave thermoacoustic device. Applied acoustics, 67(5), 402-419.

Özahi, E., Çarpınlıoǧlu, M. Ö., & Gundoǧdu, M. Y. (2010). Simple methods for low speed

calibration of hot-wire anemometers. Flow Measurement and Instrumentation, 21(2), 166-

170.

Pan, N., Shen, C., & Wang, S. (2013). Experimental study on forced thermoacoustic oscillation

driven by loudspeaker. Energy Conversion and Management, 65, 84-91.

Rott, N. (1980). Thermoacoustics. Advances in applied mechanics, 20, 135-175.

Shi, L., Yu, Z., & Jaworski, A. J. (2010a). Application of laser-based instrumentation for

measurement of time-resolved temperature and velocity fields in the thermoacoustic system.

International Journal of Thermal Sciences, 49(9), 1688-1701.

Shi, L., Yu, Z., & Jaworski, A. J. (2010b). Vortex shedding flow patterns and their transitions

in oscillatory flows past parallel-plate thermoacoustic stacks. Experimental Thermal and

Fluid Science, 34(7), 954-965.

Thompson, M. W., & Atchley, A. A. (2005). Simultaneous measurement of acoustic and

streaming velocities in a standing wave using laser Doppler anemometry. The Journal of the

Acoustical Society of America, 117(4), 1828-1838.

Valiere, J., Herzog, P., Valeau, V., & Tournois, G. (2000). Acoustic velocity measurements in

the air by means of laser Doppler velocimetry: dynamic and frequency range limitations and

signal processing improvements. Journal of sound and vibration, 229(3), 607-626.

Zhang, D.-W., He, Y.-L., Yang, W.-W., Wang, Y., & Tao, W.-Q. (2013). Particle image

velocimetry measurement on the oscillatory flow at the end of the thermoacoustic parallel

stacks. Applied Thermal Engineering, 51(1), 325-333.

Zolpakar, N. A., Mohd-Ghazali, N., & El-Fawal, M. H. (2016). Performance analysis of the

standing wave thermoacoustic refrigerator: A review. Renewable and Sustainable Energy

Reviews, 54, 626-634.

Zoontjens, L., Howard, C. Q., Zander, A. C., & Cazzolato, B. S. (2005). Development of a

low-cost loudspeaker-driven thermoacoustic refrigerator. Proc. Accoustics 2005.

Web sites:

Web-1: http://www-g.eng.cam.ac.uk/whittle/current-research/hph/hot-wire/hot-wire.html

Web-2 : http://www.ni.com/data-acquisition/what-is/


246

INTEGRATED TREATMENT OF LEACHATE BY USING

CALCITE FILTRATION AND CONSTRUCTED WETLAND

Nadia Razali, Nurhanim Zulaikha Kamarulzaman, Noraishah Abdul Harris, Zetty Nursyarafina Adam,

Nurul Fatihah Mat Jusoh

Section of Environmental Engineering Technology

Universiti Kuala Lumpur Malaysian Institute of Chemical & Bio-Engineering Technology (UNIKL

MICET) Lot 1988, Kawasan Perindustrian Bandar Vendor, Taboh Naning, Melaka. Corresponding E-

mail: [email protected]

ABSTRACT

This study was set up to compare the performance of integrated wastewater treatment process

of abiotic and biotic. This treatment system utilized calcite filter (CF) in combination with

constructed wetland system (CWS) to treat leachate from local wet market. The performance

of both treatments and their combinations were evaluated with respect to pH, Biochemical

Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Total Suspended Solid (TSS) and

Ammonia Nitrogen (NH3-N) and heavy metals. The sources of the calcite was extracted from

chicken eggshells. The performance of the calcite and constructed wetland were evaluated as

(i) single treatment and (ii) combined treatment approaches. As single treatment, CF provide

better removal of TSS compared to CWS and integrated CF-CWS. Constructed wetland was

found to be capable to provide better removal of BOD and COD with removal rate of more

than 90% compared to calcium carbonate filters but demonstrated poor performance in the

removal of TSS. However, in combined treatment approach, it was found that the removal of

BOD, COD and NH3-N were significantly improved with the removal rate of more than 90%.

In conclusion, combination of the calcite filter (CF) and constructed wetland system (CWS)

are more effective to treat leachate compared to the calcium carbonate filters and constructed

wetland as single treatments.

Key Words: Integrated treatment, Leachate treatment, abiotic and biotic

1.INTRODUCTION

Increasing of population, establishment of new industries and changes in consumerism pattern

have led to the increase of generation of solid waste generation worldwide. According to Urban

Wellbeing, Housing and Local Government, approximately 3, 192,404 tons of food waste is

produced each year from domestic household only and it is directly disposed to the landfill.

One of the sequences of disposing food waste in the landfill are the generation of leachate.

Landfill is not only the sources of leachate but the leachate also can be produced along the food

supply chain and commercial enterprises such as canteens and restaurants. In general, leachate

is contaminated with high amount of chemical oxygen demand (COD), biological oxygen

demand (BOD) with ammonia nitrogen (NH3-N), halogenated compound and heavy metals

which will lead to environmental pollution (Trebouet & Jaouen 2001) could cause severe water

pollution and threatening environment. Due to these matters, the governments have implied

more stringent regulation for the recalcitrant organic pollutant and nitrogenous compound.


247

The leachate can be treated by using biological, physical and chemical treatment

processes depending on their characteristic. Leachate treatments are usually expensive,

complicated and required multiple stages as reported Kurniawan et al. (2006). Constructed

wetland system (CWS) is one of low-cost and sustainable treatment option that can be used to

treat leachate (Wojciechowska et al. 2010). The removal of pollutant in the CWS depending on

the combination of chemical, physical and biological processes that happened naturally inside

the system with the involvement of the vegetation, sediment and microbial communities inside

the CWS (Vymazal 2014). However, the efficiency of the CWS is reduced after a period of

time due to the progressive clogging at the inlet. The clogging problem arise from solid

entrapment, sedimentation, biofilm growth, plant decay product, chemical precipitation and

characteristic of granular medium (Ying et al. 2011). So, it is necessary to pre-treat the raw

leachate to retain its maximum efficiency.

Calcite filter (CF) can be used as separated and interchangeable unit in constructed

wetland treatment system to remove any organic pollutants and also adjusting pH of leachate

(Arias et al. 2003). Previous studies have reported that calcite filtration is capable to provide

good removal of heavy metals such as copper, lead, iron and phosphorus (García-Sánchez &

Álvarez-Ayuso 2002; Leader et al. 2005). Calcite by definition is a carbonate mineral that

mainly consist of calcium carbonate (CaCO3). Examples of materials that can be used as calcite

filter are limestone, aragonite, sand, eggshell etc. (Vohla et al. 2011). Villafranco et al. (2014)

have reported that adsorption by eggshell was capable to remove more than 90% of chemical

oxygen demand (COD) from pretreated landfill leachate (pretreated with Fenton oxidation).

Combination of calcite filtration and CWS was proven capable to reduce pollutant in

wastewater and most of the research are more focusing on municipal wastewater and

agricultural wastewater (Arias et al. 2003; Leader et al. 2005).

This combination of both calcite filtration and CWS provide an alternative treatment

system that is low in cost and more environmental friendly treatment system compared to

conventional treatment system. Eggshells were used as filter media and kiambang as the

vegetation in CWS system. This paper will focus on the effectiveness of the integrated

treatment of both calcite filter and CWS to treat food waste leachate.

2.METHODOLOGY

Leachate Characterization

The raw food waste leachate sample was collected from the river near to wet market at

Simpang Ampat, Melaka (2°26'12.9"N 102°11'01.4"E). Upon collection, the leachate was

preserved at 4oC in accordance with the Standard Methods for the Examination of Water and

Wastewater. The quality of the initial raw leachate taken from the sampling point is

summarized in Table 1. The standard used in this experiment is Standard B of Environmental

Quality (Industrial Effluent) Regulations 2009 published by Department of Environment

(DOE) (Foul et al. 2009; S. Q. Aziz et al. 2010)


248

Table 1 Initial characteristic of leachate

Parameter Unit Standard Parameter Initial Leachate

pH - 6-9 4.86

Biochemical Oxygen Demand (BOD5) mg/L 20 2238

Total Suspended Solid (TSS) mg/L 50 564

Chemical Oxygen Demand (COD) mg/L 400 5950

Ammoniacal Nitrogen (NH3N) mg/L 5 22.5

Heavy Metals Lead mg/L 0.1 0.092

Copper mg/L 0.2 0.216

Generally, all the parameters considered for this experimental work were exceeded the

standard discharged limit as stated in Standard B of Environmental Quality (Industrial Effluent)

Regulations 2009. The low BOD5/COD ratio (0.09) indicated that the food waste leachate was

stabilized and difficult degraded by biologically degraded.

Preparation of Calcite Filter (Eggshells)

The eggshells were obtained from a bakery located in Tampin, Negeri Sembilan. The eggshells

were washed by using hot water to remove the inner membrane of the eggshells (Daraei at. al

2014). The eggshells samples then were dried at 40˚C in a hot air oven for 30 minutes to remove

the moisture content. The oven-dried eggshells were then grounded and sieved. The average

size of particle used in this experimental work was 3 mm - 5 mm.

Experimental Setup

The experiments were conducted by using treatment system that consist of calcite filter (CF)

and the CWS in continuous flow mode. The leachate was flowed by gravity force. A cloth bag

was used as the holding material for the eggshell calcite filter and Pistia Stratiotes or water

lettuce were planted inside the CWS with the dimension of 46 cm x 33.5 cm x 26 cm. Figure

1 shows the illustration of the continuous flow mode setup for the treatment system. The

experiment was conducted under natural environment condition with exposure to sunlight and

open area. A volume of 5 liter of raw food leachate was filled into the holding tank prior to the

experimental run. The effluents from both calcite filter and CWS were collected and analyzed.

The effluents from the CF were collected every 20 minutes while the effluents from the CWS

were collected after 24 hours of contact time. The effluent from experimental runs for

integrated system of both CF and CWS were collected at time interval between 3 hours and 24


249

hours. About 10 ml of water samples were collected and immediately stored in the freezer to

reduce the oxidation of the samples and the sample were analyzed for chemical oxygen demand

(COD), biochemical oxygen demand five days (BOD5), ammonia nitrogen (NH3-N) and heavy

metals according to Standard Methods for the Examination of Water and Wastewater.

Figure 1 Schematic diagram of experiment set up

3.DISCUSSION AND ANALYSIS

In this experiment, both of CF and CWS had significant effect in adjusting the quality of the

food waste leachate. Table 2 shows the performance of both calcite filter and constructed

wetland as individual treatment and integrated system.

Table 2 The performance of the CF, CWS and CF-CWS

Parameter Unit Standard Initial FWL CF CWS CF-CWS

pH - 6.0-9.0 4.90 7.17 7.00 6.42

BOD mg/L 50 2238 769.00 57.00 43.00

COD mg/L 100 5950 3300.00 575.00 600.00

Ammonical

Nitrogen - 5.0 22.5 9.00 11.2 4.00

Total

Suspended

Solid

mg/L 100 564 20 194.28 121.43

Copper mg/L 1.0 0.092 0.038 0 0

Lead mg/L 0.5 0.216 0 0 0


250

Overall, the treatment systems were capable to provide good removal of certain

parameters up to acceptable level of discharged of the standard.

Biological Oxygen Demand Five Days (BOD5) Removal

From the Figure 2, it can be seen that both CWS and CF-CWS treatment system provided more

than 90% of BOD5 removal within 24 hours of contact time while CF treatment system can

only provide not more than 60% of BOD5 removal. As an individual treatment, CWS provide

better removal of BOD5 than CF. Attached and suspended microbial growth is the key to the

removal of organic compounds in the leachate and the organic compound degraded aerobically

and anaerobically in CWS treatment system. The oxygen required for the aerobic degradation

is obtained directly from atmosphere by diffusion or oxygen leakage from the roots of the

vegetation into the rhizosphere (Kadlec et al. 2000). Overall, it was found that CF-CWS was

capable to reduce BOD5 to 43 mg/L which was the acceptable discharged level according to

Standard B of Environmental Quality (Industrial Effluent) Regulations 2009.

Chemical Oxygen Demand (COD) Removal

Figure 3 show that CWS treatment system alone can provide about 90% removal which same

as the performance of CF-CWS treatment system but not up to the level of discharged of the

standard. However, by prolonging the contact time of the treatment system can reduce the COD

significantly to the permissible level of discharged of COD. In CWS, the removal of chemical

constituents are usually occurred at the root zone of the CWS (Othman 2007) .

Figure 2 : BOD 5 removal by CF, CWS and CF - CWS treatment modes

0

10

20

30

40

50

60

70

80

90

100

CF CWS CF + CWS

Treatment mode


251

Total Suspended Solid (TSS) Removal

From the data in the Figure 4, it was apparent that CF alone can provide a better removal of

TSS compared to CWS treatment and CF- CWS treatment system. CF treatment capable to

reduce the TSS of the leachate from 564 mg/L to 20 mg/L which was approximately more than

90% of TSS was removed from the leachate. For both CWS and CF-CWS system, the removal

TSS can only achieved about 75% and 80% removal respectively. Low removal of TTS

common problem in the CWS treatment system. This happened due to the clogging of substrate

in the CWS which subsequently reduce the removal efficiency of TSS in this treatment system.

However the combination of CF-CWS supposedly improving the removal of the TSS from the

leachate but the treatment system can only remove about 85% of TSS from the leachate may

due to insufficient contact time.

Figure 3 : COD removal of CF, CWS and CF - CWS

0

10

20

30

40

50

60

70

80

90

100

CF CWS CF + CWS

Treatment mode

Figure 4 : TSS removal by CF, CWS and CF - CWS treatment systems

0

10

20

30

40

50

60

70

80

90

100

CF CWS CF + CWS

Treatment mode


252

Removal of Ammonia Nitrogen and Heavy Metals

From the Figure 5, it was clear that CF-CWS provide the best removal of ammonia nitrogen

with more than 80% removal. The removal of ammonia nitrogen is usually influenced by the

pH of the leachate. Initially the pH of the leachate is 4.9 and after passing through the calcite

filter the pH of the leachate increased to 7.0 at which enhance the nitrogen removal in the CWS.

In general, the increment of pH usually provide more removal of ammonia nitrogen (Hussain

et al. 2006; Kurniawan & Lo 2009). Other than that, nitrification and denitrification processes

in the CWS can be enhanced in pH range of 7 -8.

.

It was clearly shown that CF can only provide about 50% of iron the leachate but

complete removal of lead. The removal of iron in the leachate was affected by the pH of

leachate. Initially, the pH of the leachate was 4.9 which was highly acidic. In the acidic

Figure 5 Ammonia nitrogen removal by CF, CWS and CF : - CWS

6

6.2

6.4

6.6

6.8

7

7.2

7.4

0

10

20

30

40

50

60

70

80

90

CF CWS CF + CWS

Treatment modes

Figure 6 Heavy metals removal by CF, CWS and CF : - CWS

6

6.2

6.4

6.6

6.8

7

7.2

7.4

0

10

20

30

40

50

60

70

80

90

100

CF CWS CF + CWS

Treatment Mode

Cu

Lead


253

condition the ferrous iron is oxidized to ferric iron as follow (H. A. Aziz et al. 2010; Abdul

Aziz et al. n.d.):

4Fe2+(aq)+ O2 (g) +4H+(aq) → 4Fe3+(aq) + 2H2O (1)

Ferric iron (Fe3+) forms iron hydroxide (Fe(OH)3) when it is reacted with water molecules.

Fe3+(aq) + 3H2O → Fe(OH)3+3H+(aq) (Acidic) (2)

However, complete removal of iron was achieved in both CWS and CF-CWS treatment

system due to the alteration of pH calcite filter. For the lead removal, complete removal was

achieved for all the three treatment modes or systems.

4. CONCLUSION

This experiment set out to evaluate the effectiveness of the integrated treatment of leachate by

using CF and CWS. This study had shown that integrated treatment of leachate by using both

CF and CWS were highly efficient in the removal of BOD5, COD, ammonia nitrogen, TSS,

ammonia nitrogen and heavy metals (Fe, Pb). It was found that integrated system was effective

to remove BOD5 and COD with the removal efficiency more than 90%. Whereas, about 80%

of ammonia nitrogen was removed by using both CF and CWS. A complete removal of heavy

metals was successfully achieved in the CF-CWS system within 24 hours of contact time.

However, for TSS removal, CF treatment system show better performance compared to both

CWS and CF-CWS. During the experiment, the pH of the leachate did not exceed the

acceptable standard which is range from 6-9. Overall, the integrated system of CF and CWS

can provide efficient removal of pollutant from the leachate. However, not all of the parameter

of leachate complied to the Standard B of Environmental Quality (Industrial Effluent)

Regulations 2009 maybe due to short contact time. There is, therefore the contact time of the

treatment should be prolong and the data should be monitored at certain time interval to get

better and more accurate results.

REFERENCES

Abdul Aziz, H. et al., Physico-chemical removal of iron from semi-aerobic landfill leachate by

limestone filter.

Arias, C.A., Brix, H. & Johansen, N.H., 2003. Phosphorus removal from municipal

wastewater in an experimental two-stage vertical flow constructed wetland system

equipped with a calcite filter. In Water Science and Technology. pp. 51–58.

Aziz, H.A. et al., 2010. Physico-chemical treatment of anaerobic landfill leachate using

activated carbon and zeolite: batch and column studies. International Journal of

Environment and Waste Management, 5(3/4), p.269.

Aziz, S.Q. et al., 2010. Leachate characterization in semi-aerobic and anaerobic sanitary

landfills: A comparative study. Journal of Environmental Management, 91, pp.2608–

2614.


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Foul, A.A. et al., 2009. Primary treatment of anaerobic landfill leachate using activated

carbon and limestone: batch and column studies. Int. J. Environment and Waste

Management, 4(3/4), pp.282–298.

García-Sánchez, A. & Álvarez-Ayuso, E., 2002. Sorption of Zn, Cd and Cr on calcite.

Application to purification of industrial wastewaters. Minerals Engineering, 15(7),

pp.539– 547.

Hussain, S. et al., 2006. Physico - chemical method for ammonia removal from synthetic

wastewater using limestone and GAC in batch and column studies.

Kurniawan, T.A. & Lo, W., 2009. Removal of refractory compounds from stabilized landfill

leachate using an integrated H 2 O 2 oxidation and granular activated carbon ( GAC )

adsorption treatment. Water Research, 43(16), pp.4079–4091. Available at:

http://dx.doi.org/10.1016/j.watres.2009.06.060.

Leader, J.W., Reddy, K.R. & Wilkie, A.C., 2005. Optimization of low-cost phosphorus

removal from wastewater using co-treatments with constructed wetlands. Water Science

and Technology, 51(9), pp.283–290.

Rabe ’ah, S. & Othman, B., 2007. LANDFILL LEACHATE TREATMENT USING FREE WATER SURFACE CONSTRUCTED WETLANDS.

Trebouet, D. & Jaouen, P., 2001. Stabilized Landfill Leachate Treatment by Combined

Physicochemical – Nanofiltration Processes. , (September).

Vohla, C. et al., 2011. Filter materials for phosphorus removal from wastewater in treatment

wetlands-A review. Ecological Engineering.

Vymazal, J., 2014. Constructed wetlands for treatment of industrial wastewaters : A review.

Ecological Engineering, 73, pp.724–751. Available at:

http://dx.doi.org/10.1016/j.ecoleng.2014.09.034.

Wojciechowska, E., Gajewska, M. & Obarska-Pempkowiak, H., 2010. Treatment of Landfill

Leachate by Constructed Wetlands: Three Case Studies. Polish Journal of Environment

Studies, 19(3), pp.643–650.

Ying, Z. et al., 2011. Coagulation pretreatment for constructed Wetlands. Fresenius

Environmental Bulletin, 20(9), pp.2326–2334.


255

REMOVAL OF ANTIBIOTICS BY ADSORPTION ONTO

MAGNETIC BIOCHAR

Sabrina Karim, Nadia Razali , Tengku Fazli Tengku Jaya, Khairul Nadiah Ibrahim, Elmy Nahida

Othman, Salem Abu Amro.

Universiti Kuala Lumpur, Lot 1988, Taboh Naning Vendor City, 78000, Alor Gajah, Melaka.

ABSTRACT

Presence of pharmaceuticals residues are recognised as emerging pollutant in water has raised

importance concerns due to their effect to the environment. This study focused on the efficiency

of magnetic biochar to remove a broad-spectrum β-lactam antibiotic that belongs to penicillin class

organism, amoxicillin (AMX) in water. pH reaction of pH 5 was selected as an optimum pH due

to greater number of positive charge gaining by absorbing H+ ion to increase in adsorption capacity

of biochar / γ- Fe2O3 and maximize the removal percentage. These results indicated that biochar /

γ- Fe2O3 adsorbent can be used to treat the presence of emerging contaminant in water.

Key Words: Magnetic Biochar, Amoxicilin, Iron Oxides, Pharmaceutical.

1.INTRODUCTION

Emerging pollutants (EPs) are often defined as chemicals which being determined in water that

had not been detected earlier or are being detected at levels that may be significantly different than

expected. Geissen et al., 2015 reported that more than 700 emerging pollutants, their metabolites

and transformation products, are represent in the European aquatic environment. Emerging

pollutants are categorised as pharmaceuticals and personal care products, pesticides and

herbicides, chemical industry, food additives and disinfection by-products (UNESCO, 2013).

In previous studies, Anness & Conoby (2013) stated that the demand for pharmaceuticals

and personal care products (PPCPs) has nearly paralleled the increasing population. PCPs are

members of a group of chemicals newly classified as organic micro contaminants in water after

pesticide and endocrine disrupting compounds, which stably exist in nature, have properties of

being hard-biodegraded, bioaccumulation, and long-range hazardous, posing far-reaching and

unrecoverable hazard on ecosystem. The prolonged use of PPCPs has led to evident emergence in

the environment, creating the potential for adverse consequences to ecosystems and human health.

The rise in both contamination and consumption of natural resources spurs the need to protect what

we have for future generations. PPCPs, despite years of persistent usage, have become a

contemporary concern because of their widespread occurrence in the environment and their

correlation to ecological disturbance. PPCPs encompass a diversity of chemicals found in

veterinary medicine, agricultural practice, human health and cosmetic care (Anness & Conoby,

2013).


256

Baghapour et al. (2013) stated that amoxicillin is a broad-spectrum b-lactam antibiotic that

belongs to penicillin class organism used as veterinary medicine for treatment of bacterial

infections encountered in gastro-intestinal and systemic infections. Based on its chemical and

physical characteristics, amoxicillin is considered as one of the primary contaminants, which

should too slightly exist in aquatic environments (Homem & Santos, 2011; De Gusseme et al.

2011; Fent et al. 2006). Nevertheless, because of the insufficient treatments of amoxicillin in

conventional water and wastewater treatment methods, this compound enters both into the surface

and groundwater and destroys the aquatic ecosystems. It also leads to bacterial resistance and

consequently the inability to treat diseases using conventional antibiotics (Elmolla & Chaudhri,

2009; Ding et al. 2012; Fatta et al. 2007). Therefore removing amoxicillin from the environment

is a major problem to be solved.

There were several effective methods have been used to treat the presence of AMX in

environment. Firstly, coagulation and flocculation frequently used as tertiary wastewater

treatments (Yoon et al. 2005), nano filtration membrane techniques (Moarefian, 2014), advance

oxidation process (AOPs) (Petrovic et al. 2011) and biodegradation. However, these methods have

their own disadvantages. The common chemical treatment used was (coagulation and flocculation)

where various chemical reagents (aluminium chloride or ferric chloride, polyelectrolytes, etc.)

used to treat the AMX pollutant. The disadvantages of this method is get into organics onto solid

during coagulation occurs mainly with hydrophobic compounds (Snydeer et al. 2003) but AMX

antibiotic tends to hydrophilic that make this method was less effective in their removal (Nam et

al., 2014). Nanofiltration techniques are not advisable, because rejection of AMX decreased at a

higher level of initial feed concentration and have some ideal condition in order to achieve removal

efficiency (Moarefian, 2014). Meanwhile, advance oxidation process (AOPs) also have some of

its limitation such as strong dependence on the pH of the aqueous solution and the concentrations

of H2O2 and Fe2+/Fe3+ and causing production of excess iron sludge that causing pollution source

(Petrovic et al. 2011). Biodegradation treatment using submerged biological aerated filter (SBAF)

also have their own drawback like the extent of AMX loading rate was not highly effective in

biological Amoxicillin and organic removal efficiencies.

Among these, adsorption method was applied how effectively AMX removed by adsorption

onto magnetic biochar. Senthil & Gayathri (2009) stated that adsorbent able to extract certain

substances by causing them to adhere to its surface without changing the physical properties of the

adsorbent. The magnetic biochar adsorbents used in this study were chosen based on potential

removal effectiveness for the adsorbate, AMX. Biochar is black carbon created through thermal

or hydrothermal conversion of biomass for environmental applications (Wardle et al., 2008).

Biochar is a low-cost adsorbent that is receiving increased attention recently because it has many

potential environmental applications and benefits (Yao et al., 2012). However adsorbent of biochar

always been discussed as major disadvantages such as powdered biochar have difficulty to separate

from water after being used as adsorbents and have limited ability to adsorb (Stenstrom et al.,

2013). Therefore, biochar incorporated with magnetite is introduced to increase adsorption

capacity. Incorporation of some reducing agent like iron in the biochar matrix to modify the

biochar to magnetic biochar composite matrix will facilitate the capacity of treating high amount

of waste water for a short period with producing environmental friendly adsorbent. There in current

study, we examine effectiveness of magnetic biochar in removing antibiotic at various pHs

solutions.


257

METHODOLOGY

Preparation of Amoxicillin (AMX)

The stock solution of AMX (98% Sigma Aldrich) with concentration of 1000 ppm was prepared

in 100 ml volumetric flask. The stock solution of AMX (1000 ppm) was prepared by dissolving

0.1g of AMX. A few drops of 0.1 M HCL was dropped until the AMX powder dissolved well.

Then, the methanol was poured into 100 ml volumetric flask until the mark level. The solution

then was swirl using glass rod until it well mixed and transferred into conical flask.

The biochar derived from palm kernel shell (PKS) and empty fruit branch (EFB) was

prepared at Belonio House. Biochar composite were gently crushed using pestle and mortar and

sieved into 0.1 mm size of particle using a sieve shaker. The biochar was mixed with the solution

of ferric chloride. Ferric chloride was prepared by dissolving 40g of FeCI3.6H2O in 60 mL of

distilled water. After that the mixture was centrifuge using centrifugal evaporator at 60oC vacuum

of aqueous solutions (V-AQ) and monitored change in weight until it constant and dry. The

samples were stored in a desiccator.

Analysis of High Performance Liquid Chromatography

The analysis was performed by mobile phase HPLC equipped with a C-18 column (250 mm×4.6

mm, 5 μm particle size) at a room temperature. The flow rate was maintained at 0.9 mL/min with

and the injection volume was 25 uL. The chromatograms of the analysed solutions were obtained

at wavelength 270nm by HPLC-UV Series of dilutions from ranging from 20 ppm, 40 ppm, 60

ppm, 80 ppm and 100 ppm were prepared for calibrations of standards to be analysed. Calibrations

curves were constructed using peak area versus sample concentration. The results evaluated by

linear regression.

Effect of pH

Effect of pH of AMX on biochar / γ- Fe2O3 were determined by mixing 0.1g of the magnetic

biochar with 100 ppm of AMX. The AMX solution pH was adjusted from pH 3, pH 5 and pH 9

before pouring the magnetic biochar. Another set of AMX with three different pH was prepared

without adding magnetic biochar which known as control samples. The samples were then shaken

at 200 rpm for 24 hour in the incubator shaker at a room temperature. The samples were withdrawn

and filtered using 0.22 μm membrane filter to analyse by HPLC. Each sample was tested in

triplicates and expressed by determined the mean values of samples.


258

Figure 10 Standard calibration curve for AMX

3. RESULT AND DISCUSSIONS

3.1 FTIR Analysis of biochar and biochar / γ- Fe2O3

The magnetic biochar and biochar were examined using the Fourier Transform Infrared

Spectrometer (FTIR) in order to carry out analysis on this adsorption of the surface functional

groups. In Figure 2 shows the image of the surface functional group of the biochar. From the

results, biochar consist of inorganic phosphate wavenumber between 1000 cm-1 and 550 cm-1 .

The biochar used in this study derived from the Palm Kernel Shell (PKS) and Empty Fruit Branch

(EFB). Both of bio-waste has greater total phosphate can indicate a higher sorption capacity

(Brothers, 2014). The biochar also consist of N-H groups that the wavenumber from 3450 cm-1 to

3100 cm-1 . The N-H stretching and N-H bending vibration shifted slightly to the lower wave

numbers after AMX adsorption, suggesting that chemical interactions occurred between the AMX

and the amino groups on the biochar surface. Figure 2 shows the image surface functional group

of the magnetic biochar. Magnetic biochar consist of N-H groups too where the wavenumber 3450

cm-1 to 3100 cm-1. Other than that, the magnetic biochar consist of double bonds of C=O (presence

of carboxyl group). The carboxylates are primarily located at wavelength 1590 cm-1. These results

indicate a good agreement with previous researches (Mubarak et al. 2015).

y = 1152.9x + 5782.4R² = 0.9963

0

20000

40000

60000

80000

100000

120000

0 10 20 30 40 50 60 70 80 90

area

( µ

V.s

)

concentration (ppm)


259

Figure 2 FTIR analysis the surface functional group of the biochar.

3.2 Effect of pHs

The pH of the solutions playing an important role in controlling the adsorption of AMX onto

the magnetic biochar. Basically, the pH of solution affects the extent of adsorption due to the

distribution of surface charge of the adsorbent can change thus varying the extent of adsorption

based on the adsorbate functional group (Gao & Pedersen, 2005; Putra et al. 2009; Yoon et al.

2005). In order to study the effect of pH, 0.1g dosage of magnetite biochar adsorbent has been

shaken in three different pH of AMX (3.0, 5.0 and 9.0). Figure 4.1, removal percentage (%)

vs. the effect of pH for two trials of biochar / γ- Fe2O3 composite adsorbent graph. The removal

percentage of AMX was computed in Figure 3 at different pH for two trials of biochar / γ-

Fe2O3 composite adsorbent.

Figure 3 Removal of AMX at different pH solutions.

0

10

20

30

40

50

60

70

80

90

100

3 5 9

Re

mo

va

l P

erc

en

tag

e (

%)

pH

Trial 1

Trial 2


260

Based on the graph, the highest percentage removal of AMX was achieved at pH 5 with

87.03% for trial 1 and 86.17 % for trial 2. Subsequently, the percentage removal of AMX

obtained at pH 3 was 25.14% for trial 1 and 13.52% for trial 2 while at pH 9 the removal of

percentage obtained were 5.55% for trial 1 and 6.80% for trial 2 respectively. Putra et al. (2009)

& Moussavi et al. (2013) was stated that the carboxyl functional groups (-COOH) was

significantly appear in AMX molecules that was readily dissociate to carboxylate ions (-COO-

) when increasing pH from 3 to 5. It is because the surface of adsorbent gains a positive charge

by absorbing H+ ions and the electrostatic attraction between the AMX molecules and biochar

/ γ- Fe2O3 surfaces increases. Nevertheless, at a pH 9 the biochar / γ- Fe2O3 surface is negatively

charged and electrostatic repulsion between negatively charged composite adsorbent surface

lead to the reduction of AMX adsorption capacity onto biochar / γ- Fe2O3 .Based on adsorption

capacity calculated in Appendix B, the adsorption capacity of biochar / γ- Fe2O3 predominantly

depends on effect of pH. The highest adsorption capacity of adsorbent was achieved at pH 5

with 64.97 mg/g for trial 1 and 66.93 mg/g for trial 2 compare to pH 3 the adsorption capacity

obtained were 21.76 mg/g for trial 1 and 12.08 mg/g for trial 2 while at pH 5 the adsorption

capacity obtained were 5.02 mg/g for trial 1 and 6.22 mg/g for trial 2 respectively. As overall,

pH 5 was selected as an optimum pH due to greater number of positive charge gaining by

absorbing H+ ions which lead to increase in adsorption capacity of biochar / γ- Fe2O3 and

maximize the removal percentage

4. CONCLUSIONS

The first objective of research study was aimed to examine the effectiveness of magnetite

biochar in removing antibiotic by adsorption methods. In this study, the maximum percentage

removal achieved to remove the AMX by using magnetite biochar was 93% and these indicates

that magnetite biochar could be used as an effective adsorbent material for the treatment of

emerging pollutant like AMX. The last objective was aimed to determine the parameter

effecting removal efficiency such as pH of solutions and composite dosage of adsorbents. For

the effect of pH, three range of pH (3, 5 and 9) were tested to determine optimum pH for

removal of AMX antibiotic. The optimum pH obtained for the adsorption was pH 5 due to

surfaces of biochar / γ- Fe2O3 composite adsorbent that gaining number of positive charge by

absorbing H+ ions and lead to increase in adsorption capacity of biochar / γ- Fe2O3 and

maximize the removal percentage. This is also due to composites of biochar that enrich with

high iron oxides content were effective to adsorb AMX and the adsorptive capacity increased

with the superficial iron concentration.

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INDUSTRIAL CONTROLLER TUNING AND EMPIRICAL

MODEL OF HEAT EXCHANGER SYSTEM

*Mat Noor, R. A., Ahmad Mokhtar, S. H., Baharom, M. F., Mazli, N. D.

Section of Chemical Engineering Technology, Universiti Kuala Lumpur,

Malaysian Institute of Chemical and Bioengineering Technology,

Lot 1988, Bandar Vendor TabohNaning,

78000 Alor Gajah, Melaka, Malaysia

[email protected]

ABSTRACT

Energy is a thermo dynamical aspect of chemical plants that has been anatomized for quite

some time. Pruning the energy as well as optimizing the operation of the plant is one of the

major trade-offs in vast majority of operating plants. Heat exchanger is one of the crucial unit

operations in a plant in which energy is consumed and transferred through contacted mediums.

Managing and controlling the process may be tedious without a reliable and robust process

controller. Automated controller provides means to ease plant management and monitoring

system as well as plays a part on minimizing CAPEX and OPEX of a plant. A resilient

controller can be obtained by conducting tuning procedures with clear goal and good practices

employed during tuning methods. This works introduces three tuning methods; Ziegler-

Nichols, Coohen-Coon and Lambda. Based on the results, Lambda tuning methods provide

best performance based on its stability and robustness towards process error and noise.

Keywords: PID Controller, Lambda Tuning, Coohen-Coon Tuning, Process Modeling, Heat

exchanger

1. INTRODUCTION

Process control is defined as an activity involved in ensuring a process is predictable, stable

and consistently operating at the target level of performance with only normal variation where

an inevitable change in the output or result of a system because all systems vary over time and

has their own disturbance. The basic principle of heat exchanger on the other hand is obviously

transfer of heat between two fluids and close contact with each other but is prevented from

mixing by a physical barrier [1]. The performance of heat exchanger is determined through

how often the oscillation occur, the time taken for the process to achieved stability and how

long the time of the process to start response.

Despite of the straightforward principles of heat exchanger, it is also one of the unit

operations that is widely studied. This is due to the heat exchanger that is auxiliary equipment

which carried out crucial tasks of transferring the energy from one material to another based

on fundamental principles of heat transfer. As energy is consumed and produced from a



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chemical plant, thus, heat exchanger operation is important to be studied and monitored. The

traditional design of heat exchanger allows maximum contact between transferring mediums.

Nevertheless, the design grants for arising problems in heat exchanger operation, such as

pressure drop and fouling.

As a result, the process might have a frequent oscillation, took a long time to response

and slow in achieved the stability or steady state. However, different design of heat exchanger

has its own efficiency. In essence, two main types of heat exchanger which are utilized at large;

are plate heat exchanger and shell and tube heat exchanger. According to Subramanian (n.d.),

shell and tube heat exchangers are used widely in the chemical process industries, especially

in refineries because of the numerous advantages that they offer over other types of heat

exchangers. The problems of heat exchanger that were presented earlier have known to

deteriorate the heat exchanger performance.

Hassan Al-Haj Ibrahim (2012) mentioned in his work that in most industries today, a

major economic drain may be caused by fouling. He also stated that the total fouling related

costs for major industrialized nations is estimated to exceed US$4.4 or RM18.43 milliards (one

thousand million) annually. Hence, the process engineer or the responsible party in an industry

should be generating an idea to solve this difficulty in order to prevent the industry get more

substantial losses. One of the solutions is to tap the controller in order improve the overall

performance of the heat exchanger. The intrinsic approach is to tune the process to its optimum

condition in order to maintain or enhance the efficiency of the heat exchanger.

In this project, three types of tuning approaches have been studied. The first tuning rule

is Ziegler-Nichols (Z-N) tuning rule which invented since 1942 by Ziegler and Nichols. It only

uses simple mathematical procedures for tuning PID controllers [4]. Second method is the

Cohen-Coon (C-C) tuning rule which is the second in popularity only to the Z-N tuning rules.

Cohen and Coon (C-C) published their tuning method in 1953, eleven years after Ziegler and

Nichols published theirs [5]. Last but not least is originated with Dahlin in 1968, Lambda

tuning rule. This type of tuning rule is based on the same Internal Model Controller (IMC)

tuning rule theory [6].

1. On-site Tuning of Heat Exchanger

Tuning of a controller in process exist a long ago. Model-free tuning is one of the first initially

applied for controller tuning. Model-free tuning techniques do not use a process model for PID

controller tuning in a direct way but based on the observation of a process which is under

control. Controller tuning is not easy to handle. The time for tuning rules to be applied is based

on the speed of response of control loops. Smuts (2015) gives his analogy of guitar tuning; he

asserted that if a control loop is not tuned for the perfect speed of response, it will be out of

harmony with the rest of process, just as a guitar will be out of tune if its strings are not all

tuned to their own perfect pitch. The main objective of tuning method is to find proper values

of Kp, Ti and Td which is process gain, integral time and derivative or rate time. This is to ensure

the process is set back to its set point after a disturbance or set point change occurs. The

methods can be used experimentally on physical systems, but also in simulated systems.


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One of the earliest, Ziegler-Nichols has been introduced to the process control world in the

1940s which give a large impact in making PID feedback controls acceptable to control

engineers. The Ziegler-Nichols rule is a PID tuning rule that attempts to produce good values

for the three PID gain parameters which is Kp, Ti and Td [7]. The tuning formula is obtained

when the plant model is given by a first-order plus dead time (FOPDT) which can be expressed

by,

G(s) = 𝑘

1+𝑠𝑇 e-sL

This method possesses an obvious advantage in terms of immediate process response while

undergo the tuning process due to the tuning procedures of the method are conducted online.

Nevertheless, the trial-and-error method is predominantly employs in this method makes the

tuning method prone to cause process upset and aggressive tuning (Srivastava, 2015).

Cohen-Coon tuning method on the hand, are suited to a more extensive assortment of

procedures than the Ziegler-Nichols tuning rules. The Ziegler-Nichols rules function admirably

just on procedures where the dead time is not as much as a large portion of the length of the

time consistent. This tuning rules function admirably on procedures where the dead time is

under two times the length of the time consistent and they can be extended to a much further if

required. Cohen-Coon gives one of only a handful few arrangements of tuning guidelines that

has rules for PD controllers. The Cohen-Coon tuning standards are appropriate for use on self-

regulating procedures if the control target is having a quick reaction, yet it is common practice

to divide controller gain by two. On the off chance that the control target is to have an

exceptionally steady, strong control loop that ingests unsettling influences, rather utilize the

Lambda tuning rules (Smuts, 2015).

Lambda tuning rules offer a vigorous contrasting option to tuning rules going for speed,

similar to Ziegler-Nichols, Cohen-Coon, and so forth. In spite of the fact that the Lambda and

IMC guidelines are determined in an unexpected way, both create similar tenets for a PI

controller on a self-regulating process. While the Ziegler-Nichols and Cohen-Coon tuning rules

go for quarter-amplitude damping, the Lambda tuning rules go for a first-order lag plus time

delay response to a set point change.

Essentially, any process needs to be controlled in a plant. In any process, the fluctuation

might occur predominantly with the existence of disturbance in a process. The fluctuation

affects the process response and the time taken for the stability of the process. In essence,

managing pressure drop in a process is very crucial and increase heat transfer efficiency. This

fouling problem is related to the pressure drop as it is one of the reasons the pressure drop may

increase in a heat exchanger. Fouling can be worst that tubes can be filled. Technically, the

heat exchanger fouls faster because of low velocities and the affection from the fouling

material. Another two causes that contributes to escalate the pressure drop are the debris from

start-up and improper venting.

By using tuning method, it can help in reducing the fluctuation occur and the dynamic of

the process which is the dead time and lag. Dead time is the delay from when a controller output

(CO) signal is issued until when the measured process variable (PV) first begins to respond.


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The presence of dead time is never a good thing in a control loop. By reducing the fluctuation

and shorten the dead time will improving the capability of the process. Hence, the process can

give a fast response which can help increasing the quality of the product and save time for

production.

As heat exchanger involve in transfer of heat, definitely the efficiency of the process heat

transfer needs to be at higher level. The efficiency of the heat transfer can be determined

through the geometry of the heat exchanger and the flow arrangement. Mass velocity as well

influences the heat transfer co-efficient. Meanwhile tube side pressure drop varies to the square

of mass velocity. Hence, with increasing of mass velocity, pressure drop will increase more

rapidly than does the heat transfer coefficient.

Therefore, it is important in controlling the velocity or the flow rate of the feed fluid in heat

exchanger to get a maximum efficiency. By increase the efficiency of the performance heat

exchanger gives a benefit in reducing the cost production as well for maintenance. The low

maintenance is needed when the heat exchanger gives a better performance. Thus, a good

tuning method is required to improve the performance of the heat exchanger.

2. METHODOLOGY

It is crucial to have prior knowledge on the heat exchanger, design, limitations, process flow

and temperature behavior. The process model was obtained via empirical modeling method.

The tuning procedures were also conducted in the laboratory. Simulink® in MATLAB were

used to mimic, simulate and test the process and tuning parameters.

2.1 Heat Exchanger Behavior

Process model were generated by using real data. The data were obtained from shell and tube

heat exchanger system, Model WT922. It can be operated with a single loop PID Control and

it is on/off temperature control [9]. On/off temperature control is especially installed to control

temperature of heating medium. Single PID controller on the other hand, provides temperature

control for the product stream. Heat exchanger behavior was studied and analyzed by

conducting step test. The process response (i.e. temperature response) was observed until the

process reaches a new steady state condition.

The process response was then utilized to determine the process model. Graphical

method was used to analyze the process response to obtain process gain, time constant and time

delay (the process was assumed to behave as a first order plus time delay process). The process

model was also derived using System Identification Toolbox in MATLAB®.


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2.2 Determination of PID Controller Tuning Parameter

Three very prominent methods of controller tuning namely; Ziegler-Nichols (Z-N), Coohen-

Coon (C-C) and Lambda tuning methods. The following Table 6.1 shows tuning formulae for

each of the tuning methods respectively.

Figure 1 PID Formulae for the Three Controller Tuning Methods

where;

gp = process gain

τ = time constant

τd = time delay

λ = 3 x time constant

2.3 Simulink® Model

A model was developed using Simulink® to mimic real process. The calculated process

model and controller tuning parameters were applied in the model in Simulink®. Ideal

PID controller was used in this work instead of the other forms of PID controller. This

is due to a weakness of parallel where it is not impulsive to tune even though it is easy

to understand. The reason is that it has no controller which can gives effect to all three

control modes compared to ideal form which it can get over all the three control modes

[5].

Figure 2 Simulink® Model for Heat Exchanger System


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Figure 3 Sample of Simulink® Process Response based on Tuning Method for 100s

Simulation Time


3.1 Heat Exchanger Experimental Results

The process response curve generated for heat exchanger system for load changes can be seen

in Figure 3 below:

Figure 4 Temperature Behavior for Load Changes of MV = 20%

For every one minute, the temperature of the process was recorded and the result shows

increase in temperature with slight fluctuation. When the MV is increasing from 60% to 80%

(i.e. MV = 20%), the process response exhibited a dead time where it took some time for

process to begin to response to the changes in process input. From the process response curve

analysis, process temperature took about 7.2 s to start to response which the time taken is quite

long and it can be denoted as a slow process response. For the process time constant, it was

calculated that the process required 23.04s to achieve steady state condition. The steady

temperature for MV 60% is 42°C and it slowly increase after step up change for MV 80% until

it maintained at 44.3°C. It can be concluded that for one second the temperature increased by

0.1°C.


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3.2 Process Transfer Function

Table 1 display process model derived from two methods mentioned in the previous section;

graphical method and MATLAB®’s System Identification Toolbox®. By comparing the two

results, it was noticed that the dead time and the time constant for empirical modelling method

is rather large compared to the other method which is by using simulated procedures in System

Identification Toolbox®.

Table 1 Process Transfer Function Generated from Both Methods

Methods Empirical

modelling method

MATLAB®’s System

Identification Toolbox

Transfer

function

G(s)

= 0.115 𝑒7.2𝑠

23.04𝑠 + 1

G(s) = 0.11501 𝑒0.451𝑠

0.1762𝑠 + 1

3.3 PID Controller Parameters based Three Methods of Tuning

Table 2 shows PID Controller parameters based on the three methods of tuning. The value of

PB in MATLAB® Simulink® is actually referring to Kc value. For Kc value, Lambda tuning

method gives the lowest which is 1.5639 followed by Z-N tuning method and C-C tuning

method 4.0764 and 6.7575 respectively. Meanwhile for TI value, Z-N tuning method generated

the highest value which is 0.9020 compared to C-C and Lambda which the value obtained are

0.6480 and 0.1762. The last parameter of PID controller is TD value. Lambda has zero

derivative time and it is the lowest value as the TD value for Z-N tuning method is 0.2255 and

denoted as the last lowest value after C-C tuning method which is 0.1132.

Table 2 PID Controller Value


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3.3.1 Proportional Controller

As mentioned earlier, hypothetically, increase in proportional controller precisely PB value

slows the speed of the control system response. By looking at the graph for Z-N, C-C and

Lambda, it can be concluded that Lambda gives the fastest response followed by C-C and lastly

Z-N tuning method which coincide with the theory.

Figure 5 Simulated response of Z-N method for 2s simulation time

Figure 6 Simulated response of C-C method for 2s simulation time

Figure 7 Simulated response of Lambda method for 2s simulation time


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3.3.2 Integral Controller

Integral controller is affected by the amount of error in the process. Even the small error causes

the integral component to increase slowly and it continuously increases as long as the error

exists until it reaches zero. Based on Table 2, it exhibits Lambda tuning method produced the

slowest process response. The fastest process to reach steady state condition is from Z-N tuning

method with its integral time is 0.902s. All the results of integral control simulation can be in

Figure 8 to 10 below.

Figure 8 Simulation response of Z-N Method for 30s simulation time

Figure 9 Simulation response of C-C Method for 30s simulation time

Figure 10 Simulation response of Lambda Method for 300s simulation time


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3.3.3 Derivative Controller

PID controller comprises of three parameters where the last ones is derivative control which

controls the processes where it can cause the output to decrease if the process variable is

increasing rapidly. However, the control system should use small derivative control due to its

nature that very susceptive towards the presence of noise in process. In this work, 100% filter

(i.e. noise filter) was employed to suppress the noise presents in the process. Z-N tuning method

exhibits the most oscillated response in the process.

Other factor that causes the oscillation in Z-N and C-C tuning method is they were

designed for quarter-amplitude damping response. Quarter-amplitude damping is likely the

best-known tuning objective, but it is a poor choice for process stability. The main focus of this

tuning objective is to eliminate any error between setpoint and process variable very fast. It has

fast controller responds but the process variable is actually overshoots its setpoint and oscillates

a few times before it finally comes to rest (Smuts, 2013).

Figure 11 Simulation response of Z-N method for 10s simulation time

Figure 12 Simulation response of C-C method for 10s simulation time


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Figure 13 Simulation response of Lambda method for 10s simulation time

4. CONCLUSION

According to the literature, one of the latest tuning method invented by Dahlin in 1968 which

is Lambda tuning rules should be the best among these three. Lambda tuning method is

admissible although the times taken for the process to achieved stability is quite long but

fortunately, it is robustness process which refer to no oscillation occur. The oscillation was

seen in Z-N and C-C tuning rules and it shorten the time constant and hence the steady state of

the process is successfully achieved. Other than that, Lambda tuning method gives the fastest

response as its proportional controller is the highest among these three tuning method.

REFERENCES

[1] Agarwal, P., Sikand, A., & Shanthi, V. (2014). Application of Heat Exchangers in

Bioprocess Industry: a Review. International Journal of Pharmacy and Pharmaceutical

Sciences, 6(1).

[2] Definition, M. (n.d.). Shell-and-Tube Heat Exchanger, 1–16.

[3] Ibrahim, H. A. (2012). Fouling in Heat Exchangers. MATLAB - A Fundamental Tool for

Scientific Computing and Engineering Applications, 3, 57–96.

http://doi.org/http://dx.doi.org/10.5772/46462

[3] Control, P. (n.d.). Ecet- 462, 1–7.

[4] Jacques Smuts (2015), Controller Notes: Reflections of a Process Control Practitioner,

[Online]. Available at: http://blog.opticontrols.com/archives/1222

[5] Olsen, T. (Emerson), & Bialkowski, B. (Emerson). (2002). Lambda Tuning as a Promising

Controller Tuning Method for the Refinery. AIChE Spring National Meeting, (42).

[6] Anonymous (2016), Ziegler-Nichols Tuning Rules for PID, [Online]. Available at:

http://www.mstarlabs.com/control/znrule.html

[7] Exchangers, H. (2006). Classification of Heat Exchangers . A-to-Z Guide to

Thermodynamics, Heat and Mass Transfer, and Fluids Engineering, c, 1–77.

http://doi.org/10.1615/AtoZ.c.CLAOFHEAEXC

http://doi.org/http:/dx.doi.org/10.5772/46462

http://blog.opticontrols.com/archives/1222

http://www.mstarlabs.com/control/znrule.html


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STUDIES ON COD AND COLOUR REDUCTION IN POME

USING CHEMICALLY ACTIVATED EFB CARBON

Kumaran Kanapathy1, Reuben Anthony2Arasu Uttran3, Loh Soh Kheang3 1, 2,3 Manipal International University, 71800 Nilai, Negeri Sembilan, Malaysia

([email protected];[email protected]) 4Malaysian Palm Oil Board, 43000, Kajang, Selangor, Malaysia

([email protected])

ABSTRACT

The main objective of this experiment is to study the removal of COD in POME using activated carbon from EFB. The removal of organics in terms of chemical oxygen demand (COD) was studied using EFB chemically activated carbon (CAC) and EFB physically activated carbon (PAC) as adsorbent in a batch process. The adsorption study was conducted at 150 rpm (25oC) until COD removal reached equilibrium. The sample were analysed for COD, pH and color reduction by measuring the absorbance of the sample. Based on this study, various type of activated carbon and dosage shows significant effect on COD removal in POME .It was observed for the batch adsorption that the COD was reduced from an initial value of 510 mg/L to 280 mg/L in the first four days by using 1.5 g of CAC which is the highest removal percentage 45.21% (P=0.030) compared with PAC 32.70%(P=0.00). Hence significant COD removal efficiency rates 35.67%, 43.99% and 45.21% were achieved at different dosage of (0.5g,1.0g,1.5g ) respectively using CAC. Thus, Chemically Activated Carbon (CAC) find more successfully in terms of COD removal by activating reagents studied, zinc chloride gave the highest surface area which influence the adsorption of organics matters in POME sample.

Key Words: POME, Activated Carbon, Chemical Oxygen Demand

1 INTRODUCTION

Palm oil is one of the world’s most rapidly expanding equatorial crops. Oil palm currently occupies the largest acreage of farmed land in Malaysia (Rupani, 2010). The total oil palm acreage from 1970 to 2000 has increased from 320 to 3,338 hectares. In the year 2003 there were more than 3.79 million hectares of land under palm oil cultivation, occupying more than one third of the total cultivated area and 11% of the total land area of Malaysia (Rupani, 2010). Palm oil, an edible oil, is derived from the fleshy mesocarp of the fruit of oil palm (Elaeis gunineensis). One hectare of oil palm produces 10 to 35 tonnes of fresh fruit bunches (FFB) per year (Rupani, 2010).

The total oil palm cover has increased in the last few years, with a corresponding increase in palm oil production. As a result, palm oil waste which is a by-product of the milling process will also increase. The palm oil production process in mills consists of several unit operations. The processing of fresh fruit bunches of oil palm results in the generation of different types of residue (Rupani,PF,2010). Among the waste generated, palm oil mill effluent (POME) is considered the most harmful waste for the environment if discharged untreated. POME has high acidity, temperature, biological oxygen demand (BOD), and chemical oxygen demand (COD).


275

As it is discharged into waterways it can contaminate drinking water for human and

animal communities. It can be particularly harmful to aquatic communities by creating highly

acidic environments or causing eutrophication (where excessive algal growth occurs on the

surface of the water). For these obvious reasons, raw POME or partially treated POME is still

being discharged into nearby rivers or land, as this is the easiest and cheapest method for

disposal (Madaki, 2013). However, excessive quantities of untreated POME deplete a water

body of its oxygen and suffocate aquatic life. Palm oil mill effluent is a thick brownish liquid

that contains high solids, oil and grease, COD and BOD values (Madaki, 2013).

Several treatment technologies have been used for POME treatment such as

vermicomposting, activated carbon prepared from oil palm empty fruit bunch, palm kernel shell and microwave induced carbon from waste palm kernel shell activated by phosphoric acid, since the direct discharge of POME adversely affects the environment. Those techniques help to produce consistent and good effluent quality after treatment and smaller space required for membrane treatment plants. Although ,still there is some back drop like high energy requirement (aeration), rate of pathogen inactivation is lower in aerobic sludge compared to anaerobic sludge, thus unsuitable for land applications(Bala, 2014).

Activated carbon which is main material in this project has been known as an excellent adsorbent and is widely used due to its unique characteristics and large adsorption capacity.. The effective treatment of POME using activated carbon produced from oil palm empty fruit bunch by chemically activation is suggested as a good alternative sustainable management practice of this waste (Hon, 2010).

According to (Gadkaree,1998) activated carbon is a very important material industrially, with applications in a variety of areas such as adsorbers in air and water pollution control, catalysts in the chemical and petrochemical industries. Typically activated carbon is made from naturally occurring materials such as wood, coal and nutshell flour etc. via high temperature, inert atmosphere processing followed by activation to create porosity in the nanometer size range.

2. METHODOLOGY

2.1 Liquid Effluent Samples Preparation.

Liquid Effluent samples (POME) were collected from Labu Palm Oil Mill. The sample is collected approximately 3L and stored at 4oC. Next the sample was centrifuged using (Eppendorf 5430, Hamberg, Germany) at (10,000 rpm, 10 minutes) and the suspended solids were discarded while the supernatant were stored at 4oC.

2.2 Chemically Activated Carbon (CAC) Preparation

The dried-EFB samples were purchased from (Szetech Engineering, Shah Alam) impregnated with 10% ZnCl2 for 24 hours. The solution was then decanted off and the impregnated-EFB was dried in the oven at 110°C overnight. The impregnated-EFB was activated using tubular horizontal furnace (Nabertherm, R 50/250/12) under nitrogen flow (150 LPH) at 500°C for 1 hour. The activated carbon was washed 10% HCl for 2 hours followed by


276

washing with distilled water until the pH of the solution become neutral. The activated carbon was dried at 110°C for 3 hours, grinded until fine, and stored in a container. (Riny,W., 2015 ).

2.3 Physically Activated Carbon (PAC) Preparation

Physically activated carbons were prepared using EFB without chemical impregnation. The EFB was tubular horizontal furnace (Nabertherm, R 50/250/12) under nitrogen flow (150 LPH) at 500°C for 1 hour. The activated carbon was washed with distilled water until the pH of the solution become neutral. The activated carbon was dried at 110°C for 3 hours, grinded until fine, and stored in a container. (Riny,W.,2015).

2.4 CAC & PAC Characterisation

Initially, the sample were oven dried at T=100oC to calculate the moisture content. The same sample were used to determine CHNS (CHNS Leco Elemental Analyzer), volatile matter, ash content and fixed carbon were analyzed according to ASTM D5142-02a, where else pH and conductivity is calculated based on ASTM E70 method.

2.5 Adsorption study

In each adsorption experiment, 100 ml of POME solution was added to different amounts of CAC in triplicate (0.5g,1.0g,1.5 g) including blank as a Control at 150 rpm in a rotary orbital shaker in room temperature until the removal of COD reach equilibirum.The samples were centrifuged using (Eppendorf 5430, Hamberg, Germany) at 5000 rpm for 5 min, the supernatant were analyzed for COD, pH and absorbance. For COD analysis, 1 ml of sample and 1 ml of distilled water is added to the low range HACH COD Vial. The vials were mix vigorously using vortex mixture. As for the blank, 2 ml of distilled water is added into another vial and both vials incubated in heating block for 2 hours at 150oC. The COD were analysed using DR3900 colorimeter. The pH and absorbance were analysed using pH meter and UV Spectrophotometer.

The percentage of removal (%R) of each parameter and the amounts adsorbed by the adsorbents were calculated by the following equations:

(2.1)

Where qt is adsorption capacity (mg/g), and Ct are initial and equilibrium concentration (mg/L) respectively, M is the adsorbent dosage (g) and V is the volume of solution. The experiment was repeated using PAC.


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3. RESULT & DISCUSSION

3.1 Liquid effluent (POME)

The COD for raw POME collected was 2700mg/L in COD. Thus, the raw POME was diluted in ratio of 20% in 1L solution. The initial COD was measured using HR COD vial As a result, high range vial were finalised since COD measured within the range.

Table 3.1 Characteristics of Treated POME in Sime Darby Mill, Labu .

Parameters Diluted POME

COD (mg/L) 1300 – 2700

TSS (mg/L) 27000 -5000

pH 8.3 – 8.8

3.2 CAC & PAC Characteristics

The proximate composition of EFB carbon is  7.7 wt% moisture, 1.57wt% ash, 25.0 wt% volatile matter, and  65.0wt% fixed carbon, which makes it suitable precursor for obtaining activated carbon .The percent yield of EFB based activated carbon decreases as activation using chemical reagent(ZnCl2). This could be attributed to the higher reaction rate of carbon and zinc chloride to release more volatile components with concomitant improvement in the textural characteristics and carbon burn-off .

Table 3.2 Characteristics of activated carbon

Parameter CAC PAC

Fixed Carbon(%) 65.7±1.59 70.0±0.42

Volatile Matter(%) 25.0±1.74 18.9±0.43

Moisture Conten(%) 7.73±0.21 8.16±0.12

Ash content (%) 1.57±0.23 2.90±0.12

Conductivity (uS) 76.1 28.4

pH 4.7 6.8

C (%) 76.69±0.85 82.92±0.39

H (%) 2.85±0.04 2.94±0.08

N (%) 1.05±0.06 0.88±0.08

S (%) 0.018±0.02 0.021±0.06

3.3 Effect of Adsorbent Dosage for Activated Carbon (CAC & PAC)

The chemical oxygen demand (COD) indicates organic pollutants in the wastewater. Bacteria oxidises organic compounds in the wastewater for the growth and metabolism. The removal efficiency of CAC for COD was higher than PAC. The reduction of COD on both sample (CAC


278

& PAC) are significant different (P=0.030; P=0.000). So at the maximum CAC was able to remove 220 mg/L of the COD (43%) in 4 days. So PAC was able to remove 159 mg/L of the COD (32%) in 3 days. The higher removal of COD as the CAC dosage increase may due to the pore structure, high in adsorption capacity, and active surfaces makes activated carbon suitable for adsorbing organic molecules (Mohamed.N.R,2013). Higher dosage also means more surface area of active sites for COD adsorption to occur. The removal efficiency of CAC for COD was higher than PAC. Similar conclusions were reported by Ahmad (2010). The adsorption of foulants on the surface of CAC is affected by the surface charge of CAC. In addition, the low adsorption capacity of PAC was influenced by the particle size. The powder shape has a higher contact area compare to granulated shape. The contact area determines the quantity of the pollutant that can be adsorbed by the adsorbent.

Table 3.3 COD removal (%) at 150 rpm (n=3), T= 25oC

Dosage (g) CAC PAC

0.5 35.67 ±5.699a 22.50±1.78 a

1.0 43.99±1.931 ab 27.95±0.99 b

1.5 45.21±0.842 b 32.70±0.76 c

Mean that do not share a letter within the column are significantly different using Tukey Test (p=0.05)

Table 3.4 pH value for CAC and PAC (n=3), T=25oC after adsorption study

Dosage (g) CAC PAC

0.5 7.10 ±0.13 7.10±0.01

1.0 7.43±0.06 7.44±0.01

1.5 7.26±0.10 7.25±0.02

Control 8.25 8.80

Table 3.5 Absorbance recorded at 320nm for CAC and PAC (n=3), T=25oC after adsorption study

Dosage (g) CAC PAC

0.5 3.822 4.021

1.0 3.861 4.049

1.5 3.493 3.965

Control 4.428 4.420

3.4 CAC & PAC Adsorption Capacity

The adsorption capacity for a particular contaminant represents the amount of the contaminant that can be adsorbed on a unit weight of activated carbon consumed at the conditions present


279

in the application. Typical adsorption capacities for moderately adsorbed compounds range from 5 to 30 % of the weight of the carbon (Shafarul, 2011). In this experiment, adsorption capacity of CAC is more effective compare to PAC because of zinc chloride as activating reagent gave the highest surface area and high porous structure to the carbon (Das D, Samal DP, Meikap BC,2015). Thus, it adsorbs more organic contaminants even by using less dosage of CAC adsorbent. The adsorption capacity for CAC and PAC reduce as the dosage increased. It can be due as dosage increased; there are still active sites available in the carbon surface which means higher concentration of POME can be introduced.

Table 3.6 Adsorption Capacity [mg/g] for COD reduction at 25oC (n=3)

Dosage (g) CAC PAC

0.5 28.91±5.77 16.07±1.70

1.0 18.69±0.98 10.63±0.47

1.5 12.87±0.29 8.60±0.24

4. CONCLUSION

This research work has revealed usefulness and effectiveness of activated carbon produced from waste palm oil biomass (EFB). From the experimental information gathered, it has been shown in this study that granular activated carbon of <1.18mm particle size produced from Empty Fruit bunch can effectively remove organic pollutants from waste water effluents of Palm oil mill before the discharge into the river. Based on this study, both CAC and PAC can achieve on removal of COD with significant difference. It was observed for the batch adsorption that the COD was reduced from an initial value of 510 mg/L to 280 mg/L in the first four days by using 1.5 g of chemically activated carbon(CAC) which is the highest removal percentage 45.21% (P=0.030) compared with PAC 32.70% (P=0.00). Hence significant COD removal efficiency rates 35.67%, 43.99% and 45.21% were achieved at different dosage of (0.5g,1.0g,1.5g ) respectively using CAC. Thus, Chemically Activated Carbon (CAC) find more successful in terms of COD removal by activating reagents studied, zinc chloride gave the highest surface area which influences the adsorption of organics matters in POME sample. Therefore, the effectiveness of the activated carbon produced from EFB in the removal of organic contaminants has been established.

5. ACKNOWLEDGEMENTS

FirSt of all, we thank our lecturers from Manipal International University who provided insight and expertise that greatly assisted the research. We also want to thank Dr Loh Soh Kheang and her team from MPOB for helping us on completing the research, and laslty to Mr.Arasu Uttran, Lecturer, Manipal International University for comments that greatly improved the manuscript.


280

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Alam MZ, Muyibi SA, Mansor MF, Wahid R (2007). Activated carbons derived from oil palm empty-fruit bunches: Application problems. J Environ Sci (China);19:pp.103-8.

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Foo, K. Y., and Hameed, B. H. (2011). Preparation of Oil Palm (Elaeis) Empty Fruit Bunch Activated Carbon by Microwave-assisted KOH Activation for the Adsorption of Methylene Blue. Desalination. 275(1–3), 302-305.

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Activated Carbon from Various Nutshells by Chemical Activation with K2CO3. Carbon. 40, 2381-2386.

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282

THE LOW-CARBON TECHNOLOGY: EXPERT VIEW

TOWARDS TECHNOLOGY EXPECTATION TO

ENCOURAGE MALAYSIA URBAN RESIDENTS CARBON-

CAPABILITY BEHAVIOUR

Ani Shazwani Abas1, Mohd Yazid Mohd. Yunos1*, Nor Kalsum Mohd. Isa2, Nor Atiah Ismail1, Faziawati

Abdul Aziz1 1Department of Landscape Architecture, Faculty of Design and Architecture, Universiti Putra Malaysia, 43400

UPM Serdang, Malaysia, 2Department of Geography and Environment, Faculty of Science and Humanity, Sultan Idris University of

Education, Tanjung Malim, Perak,

[email protected]* ,[email protected], [email protected], [email protected],

[email protected]

ABSTRACT

Malaysia, including in the Southeast Asia countries, is one of the most vulnerable regions to

the global warming threats. Even though we are not the highest releases global carbon dioxide

(CO2) countries, community action is essential to reduce the emissions significances. The

carbon-capability behaviour, which promotes people’s ability and motivation to reduce daily

emissions, somehow requires the technology interventions to facilitate such behaviours. This

paper aims to present the expert view towards technology expectation among Malaysia urban

residents in order to encourage their low-carbon capability behaviour. This study uses the

qualitative approach by adopting the content analysis and the focus group discussions held

among expert panels in relevant field. The analysis and discussion briefly discuss on the

expert’s opinion and suggestion towards technological aspects that could assist Malaysia urban

residents to at least perform the low-carbon capability behaviour. The issues concerning on the

low-carbon technology related to urban residents is also highlighted in the summary.

Keywords low-carbon technology, expert view, technology expectation, Malaysia urban

residents

1. INTRODUCTION

It is widely documented that CO2 emissions due to anthropogenic activity are increasingly

either causing or making climate change worse (IPCC, 2007; 2013). The role of local

community towards reducing climate change impact has been discussed before, as they were

locally be impacted by global climate change phenomenon. As many researchers have pointed

out that human activity as the main contributor towards climate change, individual’s behaviour

change should be initiated and taking as a collective action. As the world is experiencing some

of the effects of global warming, community do need to move fast towards low-carbon

community as an effort towards mitigating global climate change. This important step towards

low-carbon community are made up of decisions by government officials at the national, state,

and local levels and by investors, community leaders, and most important of all by actively

engaged citizens working together (Shulman, 2012). As Malaysian government already has

taken the steps towards promoting low-carbon communities by introducing the framework of

low-carbon cities at the national level, hence, in this study, attention was given to the




283

technology interventions and expectations towards promoting behavioural change among

individual and urban residents.

Numerous studies has associated low-carbon community with the pro-environmental

behaviour. Such indicator of low-carbon community normally associated with the energy

saving consumption, renewable energy and technologies, recycling and waste reduction and

mode of transportation, that aims to reduce CO2 emissions (Shulman, 2012; Dawood et al.,

2013; Whitmarsh and O’Neill, 2010; Banister and Hickman, 2011). Nevertheless, Heiskanen

et al., (2010) define low-carbon community as a form of cooperation and collaboration that aim

to reduce the carbon intensity of their members’ lifestyles by providing amenable contexts and

mechanisms that encourage behaviour change. Hence, the issues related to low-carbon

capability behaviour, to certain level must require technology intervention to facilitate people

in performing the behaviours. The introduction of new technologies as an intervention to

promote low-carbon capability behaviour is therefore, undoubted necessary. For that reasons,

this study is focusing on the importance of technology to support low-carbon capability

behaviour and the expert views towards the technology expectations in an urban residential

area, for realizing the transitions of community towards low-carbon. It is also noted that, the

low-carbon technology expectation in this study is related to the technology which allows

people to become more capable in performing the low-carbon capability behaviour (Zhang et

al., 2013, Arinah et al.,2015).

2. METHODOLOGY

This study adopted the qualitative method of content analysis and focus group discussions.

This method is best adopted, as it can reveal a wealth of detailed information and deep insight

from the panel of experts (Eliot, 2005). Besides, focus groups are efficient in providing a wide

overviews of issues interest in cultural groups or subgroups represented (Collector & Module,

2011), in this case the Malaysia urban residents. First, the national and international policies,

plan and framework of several countries was used in the content analysis, to acquire the criteria

needs for technology expectation to assist low-carbon capability behavior. Then, a preliminary

theoretical framework of low-carbon technology expectation is developed.

Afterwards, the focus group discussions is organized involving the Malaysia’s expert

panels. A fifteen panel of experts was carefully selected based on their involvements and

contributions in the low-carbon area. However, only six of panel experts were presented during

the focus group discussions, with several couldn’t attend due to time constraint and

commitment restriction. During the focus group discussions, an evaluation form was circulated

and expert of panels needs to validate on each of the item under the low-carbon technology

expectations. A rich discussions were also held in verification of each item and the discussions

were recorded carefully for further analysis.

3. RESULTS AND DISCUSSIONS

From the Table 1, it is analysed by authors, through the content analysis, that the technology

expectation in facilitating urban residents low-carbon capability behaviour, should cover the

main three aspects which are low-carbon mobility, low-carbon living and housing, and low-

carbon community choices (Ani et al., 2015). In the section A, Item 1, according to E5, it is

actually available at current situation of urban residents. E1 also pointed out on the use of smart


284

phone application technology like Google Maps, Waze and MyTaxi, where people nowadays

can access to help with their daily mobility. Hence, the expert pointed-out on further study that

should focus on how much urban residents found this application technology could help

facilitate them to reduce their daily mobility carbon emissions. Whereas, Item 2 and 4, is found

accepted where this kind of display technologies could help people to keep aware on the

amount of carbon they would emitted by taking the differences type of public and individual

transportation. In contrast with Item 3, it is learnt to be larger scales and beyond the residents

control. It is therefore, suggested to be specify explicitly within the scale of urban residential

area (E4, E5, E6). Besides, Item 5, is realized not suitable for Malaysia community context

(E3). This is due to the emissions of carbon is actually based on the car model itself. Besides,

he convinces that not all urban residents can afford to buy an electric car, due to the element

under national automobile policies, which is not in control of people. Even though the Malaysia

government has provided incentives for hybrid car by lowering the price, and the demand for

hybrid car seems good, however people’s interest towards hybrid car also stops when the

government scheme ended recently (E3). Hence, E4 suggested on focusing how to make the

type of technology affordable and accessible among urban residents.

Meanwhile, in the section B, technology expectations to facilitate low-carbon living

and housing aspects, Item 6, 7, 8, 9 and 11, is accepted by the expert panels, which found very

useful and relevant in current context of urban residents. Item 10, also accepted in facilitating

urban residents to keep aware with the amount of carbon they emitted in daily life, particularly

related to energy and resources use. Yet, E4 suggested on available technology system that has

been develop recently, which is the use of ‘Home Energy Monitoring Systems (HEMS)’.

While, in the section C, technology expectations to facilitate low-carbon community choices,

Item 12 and 15 was acknowledged as pertinent to current situation. Item 14, was also accepted

but with slightly considerations on online shopping to reduce mobility and individual

transportation cost (E1, E5). E3 also recommended on the use of ‘environmentally-friendly’

terms, which much more relevant and easy to be accepted by urban residents. The expert panels

also recommend on the research to investigate the level of urban residents’ awareness and their

commitment towards low-carbon capability behaviour. This is also crucial when various

barriers exist in related to people’s awareness such as individual and social barriers which

further limit their low-carbon behaviour (Whitmarsh et al., 2011).

Table 1 Expert of Panel Views towards Technology Expectation to Support Urban Residents

Low-Carbon Capability Behaviour.

ITEM PROPOSED

UNDER PRELIMINARY

THEORETICAL

FRAMEWORK

EXPERT

VALIDATION

Average Level

of Agreement

(Scale 1-10)

EXPERT VIEW AND

ANALYSIS

A. Technology Expectations to Facilitate Low-Carbon Mobility

1. Technology applications

through smart phone to

access traffic route for

efficient mobility.

7,10,10,9,6,10

Mean = 8.7

E1: Consideration on current

smart phone application like

MyTaxi, Waze etc.

E5: Currently available at local

context

2. Display system on public

transportation and

7,10,7,10,10,10

Mean = 9

Accepted


285

terminal for current traffic

information.

3. Central advance

technology controlling the

traffic route for smooth

traffic and decrease

carbon dioxide (CO2)

emissions.

3,5,8,2,2,3

Mean = 3.8

E1: Not relevant to the residential

concept

E4: Maybe larger scale, unless

specify explicitly within the scale

of urban residential area.

E5/E6: Large scale, refine into

residents scale more on facilities

and connectivity

4. Display system on

individual transport to

show the amount of

carbon discharge for each

kilometre of the journey.

8,10,9,10,10,10

Mean = 9.5

Accepted

5. Individual efficient

transportation like hybrid

car and electric car.

8,10,9,2,2,2

Mean = 5.5

E3: Income constraint among

urban residents

B. Technology Expectations to Facilitate Low-Carbon Living and Housing

6. Energy-efficient

appliances use at home.

9,10,10,10,9,3

Mean = 8.5

Accepted

7. Electrical appliances that

operate base on user’s

movement.

9,10,10,8,9,10

Mean = 9.3

Accepted

8. Electrical devices that

display the amount of

energy use per day

9,10,10,10,9,10

Mean = 9.6

Accepted

9. Technology and rebate

system that rewards based

on energy saved per

month and deducted

through electricity bill

9,10, 10,10,9,10

Mean = 9.6

Accepted

10. Technology development

and the implementation of

monitoring and control

system for carbon dioxide

(CO2) emitted in every

home

9,10, 8,10,9,10

Mean = 9.3

E4/E6: May consider the use of

‘Home Energy Monitoring

Systems (HEMS)’.

11. Technology systems for

rainwater harvesting

9,10,9,7,9,10

Mean = 9

Accepted

C. Technology Expectations to Facilitate Low-Carbon Community Choices

12. Manufacturer, suppliers

and service providers to

provide products and

services that have an

environmentally friendly

tag and low-carbon labels.

9,10,10,8,10,10

Mean = 9.5

Accepted


286

13. Separating local product

and imported product at

shops/mall

3,6,10,8,2,8

Mean = 6.1

E1: Beyond scope area

E4: Certificate and labelling

system needed.

14. Technology application

which help users to

purchase low-carbon

products.

9,10,10,8,9,9

Mean = 9.1

E1/E5: Consideration on online

shopping to reduce

mobility/transportation cost

E3: Change the terms to

environmentally-friendly

15. Technology which

facilitate users to obtain

low-carbon goods and

services on-line.

9,10,10,8,10,10

Mean = 9.5

Accepted

*E1-E6: Representing the six expert panels

4. SUMMARY AND CONCLUSIONS

The expert panels view towards technology expectation which could facilitate urban residents

in performing the low-carbon capability behaviour was discovered to be applicable for the

current context. However, it is also noted that, the common issues related to technology is that

of level of affordability and the payback period, especially the technology for low-carbon living

and housing aspects. For instances, not every urban residents would prefer to purchase energy

efficient appliances at home, as the price would be higher in market. Nevertheless, to promotes

the low-carbon mobility related to public transportation as examples, required an in depth

understanding and the community preferences to increase the use of public transportation

services is also depends on the efficiency and accessibility of the public transport (Lorenzoni

et al., 2007). This is where, such display system suggested in public transportations, will

increase comfort of use among urban residents, and increase the tendency to use the public

transport. According to (Xenias and Whitmarsh, 2013 and Slovic, 2000), there were often

differences in the preferred policy between experts and non-experts or the public. Hence, the

strategies to promote low-carbon technology in the three aspects, among urban residents is also

necessary, in which could help as a solution to achieve low-carbon community in Malaysia.

Hence, further research related to low-carbon technology should focusing on the community

strategies, policies and implementation towards urban residential area.

ACKNOWLEDGEMENTS

This research is founded by Universiti Putra Malaysia (UPM) and Ministry of Higher

Education (KPT) Malaysia, under the research grant ERGS/1/2013/STWN08/UPM/02/1.

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