optimisation of coagulation process in water...
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OPTIMISATION OF COAGULATION PROCESS IN WATER TREATMENT
PLANT USING STATISTICAL APPROACH
MUZAFFAR BIN ZAINAL ABIDEEN
A thesis submitted in fulfilment of the
requirements for the award of the degree of
Doctor of Philosophy (Civil Engineering)
Faculty of Civil Engineering
Universiti Teknologi Malaysia
JUNE 2016
ii
I declare that this thesis entitled “Optimisation Of Coagulation Process In Water
Treatment Plant Using Statistical Approach” is the result of my own research except
as cited in the references. This thesis has not been accepted for any degree and is not
concurrently submitted in candidature of any other degree.
Signature : ………………………………
Name : MUZAFFAR BIN ZAINAL ABIDEEN
Date : 5th JUNE, 2016
iii
Love, Thoughts and Du’a to
my late mak (Raja Arbaiah) and abah (Hj Zainal Abideen);
my beloved wife, Dzurina;
my children, Iffah, Harraz, Asyraf and Ammar;
my lovely makcik (Hjh Jamaliah) and mama (Hjh Rokiah).
iv
ACKNOWLEDGMENTS
In the name of Allah, the Most Gracious, the Most Merciful. All the praises and thanks are to Allah, the Lord of the Alamin. May His peace and blessings be upon His messenger, Prophet Muhammad Sallahu Alaihi Wassalam, his family and his companions.
First and foremost, I would like to express my gratefulness to Allah Azza wa
Jalla for giving me the ability and strength to complete my doctorate study. I sincerely extend gratitude and appreciation to my main supervisor, Professor Dr. Azmi bin Aris, for very many reasons, especially for his guidance, advice, patience and words of wisdom. His confidence in me and his undivided support given over countless days and nights, have been very important for me in completing this long and tumultuous task. My thanks also go to Associate Professor Dr. Zaiton binti Abdul Majid and Associate Professor Dr. Fadhilah binti Yusof for serving as co-supervisors. Their help and commitment in the discussion and interpretation of results presented in this thesis are immensely invaluable.
I would also like to take this opportunity to thank my parents and my parents-
in-law for their love and support throughout my life. My wholehearted love and thanks are also dedicated to my beloved wife, Dzurina; the apples of my eye, Iffah, Harraz, Asyraf and Ammar; for their continuous du’a, sacrifice and undivided support throughout this study. My beloved friends all over the world and especially in Johor, whom I have considered to be my brothers and sisters, have helped me a lot, physically and emotionally. They, as well as all family members deserve my utmost thanks too.
My appreciation also goes to Syarikat Air Johor Holdings for providing fund
and permitting me to carry out my study at the Bandar Tenggara, Sungai Gembut and Sri Gading Water Treatment Plants. I would also like to thank the Ministry of Higher Education (MOHE) for generously awarding me the scholarship. Last but not least, I would like to thank Universiti Teknologi Malaysia, and especially the Faculty of Civil Engineering and Faculty of Science, for allowing me to use their laboratories, as well as to all who contributed directly or indirectly in accomplishing this thesis.
v
ABSTRACT
The typical jar test practice at water treatment plants to determine the optimum coagulation conditions is statistically inappropriate as it is based on one-factor-at-a-time (OFAT) approach. This approach, which does not cover the whole experimental space, could miss the actual optimum values results in higher cost and less effective coagulation performance. Additionally, the jar test exercise is time consuming and is therefore conducted once a day or when it is really needed. This study carried out a long-term comparison between the use of Response Surface Method (RSM) and the traditional (a modified OFAT) jar test in optimising the coagulation process. The study was carried out at Bandar Tenggara WTP (BTWTP), Sungai Gembut WTP (SGWTP) and Sri Gading WTP (SRGWTP) as these WTPs have different raw water characteristics. Characterisation of natural organic matters (NOMs) in terms of dissolved organic carbon (DOC) and UV254 and their removal via coagulation process were explored. The relationship between the raw water characteristics and coagulation optimum conditions were also developed. The results showed that the RSM and traditional approaches acquired almost identical optimum coagulation conditions at BTWTP and SGWTP. At SRGWTP, RSM technique was found to be better than the traditional method as the coagulant (alum) and flocculant (polymer) optimum concentrations produced by the RSM technique were respectively 50% and 20% of the optimum values obtained by the traditional method. The raw waters of BTWTP and SGWTP were identified as hydrophilic, non-humic, with low molecular mass of NOMs. At optimum coagulation conditions (based on turbidity removal), the average DOC and UV254 removals were about 11% and 70%, respectively. The models predicting optimum pH and coagulant dosing from raw water quality data were formulated from the RSM and traditional approach and was found to be reliable. From the models, it was found that NH3–N in the raw water at BTWTP and turbidity, Mn and NH3–N in the raw water at SGWTP did not affect the optimum coagulation conditions. The detail optimisation model derivation procedures were also developed.
vi
ABSTRAK
Ujian balang yang biasa digunakan untuk menentukan keadaan optimum koagulasi adalah tidak tepat secara statistik kerana ia menggunakan pendekatan satu-faktor-dalam-satu-masa (OFAT). Pendekatan yang tidak merangkumi keseluruhan ruang eksperimen ini, mungkin terlepas di dalam mendapatkan nilai optimum sebenar yang menyebabkan peningkatan kos serta menghasilkan prestasi koagulasi yang kurang efektif. Tambahan lagi, pelaksanaan ujian balang agak mengambil masa yang panjang dan oleh itu, ia hanya dilakukan sehari sekali atau apabila berkeperluan. Kajian ini membuat perbandingan jangka panjang di antara penggunaan ujian balang berasaskan Kaedah Permukaan Maklumbalas (RSM) dengan ujian balang berasaskan kaedah tradisional (OFAT Terubahsuai) di dalam mengoptimumkan proses koagulasi. Kajian dilaksanakan di Loji Olahan Air Bandar Tenggara (BTWTP), Sungai Gembut (SGWTP) dan Sri Gading (SRGWTP) kerana loji-loji ini mempunyai ciri-ciri air mentah yang berbeza. Pencirian bahan organik semulajadi (NOM) dalam bentuk karbon organik terlarut (DOC) dan UV254 serta penyingkirannya melalui proses koagulasi juga diterokai. Hubungan di antara ciri-ciri air mentah dan keadaan optimum koagulasi juga dihasilkan. Berdasarkan pemerhatian, kaedah RSM dan tradisional yang dijalankan di BTWTP dan SGWTP memberikan keadaan optimum yang hampir serupa. Di SRGWTP, kaedah RSM yang dilaksanakan didapati lebih baik daripada kaedah tradisional kerana dos optimum koagulan (alum) dan flokulan (polimer) yang diperoleh daripada kaedah RSM adalah masing-masing 50% dan 20% daripada dos optimum yang diperoleh melalui kaedah tradisional. Air mentah dari BTWTP dan SGWTP dikenalpasti mengandungi NOM yang hidrofilik, bukan humik dan rendah jisim molekulnya. Pada keadaan koagulasi yang optimum (berasaskan penyingkiran kekeruhan), purata penyingkiran DOC dan UV254 adalah masing-masing sebanyak kira-kira 11% dan 70%. Model-model yang dijanakan untuk meramalkan hubungan di antara dos koagulan dan pH optimum dengan data kualiti air mentah melalui pendekatan RSM dan tradisional, didapati boleh dipercayai. Menerusi model-model ini, kandungan NH3–N di dalam air mentah di BTWTP dan kekeruhan, Mn dan NH3–N di dalam air mentah di SGWTP ini tidak memberi kesan terhadap keadaan optimum koagulasi loji terbabit. Perincian tentang prosedur penerbitan model pengoptimuman juga dihasilkan di dalam kajian ini.
vii
TABLE OF CONTENTS
CHAPTER TITLE PAGE DECLARATION ii DEDICATION iii ACKNOWLEDGMENT iv ABSTRACT v ABSTRAK vi TABLE OF CONTENTS vii LIST OF TABLES xii
LIST OF FIGURES xv LIST OF ABBREVIATIONS xxiv LIST OF SYMBOLS xxvi LIST OF APPENDICES xxvii
1 INTRODUCTION 1 1.1 Preamble 1 1.2 Problem Statement 3 1.3 Objectives of Study 6 1.4 Scope of Study 7 1.5 Significance of Study 7 1.6 Thesis Outline 9 2 LITERATURE REVIEW 10 2.1 Impurities in Water 10 2.1.1 Colloids 10
viii
2.1.2 Natural Organic Matters 11
2.1.3 Removal of Natural Organic Matters by Coagulation
16
2.2 Coagulation Process 18 2.2.1 Theory of Coagulation Process 18 2.2.2 Mechanisms of Coagulation 22 2.2.2.1 Double Layer Compression 23 2.2.2.2 Adsorption and Charge Neutralisation 24 2.2.2.3 Sweep Coagulation 27 2.2.2.4 Adsorption and Interparticle Bridging 27 2.2.2.5 Complexation and Co-precipitation 28 2.2.3 Factors Affecting Coagulation Process 29 2.2.3.1 Characteristics of Raw Water 31 2.2.3.2 Temperature 32 2.2.3.3 Mixing 32 2.2.3.4 pH 34 2.2.3.5 Coagulants and Coagulant Aids
(Flocculants)
38 2.2.4 Determination of Optimum Condition for
Coagulation Process
44 2.2.4.1 Measurement of Zeta Potential 44 2.2.4.2 Jar Test 44 2.3 Design of Experiments: Traditional versus Statistical 45 2.3.1 Response Surface Method 47 2.4 Conclusions 52
3 METHODOLOGY 53 3.1 Introduction 53 3.2 Study Sites 53 3.3 Materials and Equipment 57 3.4 Analytical Procedures 57 3.4.1 Temperature and pH 60 3.4.2 Turbidity 60 3.4.3 Colour 60 3.4.4 Aluminium 61
ix
3.4.5 Iron (III), Manganese And Ammonium Ions 61 3.4.6 Total Dissolved Solids 62 3.4.7 Characterisation of Natural Organic Matters 62 3.4.7.1 Dissolved Organic Carbon 63 3.4.7.2 UV254 Absorbance 64 3.5 Experimental Procedures 64 3.5.1 Historical Data Collection 64 3.5.2 Determination of Raw Water Quality Parameters 65 3.5.3 Jar Test Procedure 65
3.5.3.1 Preparation of Stock Solution 66 3.5.3.2 Traditional Jar Test 67
3.5.3.3 Response Surface Methodological Jar Test 69 3.5.3.4 Optimum Conditions for Jar Tests 70 3.5.4 Development of Statistical Models 71 3.5.5 Natural Organic Matters Characteristics and
Removal
74 3.5.6 Development of Standard Procedure 74
4 OPTIMISATION OF JAR TESTS AND NATURAL ORGANIC MATTERS REMOVAL
75
4.1 Introduction 75
4.2 Characteristics of the Raw Water 76 4.2.1 Bandar Tenggara WTP 76
4.2.2 Sungai Gembut WTP 86 4.2.3 Sri Gading WTP 95
4.2.4 Conclusion on the Raw Water Quality Parameters at the three WTPs
101
4.3 Derivation of Jar Test Experimental Conditions 104 4.3.1 Chemicals Dosage and operating pH for Traditional
Jar Test
105 4.3.1.1 Bandar Tenggara WTP 105 4.3.1.2 Sungai Gembut WTP 107 4.3.1.3 Sri Gading WTP 109 4.3.1.4 Summary of Chemicals Dosage and
Operating pH for Traditional Jar Tests
111
x
4.3.2 Chemicals Dosing and operating pH for Response Surface Methodology Jar Test
112
4.3.2.1 Bandar Tenggara WTP 113 4.3.2.2 Sungai Gembut WTP 115 4.3.2.3 Sri Gading WTP 116 4.4 Comparison between Traditional and RSM Jar Test 116 4.4.1 Bandar Tenggara WTP 118 4.4.1.1 Determination of Optimum Coagulation
Conditions from Traditional and RSM Jar Test at Bandar Tenggara WTP
118 4.4.1.2 Verification of RSM Jar Test Optimisation
Experimental Results at Bandar Tenggara WTP
130 4.4.1.3 Traditional versus RSM Optimisation at
Bandar Tenggara WTP
132 4.4.2 Sungai Gembut WTP 136 4.4.2.1 Determination of Optimum Coagulation
Conditions from Traditional and RSM Jar Test at Sungai Gembut WTP
136 4.4.2.2 Verification of RSM Jar Test Optimisation
Experimental Results at Sungai Gembut WTP
148 4.4.2.3 Traditional versus RSM Optimisation at
Sungai Gembut WTP
149 4.4.3 Sri Gading WTP 155 4.4.3.1 Determination of Optimum Coagulation
Conditions from Traditional and RSM Jar Test at Sri Gading WTP
155 4.4.3.2 Traditional versus RSM Optimisation at Sri
Gading WTP
166 4.4.4 Conclusions on Comparison between Traditional
and RSM Jar Test
172 4.5 Natural Organic Matters Removal By Coagulation
Process
173
4.5.1 Natural Organic Matter Removal Through Traditional Jar Test
173
4.5.1.1 Bandar Tenggara WTP 173
xi
4.5.1.2 Sungai Gembut WTP 177
4.5.2 Natural Organic Matter Removal at Optimum Turbidity Removal Conditions by Traditional Jar Test
180
4.5.2.1 Bandar Tenggara WTP 180
4.5.2.2 Sungai Gembut WTP 183 4.5.3 Conclusion on Natural Organic Matters Removal
Rates by Traditional Jar Test at Bandar Tenggara and Sungai Gembut WTPs
186
5 REGRESSION MODEL – FINDINGS AND
DERIVATION PROCEDURES
187 5.1 Introduction 187 5.2 Establishment of Statistical Models 187
5.2.1 Bandar Tenggara WTP 188 5.2.2 Sungai Gembut WTP 192
5.2.3 Sri Gading WTP 197 5.2.4 Validation of the Statistical Models 203
5.2.4.1 Validation at Bandar Tenggara WTP 204 5.2.4.2 Validation at Sungai Gembut WTP 208
5.2.5 Conclusions on the Statistical Models Findings 211 5.3 Statistical Models Derivation Procedure 214 5.3.1 Historical Data Gathering 216 5.3.2 Regression Models Generation 216 5.3.3 Model Validation and Selection 219 5.3.4 Conclusion on Statistical Models Derivation
Procedure
220 6 CONCLUSIONS AND RECOMMENDATIONS 221 6.1 Conclusions 221 6.2 Recommendations 223 REFERENCES 225 Appendices A – C 243 – 279
xii
LIST OF TABLES
TABLE NO. TITLE PAGE
2.1 Selected review of techniques applied to characterise
NOM
14
2.2 NOM and turbidity recorded for some natural water 16
2.3 SUVA, composition of NOM, coagulation process and
DOC removal (Matilainen et al., 2010)
17
2.4 Selected studies on effect of temperature on coagulation
efficiency
33
2.5 Selected studies on effect of mixing on coagulation
efficiency
35
2.6 Selected studies on effect of pH on coagulation efficiency 39
2.7 Summary on coagulants and flocculants 40
3.1 List of equipment used in the study 58
3.2 List of chemicals and reagent used in the study 59
4.1 UV254 versus raw water sources 84
4.2 Summary of the raw water quality parameters at Bandar
Tenggara, Sungai Gembut and Sri Gading WTP
103
4.3 Ranges of PAC and pH dosage used in the traditional jar
test at Bandar Tenggara WTP
106
4.4 Ranges of alum and pH dosage used in the traditional jar
test at Sungai Gembut WTP
108
4.5 Ranges of initial pH, alum, and polymer concentrations
used in the traditional jar test at Sri Gading WTP
110
xiii
4.6 Summary of Chemicals Dosage and operating pH for
Traditional Jar Tests at Bandar Tenggara, Sungai Gembut
and Sri Gading WTPs
112
4.7 RSM Jar Test conditions for Bandar Tenggara WTP 114
4.8 RSM Jar Test conditions for Sungai Gembut WTP 116
4.9 RSM Jar Test conditions for Sri Gading WTP 117
4.10 Raw water quality of Bandar Tenggara WTP 119
4.11 Traditional jar test result for Bandar Tenggara WTP 120
4.12 Experimental range and levels of factors for Bandar
Tenggara WTP
120
4.13 CCD and response results for the study of two
experimental factors (variables) in coded units for Bandar
Tenggara WTP
121
4.14 ANOVA results for response parameters in RSM jar test 123
4.15 Experimental and predicted values of the responses at the
optimum levels predicted by RSM
130
4.16 Raw water quality of Sungai Gembut WTP 137
4.17 Traditional jar test result of Sungai Gembut WTP 138
4.18 Experimental range and levels of factors of Sungai
Gembut WTP
139
4.19 CCD and response results for the study of two
experimental factors (variables) in coded units for Sungai
Gembut WTP
140
4.20 ANOVA results for response parameters in RSM jar test 141
4.21 Experimental and predicted values of the responses at the
optimum levels predicted by RSM at Sungai Gembut
WTP
148
4.22 Water quality parameters for raw water sample from Sri
Gading WTP
155
4.23 Traditional jar test result for Sri Gading WTP 156
4.24 Experimental range and levels of factors for Sri Gading
WTP
156
xiv
4.25 CCD and response results for the study of three
experimental factors (variables) in coded units for Sri
Gading WTP
157
4.26 ANOVA results for response parameters in RSM jar test 159
4.27 Experimental and predicted values of the responses at the
optimum levels predicted by RSM at Sri GadingWTP
161
4.28 Comparison between traditional, direct reading from
RSM table and RSM optimisation techniques on the
amount and cost of chemicals at Sri Gading WTP
168
4.29 Raw and treated turbidity, DOC, UV254 and SUVA at
optimum traditional jar test conditions based on the
turbidity, settling pH and residual aluminium at Bandar
Tenggara WTP
182
4.30 Raw and treated turbidity, DOC, UV254 and SUVA at
optimum traditional jar test conditions based on the
turbidity, settling pH and residual aluminium at Sungai
Gembut WTP
185
5.1 Final “refined” regression models for Sungai Gembut
WTP
209
xv
LIST OF FIGURES
FIGURE NO. TITLE PAGE
1.1 Design of Experiment; (a) OFAT Approach and (b) All
Factors Varied Systematically Approach
4
2.1 Hypothetical molecular structure of humic acid
(Matilainen et al., 2010)
12
2.2 Schematic diagram showing the electrical double layer
and potentials (Sawyer et al., 1994)
20
2.3 Forces acting between colloids (Peavy et al., 1995) 22
2.4 (a) Forces acting on colloids without the presence of
chemical coagulants; (b) Compression of the double-layer
charge on colloids (destabilisation) by addition of
chemical coagulants (Hammer and Hammer, 2005).
24
2.5 Interparticle bridging with polymers (Hammer and
Hammer, 2005)
28
2.6 The model interaction of coagulant hydrolysed species and
organic matters (Yan et al., 2008a)
30
2.7 OFAT Jar Test Experimental Approach 46
2.8 Graphical representation between factors and response in
RSM (Mouafi et al., 2016)
48
2.9 Central Composite Design (CCD) of a RSM (Multifactor
RSM Tutorial, 2007)
49
3.1 Research Framework 54
xvi
3.2 Locations of (a) the WTPs on the Peninsular Malaysia
map; (b) Bandar Tenggara WTP and Sungai Pengeli; (c)
Sungai Gembut WTP and Sungai Gambul; (d) Sri Gading
WTP and Sungai Bekok
55
3.3 The WTPs involved in the study: (a) Bandar Tenggara;
(b) Sungai Gembut and (c) Sri Gading
56
4.1 Raw water pH profile of Bandar Tenggara WTP from
November 2008 to December 2009
77
4.2 Raw water turbidity profile of Bandar Tenggara WTP
from November 2008 to December 2009
78
4.3 Raw water colour profile of Bandar Tenggara WTP from
November 2008 to December 2009
78
4.4 Variation of NH3–N and Fe present in raw water of
Bandar Tenggara WTP (November 2008 – December
2009)
79
4.5 Variations of Al levels in raw water of Bandar Tenggara
WTP from November 2008 to December 2009
80
4.6 Mn profile in raw water of Bandar Tenggara WTP from
November 2008 to December 2009
81
4.7 DOC profile in raw water of Bandar Tenggara WTP
(April – July 2011)
82
4.8 UV254 profile in raw water of Bandar Tenggara WTP
(April – July 2011)
83
4.9 SUVA profile in raw water of Bandar Tenggara WTP
(April – July 2011)
85
4.10 Raw water pH profile of Sungai Gembut WTP in 2007,
and June 2008 to January 2010
87
4.11 Raw water turbidity profile of Sungai Gembut WTP in
2007, and June 2008 until January 2010
88
4.12 Raw water colour profile of Sungai Gembut WTP in
2007, and June 2008 to January 2010
89
4.13 Raw water Fe profile of Sungai Gembut WTP in 2007,
and June 2008 to January 2010
90
xvii
4.14 Raw water NH3-N profile of Sungai Gembut WTP in
2007, and June 2008 to January 2010
90
4.15 Raw water Al profile of Sungai Gembut WTP in 2007,
and June 2008 to January 2010
91
4.16 Raw water Mn profile of Sungai Gembut WTP in 2007,
and June 2008 to January 2010
92
4.17 Raw Water DOC profile of Sungai Gembut WTP (March
– July 2011)
93
4.18 Raw Water UV254 profile of Sungai Gembut WTP (March
– July 2011)
94
4.19 Raw Water SUVA profile of Sungai Gembut WTP
(March – July 2011)
95
4.20 pH profile of raw water of Sri Gading WTP in 2007, and
from May to December 2008
96
4.21 Raw water turbidity profile of Sri Gading WTP in 2007,
and from May to December 2008
97
4.22 Colour profile of raw water of Sri Gading WTP in 2007,
and from May to December 2008
98
4.23 NH3–N profile of raw water of Sri Gading WTP in 2007,
and from May to December 2008
98
4.24 Variation of Fe in raw water at Sri Gading WTP in 2007,
and from May 2008 to December 2008
99
4.25 Al profile of raw water of Sri Gading WTP in 2007, and
from May 2008 to December 2008
100
4.26 Mn profile of raw water of Sri Gading in 2007, and from
May 2008 to December 2008
101
4.27 Total Dissolved Solids (TDS) profile of raw water of Sri
Gading in 2007, and from May 2008 to December 2008
102
4.28 Minimum and maximum PAC dosing commonly applied
at Bandar Tenggara WTP (Bandar Tenggara WTP, 2009)
106
4.29 Operating pH used in the traditional jar test obtained from
historical data at Bandar Tenggara WTP (Bandar
Tenggara WTP, 2009)
107
xviii
4.30 Maximum and minimum alum dosing commonly applied
at Sungai Gembut WTP (Sungai Gembut WTP, 2008)
108
4.31 Operating pH used in the traditional jar test obtained from
historical data at Sungai Gembut WTP (Sungai Gembut
WTP, 2008)
109
4.32 Maximum and minimum alum dosing commonly applied
at Sri Gading WTP (Sri Gading WTP, 2008)
110
4.33 Operating pH used in the traditional jar test obtained from
historical data at Sri Gading WTP (Sri Gading WTP,
2008)
111
4.34 Optimum PAC dosage obtained from Bandar Tenggara
WTP historical data (Bandar Tenggara WTP, 2009)
114
4.35 Optimum alum dosing obtained from Sungai Gembut
WTP historical data (Sungai Gembut WTP, 2008)
115
4.36 Optimum alum dosing obtained from Sri Gading WTP
historical data (Sri Gading WTP, 2008)
117
4.37 One-to-one plot; predicted vs. observed values plot for (a)
turbidity, (b) settling pH, (c) residual aluminium of
treated water sample by RSM jar test
127
4.38 Overlay plot for optimum region for sample taken from
Bandar Tenggara WTP
128
4.39 Overall desirability to obtain predicted responses of final
turbidity, coagulated pH and residual aluminium at
suggested optimum conditions for samples taken from
Bandar Tenggara WTP in (a) response surface and (b)
contour plots
129
4.40 Predicted obtained values from RSM optimisation of (a)
final turbidity (b) coagulated pH (c) residual aluminium
and their average observed values
131
4.41 Optimum PAC dosage obtained at Bandar Tenggara WTP 133
4.42 Optimum pH setting for coagulation process at Bandar
Tenggara WTP
134
xix
4.43 Turbidity after flocs settling when applying optimum
coagulation conditions at Bandar Tenggara WTP
135
4.44 Coagulated pH after optimum conditions at Bandar
Tenggara WTP
136
4.45 Residual aluminium after applying optimum coagulation
conditions at Bandar Tenggara WTP
137
4.46 One-to-one plot; predicted vs. observed values plot for (a)
square root of turbidity, (b) settling pH, (c) residual
aluminium of treated water sample through RSM jar test
144
4.47 Overlay plot for optimum region for sample taken from
Sungai Gembut WTP
146
4.48 Overall desirability to obtain predicted responses of final
turbidity, coagulated pH and residual aluminium at
suggested optimum conditions for samples taken from
Sungai Gembut WTP in (a) response surface and (b)
contour plots
147
4.49 Predicted – observed values from RSM optimisation of
(a) final turbidity (b) coagulated pH (c) residual
aluminium at Sungai Gembut WTP
150
4.50 Optimum alum dosage obtained at Sungai Gembut WTP 151
4.51 Optimum pH setting for coagulation process at Sungai
Gembut WTP
152
4.52 Turbidity after flocs settling when applying optimum
coagulation conditions at Sungai Gembut WTP
152
4.53 Coagulated pH after optimum coagulation conditions at
Sungai Gembut WTP
153
4.54 Residual aluminium after applying optimum coagulation
conditions at Sungai Gembut WTP
154
4.55 One-to-one plot; predicted vs. observed values plot for (a)
turbidity, (b) settling pH, (c) of
coagulated water sample through RSM jar test
162
Aluminium Residual1
xx
4.56 Overlay plot for optimum region when polymer dosing
0.004 mg/L for a sample taken from Sri Gading WTP
163
4.57 Overall desirability to obtain predicted responses of final
turbidity, coagulated pH and residual aluminium at
suggested optimum conditions for samples taken from Sri
Gading WTP in (a) response surface and (b) contour plots
164
4.58 Optimum alum dosing obtained at Sri Gading WTP 166
4.59 Optimum polymer dosing obtained at Sri Gading WTP 167
4.60 Optimum initial pH setting for coagulation at Sri Gading
WTP
169
4.61 Turbidity after flocs settling at optimum coagulation
conditions at Sri Gading WTP
170
4.62 Coagulated pH after optimum coagulation conditions at
Sri Gading WTP
170
4.63 Residual aluminium after applying optimum coagulation
conditions at Sri Gading WTP
171
4.64 Percentage removal of dissolved organic carbon (DOC)
through traditional jar test carried out at Bandar Tenggara
WTP
174
4.65 DOC concentration in 1% solution of CK442B and soda
used in the jar test
175
4.66 Percentage removal of UV254 by traditional jar test carried
out at Bandar Tenggara WTP
176
4.67 Percentage removal of dissolved organic carbon (DOC)
by traditional jar test carried out at Sungai Gembut WTP
177
4.68 Amount of DOC in 1% stock solution of alum and soda
ash dense used in the jar test
178
4.69 Percentage removal of UV254 by traditional jar test carried
out at Sungai Gembut WTP
179
4.70 Percentage removal of turbidity, DOC and UV254 by
optimum coagulation conditions obtained by traditional
jar test carried out at Bandar Tenggara WTP
180
xxi
4.71 Percentage removal of DOC and UV254 by optimum
coagulation conditions obtained by traditional jar test
carried out at Sungai Gembut WTP
183
5.1 RMSE values for optimum dosing for PAC regression
models acquired from traditional jar test method
189
5.2 Actual versus predicted optimum pH setting obtained
through traditional jar test at Bandar Tenggara WTP
190
5.3 RMSE values for optimum dosing for PAC regression
models acquired from RSM optimisation method
191
5.4 Actual versus predicted optimum pH setting obtained
through RSM Optimisation at Bandar Tenggara WTP
192
5.5 RMSE values for optimum dosing for alum regression
models acquired from traditional jar test method at Sungai
Gembut WTP
193
5.6 RMSE values for optimum dosing for initial pH
regression models acquired through traditional jar test
method at Sungai Gembut WTP
194
5.7 RMSE values for optimum dosing for initial pH
regression models acquired through direct reading from
RSM table method at Sungai Gembut WTP
195
5.8 RMSE values for optimum dosing for alum regression
models acquired from RSM Optimisation at Sungai
Gembut WTP
196
5.9 RMSE values for optimum dosing for alum regression
models acquired from traditional jar test method at Sri
Gading WTP
198
5.10 RMSE values for optimum pH setting regression models
acquired from traditional jar test method at Sri Gading
WTP
198
5.11 RMSE values for optimum alum dosing regression
models acquired through direct reading from RSM table
data at Sri Gading WTP
200
xxii
5.12 Actual versus predicted optimum pH setting obtained
through direct reading from RSM table data at Sri Gading
WTP
201
5.13 Actual versus predicted optimum dosing for polymer
obtained through direct reading from RSM table data at
Sri Gading WTP
201
5.14 RMSE values for optimum dosing for alum regression
models acquired from RSM optimisation method at Sri
Gading WTP
202
5.15 RMSE values for optimum dosing for polymer regression
models acquired from RSM optimisation method
203
5.16 Turbidity observed after applying optimum Bandar
Tenggara WTP coagulation conditions calculated from
traditional and RSM regression models
205
5.17 The pH of water observed after applying optimum Bandar
Tenggara WTP coagulation conditions calculated from
traditional and RSM regression models
206
5.18 Residual aluminium concentration observed after
applying optimum Bandar Tenggara WTP coagulation
conditions calculated from traditional and RSM
regression models
206
5.19 Comparison between optimum PAC dosing generated by
regression models (Equations 5.1 and 5.3) and the actual
dosing used at Bandar Tenggara WTP
207
5.20 Comparison between optimum pH dosing generated by
regression models (Equations 5.2 and 5.4) and the actual
dosing used at Bandar Tenggara WTP
207
5.21 Turbidity observed after applying optimum Sungai
Gembut WTP coagulation conditions calculated from
traditional, direct reading of RSM table and RSM
regression models
208
xxiii
5.22 pH of water observed after applying optimum Sungai
Gembut WTP coagulation conditions calculated from
traditional, direct reading of RSM table and RSM
regression models
209
5.23 Residual aluminium concentration observed after
applying optimum Sungai Gembut WTP coagulation
conditions calculated from traditional and RSM
regression models
210
5.24 Comparison between optimum alum dosing generated by
regression models (Equations 5.19, 5.21 and 5.23) and the
actual dosing used at Sungai Gembut WTP
211
5.25 Comparison between optimum pH dosing generated by
regression models (Equations 5.20, 5.22 and 5.24) and the
actual dosing used at Sungai Gembut WTP
212
5.26 Development of empirical relationship regression model 215
5.27 Example of a Data View for raw water quality parameters
and optimum jar test conditions in SPSS
217
5.28 Producing empirical relationship between independent
and dependent variables through clicking linear regression
in SPSS
218
5.29 Choosing either stepwise or forward method, filling the
dependent and independent to analyse
218
xxiv
LIST OF ABBREVIATIONS
BBD – Box Behnken Design
BTWTP – Bandar Tenggara WTP
CCD – Central Composite Design
COD – Chemical Oxygen Demand
CRD – Completely Randomised
DOC – Dissolved Organic Carbon
DoE – Design of Experiment
FCD – Face-centred Central Composite Design
FCS – Ferric Chloride Sludge
G – Velocity Gradient
IC – Inorganic Carbon
nC60 – nanoscale colloidal product of carbon fullerene
NOM – Natural Organic Matters
OFAT – One-Factor-at-A-Time
PAC – Polyaluminium chloride
PACS – Polyaluminium chloride Sludge
RCBD – Randomised Complete Block
RMSE – Root Mean Square Error
RSM – Respond Surface Method
SGWTP – Sungai Gembut Water Treatment Plant
SRGWTP – Sri Gading Water Treatment Plant
SUVA – Specific Ultra-Violet Absorbance
SVI – Sludge Volume Index
TC – Total Carbon
TOC – Total Organic Carbon
xxv
TSS – Total Suspended Solids
USEPA – United States of America Environmental Protection Agency
UV254 – Ultra-violet 254 nm
WTP – Water Treatment Plant
xxvi
LIST OF SYMBOLS
α − constants associated with raw water quality
β − constants associated with raw water quality
γ − constants associated with raw water quality
X1 − pH
X2 − turbidity
X3 − colour (apparent colour)
X4 − Iron (Fe)
X5 − Aluminium (Al)
X6 − temperature
X7 − Manganese (Mn)
X8 − Ammonium (NH3–N)
X9 − Total Dissolved Solids (TDS)
xxvii
LIST OF APPENDICES
APPENDIX TITLE PAGE
A1 Borang LRA/B_Tenggara 243
A2 Borang LRA/Sg_Gembut 245
A3 Borang LRA/S_Gading 247
B1 ANOVAs for Turbidity, Settling pH & Residual Aluminium for
Bandar Tenggara WTP
251
B2 ANOVAs for Turbidity, Settling pH & Residual Aluminium for
Sungai Gembut WTP
254
B3 ANOVAs for Turbidity, Settling pH & Residual Aluminium for
Sri Gading WTP
257
C1 Statistical Models Generated From Traditional Jar Test at
Bandar Tenggara WTP
264
C2 Statistical Models Generated From RSM Optimisation at
Bandar Tenggara WTP
266
C3 Statistical Models Generated From Traditional Jar Test at
Sungai Gembut WTP
268
C4 Statistical Models Generated From Direct Reading from RSM
Table at Sungai Gembut WTP
270
C5 Statistical Models Generated From RSM Optimisation at
Sungai Gembut WTP
272
C6 Statistical Models Generated From Traditional Jar Test at Sri
Gading WTP
274
C7 Statistical Models Generated From Direct Reading from RSM
Table at Sri Gading WTP
276
xxviii
C8 Statistical Models Generated From RSM Optimisation at Sri
Gading WTP
278
CHAPTER 1
INTRODUCTION
1.1 Preamble
The presence of colloids and natural organic matters (NOM) in raw water
sources excessively can cause a lot of problems. During intensive raining period,
excessive soil erosion occurs and this increases the concentration of colloids and
subsequently the raw water surface turbidity will multiply considerably. Having
high turbidity for a raw water source may disturb the operation at the water treatment
plant (WTP) and can be very costly (Chang and Liao, 2012). A huge amount of
chemicals and coagulants must be used to ensure the turbidity is removed until it
reaches the allowable turbidity for drinking water of less than 5 NTU outlined by the
National Standard for Drinking Water Quality (NSDWQ) (Ministry of Health, 2004).
Large pre-sedimentation basins may need to be constructed prior to the upstream of a
WTP to remove the colloids. High concentration of sediments trapped in these
basins needs to be treated too (Lin et al., 2008).
The NOM is known to cause colour (Jiang and Graham, 1998; Fabris et al.,
2008; Matilainen et al., 2010), unpleasant taste and odour problems in surface water
(Matilainen et al., 2010). It also acts as substrate for microbial and causes
2
bacterial regrowth problem (Yan et al., 2008b; Liang and Ma, 2009) and able to
block membranes and activated carbon pores for adsorption site hence reducing
adsorption efficiency (Fabris et al., 2008; Matilainen et al., 2010) in water supplies.
More importantly, they have been reported to be one of the precursors for
disinfection by-products (DBPs) (Amirtharajah and O'Melia, 1990; McGhee, 1991;
Edzwald, 1993; Iriarte-Velasco et al., 2007b) that may cause cancer to human (Bob
and Walker, 2001; Abdullah et al., 2003; Matilainen et al., 2010; Chow et al., 2011;
Fooladvand et al., 2011; Gan et al., 2013).
Looking at the adverse impacts of colloids and NOM, it is therefore essential
to remove these impurities. Coagulation is known to be an effective method to
remove the colloidal particles of high and intermediate molecular weight that result
in high turbidity (Lin et al., 2008; AlMubaddal et al., 2009) and NOM (Fabris et al.,
2008). It is an established agglomeration process to transform small particles into
larger aggregates (flocs), which involves addition of chemicals. These chemicals will
destabilise kinetically stable suspensions such as dissolved and colloid impurities
hence producing larger flocs that can be removed at the clarification or filtration
stage (Jiang and Graham, 1998; Gao et al., 2002).
The most widely used chemical in this process is aluminium (Al) based
coagulant. Though Al based coagulant is known to be effective in coagulation
process, it raises serious concerns due to the increase of residual Al in treated water.
Among the problems associated with the presence of Al in potable water are it may
increase the turbidity owing to the formation of Al precipitates, raise the pressure of
water distribution network, inhibit to the effect of disinfection and damage human’s
nervous system (Jiao et al., 2015). Medical reports state that aluminium may induce
Alzheimer’s disease too (Zouboulis et al., 2004; Kimura et al., 2013).
Therefore, coagulation process must be carried out in an optimum way as it
has direct impact on the reliability of the treatment plant operations and the final
water quality. It also has significant contribution to the operational cost of the
3
treatment plant. Any Al concentrations in treated water detected to be greater than
0.3 mg/L shows a lack of optimisation in coagulation process of the conventional
water treatment method (Qaiyum et al., 2011). The effectiveness of the process is
highly dependent on several factors including pH of the operation and dosage of
coagulant and coagulant aids.
1.2 Problem Statement
Over the years, jar test is the most common method to determine the best pH
and dosage of the chemicals used in the coagulation process. It is normally carried
out at the WTP once or twice a day or whenever any significant changes occurred in
the raw water due to many factors including the change in the weather conditions and
contaminant intrusion from the urbanization activities. Since the raw water quality
parameters are continuously changing over time resulting the optimum doses of pH
and chemical should be changing as well, it is insufficient to carry out the jar test at
the said rate above.
In the current jar test approach, the WTP operator determines the best pH and
chemical dosages by systematically changing the level of the factors, that are pH and
dosage, one at a time while holding the level of other factors constant. The level of
that factor which results in the best response (for example, lowest turbidity value) is
then selected and used in subsequent tests which continue in the same manner on
other factors. While the approach, termed as One-Factor-at-A-Time (OFAT) (Figure
1.1 (a)) is rather straightforward, it suffers from shortcomings which may lead to a
wrong conclusion. It is time-consuming and does not fully explore the space of
possible solutions and hence, it is incapable of identifying the interaction effects
resulted from the factors being considered (Montgomery, 2005). Due to these
reasons, the current jar test approach could have missed the actual best pH and
4
dosage that are possibly hidden in the experimental space not covered by the OFAT
approach.
To overcome this problem, a better method to acquire the best pH and
chemical dosage is to adopt an experimental approach as shown in Figure 1.1 (b). In
this approach, all levels of factors are altered systematically (one-by-one) to ensure
that the experimental space is fully covered. The best response could not possibly be
missed through this approach. Nonetheless, it is very time-consuming and costly.
(a) (b)
Figure 1.1: Design of Experiment; (a) OFAT Approach and (b) All Factors
Varied Systematically Approach
Response surface methodology (RSM) jar test has been proposed to
overcome these problems. The RSM is a statistical technique for designing
experiment and involves relatively small number of experiments. It is able to build
mathematical models from the outcome of the experiments and search for the
optimum conditions for desirable factors and responses. With RSM, the interaction
between factors and responses can also be determined (Montgomery, 2005).
pH
Coagulant
Coagulant
pH Flocculant Flocculant
5
RSM has been used in many optimisation experiments (Wang et al., 2007,
Pinzi et al., 2010; Moradi and Ghanbari, 2014). Ahmad et al. (2005) managed to
explain the effect and interaction between coagulant dose, flocculant dose and pH
when treating palm oil mill effluent (POME) through coagulation-flocculation
process incorporated with membrane separation technology. Wang et al. (2007)
optimised the coagulation-flocculation process to achieve minimum turbidity and
sludge volume index (SVI) for paper-recycling wastewater treatment. Pinzi et al.
(2010) used RSM to optimise the transesterification reaction for several types of
vegetable oils. Moradi and Ghanbari (2014) applied RSM technique to treat landfill
leachate and successfully obtained the optimum conditions for an integrated
coagulation-fenton process in removing the chemical oxygen demand, colour and
total suspended solids of the leachate. Despite the application of RSM in many
experimental studies, its usage in optimising coagulation conditions through jar test
in water treatment is apparently uncommon.
The raw water quality at any WTP keeps changing very frequently but the jar
test is only carried out once or twice a day. Therefore, the optimum chemical doses
obtained through the jar test are only valid for the period of sampling. It is
impractical to carry out the jar test whenever the quality of the water changes, as it is
very time-consuming. Therefore, there is a need to develop statistical models
relating the historical data of a WTP’s raw water quality parameters and the best
coagulation conditions acquired through jar test. Once the statistical models are
established, the optimum chemical doses may be known almost instantaneously by
plugging the raw water parameters data into the models. The generated statistical
models may also be used to monitor or check whether the chemical doses used in the
plant are at optimum condition. The steps taken to produce the statistical models has
got to be properly recorded and verified so that a standard procedure to develop the
statistical models relating raw water quality parameters and optimum doses of
chemical used for any WTP may be established.
Even though the negative effects of NOM present in water and how
coagulation process is able to remove NOM are widely known, no maximum
6
concentration limit for NOM is stated in the National Standard for Drinking Water
Quality (NSDWQ) (Ministry of Health, 2004). It is believed that due to this fact,
NOM are hardly analysed at any WTPs in Malaysia even though simple technique
such as the analysis of dissolved organic carbon (DOC) and the ultra-violet 254 nm
absorbance (UV254) may be applied to characterise the NOM present in the WTP’s
raw water. Hence, the performance of coagulation process carried out daily at any
WTP in removing NOM has never been explored by most, if not all WTPs in
Malaysia, unlike turbidity that is clearly spelt out in the NSDWQ.
1.3 Objectives of Study
The objectives are as follows:
i) To carry out a long-term comparison between the optimum coagulation
conditions obtained from the traditional (an adjusted OFAT) jar test
with the one obtained from the RSM jar test for different sources of raw
water
ii) To develop statistical models that correlate the relationship between
raw water quality parameters normally analysed at WTP and the best
coagulation conditions in terms of pH, chemical dosing and residual
aluminium concentration.
iii) To characterise the NOM present in the raw water source in terms of its
affinity towards water as well as to quantify the removal of NOM based
on typical traditional jar test carried out at the WTP.
iv) To establish a standard procedure to obtain statistical model that
correlates optimum coagulation conditions and raw water quality
parameters for any WTP.
7
1.4 Scope of Study
The coagulation process in this study focussed solely on the water treatment
process. The research was carried out for three Syarikat Air Johor Holdings Sdn.
Bhd. (SAJ) WTPs that have different characteristics of raw water. These WTPs were
Bandar Tenggara WTP (high turbidity water), Sungai Gembut WTP (yellowish-
orange coloured acidic water) and Sri Gading WTP (low turbidity acidic water). The
traditional and RSM jar tests were carried out at the WTPs by the operators on a
daily basis for a minimum of six months and at Universiti Teknologi Malaysia
(UTM) on weekly basis. Raw water quality parameters analysed daily at these
WTPs were pH, turbidity, colour (apparent colour), ammonia nitrogen (NH3-N), iron
(Fe), aluminium (Al), manganese (Mn) and other parameters that suited the
requirement of the WTPs. Parameters analysed for the jar tests were coagulant dose
(and coagulant aid dose for Sri Gading WTP), pH (during initial setting for the jar
test and after flocs settlement), water turbidity and residual aluminium after
conducting the jar tests. The NOM present at the WTP was characterised by their
specific ultra-violet absorbance (SUVA) values through the analysis of the dissolved
organic carbon (DOC) and the ultra-violet 254 nm absorbance (UV254). Design
Expert Version 7.1 and Statistical Package for the Social Sciences Version 10.0
(SPSS) softwares were used to assist the results analyses.
1.5 Significance of Study
The study is important as it develops a more systematic approach to
overcome the shortcomings of the traditional jar test typically carried out at most
WTPs in Malaysia. In Malaysia, most WTPs have adopted an adjusted OFAT jar
test whereby only the coagulant dosing is systematically altered and not the
coagulant aid nor the pH of the coagulation. This is because these WTPs are more
concerned on the amount of coagulant used as compared to any other chemicals
8
since its usage is considerably higher than the others. The adjusted OFAT jar test
has definitely neglected the determination of optimum values of pH and coagulant
aid and hence it will not lead to the actual best values for these entities. As for the
optimum coagulant, the jar test does not fully explore the experimental space of
possible solutions and hence, it may miss the actual optimum value too. The wastage
of chemicals used in the coagulation process at these WTPs is unavoidable.
The RSM jar test experiment is implemented in this study to overcome the
stated problems earlier as RSM has been proven to be very successful in optimisation
experiments (Wang et al., 2007, Pinzi et al., 2010; Moradi and Ghanbari, 2014).
RSM involves small number of experiments, builds mathematical models from the
outcome of the experiments and searches the optimum conditions for desirable
factors and responses. With RSM, the interaction between factors and responses can
also be determined (Montgomery, 2005). This study also eases the determination of
optimum pH and chemicals dosage of coagulation process in producing acceptable
water quality through the establishment of statistical models relating the raw water
quality parameters and the jar test optimum conditions.
NOM characteristics present in the raw waters for two WTPs in Johor in
terms of their affinity towards water and their interaction with coagulation process
will be determined conducted by the traditional jar test at these WTPs. This study
also determines the characteristics of the NOM present in the raw water for several
WTPs in terms of their affinity towards water and how it interacts with the
coagulation process carried out by the traditional jar test at these WTPs. Finally, this
study establishes a standard procedure to obtain statistical model that correlates
optimum coagulation conditions and their raw water quality parameters for any
WTP.
9
1.6 Thesis Outline
This thesis is divided into six chapters. Chapter 1 is an introduction chapter.
It contains the problem statement, objectives, scope and the significance of the study
as well as the thesis outline. Chapter 2 consists of the literature review on
coagulation process, jar test, NOM, design of experiment (DoE) and RSM topics.
Chapter 3 describes the research methodology in detail followed by Chapter 4. In
Chapter 4, the analysis of water characteristics, long-term comparison on the
traditional and RSM jar tests, the generation of regression models relating the
optimum jar test conditions with the raw water quality parameters and NOM removal
through traditional jar test are related. Chapter 5 relates the standard procedure
obtained from this study to acquire statistical model that correlates optimum
coagulation conditions and their raw water quality parameters for any WTP. Chapter
6, the final chapter of the thesis, presents the conclusions and recommendations for
future study.
225
REFERENCES
Abdullah, Md Pauzi, Yew, C.H., Ramli, Mohamad Salleh, & Ali, Rahmah. (2003).
Trihalomethanes (THMs) in Malaysian Drinking Water. Malaysian Journal
of Chemistry, 5(1), 056-066.
Abuzaid, Nabil S., Bukhari, Alaadin A., & Al-Hamouz, Zakariya M. (2002). Ground
water coagulation using soluble stainless steel electrodes. Advances in
Environmental Research, 6(3), 325-333.
Ahmad, A.L, Ismail, S., & Bhatia, S. (2005). Optimization of Coagulation-
Flocculation Process for Palm Oil Mill Effluent Using Response Surface
Methodology. Environmental Science & Technology, 39(8), 2828-2834.
Ahmed, T., Kanwal, R., Hassan, M., Ayub, N., Scholz, M., & McMinn, W. (2010).
Coagulation and disinfection in water treatment using Moringa. Proceedings
of the Institution of Civil Engineers: Water Management, 163(8), 381-388.
Akter, A., & Ali, M. (2011). Arsenic contamination in groundwater and its proposed
remedial measures. International Journal of Environmental Science and
Technology : (IJEST), 8(2), 433.
AlMubaddal, F., AlRumaihi, K., & Ajbar, A. (2009). Performance optimization of
coagulation/flocculation in the treatment of wastewater from a polyvinyl
chloride plant. Journal of Hazardous Materials, 161(1), 431-438.
Amirtharajah, Appiah, & O'Melia, Charles R. (1990). Coagulation Processes:
Destabilization, Mixing, and Flocculation. In F. W. Pontius (Ed.), Water
Quality and Treatment A Handbook of Community Water Supplies (pp. 269-
366). United States of America: McGraw-Hill, Inc.
Amon, R. M. W., Rinehart, A. J., Duan, S., Louchouarn, P., Prokushkin, A.,
Guggenberger, G., . . . Zhulidov, A. V. (2012). Dissolved organic matter
sources in large Arctic rivers. Geochimica et Cosmochimica Acta, 94(0), 217-
237.
Anderson, Mark J., & Whitcomb, Patrick J. (2005). RSM Simplified (First ed.). New
York: Productivity Press.
226
Anderson, Mark J., & Whitcomb, Patrick J. (2007). DOE Simplified (Second ed.).
New York: Productivity Press.
APHA, AWWA, & WEF. (2005). Standard Methods for the Examination of Water
and Wastewater - 21st Edition. Washington: American Public Health
Association.
Archer, Aaron D., & Singer, Philip C. (2006). EFFECT OF SUVA and enhanced
coagulation on removal of TOX precursors. American Water Works
Association. Journal, 98(8), 97.
Aris, A., Mokhtar, N., Muslim, R., Ujang, Z., & A-Majid, Z. (2007). Treatment of
acidic water from Bekok River using open limestone channel. Water Science
and Technology: Water Supply, 7(4), 65-71. doi: 10.2166/ws.2007.145
Atkins, P.W. (1994). Physical Chemistry (5th. ed. ed.). Somerset, Great Britain:
Oxford University Press.
Awad, John, van Leeuwen, John, Liffner, Joel, Chow, Christopher, & Drikas, Mary.
(2016). Treatability of organic matter derived from surface and subsurface
waters of drinking water catchments. Chemosphere, 144, 1193-1200. doi:
http://dx.doi.org/10.1016/j.chemosphere.2015.09.066
Bachand, P. A. M., Heyvaert, A. C., Lopus, S. E., Reuter, J. E., Teh, S. J., & Werner,
I. (2009). Potential toxicity concerns from chemical coagulation treatment of
stormwater in the Tahoe basin, California, USA. Ecotoxicology and
Environmental Safety, 72(7), 1933+.
Baeza, A., Fernandez, M., Herranz, M., Legarda, F., Miro, C., & Salas, A. (2006).
Removing uranium and radium from a natural water. Water Air and Soil
Pollution, 173(1-4), 57-69. doi: 10.1007/s11270-005-9026-5
Bandar Tenggara WTP, Syarikat Air Johor Holdings (2009). [PAC dosage and
operating pH applied at Bandar Tenggara WTP].
Barreto, Humberto, & Howland, Frank M. (2006). Introductory Econometric Using
Monte Carlo Simulation with Microsoft Excel (1st. ed. ed.). New York,
United States of America: Cambridge University Press.
Bassandeh, Mojgan, Antony, Alice, Le-Clech, Pierre, Richardson, Desmond, &
Leslie, Greg. (2013). Evaluation of ion exchange resins for the removal of
dissolved organic matter from biologically treated paper mill effluent.
Chemosphere, 90(4), 1461-1469. doi:
http://dx.doi.org/10.1016/j.chemosphere.2012.09.007
227
Beltrán Heredia, J., & Sánchez Martín, J. (2009). Removing heavy metals from
polluted surface water with a tannin-based flocculant agent. Journal of
Hazardous Materials, 165(1-3), 1215-1218.
Beltrán-Heredia, J., Sánchez-Martín, J., & Barrado-Moreno, M. (2012). Long-chain
anionic surfactants in aqueous solution. Removal by Moringa oleifera
coagulant. Chemical Engineering Journal, 180(0), 128-136.
Bérubé, D. , & Dorea, C.C. (2008). Optimizing alum coagulation for turbidity,
organics, and residual Al reductions. Water Science & Technology: Water
Supply, 8(5), 505–511.
Bilici Baskan, Meltem, & Pala, Aysegul. (2010). A statistical experiment design
approach for arsenic removal by coagulation process using aluminum sulfate.
Desalination, 254(1-3), 42-48.
Bob, Mustafa, & Walker, Harold W. (2001). Enhanced adsorption of natural organic
matter on calcium carbonate particles through surface charge modification.
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 191(1-
2), 17-25.
Bob, Mustafa, & Walker, Harold W. (2006). Lime-Soda Softening Process
Modifications for Enhanced NOM Removal. Journal of Environmental
Engineering, 132(2), 158-165.
Bridgeman, J., Bieroza, M., & Baker, A. (2011). The application of fluorescence
spectroscopy to organic matter characterisation in drinking water treatment.
Reviews in Environmental Science and Bio-Technology, 10(3), 277-290. doi:
10.1007/s11157-011-9243-x
Bridgeman, John, Jefferson, Bruce, & Parsons, Simon. (2008). Assessing floc
strength using CFD to improve organics removal. Chemical Engineering
Research and Design, 86(8), 941-950.
Chang, Chia-Ling, & Liao, Chung-Sheng. (2012). Assessing the risk posed by high-
turbidity water to water supplies. Environmental Monitoring and Assessment,
184(5), 3127-3132. doi: 10.1007/s10661-011-2176-6
Chen, C. Y., & Chung, Y. C. (2011). Comparison of Acid-Soluble and Water-
Soluble Chitosan as Coagulants in Removing Bentonite Suspensions. Water
Air and Soil Pollution, 217(1-4), 603-610. doi: 10.1007/s11270-010-0613-8
228
Chen, Kuan-Chung, & Wang, Yu-Hsiang. (2011). Control of disinfection by-product
formation using ozone-based advanced oxidation processes. Environmental
Technology, 33(4), 487-495. doi: 10.1080/09593330.2011.580009
Cheng, L. H., Bi, X. J., Liu, C. Q., You, X. H., Zhu, W., & Ieee. (2009). Effect of
Enhanced Coagulation with Diatomite on the treatment of oilfield produced
water. New York: Ieee.
Chiemchaisri, C., Passananon, S., Ngo, H. H., & Vigneswaran, S. (2008). Enhanced
natural organic matter removal in floating media filter coupled with
microfiltration membrane for river water treatment. Desalination, 234(1-3),
335-343.
Chow, Alex T., O'Geen, Anthony T., Dahlgren, Randy A., Diaz, Francisco J., Wong,
Kin-Hang, & Wong, Po-Keung. (2011). Reactivity of litter leachates from
California oak woodlands in the formation of disinfection by-products.
Journal of Environmental Quality, 40(5), 1607-1616. doi:
10.2134/jeq2010.0488
Chow, Christopher W. K., van Leeuwen, John A., Fabris, Rolando, & Drikas, Mary.
(2009). Optimised coagulation using aluminium sulfate for the removal of
dissolved organic carbon. Desalination, 245(1-3), 120-134.
Chu, Xuan-Quang, Kim, Jongwon, Park, Kyhyuk, Choi, Sungyong, & Kim, Hyung-
Soo. (2009). Coagulation pre-treatment to reduce membrane fouling in the
microfiltration process of Nakdong River water. Water Science and
Technology: Water Supply, 9(4), 357-367. doi: 10.2166/ws.2009.486
Citulski, Joel, Farahbakhsh, Khosrow, & Kent, Fraser. (2009). Optimization of
phosphorus removal in secondary effluent using immersed ultrafiltration
membranes with in-line coagulant pretreatment - implications for advanced
water treatment and reuse applications. Canadian Journal of Civil
Engineering, 36(7), 1272-1283. doi: 10.1139/l09-062
Deng, Shubo, Zhou, Qin, Yu, Gang, Huang, Jun, & Fan, Qing. (2011). Removal of
perfluorooctanoate from surface water by polyaluminium chloride
coagulation. Water Research, 45(4), 1774-1780. doi:
http://dx.doi.org/10.1016/j.watres.2010.11.029
Dorea, C. C. (2009). Coagulant-based emergency water treatment. Desalination,
248(1-3), 83-90.
229
. DR 5000 Spectrophotometer Procedures Manual. (2005). In H. Company (Ed.), (02
ed.). Germany.
Droste, Ronald L. (1997). Theory and Practice of Water and Wastewater Treatment
(1st. ed. ed.). United States of America: John Wiley & Sons, Inc.
EC. (1998). E.C. Directive on ‘Drinking Water Quality Intended for Human
Consumption’ (Vol. Drinking Water Directive 98/83/EEC). Brussels: European
Commission.
Edmonds, Jennifer W., & Grimm, Nancy B. (2011). Abiotic and biotic controls of
organic matter cycling in a managed stream. Journal of Geophysical
Research. Biogeosciences, 116(2), n/a. doi: 10.1029/2010jg001429
Edzwald, J. K. (1993). Coagulation in drinking water treatment: Particles, organics
and coagulants. Water Science and Technology, 27(11), 21-35.
Fabris, Rolando, Chow, Christopher W. K., Drikas, Mary, & Eikebrokk, Bjørnar.
(2008). Comparison of NOM character in selected Australian and Norwegian
drinking waters. Water Research, 42(15), 4188-4196.
Fagnani, Enelton, Guimarães, José Roberto, & Fadini, Pedro Sérgio. (2012). Mercury
in the Waters of the Jundiai River, SP, Brazil: The Role of Dissolved Organic
Matte. Aquatic Geochemistry, 18(5), 445-456.
Felder, Richard M., & Rousseau, Ronald W. (1986). Elementary Principles of
Chemical Processes (2nd. Ed. ed.). Canada: John Wiley & Sons.
Fooladvand, M., Ramavandi, B., Zandi, K., & Ardestani, M. (2011). Investigation of
trihalomethanes formation potential in Karoon River water, Iran.
Environmental Monitoring and Assessment, 178(1-4), 63-71. doi:
10.1007/s10661-010-1672-4
Fu, F., & Wang, Q. (2011). Removal of heavy metal ions from wastewaters: A
review. Journal of Environmental Management, 92(3), 407-418.
Gan, Wenhui, Guo, Wanhong, Mo, Jianmin, He, Yisen, Liu, Yongjian, Liu, Wei, . . .
Yang, Xin. (2013). The occurrence of disinfection by-products in municipal
drinking water in China's Pearl River Delta and a multipathway cancer risk
assessment. Science of The Total Environment, 447(0), 108-115. doi:
http://dx.doi.org/10.1016/j.scitotenv.2012.12.091
Gao, B. Y., Hahn, H. H., & Hoffmann, E. (2002). Evaluation of aluminum-silicate
polymer composite as a coagulant for water treatment. Water Research,
36(14), 3573-3581.
230
Garcia, Indiana, & Moreno, Luis. (2012). Removal of nitrogen and carbon organic
matter by chitosan and aluminium sulphate. Water Science and Technology:
Water Supply, 12(1), 1-10. doi: 10.2166/ws.2011.111
Ghafari, Shahin, Aziz, Hamidi Abdul, Isa, Mohamed Hasnain, & Zinatizadeh, Ali
Akbar. (2009). Application of response surface methodology (RSM) to
optimize coagulation-flocculation treatment of leachate using poly-aluminum
chloride (PAC) and alum. Journal of Hazardous Materials, 163(2-3), 650-
656.
Ghebremichael, Kebreab, Abaliwano, Juliet, & Amy, Gary. (2009). Combined
natural organic and synthetic inorganic coagulants for surface water
treatment. Journal of Water Supply: Research and Technology - AQUA,
58(4), 267-276. doi: 10.2166/aqua.2009.060
Gough, Rachel, Holliman, Peter J., Willis, Naomi, & Freeman, Christopher. (2014).
Dissolved organic carbon and trihalomethane precursor removal at a UK
upland water treatment works. Science of The Total Environment, 468–
469(0), 228-239. doi: http://dx.doi.org/10.1016/j.scitotenv.2013.08.048
Gregory, Dean, & Carlson, Kenneth. (2003). Relationship of pH and Floc Formation
Kinetics to Granular Media Filtration Performance. Environmental Science &
Technology, 37(7), 1398-1403.
Guan, Di, Zhang, Zhen, Li, Xing, & Liu, Hui. (2011). Effect of pH and temperature
on coagulation efficiency in a North-China water treatment plant. Paper
presented at the 1st International Conference on Civil Engineering,
Architecture and Building Materials, CEABM 2011, June 18, 2011 - June 20,
2011, Haikou, China.
Hammer, Mark J., & Hammer, Mark J. Jr. (2005). Water and Wastewater
Technology (5th ed. ed.). Singapore: Prentice-Hall.
Haydar, S., Ahmad, H., & Aziz, J. A. (2010). Optimization of coagulation-
flocculation in the treatment of canal water. Environmental Engineering and
Management Journal, 9(11), 1563-1570.
Heddam, Salim, Bermad, Abdelmalek, & Dechemi, Noureddine. (2011). ANFIS-
based modelling for coagulant dosage in drinking water treatment plant: a
case study. 1-19. doi: 10.1007/s10661-011-2091-x
231
Hering, Janet G., Chen, Pen-Yuan, Wilkie, Jennifer A., & Elimelech, Menachem.
(1997). Arsenic Removal from Drinking Water during Coagulation. Journal
of Environmental Engineering, 123(8), 800-807.
Herzsprung, Peter, von Tümpling, Wolf, Hertkorn, Norbert, Harir, Mourad, Büttner,
Olaf, Bravidor, Jenny, . . . Schmitt-Kopplin, Philippe. (2012). Variations of
DOM Quality in Inflows of a Drinking Water Reservoir: Linking of van
Krevelen Diagrams with EEMF Spectra by Rank Correlation. Environmental
Science & Technology, 46(10), 5511-5518. doi: 10.1021/es300345c
. HI 93703 Portable Microprocessor Turbidity Meter [Instruction Manual]. (1998). In
H. Instruments (Ed.). Sarmeola di Rubano, Italy: Hanna Instruments.
Holdings, Syarikat Air Johor. (2008). Ujian Balang di Bilik Makmal. Johor: Syarikat
Air Johor Holdings.
Holdings, Syarikat Air Johor. (2012a). SAJ: Loji Rawatan Air Bandar Tenggara.
Johor.
Holdings, Syarikat Air Johor. (2012b). Selamat Datang ke Loji Air Sg Gembut SAJ
Holdings Sdn Bhd Kota Tinggi. Johor.
Hu, Chengzhi, Chen, Qingxin, Chen, Guixia, Liu, Huijuan, & Qu, Jiuhui. (2015).
Removal of Se(IV) and Se(VI) from drinking water by coagulation.
Separation and Purification Technology, 142, 65-70. doi:
http://dx.doi.org/10.1016/j.seppur.2014.12.028
Huang, G. C., Meng, F. G., Zheng, X., Wang, Y., Wang, Z. G., Liu, H. J., & Jekel,
M. (2011). Biodegradation behavior of natural organic matter (NOM) in a
biological aerated filter (BAF) as a pretreatment for ultrafiltration (UF) of
river water. Applied Microbiology and Biotechnology, 90(5), 1795-1803. doi:
10.1007/s00253-011-3251-1
Hyung, Hoon, & Kim, Jae-Hong. (2009). Dispersion of C60 in natural water and
removal by conventional drinking water treatment processes. Water
Research, 43(9), 2463-2470.
Iriarte-Velasco, Unai, Álvarez-Uriarte, Jon I., & González-Velasco, Juan R. (2007a).
Enhanced coagulation under changing alkalinity-hardness conditions and its
implications on trihalomethane precursors removal and relationship with UV
absorbance. Separation and Purification Technology, 55(3), 368-380.
232
Iriarte-Velasco, Unai, Álvarez-Uriarte, Jon I., & González-Velasco, Juan R. (2007b).
Removal and structural changes in natural organic matter in a Spanish water
treatment plant using nascent chlorine. Separation and Purification
Technology, 57(1), 152-160.
Ives, K. J. (1959). The significance of surface electric charge on algae in water
purification. Journal of Biochemical and Microbiological Technology and
Engineering, 1(1), 37-47.
Jarvis, Peter, Sharp, Emma, Pidou, Marc, Molinder, Roger, Parsons, Simon A., &
Jefferson, Bruce. (2012). Comparison of coagulation performance and floc
properties using a novel zirconium coagulant against traditional ferric and
alum coagulants. Water Research, 46(13), 4179-4187. doi:
http://dx.doi.org/10.1016/j.watres.2012.04.043
Jiang, JQ, & Graham, NJD. (1998). Pre-polymerised inorganic coagulants nad
phosphorus removal by coagulation - A review. Water SA, 24(3), 237-244.
Jiao, Ruyuan, Xu, Hui, Xu, Weiying, Yang, Xiaofang, & Wang, Dongsheng. (2015).
Influence of coagulation mechanisms on the residual aluminum – The roles of
coagulant species and MW of organic matter. Journal of Hazardous
Materials, 290(0), 16-25. doi:
http://dx.doi.org/10.1016/j.jhazmat.2015.02.041
Kang, Hua, He, Wen-Jie, Han, Hong-Da, & Li, Chen. (2011). Pilot study on
treatment of low turbidity and low temperature water by coagulation-
immersed membrane process. Journal of Harbin Institute of Technology
(New Series), 18(2), 37-42.
Kim, Myung-Man, Au, James, Rahardianto, Anditya, Glater, Julius, Cohen, Yoram,
Gerringer, Fredrick W., & Gabelich, Christopher J. (2009). Impact of
conventional water treatment coagulants on mineral scaling in RO desalting
of brackish water. Industrial and Engineering Chemistry Research, 48(6),
3126-3135. doi: 10.1021/ie800937c
Kimura, Masaoki, Matsui, Yoshihiko, Kondo, Kenta, Ishikawa, Tairyo B.,
Matsushita, Taku, & Shirasaki, Nobutaka. (2013). Minimizing residual
aluminum concentration in treated water by tailoring properties of
polyaluminum coagulants. Water Research, 47(6), 2075-2084. doi:
http://dx.doi.org/10.1016/j.watres.2013.01.037
233
Kobya, M., Demirbas, E., Bayramoglu, M., & Sensoy, M. T. (2011). Optimization of
Electrocoagulation Process for the Treatment of Metal Cutting Wastewaters
with Response Surface Methodology. Water Air and Soil Pollution, 215(1-4),
399-410. doi: 10.1007/s11270-010-0486-x
Konieczny, Krystyna, Sąkol, Dorota, Płonka, Joanna, Rajca, Mariola, & Bodzek,
Michał. (2009). Coagulation—ultrafiltration system for river water treatment.
Desalination, 240(1–3), 151-159.
Lee, Chai Siah, Robinson, John, & Chong, Mei Fong. (2014). A review on
application of flocculants in wastewater treatment. Process Safety and
Environmental Protection, 92(6), 489-508. doi:
http://dx.doi.org/10.1016/j.psep.2014.04.010
Lee, Jeong-Dae, Lee, Sang-Ho, Jo, Min-Ho, Park, Pyung-Kyu, Lee, Chung-Hak, &
Kwak, Jong-Woon. (2000). Effect of Coagulation Conditions on Membrane
Filtration Characteristics in Coagulation−Microfiltration Process for
Water Treatment. Environmental Science & Technology, 34(17), 3780-3788.
doi: doi:10.1021/es9907461
Li, Xiao-Xiao, Zhang, Yue-Jun, & Jia, Jin-Zhou. (2010). Application of AS/PDM
composite coagulants in turbidity removal treatment of Yangtze River water
in autumn. Nanjing Li Gong Daxue Xuebao/Journal of Nanjing University of
Science and Technology, 34(2), 266-270.
Li, Xiaoming, Peng, Ping’an, Zhang, Sukun, Man, Ren, Sheng, Guoying, & Fu,
Jiamo. (2009). Removal of polychlorinated dibenzo-p-dioxins and
polychlorinated dibenzofurans by three coagulants in simulated coagulation
processes for drinking water treatment. Journal of Hazardous Materials,
162(1), 180-185.
Liang, Tao, & Ma, Jun. (2009). Variation of assimilable organic carbon during
coagulation by aluminum and iron in drinking water treatment. Journal of
Water Supply: Research and Technology - AQUA, 58(6), 416-423. doi:
10.2166/aqua.2009.091
Lin, Jr-Lin, Huang, Chihpin, Pan, Jill Ruhsing, & Wang, Dongsheng. (2008). Effect
of Al(III) speciation on coagulation of highly turbid water. Chemosphere,
72(2), 189-196.
Lobanga, KP, Haarhoff, J, & van Staden, SJ. (2014). Treatability of South African
surface waters by enhanced coagulation. Water SA, 40(3), 529-534.
234
Ma, R., & Lu, X. (2012). Modeling of THMs and HAAs formation in distribution
system upon chlorination. Paper presented at the 2011 SSITE International
Conference on Future Material Research and Industry Application, FMRIA
2011, Macau. http://www.scopus.com/inward/record.url?eid=2-s2.0-
84857184821&partnerID=40&md5=1e05f1e677f1ba4318a0dcc641ab0f78
Maloletnev, A. S., Zekel, L. A., Krasnobaeva, N. V., Shpirt, M. Ya, Naumov, K. I.,
& Shvedov, I. M. (2010). Preparation of a coagulant for water treatment from
waste coal from the Moscow Coal Basin. Solid Fuel Chemistry, 44(6), 382-
386. doi: 10.3103/s0361521910060030
Matilainen, Anu, Vepsäläinen, Mikko, & Sillanpää, Mika. (2010). Natural organic
matter removal by coagulation during drinking water treatment: A review.
Advances in Colloid and Interface Science, 159(2), 189-197.
Mbogo, S. PhD. (2008). A Novel Technology to Improve Drinking Water Quality
Using Natural Treatment Methods in Rural Tanzania. Journal of
Environmental Health, 70(7), 46.
McGhee, Terence J. (1991). Water Supply and Sewerage (6th. ed. ed.). Singapore:
McGraw-Hill.
Mertens, J. (2011). Al nanoclusters in coagulants and granulates: application in
arsenic removal from water. Reviews in Environmental Science and
Biotechnology, 10(2), 111.
Mertens, Laurence, Van Derlinden, Eva, & Van Impe, Jan F. (2012). Comparing
experimental design schemes in predictive food microbiology: Optimal
parameter estimation of secondary models. Journal of Food Engineering,
112(3), 119-133.
Michaowicz, Jaromir, Stufka-olczyk, Jadwiga, Milczarek, Anna, & Michniewicz,
Magorzata. (2011). Analysis of annual fluctuations in the content of phenol,
chlorophenols and their derivatives in chlorinated drinking waters.
Environmental Science and Pollution Research International, 18(7), 1174-
1183. doi: 10.1007/s11356-011-0469-5
Ministry of Health, Malaysia. (2004). National Standard for Drinking Water Quality
- 2nd version. Malaysia: Ministry of Health, Malaysia.
235
Moghaddam, S. S., Moghaddam, M. R. A., & Arami, M. (2011). Response surface
optimization of acid red 119 dye from simulated wastewater using Al based
waterworks sludge and polyaluminium chloride as coagulant. Journal of
Environmental Management, 92(4), 1284-1291. doi:
10.1016/j.jenvman.2010.12.015
Montgomery, Douglas C. (2005). Design and Analysis of Experiments (Sixth ed.).
United States of America: John Wiley and Sons, Inc. .
Moradi, Mahsa, & Ghanbari, Farshid. (2014). Application of response surface
method for coagulation process in leachate treatment as pretreatment for
Fenton process: Biodegradability improvement. Journal of Water Process
Engineering, 4(0), 67-73. doi: http://dx.doi.org/10.1016/j.jwpe.2014.09.002
Mouafi, Foukia E., Abo Elsoud, Mostafa M., & Moharam, Maysa E. (2016).
Optimization of biosurfactant production by Bacillus brevis using response
surface methodology. Biotechnology Reports, 9, 31-37. doi:
http://dx.doi.org/10.1016/j.btre.2015.12.003
Moussas, P. A., & Zouboulis, A. I. (2012). Synthesis, characterization and
coagulation behavior of a composite coagulation reagent by the combination
of polyferric sulfate (PFS) and cationic polyelectrolyte. Separation and
Purification Technology, 96, 263-273. doi:
http://dx.doi.org/10.1016/j.seppur.2012.06.024
Müller, S., & Uhl, W. (2009). Influence of hybrid coagulation-ultrafiltration
pretreatment on trace organics adsorption in drinking water treatment.
Journal of Water Supply: Research and Technology - AQUA, 58(3), 170-180.
. Multifactor RSM Tutorial (Part 1 – The Basics) (2007). In M. Anderson (Ed.),
Design-Expert 7.1 User’s Guide. Minneapolis: Stat-Ease, Inc.
Mustafa, Akhmad, Hasnawi, Hasnawi, Asaad, Andi Indra Jaya, & Paena, Mudian.
(2014). Characteristics, suitability and recommendations for management of
land in acid sulfate soil-affected brackishwater ponds for tiger prawn
(Penaeus monodon) culture in Luwu Regency, Indonesia. Journal of Coastal
Conservation, 18(6), 595-608. doi: 10.1007/s11852-014-0327-y
Myers, Raymond H., & Montgomery, Douglas C. (2002). Response Surface
Methodology: Process and Product Optimization Using Design Experiments
(Second ed.). United States of America: John Wiley & Sons, Inc.
236
Naidu, C. V., Satyanarayana, G. Ch, Durgalakshmi, K., Malleswara Rao, L., Jeevana
Mounika, G., & Raju, A. Dharma. (2012). Changes in the frequencies of
northeast monsoon rainy days in the global warming. Global and Planetary
Change, 92–93(0), 40-47. doi:
http://dx.doi.org/10.1016/j.gloplacha.2012.04.009
Nam, Seung –Woo, Jo, Byung–Il, Kim, Moon-Kyung, Kim, Won-Kyung, & Zoh,
Kyung-Duk. (2013). Streaming current titration for coagulation of high
turbidity water. Colloids and Surfaces A: Physicochemical and Engineering
Aspects, 419(0), 133-139. doi:
http://dx.doi.org/10.1016/j.colsurfa.2012.11.051
Nawani, N. N., & Kapadnis, B. P. (2005). Optimization of chitinase production using
statistics based experimental designs. Process Biochemistry, 40(2), 651-660.
Nguyen, Hang Vo-Minh, & Hur, Jin. (2011). Tracing the sources of refractory
dissolved organic matter in a large artificial lake using multiple analytical
tools. Chemosphere, 85(5), 782-789.
NIEA. (2009). European and National Drinking Water Quality Standards. Belfast:
Northern Ireland Environment Agency.
Park, Hosik, Kim, Yohan, An, Byungryul, & Choi, Heechul. (2012). Characterization
of natural organic matter treated by iron oxide nanoparticle incorporated
ceramic membrane-ozonation process. Water Research, 46(18), 5861-5870.
Peavy, Howard S., Rowe, Donald R., & Tchobanoglous, George. (1995).
Environmental Engineering (International Ed. ed.). Singapore: McGraw-Hill.
Pinzi, S., Lopez-Gimenez, F. J., Ruiz, J. J., & Dorado, M. P. (2010). Response
surface modeling to predict biodiesel yield in a multi-feedstock biodiesel
production plant. Bioresource Technology, 101(24), 9587-9593.
Pourrezaei, P., Drzewicz, P., Wang, Y. N., El-Din, M. G., Perez-Estrada, L. A.,
Martin, J. W., . . . Giesy, J. P. (2011). The Impact of Metallic Coagulants on
the Removal of Organic Compounds from Oil Sands Process-Affected Water.
Environmental Science & Technology, 45(19), 8452-8459. doi:
10.1021/es201498v
Puntoriero, María Laura, Cirelli, Alicia Fernández, & Volpedo, Alejandra Vanina.
(2015). Geochemical mechanisms controlling the chemical composition of
groundwater and surface water in the southwest of the Pampean plain
(Argentina). Journal of Geochemical Exploration, 150(0), 64-72.
237
Qaiyum, M., Shaharudin, M., Syazwan, A., & Muhaimin, A. (2011). Health Risk
Assessment after Exposure to Aluminium in Drinking Water between Two
Different Villages. Journal of Water Resource and Protection, 3(4), 268-274.
Racoviteanu, Gabriel, & Spinu, Daniela. (2014). Behavior of Aluminum Based
Coagulants in Treatment of Surface Water–Assessment of Chemical and
Microbiological Properties of Treated Water. Mathematical Modelling in
Civil Engineering, 10(1), 9-20.
Radchenko, S., Novakov, I., Radchenko, P., Le Van, C., & Rybakova, E. (2011).
Flocculating Properties of Water-Soluble Polymer-Colloid Complexes of
Aluminoxane Particles with Weakly Charged Cationic Polyelectrolytes1.
Journal of Water Resource and Protection, 3(4), 213.
Roccaro, Paolo, Lombardo, Giacomo, & Vagliasindi, Federico GA. (2014).
Optimization of the Coagulation Process to Remove Total Suspended Solids
(TSS) from Produced Water. CHEMICAL ENGINEERING, 39, 115-120.
Russell, Caroline G., Lawler, Desmond, F., & Speitel, Gerald E., Jr. (2009). NOM
coprecipitation with solids formed during softening. American Water Works
Association. Journal, 101(4), 112.
Sadri Moghaddam, S., Alavi Moghaddam, M. R., & Arami, M. (2010).
Coagulation/flocculation process for dye removal using sludge from water
treatment plant: Optimization through response surface methodology. Journal
of Hazardous Materials, 175(1-3), 651-657.
Safarikova, Jana, Baresova, Magdalena, Pivokonsky, Martin, & Kopecka, Ivana.
(2013). Influence of peptides and proteins produced by cyanobacterium
Microcystis aeruginosa on the coagulation of turbid waters. Separation and
Purification Technology, 118(0), 49-57. doi:
http://dx.doi.org/10.1016/j.seppur.2013.06.049
Santhi, V. A., Sakai, N., Ahmad, E. D., & Mustafa, A. M. (2012). Occurrence of
bisphenol A in surface water, drinking water and plasma from Malaysia with
exposure assessment from consumption of drinking water. Science of The
Total Environment, 427–428(0), 332-338. doi:
http://dx.doi.org/10.1016/j.scitotenv.2012.04.041
Sawyer, Clair N., McCarty, Perry L., & Parkin, Gene F. (1994). Chemistry For
Environmental Engineering (4th. ed. ed.). Singapore: McGraw-Hill
International Editions.
238
Serra, Teresa, Colomer, Jordi, & Logan, Bruce E. (2008). Efficiency of different
shear devices on flocculation. Water Research, 42(4–5), 1113-1121.
Sitnichenko, T. N., Vakulenko, V. F., & Goncharuk, V. V. (2011). Photocatalytic
Destruction of Fulvic Acids by Oxygen in the TiO2 Suspension. Journal of
Water Chemistry and Technology, 33(4), 236-247. doi:
10.3103/s1063455x11040059
Smoczynski, L., Bukowski, Z., Wardzynska, R., Zaleska-Chrost, B., & Dluzynska,
K. (2009). Simulation of Coagulation, Flocculation, and Sedimentation.
Water Environment Research, 81(4), 348.
Sri Gading WTP, Syarikat Air Johor Holdings (2008). [Alum dosage and operating
pH applied at Sri Gading WTP].
Sun, Nan, Yu, Shui-Li, Ma, Li-Xin, Xu, Xiao-Bei, & Yi, Xue-Song. (2011).
Coagulant optimization and effect research of low-temperature and high-
color source water treatment. Paper presented at the 2011 International
Conference on Environmental Biotechnology and Materials Engineering,
EBME 2011, March 26, 2011 - March 28, 2011, Harbin, China.
Sungai Gembut WTP, Syarikat Air Johor Holdings (2008). [Alum dosage and
operating pH applied at Sungai Gembut WTP].
Tchobanoglous, George, & Burton, Franklin L. (1991). Wastewater Engineering
(3rd. ed. ed.). Singapore: McGraw-Hill.
Tchobanoglous, George, Theisen, Hilary, & Vigil, Samuel. (1993). Integrated Solid
Waste Management - Engineering Principles and Management Issues (1st ed.
ed.). Singapore: McGraw-Hill, Inc.
Teixeira, M. R., Rosa, S. M., & Sousa, V. (2011). Natural Organic Matter and
Disinfection By-products Formation Potential in Water Treatment. Water
Resources Management, 25(12), 3005-3015. doi: 10.1007/s11269-011-9795-
0
Tombácz, Etelka, Libor, Zsuzsanna, Illés, Erzsébet, Majzik, Andrea, & Klumpp,
Erwin. (2004). The role of reactive surface sites and complexation by humic
acids in the interaction of clay mineral and iron oxide particles. Organic
Geochemistry, 35(3), 257-267.
239
Torres, L. G., Jaimes, J., Mijaylova, P., Ramirez, E., & Jimenez, B. (1997).
Coagulation-flocculation pretreatment of high-load chemical-pharmaceutical
industry wastewater: Mixing aspects. Water Science and Technology, 36(2-
3), 255-262. doi: 10.1016/s0273-1223(97)00395-8
Trinh, Thuy Khanh, & Kang, Lim Seok. (2011). Response surface methodological
approach to optimize the coagulation–flocculation process in drinking water
treatment. Chemical Engineering Research and Design, 89(7), 1126-1135.
Umbanhowar, C. E., Camill, P., Edlund, M. B., Geiss, C., Henneghan, P., & Passow,
K. (2015). Lake-landscape connections at the forest-tundra transition of
northern Manitoba. Inland Waters, 5(1), 57-74. doi: 10.5268/iw-5.1.752
Vepsäläinen, Mikko, Ghiasvand, Mohammad, Selin, Jukka, Pienimaa, Jorma, Repo,
Eveliina, Pulliainen, Martti, & Sillanpää, Mika. (2009). Investigations of the
effects of temperature and initial sample pH on natural organic matter (NOM)
removal with electrocoagulation using response surface method (RSM).
Separation and Purification Technology, 69(3), 255-261.
Volk, Christian, Bell, Kimberly, Ibrahim, Eva, Verges, Debbie, Amy, Gary, &
LeChevallier, Mark. (2000). Impact of enhanced and optimized coagulation
on removal of organic matter and its biodegradable fraction in drinking water.
Water Research, 34(12), 3247-3257.
Volkova, T. S., Medvedev, V. P., & Fedorova, O. V. (2011). Coagulation treatment
of radioactively contaminated waters using sodium ferrate. Radiochemistry,
53(3), 308-313.
Wahid, Zularisam Ab. (2008). Natural Organic Matter Removal From Surface Water
Using Submerged Ultrafiltration Membrane Unit. (Doctor of Philosophy),
Universiti Teknologi Malaysia Skudai.
Wall, Nathalie A., & Choppin, Gregory R. (2003). Humic acids coagulation:
influence of divalent cations. Applied Geochemistry, 18(10), 1573-1582.
Wang, Jian-Ping, Chen, Yong-Zhen, Ge, Xue-Wu, & Yu, Han-Qing. (2007).
Optimization of coagulation-flocculation process for a paper-recycling
wastewater treatment using response surface methodology. Colloids and
Surfaces A: Physicochemical and Engineering Aspects, 302(1-3), 204-210.
240
Wang, Jun, Li, Haibo, Li, Aimin, Shuang, Chendong, & Zhou, Qing. (2014).
Dissolved organic matter removal by magnetic anion exchange resin and
released ion elimination by electrolysis. Chemical Engineering Journal,
253(0), 237-242. doi: http://dx.doi.org/10.1016/j.cej.2014.05.060
Wang, Qiongjie, Li, Aimin, Wang, Jinnan, & Shuang, Chengdong. (2012). Selection
of magnetic anion exchange resins for the removal of dissolved organic and
inorganic matters. Journal of Environmental Sciences, 24(11), 1891-1899.
doi: http://dx.doi.org/10.1016/S1001-0742(11)61066-8
Waseem, S., & Mohsin, I. (2011). Evolution and Fate of Haloacetic Acids before and
after Chlorination within the Treatment Plant Using SPE-GC-MS. American
Journal of Analytical Chemistry, 2(5), 522.
Weber, Walter J. Jr. (1972). Physicochemical Processes For Water Quality Control
(First ed.). United States of America: Wiley-Interscience Publication.
Wei, J. C., Gao, B. Y., Yue, Q. Y., Wang, Y., & Lu, L. (2009). Performance and
mechanism of polyferric-quaternary ammonium salt composite flocculants in
treating high organic matter and high alkalinity surface water. Journal of
Hazardous Materials, 165(1-3), 789-795.
WHO. (2008). Guidelines for Drinking-water Quality: Incorporating The First And
Second Addenda, Volume 1, Recommendations – 3rd Edition. Geneva:
World Health Organization.
Wu, F. C., Evans, R. D., & Dillon, P. J. (2003). Separation and Characterization of
NOM by High-Performance Liquid Chromatography and On-Line Three-
Dimensional Excitation Emission Matrix Fluorescence Detection.
Environmental Science & Technology, 37(16), 3687-3693.
Xing, Linan, Fabris, Rolando, Chow, Christopher W. K., van Leeuwen, John, Drikas,
Mary, & Wang, Dongsheng. (2012a). Prediction of DOM removal of low
specific UV absorbance surface waters using HPSEC combined with peak
fitting. Journal of Environmental Sciences, 24(7), 1174-1180.
Xing, Linan, Murshed, Mohamad Fared, Lo, Theodore, Fabris, Rolando, Chow,
Christopher W. K., van Leeuwen, John, . . . Wang, Dongsheng. (2012b).
Characterization of organic matter in alum treated drinking water using high
performance liquid chromatography and resin fractionation. Chemical
Engineering Journal, 192(0), 186-191.
241
Xu, Weiying, Gao, Baoyu, Wang, Yan, Yue, Qinyan, & Ren, Haijing. (2012). Effect
of second coagulant addition on coagulation efficiency, floc properties and
residual Al for humic acid treatment by Al13 polymer and polyaluminum
chloride (PACl). Journal of Hazardous Materials, 215–216(0), 129-137.
Yan, Mingquan, Wang, Dongsheng, Ni, Jinren, Qu, Jiuhui, Chow, Christopher W.
K., & Liu, Hailong. (2008a). Mechanism of natural organic matter removal
by polyaluminum chloride: Effect of coagulant particle size and hydrolysis
kinetics. Water Research, 42(13), 3361-3370.
Yan, Mingquan, Wang, Dongsheng, Ni, Jinren, Qu, Jiuhui, Ni, Wenjin, & Van
Leeuwen, John. (2009). Natural organic matter (NOM) removal in a typical
North-China water plant by enhanced coagulation: Targets and techniques.
Separation and Purification Technology, 68(3), 320-327.
Yan, Mingquan, Wang, Dongsheng, Yu, Jianfeng, Ni, Jinren, Edwards, Marc, & Qu,
Jiuhui. (2008b). Enhanced coagulation with polyaluminum chlorides: Role of
pH/Alkalinity and speciation. Chemosphere, 71(9), 1665-1673.
Yang, Y., & Liu, W. (2012). Treatment of Raw Water with Ultrafiltration
Membrane/PAC. Paper presented at the 2011 International Conference on
Material Engineering, Architectural Engineering and Informatization,
MEAEI2011, Wuhan. http://www.scopus.com/inward/record.url?eid=2-s2.0-
81455142211&partnerID=40&md5=74ef3ab80536d659840829d88f1023b5
Zhan, X. A., Gao, B. Y., Wang, Y., & Yue, Q. Y. (2011). Influence of velocity
gradient on aluminum and iron floc property for NOM removal from low
organic matter surfacewater by coagulation. Chemical Engineering Journal,
166(1), 116-121. doi: 10.1016/j.cej.2010.10.037
Zhan, Xiao, Gao, Baoyu, Yue, Qinyan, Wang, Yan, & Cao, Baichuan. (2010).
Coagulation behavior of polyferric chloride for removing NOM from surface
water with low concentration of organic matter and its effect on chlorine
decay model. Separation and Purification Technology, 75(1), 61-68.
Zhang, Guanghui, Li, Xiaobo, Wu, Shuibo, & Gu, Ping. (2012a). Effect of source
water quality on arsenic (V) removal from drinking water by
coagulation/microfiltration. Environmental Earth Sciences, 66(4), 1269-1277.
doi: 10.1007/s12665-012-1549-7
242
Zhang, J., He, J., & Li, G. (2012c). Study on the Treatment of Algae-Rich Water
with PPC Preoxidation-Coagulation/Sedimentation/Ultrafiltration (UF)
Process. Advanced Materials Research, 518-523, 2858-2865.
Zhang, Y., Yu, T., & Hu, C. M. (2012b). Characterization of degradation of dom
from taihu lake under different conditions using multiple analytical
techniques. Fresenius Environmental Bulletin, 21(5), 1118-1126.
Zhao, Y. X., Gao, B. Y., Shon, H. K., Qi, Q. B., Phuntsho, S., Wang, Y., . . . Kim, J.
H. (2013). Characterization of coagulation behavior of titanium tetrachloride
coagulant for high and low molecule weight natural organic matter removal:
The effect of second dosing. Chemical Engineering Journal, 228(0), 516-525.
doi: http://dx.doi.org/10.1016/j.cej.2013.05.042
Zhao, Y. X., Gao, B. Y., Zhang, G. Z., Phuntsho, S., & Shon, H. K. (2014).
Coagulation by titanium tetrachloride for fulvic acid removal: Factors
influencing coagulation efficiency and floc characteristics. Desalination,
335(1), 70-77. doi: http://dx.doi.org/10.1016/j.desal.2013.12.016
Zhou, Zhiwei, Yang, Yanling, Li, Xing, Ji, Siyang, Zhang, Hao, Wang, Shuai, . . .
Han, Xinghang. (2016). The removal characteristics of natural organic matter
in the recycling of drinking water treatment sludge: Role of solubilized
organics. Ultrasonics Sonochemistry, 28, 259-268. doi:
http://dx.doi.org/10.1016/j.ultsonch.2015.07.016
Zouboulis, A. I., & Tzoupanos, N. D. (2009). Polyaluminium silicate chloride—A
systematic study for the preparation and application of an efficient coagulant
for water or wastewater treatment. Journal of Hazardous Materials, 162(2–
3), 1379-1389.
Zouboulis, Anastasios I., Xiao-Li, Chai, & Katsoyiannis, Ioannis A. (2004). The
application of bioflocculant for the removal of humic acids from stabilized
landfill leachates. Journal of Environmental Management, 70(1), 35-41.