synopsis report final 19th april

8/13/2019 Synopsis Report Final 19th April

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1. IntroductionThe presence of various contaminants in the water system, arising from the discharge of

industrial effluents containing different toxic substances, is one of the major environmental

issues in the field of waste management. The quality of both surface and ground water is

deteriorating day by day with rapid industrialization and increasing population all around the

world. Typical industrial contaminants such as various dyes, heavy metals, pharmaceutical

compounds etc. in excess of their respective tolerance limits, can be detrimental to aquatic life

and pose potential health hazard (Zadaka et al., 2007). It therefore becomes necessary to remove

such pollutants from the effluent streams before discharging to any water body. Different

techniques are used for removal of pollutants for water but adsorption process is worth

mentioning amongst all as it can be applied for the removal of pollutants even if they present atvery low concentration. Adsorption by activated carbon has been widely used for the removal of

various pollutants due to its simplicity of operation. But the widespread use of activated carbon

is however restricted due its high cost. Therefore, development of low cost adsorbents as an

alternative of commercial activated carbon and application of this low cost adsorbent for the

removal of various pollutants has become a growing field of research.

2. Literature SurveyActivated carbon can be prepared from various agricultural wastes by physical, chemical or

microwave activation method. Generally, a physical process such as, the carbonization process

or the adsorption process is optimized by statistical approach such as, the response surface

methodology (RSM) to determine the optimum process conditions. The response surface

methodology (RSM) is a statistical design procedure that optimizes a process by correlating the

process variables through regression analysis (Lee, et al., 2000). The RSM optimization can be

done through Box-Behnken design (BBD) or central composite design (CCD). Activated carbon

prepared from various sources by carbonization method was used to remove wide verities of

pollutants from water. Nemr et al. (2009) and Khan and Chaudhuri (2009) investigated the

adsorption of Direct Blue 86 from the aqueous solution by using orange peel derived activated

carbon and coconut coirbased activated carbon respectively. In another study, the adsorption of


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ibuprofen was studied by using activated carbons derived from sisal waste (Mestre et al. 2011).

Issabayeva et al. (2006) investigated the adsorption of Pb(II) by using activated carbon derived

from palm shell (Issabayeva et al. 2006) and Sea-buckthorn stones (Mohammadi et al., 2010)

respectively. It was observed in the previous literature that Gaikwad (2011) used coconut shell

based activated carbon for the adsorption of Cu(II). In another investigation the adsorption of

fluoride was investigated by using activated carbon derived from plant materials (Emmanuel et

al., 2008).

Recent research reviews show that exploiting or utilizing local resources to be a current

trend. This leads to developing of technology based on availability of local raw material and its

use for water pollution. Therefore, in the present research an activated carbon was prepared from

a waste scrap wood available locally and then prepared adsorbent was applied to remove

different pollutants from their aqueous phases.

3. Objective of the present researchThe objective of the present research is therefore set as- development of activated carbon

from locally available scrap wood, its characterization and its application for adsorption of

different pollutants from aqueous phase.

4. Steps to achieve the objectivesThe following steps were carried out in order to achieve the objective.

i). Selection of suitable raw material from waste scrap wood available locally. This is carriedout by evaluating the quality of the chars produced through carbonization of various scrap

woods in different cases. Optimization of the carbonization process for the selected raw

material (Acacia Auriculiformis scrap wood). The activation of the char through microwave

treatment to produce activated carbon and its physiochemical characterization.

ii). Adsorption studies with synthetic and real pollutants to establish the applications of theactivated carbon produced.


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5. Work doneThe experimental work comprises of experimental work for preparation of

Char by carbonization of raw material.Microwave activation of the char to produce activated carbon.Adsorption studies with different pollutants in aqueous phase.

5.1 ExperimentalCarbonization

The activated carbon was prepared by carbonization of scrap wood followed by microwave

activation. The carbonization was carried out in a 65-mm i.d tubular furnace where the wood

scraps were heated from ambient temperature to the carbonization temperature at the rate of 4

C/min in a continuous flow of N2. Then the temperature was kept constant for 1h. The product

was then allowed to cool to ambient temperature in presence of N2flow.

Microwave activation

The prepared char sample was then activated in a microwave oven (IF20PG3S) for five

minutes at a constant input power of 800 W and at a frequency of 2450 MHz to develop the

activated carbon. The activated carbon was characterize to determine the following properties

such as, surface area, total pore volume, average pore size, surface morphology, apparent

density, ash content and point of zero charge (pHZPC) property etc.

Adsorption study

The batch adsorption study was carried out by adding 0.1 g of adsorbent into a series of 250

mL conical flasks containing 100 mL adsorbate solution. The flasks were shaken in an incubator

shaker at a constant speed of 200 rpm for 2 h. The aliquots were collected at predetermined time

intervals and centrifuged for 5 min. The supernatant liquids were analyzed for determining the

residual adsorbate concentration. The amount of adsorbate uptake at any time t can be calculated

from the relationship:

Vw

CCq tt

)( 0

(1)


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Where, qt(mg/g) is the amount of adsorbate adsorbed per gram of adsorbent at any time t (min),

V is the volume of solution (L), w is the weight of adsorbent (g), C 0 and Ct are the initial

adsorbate concentration and adsorbate concentration at any time t (mg/L). The equilibrium

study was performed by varying the temperatures (10-50 C). In the equilibrium study, the

adsorbate solutions containing fixed amount of adsorbent were shaken in an incubator shaker till

the equilibrium was attained and then the samples were centrifuged for 5 minutes and were

analyzed to determine the residual adsorbate concentration in the solution. After the equilibrium

study the saturated activated carbon was then washed with distilled water, dried in an oven and

finally was used for the desorption study.

5.2Preparation of the activated carbon from Acacia Auriculiformis scrap woodThe char prepared from Acacia Auriculiformis showed high surface area (442.40 m2/g) and

total pore volume (0.320 cm3/g) with a high carbon yield (29.50%) in comparison to the char

prepared from other wood species such as, Ziziphus Jujube, Cedrus Deodara, Albizzia Lebbek,

Anthecephalus Kadamba. Hence, Acacia Auriculiformis was selected as raw material for the

present study. The surface area, total pore volume and average pore size of the prepared char

were found to increase with increase in temperature up to 700 C but as the temperature was

increased further these values were observed to decrease. Besides, the surface area and total pore

volume increased with the increase in carbonization time and decrease in N2 flowrate.

The carbonization process was optimized statistically by using three level Box-Behnken

design (BBD) with three input variables such as, carbonization temperature (x1,C),

carbonization time (x2, min) and nitrogen flow rate (x3, mL/min) and three output variables such

as, surface area (Y1, m2/g), total pore volume (Y2, cc/g) and the carbon yield (Y3, %). Using

analysis of variance (ANOVA), the model F-value for surface area, total pore volume and carbon

yield were found to be 121.03, 55.16 and 128.03 respectively. The overall determination

coefficient for surface area, total pore volume and carbon yield were observed to be 0.9954, 0.99

and 0.9957 respectively. The regression equation for surface area was:

Y1= 514.20 + 89.29x1+ 8.55x267.41x3+ 17.58x1x2-29.45x1x3-25.72x2x3140.35x1

21.07x22+ 4.05x3

2 (2)The regression equation for total pore volume (Y2) was:


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Y2 = 0.36 + 0.052x1+ 0.019x2 0.009x3+ 0.018x1x2+ 0.006x1x3+0.019x2x30.079x1 -

0.01 x22 0.004 x3

2 (3)

The regression equation for carbon yield was:

Y3 = 20.326.99x11.91x2+1.32x3-0.94x1x2-0.24x1x3+1.50x2x3+1.25 x1- 2.09 x2

+ 0.87

x32 (4)

The optimum values of carbonization temperature, time and nitrogen flow rate were found to be

750 C, 3.5 h and 300 mL/min respectively. The char prepared under this optimum condition

(C750N) was found to have surface area, total pore volume and average pore size of 514.2 m2/g,

0.36 cc/g and 27.99 . The prepared char was further treated in a microoven to prepare the

activated carbon (AC750NMW5) which had surface area, total pore volume and average pore

size of 695 m2/g, 0.50 cc/g and 28.55 . The ash content, density and point of zero charge

(pHZPC) of the prepared activated carbon were found to be 2 %, 2.4 g/cc and 7.92 respectively.

The maximum Methylene Blue adsorption capacity of the microwave assisted activated carbon

(AC750NMW5) was fond to be 413 mg/g which was close to the adsorption capacity of

commercial activated carbon (414.3 mg/g).

5.3Adsorption studies to evaluate the activated carbon preparedThe prepared activated carbon was used to adsorp different pollutants from their aqueous phase.

5.3.1 Application of microwave assisted activated carbon for the removal of DB 86Through the batch adsorption study, the DB 86 adsorption capacity of 85.71 mg/g was

obtained with solution pH of 2, initial concentration of 100 mg/L, adsorbent concentration of

1.00 g/L, particle size and agitation speed of 61-150 m (average size 105.5 m) and 200 rpm.

The Langmuir isotherm was found to be best correlated with high values of regression

coefficient (R2=0.99) and lower value of chi-squared (2 < 2.6) among various isotherms

investigated. The monolayer adsorption capacity increased from 184.98 to 487.81 mg/g with

increase in temperature from 283-313K. The adsorption data was best fitted to the pseudo

second-order model (R2>0.99). The DB 86 adsorption process was found to be endothermic in

nature. The DB 86 adsorption capacity of AC750NMW5 (484.57 mg/g ) was found to

comparable with the adsorption capacity of the commercial activated carbon (497.93 mg/g).The

activated carbon was found to have a desorption efficiency of 48.93%.


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The DB 86 adsorption process was optimized by using Box Behnken design (BBD) with

five input variables namely the solution pH (x1), initial adsorbate concentration (x2), adsorbent

concentration (x3), contact time (x4) and temperature (x5) and one output variable as the amount

of DB 86 adsorbed per gram of adsorbent (Y, mg/g). Using ANOVA, the model F value and

determination coefficient value were found to be 59.89 and 0.979 respectively. The regression

equation for DB 86 adsorption capacity was:

Y = 14.259.73x1 + 7.18x211.18x3 + 3.13x4 + 4.85x5 - 9.63x1x2 + 5.34x1x3 +3.18x1x4

+1.06x1x5 -12.05x2x3+ 1.23x2x4 +0.26x2x54.4x3x45.12x3x5 + 0.03x4x5+ 8.02x12+0.02x2

2

+ 4.56x321.31x4

2+ 2.06x52 (5)

The optimum condition for DB 86 adsorption was obtained at pH of 2, initial concentration 100

mg/L, adsorbent concentration 1 g/L, contact time 120 min and temperature of 30 C. At this

optimum condition, the model predicted (85.95 mg/g) and experimental (85.71 mg/g) DB 86

adsorption capacity were found to be close to each other.

5.3.2Application of microwave assisted activated carbon for the removal of ibuprofenThe batch adsorption study revealed that the ibuprofen adsorption capacity of 59.98 mg/g

was obtained at pH, initial concentration and adsorbent concentration of 2, 60 mg/L and 1 g/L

respectively and with particle size of 61-150 m (average size 105.5 m), agitation speed of 200

rpm. In comparison to other isotherm models, Langmuir isotherm exhibited a better fit (R2=0.99

and 2


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as the output variable. The model F value and overall determination coefficient value were found

to be 55.55 and 0.9780 respectively. The regression equation for ibuprofen adsorption was

Y = 17.59- 3.18x1 + 9.60x2 - 11.34x3 + 0.79x4 - 1.40x5 - 1.71x1x2 + 0.28x1x3 - 0.81x1x4 -

1.95x1x5 - 5.94x2x3+ 0.076x2x4- 0.20x2x5 + 0.90x3x4+ 0.19x3x5 -0.35x4x5 - 1.37x12

-0.83x22

+ 6.31x3

2 - 1.29x42- 2.62x5

2 (6)

The optimum ibuprofen adsorption condition was found to be at pH 2, initial concentration 60

mg/L, adsorbent concentration 1g/L, contact time 110 min and temperature 30 oC. The

experimental (59.9 mg/g) and model-predicted (54.00 mg/g) ibuprofen adsorption capacity at

optimum conditions were found to be in reasonable agreement with each other.

5.3.3Application of microwave assisted activated carbon for the removal of Pb(II)From the batch adsorption study, the Pb(II) adsorption capacity of 117.55 mg/g was obtained

at pH, initial concentration and adsorbent concentration of 6, 120 mg/L and 1g/L respectively

and with particle size of 61-150 m (average size 105.5 m), agitation speed of 200 rpm. The

equilibrium analysis showed that the data exhibited a better fit to Langmuir isotherm and the

monolayer adsorption capacity was found to be 199.90 mg/g at 303K which was pretty close to

the adsorption capacity of commercial activated carbon (200 mg/g). The monolayer adsorption

capacity decreased from 199.98 to 191.04 mg/g when the temperature increased from 283 to 323

K. The experimental data best fitted to pseudo second order model. The Pb(II) desorption

efficiency of the activated carbon was found to be 75.04%.

The Pb(II) adsorption process was successfully optimized by using a central-composite

design (CCD) with solution pH (x1), adsorbent concentration (x2), initial adsorbate concentration

(x3), contact time (x4) and temperature (x5) as input variables and amount of Pb(II) adsorbed per

gram of adsorbent or Pb(II) adsorption capacity Y (mg/g) was chosen as the output variable. The

model F value and overall determination coefficient were found to be 228 and 0.998

respectively. The regression equation for optimization of Pb(II) adsorption process was:

Y = 60.17+ 7.57x15.84x2 + 6.61x3 + 1.43x412.83x5 + 3.56x1x22.82x1x31.83x1x4

4.59x1x5 2.31x2x3 1.50x2x4 + 8.42x2x5 + 3.37x3x4 3.12x3x5 -0.94x4x5 4.11x12

2.71x222.79x3

25.51x4

27.15x52 (7)


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The optimum Pb(II) adsorption condition was found to be at pH 6, initial concentration 120

mg/L, adsorbent concentration 1.5 g/L, contact time 80 min and temperature 20oC. The

experimental (79.43 mg/g) and model-predicted (76.60 mg/g) Pb(II) adsorption capacity at

optimum conditions were found to be in reasonable agreement with each other.

5.3.4Application of microwave assisted activated carbon for the removal of fluorideThe fluoride adsorption capacity of 8.8 mg/g was obtained at pH, initial concentration

and adsorbent concentration of 4.4, 10 mg/L, and 1g/L respectively and with particle size of 61-

150 m (average size 105.5 m), agitation speed of 200 rpm. The equilibrium analysis showed

that the data exhibited a better fit to Langmuir isotherm and the monolayer adsorption capacity

was found to be 18.95 mg/g at 303K which was comparable with adsorption capacity of

commercial activated carbon (19.30 mg/g). The monolayer adsorption capacity increased from

18.95 to 19.26 mg/g when the temperature increased from 303 to 323 K. The experimental data

best fitted to pseudo second order model (R2=0.99). The fluoride adsorption process was

endothermic in nature having enthalpy of 6.094 kJ/mol. The fluoride desorption efficiency of this

activated carbon was found to be 80.54%.

5.3.5Application of microwave assisted activated carbon for the removal Cu(II)Through the batch adsorption study, the Cu(II) adsorption capacity of 99.96 mg/g using

synthetic solution was obtained at pH, initial concentration and adsorbent concentration of 6, 100

mg/L, and 1g/L respectively and with particle size of 61-150 m (average size 105.5 m),

agitation speed of 200 rpm. Langmuir isotherm exhibited better fit to the equilibrium data and

monolayer adsorption capacity of Cu(II) was found to be 398.52 mg/g which was quite close to

the adsorption capacity of commercial activated carbon (399.74 mg/g). The equilibrium Cu(II)

adsorption capacity decreased from 398.52-386.29 mg/g as the temperature was increased from

303-323 K. Pseudo second order model exhibited a better fit (R2 =.99) in comparison to other

studied kinetic models. The Cu(II) desorption efficiency was found to be 81.60%.

An effluent from copper plating industry consisting of a Cu(II) concentration of 250 mg/L

and chemical oxygen demand (COD) of 160 mg/L was also selected for the study. It was

observed that the Cu(II) adsorption capacity of 99 mg/g (99% removal) was achieved at pH,

initial concentration and adsorbent concentration of 6, 100 mg/L, and 1g/L respectively and with


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particle size of 61-150 m (average size 105.5 m), agitation speed of 200 rpm. The kinetic data

exhibited better fit to pseudo-second-order model.

6. ConclusionIn the present research an activated carbon activated carbon (AC750NMW5) was developed

by microwave activation of the char prepared through carbonization of Acacia Auriculiformis

scrap wood at a temperature of 750 oC for 3.5 h in presence of nitrogen (N2) flow (300 mL/min).

The prepared activated carbon was used to remove a textile dye (Direct Blue 86), a

pharmaceutical compound (ibuprofen), an inorganic pollutant (fluoride) and heavy metals (Pb(II)

and Cu(II)) through batch adsorption study. The prepared activated carbon was found to have a

DB 86 and ibuprofen adsorption capacity of 85.71 mg/g and 59.98 mg/g respectively. The

activated carbon was also found to have good adsorption capacity for fluoride (8.8 mg/g) andvarious heavy metals such as, Pb(II) and Cu(II). The Pb(II) and Cu(II) adsorption capacity of the

prepared activated carbon were found to be 117.55 mg/g and 99.96 mg/g. The activated carbon

also exhibited good adsorption capacity (99 mg/g) for removal of Cu(II) from industrial effluent.

7. Contribution made by scholarDevelopment of an effective adsorbent by carbonization of locally available scrap wood is

studied in detail. The adsorption efficiency of the prepared activated carbon for different

pollutants is also explored for the first time. The optimization of the adsorption process is also

investigated. The publications resulted from this research work are given bellow.

8. PublicationBasu, J.K., Dutta, M., 2011. Application of statistical design approach to develop a low costactivated carbon for the removal of textile dye Direct Blue 86. Int. J. Environ. Dev. 8 (2), 217-239.

Dutta, M., Ghosh, P., Basu, J.K., 2012. Statistical optimization for the prediction of ibuprofenadsorption capacity by using microwave assisted activated carbon. Arch. Appl. Sci. Res. 4 (2),1053-1060.

Dutta, M., Ray, T., Basu, J.K., 2012. Batch adsorption of fluoride ions onto microwave assistedactivated carbon derived from Acacia Auriculiformis scrap wood. Arch. Appl. Sci. Res. 4 (1),536-550.


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Dutta, M., Basu, J.K., 2011. Application of response surface methodology for the removal ofMethylene Blue by Accacia Auriculiformis scrap wood char. Res. J. Environ. Toxic. 5 (4), 266-278.

Dutta, M., Basu, J.K., 2012. Statistical optimization for the adsorption of Acid Fuchsin onto thesurface of carbon alumina composite pellet: an application of response surface methodology. J.Environ. Sci. Technol. 5 (1), 42-53.

Dutta, M., Basu, J.K., 2012. Application of Artificial Neural Network for Prediction of Pb(II)Adsorption Characteristics. Environ. Sci. Pollut. Res., [Published, DOI 10.1007/s11356-012-1245-x].

8.1 ReferencesEmmanuel, K.A., Ramaraju, K.A., Rambabu, G., Veerabhadra Rao, A., 2008. Removal offluoride from drinking water with activated carbons prepared from HNO3 activation - acomparative study. Rasayan J. Chem., 1 (4), 802-818.

Gaikwad, R.W., 2011. Mass transfer studies on the removal of copper from wastewater usingactivated carbon derived from coconut shell. J. University Chem. Technol. Metallurgy 46 (1),53-56.

Gurses, A., Yalcin, M., Dogar, C., 2001. Electrocogulation of some reactive dyes: a statisticalinvestingation of some electrochemical variables. Waste Manage. 491499.

Issabayeva, G., Aroua, M.K., Sulaiman, N.M.N., 2006. Removal of lead from aqueous solutionson palm shell activated carbon. Bioresour. Technol. 97 (18), 23502355.

Khan, T., Chaudhuri, M., 2009. Adsorptive removal of Direct Blue 86 by coconut coir activated

carbon. Environ. Sci. Technol. Conf. 7-8, 237-241.Lee, J., Ye, L., Landen Jr, W.O., Eitenmiller, R.R., 2000. Optimization of an extractionprocedure for the quantification of vitamin E in tomato and broccoli using response surfacemethodology. J. Food Comp. Anal. 13 (1), 4557.

Mestre, A.S., Bexiga, A.S., Proena, M., Andrade, M., Pinto, M.L., Matos, I., Fonseca, I.M.,Carvalho, A.P., 2011. Activated carbons from sisal waste by chemical activation with K2CO3:kinetics of paracetamol and ibuprofen removal from aqueous solution. Bioresour. Technol. 102(17), 82538260.

Mohammadi, S.Z., Karimi, M.A., Afzali, D., Mansouri, F., 2010. Removal of Pb(II) from

aqueous solutions using activated carbon from Sea-buckthorn stones by chemical activation.Desalination 262 (1-3), 8693.

Nemr, A.E., Abdelwahab, O., El-Sikaily, A., Khaled, A., Removal of direct blue-86 fromaqueous solution by new activated carbon developed from orange peel. J. Hazard. Mater. 161(1), 102110.


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Zadaka, D., Mishael, Y.G., Polubesova, T., Serban, C., Nir, S., 2007. Modified silicates andporous glass as adsorbents for removal of organic pollutants from water and comparison withactivated carbons. Appl. Clay Sci. 36 (1-3), 174181.

synopsis report final 19th april

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