POST-TREATMENT OF PALM OIL MILL EFFLUENT USING MODIFIED

SEQUENCING BATCH REACTOR AUGMENTED WITH ZEOLITE

HOSSEIN FARRAJI

UNIVERSITI SAINS MALAYSIA

2018

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POST-TREATMENT OF PALM OIL MILL

EFFLUENT USING MODIFIED SEQUENCING

BATCH REACTOR AUGMENTED WITH ZEOLITE

by

HOSSEIN FARRAJI

Thesis submitted in fulfillment of

the requirements for the degree of

Doctor of Philosophy

July 2018

ii

ACKNOWLEDGEMENT

All praises are due to the Creator without Whom I wouldn’t have finished this Ph.D.

research work. Firstly, I would like to express my sincere gratitude to my supervisor

Associate Prof Dr. Nastaein Qamaruz Zaman for the continuous support of my study

and related research, for her patience and motivation.

Besides my advisor, I would like to thank my co-supervisors, Prof. Dr. Hamidi

Abdul Aziz, and Dr. Mohammad Aqeel Ashraf for their insightful comments and

encouragement. I also would like to thank Dr. Amin Mojiri, Dr. Ali Arab, Mr. Parsa

Mohajeri and Dr. Amirhossein Vakili for their encouragement and support especially at

times when things were going very tough. I would also thank all lab technicians, as

without their wise knowledge and assistance this study would not have been successful.

This research was funded by the iconic ‘Grant for Research Associated with the Solid

Waste Management Cluster’ (Grant no. 1001/CKT/870023), Engineering campus,

Universiti Sains Malaysia. Finally, I must express my very profound gratitude to my

mother for providing me with unfailing support and continuous encouragement

throughout my life. My honest appreciate to my family for their patient and support. At

last but not the least, my brother Dr. Hamed Faraji and my brother in law Mr. Smaeil

Jafari who their continuous support and supplies helped me. This acknowledgement will

not be fair without superior thanks and appreciate Mr. Taib yacob, the person who spend

a major part of his time for teaching skills and improving creative thinking through the

designing and manufacturing several types of reactors as well as a brother.

iii

TABLE OF CONTENTS

Page

ACKNOWLEDGEMENT ii

TABLE OF CONTENTS iii

LIST OF TABLES ix

LIST OF FIGURES xi

LIST OF ABBREVIATION xiv

LIST OF SYMBOLS xvi

ABSTRAK xvii

ABSTRACT xix

CHAPTER ONE - INTRODUCTION

1.1 Overview 1

1.2 Problem statement 2

1.3 Research Objectives 4

1.4 Scope of Study 4

1.5 Thesis Organization 4

iv

CHAPTER TWO - LITERATURE REVIEW

2.1 Palm Oil Production 6

2.2 POME as an Agro-industry Wastewater 7

2.3 Characteristics of POME 8

2.3.1 Total Suspended Solids (TSS) 12

2.3.1(a) Volatile Suspended Solid (VSS) 13

2.3.2 Biological Oxygen Demand (BOD) 13

2.3.3 Chemical Oxygen Demand (COD)

14

2.3.4 Color 158

2.3.5 Ammonia and total nitrogen 16

2.3.6 Phosphorus 17

2.4 Biodegradability of POME 20

2.5 POME Treatment Methods 22

2.5.1 Commercial Treatment Method 22

2.5.1(a) Ponding Treatment 22

2.5.1(b) Continuously Stirred Tank Reactor 23

2.5.1(c) Anaerobic Digestion for Methane Production 23

26 2.5.2 Non-commercial Treatment Methods

2.6 SBR as a POME Treatment System 27

2.6.1 SBR System 27

2.6.1(a) Fundamental and Mechanism of SBR Treatment

Process

30

2.6.2 Advantages and Disadvantages of SBR 32

v

2.6.2(a) Simple Construction 32

2.6.2(b) Combination Ability 33

2.6.2(c) Augmentation and Specific Treatment 34

2.6.2(d) Wide Range of Application 34

2.6.3 The Application of the SBR in POME Treatment 35

2.6.3(a) Factors Affecting SBR System 37

2.6.3(b) Microbial Augmentation for POME 38

2.6.3(c) Adsorbent Augmentation 39

2.7 Response Surface Method (RSM) 42

2.8 Summary 45

CHAPTER THREE - MATERIALS AND METHODS

3.1 Introduction 46

3.2 Case Study Sites 49

3.2.1 Site Description and POME Sampling 49

3.2.2 Site Description and Municipal Wastewater Sampling 50

3.3 Design of Sequencing Batch Reactor 51

3.3.1 SBR Operating 54

3.3.1(a) Different between LL and POME 55

3.4 Zeolite 57

3.4.1 Characterization of zeolite 58

3.4.2 Determination of Zeolite Dosage 59

3.5 Analytical Methods 60

vi

3.6 Determination of Settling Time 61

3.7 Optimization of RSM 61

3.7.1 Validation of RSM Prediction 66

3.8 Efficiency of Removal 67

CHAPTER FOUR - RESULTS AND DISCUSSIONS

4.1 Introduction 69

4.2 Characteristics of the POME, MWW and Zeolite 69

4.2.1 Characteristics of POME 69

4.2.2 Characteristics of Municipal Wastewater 70

4.2.3 Characteristics of Zeolite before Treatment 71

4.2.4 Zeolite Characteristics after Pollutant Loading 79

4.2.4(a) Mineral Characteristics 79

4.2.4(b) Microbial Content 85

4.3 Identification of Suitable Zeolite Dosage using Batch Tests 87

4.3.1 Settling Time 90

4.4 Establishment of Optimum Operating Conditions for the Modify SBR

System

92

4.4.1 TSS Removal 92

4.4.1(a) Turbidity Removal 94

4.4.2 BOD Removal 96

4.4.3 COD Removal 98

4.4.4 Color Removal 101

4.4.5 Total Nitrogen Removal 103

vii

4.4.6 Ammonia Nitrogen Removal 105

4.4.7 Total Phosphorus Removal 107

4.5 Mechanism of Pollutants Removal by Zeolite 108

4.5.1 Introduction 108

4.5.2 Ion Exchange Capacity 110

4.5.3 Bridge Mechanism 111

4.5.4 Surface Adsorption 113

4.5.5 Micro-Pollutants 113

4.6 The Role of Municipal Wastewater in the Treatment Mechanism 114

4.7 Biodegradation 115

4.7.1 Total Count and E.coli 116

4.8 Adsorption 117

4.8.1 Macro Pollutants 118

4.9 Summary of Removal Mechanisms 119

4.10 Continuous Experimental Results 119

4.11 Establishment of Prediction RSM Model for POME Treatment 123

4.11.1 TSS Removal 123

4.11.2 COD Removal 125

4.11.3 Nitrogen Removal 128

4.11.4 Biodegradability 129

4.11.4.a Discussion on pollutant removal 134

4.11.5 Desirability 135

4.11.6 Summary of RSM Modelling 138

viii

4.12 Recommended Economical SBR Operating 139

CHAPTER FIVE - CONCLUSION AND RECOMMENDATIONS

5.1 Conclusions 141

5.2 Recommendation for Future Studies 143

REFERENCES

APPENDICCES

144

PUBLICATIONS

ix

LIST OF TABLES

Page

Table 2.1 World's vegetable oil critical specifications 6

Table 2.2 World's main palm oil production countries 7

Table 2.3 Different agroindustry wastewater characteristics 8

Table 2.4 The centrifugal fraction of POME 9

Table 2.5 Characteristics of raw POME 19

Table 2.6 Characteristics of raw POME, Malaysian discharge standards

and required efficiency for passing discharge standards

25

Table 2.7 The effectiveness of aerobic SBR treatment for POME 36

Table 2.8 Characteristics of natural zeolite in literature 39

Table 2.9 Summary of natural zeolite application for POME treatment in

literature

41

Table 3.1 Characteristics of Landfill leachate and POME 56

Table 3.2 Actual values for variable factors 64

Table 3.3 Experimental variable factors for SBRs 65

Table 4.1 Characteristics of anaerobically treated POME and Malaysian

discharge standards

70

Table 4.2 Characteristics of MWW collected for this study 70

Table 4.3 Weight and atomic percentage of natural zeolite elements 75

Table 4.4 XRF characteristics of the natural zeolite 77

Table 4.5 BET test results in natural zeolite before treatment 78

Table 4.6 ICP characteristics of raw POME before treatment 79

x

Table 4.7 Weight and atomic percentage of zeolite elements after

treatment

82

Table 4.8 BET test results in natural zeolite after treatment 85

Table 4.9 ICP results of treated POME 85

Table 4.10 Total count and E.coli in treated SBR system 86

Table 4.11 Operation conditions and TSS removal performance 94

Table 4.12 Operation conditions and turbidity removal performance 96

Table 4.13 Operation conditions and BOD5 removal performance 98

Table 4.14 Operation conditions and COD removal performance 101

Table 4.15 Operation conditions and color removal performance 103

Table 4.16 Operation conditions and total nitrogen removal performance 105

Table 4.17 Operation conditions and ammonia nitrogen removal

performance

107

Table 4.18 Operation conditions and total phosphorus removal performance 108

Table 4.19 Operation factors and results of selected responses in continuous

test

121

Table 4.20 Experimental condition and results of collected responses for

RSM modeling

132

Table 4.21 ANOVA results for the equation of the Design Expert 10.0.3 for

collected responses

133

Table 4.22 Efficiency report for desirability in different operations, targets,

and other responses

137

Table 4.23 Economic SBR for achieving the highest efficiency in the lowest

cost of operation factors

139

xi

LIST OF FIGURES

Page

Figure 2.1 Particle size distribution data for raw POME 10

Figure 2.2 Figure 2.2: PSA system of POME (Khanam et al., 2016) 11

Figure 2.3 Biodegradability line for wastewater (Metcalf and Eddy,

2014) and collected biodegradability in previous studies on

POME, COD, and BOD

21

Figure 2.4 Process Flow Diagram of anaerobic digestion 24

Figure 2.5 SBR operation for one cycle 29

Figure 2.6 SBR 32

Figure 3.1 Flowchart of the methodology 48

Figure 3.2 Aerial view of the UOPM 49

Figure 3.3 Anaerobically treated POME sampling (Pond number 8) 50

Figure 3.4 Municipal wastewater sampling point 51

Figure 3.5 Schematic characteristics of SBR with CBA system, air

pump, and air flow meter

53

Figure 3.6 All 20 SBR reactors running simultaneously in same

environmental condition

57

Figure 3.7 Batch test process and optimum dosage of adsorbent 60

Figure 4.1 SEM micrograph of natural zeolite 74

Figure 4.2 Element content (EDS mapping) before treatment in natural

zeolite structure (a:Oxygen, b:Aluminum, c:Silicon,

d:Carbon, and e:Magnesium)

76

Figure 4.3 Natural zeolite spectrum (EDS of the plotted area) before 77

xii

treatment

Figure 4.4 SEM micrograph of a pollutant-loaded natural zeolite

(a:10000, b:20000, and c: 35000 magnified )

81

Figure 4.5 Element content (EDS mapping) after treatment in natural

zeolite structure (a:Oxygen, b:Aluminum, c:Silicon,

d:Carbon, and e:Magnesium)

83

Figure 4.6 Zeolite spectrum (EDS of the plotted area) after treatment 84

Figure 4.7 Removal efficiency of ammonia, COD, TSS, TP, and color

in batch test against zeolite dosage

87

Figure 4.8 Anaerobically treated POME and 11 g/L dosage zeolite

treatment in batch study

88

Figure 4.9 Effect of settling time on concentration of dissolved oxygen

in modify SBR

91

Figure 4.10 The 3D surface plots and 2D contour plot for TSS removal 124

Figure 4.11 Predicted vs. Actual contour plot for TSS removal 125

Figure 4.12 The 3D surface plots and 2D contour plot for COD removal 126

Figure 4.13 Predicted vs. Actual contour plot for COD removal 127

Figure 4.14 The 3D surface plots for total and ammonia nitrogen removal

(contact time of 12 h)

129

Figure 4.15 The 3D surface plots and 2D contour plot for

biodegradability

136

Figure 4.16 Two-dimensional plot count of highest desirability in

operation considering TSS, BOD, COD, and color as target

pollutants

137

xiii

Figure 4.17 Two-dimensional plot count of engineered desirability

operation considering TSS, BOD, COD, and color as target

pollutants (minimum aeration).

138

xiv

LIST OF ABBREVIATIONS

BET Brunauer-Emmer-Teller

BOD Biological Oxygen Demand

CCD Central Composite Design

CEC Cation Exchange Capacity

cfu Colony Forming Units

COD Chemical Oxygen Demand

CPO Crude Palm Oil

HDPE High Density Polyethylene

MLVSS Mixed liquor volatile suspended solids

MNDWQS Malaysian National Drinking Water Quality Standards

MWW Municipal Wastewater

NG Not Given

Neg Negative

POME Palm Oil Mill Effluent

PSA Particle Size Analyze

Rem Removal

rpm Round Per Minute

RSM Response Surface Methodology

xv

SBR Sequencing Batch Reactor

SSA Specific Surface Area

SEM Scanning Electron Microscope

SERC Science and Engineering Research Centre

TDS Total Dissolved Solids

TN Total Nitrogen

TP Total Phosphorus

TS Total Solids

TSS Total Suspended Solids

UASB Up flow Anaerobic Sludge Blanket

UNFCCC United Nations Framework Convention on Climate Change

Program

UOPM United Oil Palm Mill

USDA United States Department of Agriculture

USEPA United States Environmental Protection Agency

USM Universiti Sains Malaysia

VSS Volatile Suspended Solids

XRF X-Ray Fluorescence

xvi

LIST OF SYMBOLS

µm Micrometer

nm Nano meter

O Oxygen

H Hydrogen

C Carbon

Al Aluminum

Fe Ferron

Ca Calcium

Cº Degree Celsius

L Liter

W Weight

N North

E East

g Gram

h Hour

ha Hectare

Å Angstrom

R2 Coefficient of Determination

xvii

PASCA-OLAHAN EFLUEN KILANG KELAPA SAWIT MENGGUNAKAN

REAKTOR KELOMPOK PERJUJUKAN TERUBAHSUAI DITINGKATKAN

DENGAN ZEOLITE

ABSTRAK

Salah satu sistem olahan air sisa adalah penjujukan reaktor kelompok (PRK). Pasca

olahan effluen kilang kelapa sawit (EKKS) dengan aplikasi air sisa bandar dan

penggunaan zeolit semulajadi dalam sistem PRK aerobic terubahsuai. EKKS

mengandungi kepekatan pencemar organik yang sangat tinggi, kepekatan elemen logam

toksik yang rendah bersama kandungan mikrob yang rendah. Aplikasi terus air sisa

bandar sebagai pembekal mikrob dan zeolite sebagai penggumpal semulajadi dalam

PRK diubahsuai dijalankan bagi menghapuskan aklimitasi enapcemar bagi menjimatkan

kos dan masa operasi melalui proses aerobik. Pengudaraan digunakan untuk mengadun

dan sebagai sumber oksigen dalam sistem PRK. Kajian kelompok dijalankan dengan 5,

10, 15, 20, 25, 30 dan 35 g/L zeolite. 15 g/L zeolite dikenalpasti sebagai dos yang

optimum. Zeolit semulajadi yang digunakan mempunyai saiz dari 75 µm to 150 µm.

Kaedah Permukaan Tindak Balas (RSM) dan Rekabentuk Komposit Pusat (CCD)

digunakan bagi mendapatkan keadaan operasi optimum (pembolehubah bebas) bagi

nisbah air sisa bandar kepada EKKS, kadar pengudaraan dan masa sentuh. Tujuh

parameter dipilih sebagai pembolehubah tanggungan (respons) iaitu Jumlah Pepejal

xviii

Terampai, Keperluan Oksigen Biologi, Keperluan Oksigen Kimia, Nitrogen Ammonia,

Jumlah Nitrogen dan Jumlah Fosforus. Hasil pengumpulan data menunjukkan, kaedah

rawatan tunggal mampu mengolah EKKS dalam masa yang singkat tanpa memerlukan

proses aklimitasi enap cemar. Dalam keadaan optimum dengan nisbah air sisa bandar

kepada EKKS (58.7 v/v,%), kadar pengudaraan (6.85 L/min) dan masa sentuh (17.9

jam) bagi PRK, keberkesanan pengurangan TSS, BOD, COD, warna, nitrogen

ammonia, jumlah nitrogen dan jumlah fosforus adalah 99.16%, 90.67%, 98.4%, 84.34%,

98.33%, 96.26% dan 93.49% setiapnya. Mekanisme penyingkiran adalah melalui

degradasi mikrob, penggumpalan, kapasiti penukaran kation dan penjerapan permukaan.

Kesan spesifik oleh air sisa bandar melalui proses olahan mikrobiologi dengan bantuan

zeolite bagi pertimbuhan mikrob dan penggumpalan bahan tidak boleh terdegradasi

adalah aspek utama keberkesanan. Gabungan air sisa bandar dan EKKS ditingkatkan

dengan bantuan zeolite semulajadi dalam sistem PRK terubahsuai aerobik boleh

digunapakai sebagai kaedah mikrobiologi yang berkebolehan untuk rawatan EKKS

dengan kos yang efektif dan dalam masa yang singkat.

xix

POST-TREATMENT OF PALM OIL MILL EFFLUENT USING MODIFIED

SEQUENCING BATCH REACTOR AUGMENTED WITH ZEOLITE

ABSTRACT

One of the biological treatment system for wastewater treatment is sequencing

batch reactor (SBR). Post-treatment of palm oil mill effluent by direct application of

municipal wastewater and augmentation of natural zeolite in aerobic modified SBR

system. POME contain extremely high concentration of organic pollutants, very low

concentration of toxic metallic elements, and low microbial content. Direct application

of municipal wastewater as microbial supply and zeolite as natural coagulant in

modified aerobic sequencing batch reactor (SBR) conducted in order to decreasing

operation time and cost of operation process through the aerobic treatment. Aeration

used for mixing and oxygen source in SBR system. Batch study carried out with 5, 10,

15, 20, 25, 30, and 35 g/L zeolite. 15g/L zeolite collected as optimum adsorbent dosage.

The size of natural zeolite ranged from 75 µm to 150 µm. Response Surface

Methodology (RSM) and Central Composite Design (CCD) were used for collecting the

optimum operating conditions (independent variables) which were ratio of municipal

wastewater (MWW) to POME, aeration flow and contact time. Seven parameters

namely total suspended solids (TSS), biological oxygen demand (BOD5), chemical

oxygen demand (COD), ammonia nitrogen (NH3-N), total nitrogen and total phosphorus

selected as dependent parameters (responses). Collected results indicates that this single

xx

treatment method has capability for effective POME treatment in short time without

requiring to sludge acclimatization process. In the optimum condition of municipal

wastewater to POME ratio (58.7 v/v; %), aeration rate (6.85 L/min) and contact time

(17.9h) for the SBR, efficiency of the reduction for TSS, BOD, COD, colour, ammonia

nitrogen, total nitrogen and phosphorus were 99.16%, 90.67%, 98.4%, 84.34%,

98.33%, 96.26% and 93.49% respectively. Mechanism of removal mostly were

microbial biodegradation, coagulation, cation exchangeable capacity, and surface

adsorbent. Specific effect of municipal wastewater through the microbiological

treatment process and assistance influence of zeolite for microbial growth and non-

degradable maters coagulation are main aspects of efficiency. Combining municipal

wastewater with POME and augmenting with natural zeolite in aerobic modified SBR

system, could be considered as a capable microbiological method for POME in cost

effective and short time treatment.

1

CHAPTER ONE

INTRODUCTION

1.1 Overview

Nowadays, oil palm production in Malaysia reached to 20,000,000 tons

(MPOB, 2016). Activities of 426 mills, production and by products have a positive

effect on the Malaysian economy. Other side of this industry is environmental

impacts of palm oil industry which means 60,000,000 tons effluent being a major

concern for Malaysia as the leader of scientific researches in green improvement.

Due to aforementioned facts, the palm oil industry as main agroindustry; faces a big

challenge in balancing the economic viability, environmental protection and

sustainable development. Thus, there is an urgent need to finding a suitable way to

keep our economy growth while preserving the environment (Chin et al., 2013).

The conventional treatment method for palm oil mill effluent is ponding system

which is an easy operation, time consuming process in several ponds or digesting

system, with high cost operation in a big land area and environmental impacts

(Mansor et al., 2017). On the other hand, this method is highly dependent to land

application and rivers as final destination of effluent discharge. Unfortunately,

inability of this anaerobic-aerobic method in passing discharge standards (Bhatia et

al., 2007) has led to concerning on numerous scientific researches on high efficiency,

cost effective, easy operation and short time treatment methods. Ponding system

which has been applied in 85% of oil palm industry is the most common commercial

treatment method (Poh and Chong 2009) while the remaining 15% are operated by

2

using tank digestion system. Finding effective treatment method for Palm Oil Mill

Effluent (POME) will be more serious when Malaysian authorities aim to strengthen

standard limits to BOD5 equals to 20 mg/L (Liew et al., 2015) .

Anaerobic digestion of POME in covered ponds which known as methane

production process, have positive attraction on environmental footprint by decreasing

the greenhouse gas emission and methane gas collection despite the, expensive

construction, high maintenance fee, operation, high land requirement caused to slow

improving trend in this traditional treatment system. This method is based on the

microbial activity in anaerobic circumstances on organic matter in aquatic nutrient

media for methane production. Raw POME is an acidic media with temperature of

80-90 oC (Chin et al., 2013) will caused low content of microbial population. Long

period of time is required for available microbial population to adapt and starting

digestion process. However, low biodegradability of lignin compounds (Oswal et al.,

2002), makes the digestion process longer as well as decreasing in pollutant removal

efficiency and methane production. Further studies should be conducted to develop

innovative methods to reduce the cost of treatment and increase treated water quality

(Mansor et al., 2017).

1.2 Problem Statement

Biological treatment could be a high effective treatment method for wastewater

with high biodegradability index and low concentration of non-biodegradable

compound such as lignin (Pérez et al., 2002). Approximately 50 % of POME

pollutants are low or non-biodegradable organic matters which should be separate

from fine, easily degradable organic compound such as fatty acids by suitable

coagulation mechanism (Ahmad et al., 2005a). Efficiency of pollutant removal can

3

be improved using aerobic sequencing batch reactor (SBR) (Wang and Li, 2009).

Augmentation of municipal wastewater is an advanced treatment technique for

enhancing the efficiency of pollutant removal in strength wastewaters and often have

been used in landfill leachate (Mojiri et al., 2014, Aziz et al., 2011b). Activated

sludge recognized as one of the most effective aerobic treatment meanwhile, it is the

least applied by oil palm mills since of its higher operation cost (Chan et al., 2010).

In a SBR system sludge acclimatization is necessary for microorganisms adaptation

to new condition, and it takes 10 days when treating landfill leachate (Aziz et al.,

2011b). On the other hand, high concentration of ammonia nitrogen is another factor

cause low efficiency of SBR treatment and high concentration of ammonia nitrogen

which is very toxic for microorganisms population and gradually could be protected

by sludge acclimatization process (Aziz et al., 2011b). Since POME has nontoxic

properties (Rupani et al., 2010) and contain very low concentration or absence of

hazardous heavy metals such as Pb and Cu (Agustin et al., 2008), Cd and Cr (Ubani

et al., 2017).

The knowledge of natural adsorbent (zeolite) application in SBR for POME

treatment contain some gaps and need more development. Literature indicate that

single pollutant removal such as oil (Shavandi et al., 2012a) and heavy metal

(Shavandi et al., 2012b) have been studied in POME which the main pollutants are

BOD5, COD, TSS and color (Liew et al., 2015).

Since of two major types of pollutants (biodegradable and capable for

coagulation) in POME a new finding is needed to present direct application of

municipal wastewater as microbial community supplier and natural adsorbent as

coagulation and microbial biofilm formation is required as a novel combined

microbiological treatment method for POME in aerobic SBR system.