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vii TABLE OF CONTENTS CHAPTER TITLE PAGE THESIS STATUS DECLARATION SUPERVISOR’S DECLARATION 1 TITLE PAGE i DECLARATION ii DEDICATION iii ACKNOWLEDGEMENT iv ABSTRACT v ABSTRAK vi TABLE OF CONTENTS vii LIST OF TABLES xii LIST OF FIGURES xiv LIST OF SYMBOLS xviii LIST OF ABBREVIATIONS xix LIST OF APPENDICES xxi INTRODUCTION 1 1.1 Introduction 1 1.2 Rice Husk Ash 2 1.3 Zeolite 4 1.3.1 Zeolite NaY 7 1.3.2 Synthesis of Zeolite NaY 10 1.3.2.1 15 Seeding Technique viii 1.3.2.2 1.3.3 Ageing 16 Characterization 17 1.3.3.1 X-Ray Diffraction Technique 17 1.3.3.2 Infrared Spectroscopy 20 1.3.3.3 Elemental Analysis 24 1.3.3.4 Ion Exchange Capacity 25 1.4 Surfactant Modified Zeolite 28 1.5 Toxic Metals in Water 33 1.5.1 Chromium 36 1.5.2 Arsenic 38 1.6 Removal of Toxic Metals in Water 1.6.1 Adsorption Theory 1.7 Research Background and Objectives of the 41 43 45 Study 2 MATERIALS AND METHODS 47 2.1 Preparation of Rice Husk Ash 47 2.2 Characterization of Rice Husk Ash 48 2.2.1 X-Ray Diffraction Technique 48 2.2.2 Infrared Spectroscopy 48 2.2.3 Elemental Analysis 49 2.3 Synthesis of Zeolite NaY 50 2.4 Characterization of Zeolite NaY 52 2.4.1 Surface Area and Porosity 52 2.4.2 Elemental Analysis 53 2.4.2.1 Decomposition of Zeolite Samples 53 2.4.2.2 Determination of Sodium 54 2.4.2.3 Determination of Aluminum 54 2.4.2.4 Determination of Loss on Ignition and Percentage of Silica 2.4.3 Determination of Unit Cell 55 56 ix 2.4.4 Determination of Cation Exchange 57 Capacity 2.4.4.1 Total Cation Exchange Capacity 2.4.4.2 External Cation Exchange Capacity 57 58 2.5 Preparation of Surfactant Modified Zeolite Y 59 2.6 Characterization of Surfactant Modified Zeolite Y 61 2.6.1 Elemental Analysis 61 2.6.2 Dispersion Behavior 63 2.6.3 Maximum Adsorption of HDTMA 63 2.7 Adsorption Studies 2.7.1 Adsorption of Cr(III) 64 2.7.1.1 Kinetic Study 65 2.7.1.2 Effect of Initial pH 65 2.7.1.3 Isotherm Study 66 2.7.1.4 Determination of Cr(III) by FAAS 2.7.2 67 2.7.2.1 Effect of Initial pH 68 2.7.2.2 Isotherm Study 68 2.7.2.3 SMZY-Chromate Structure 2.7.2.4 69 Determination of Cr(VI) by UVVis Spectrophotometer 2.7.4 66 Adsorption of Cr(VI) Study 2.7.3 64 69 Adsorption of As(V) and As(III): Preliminary Study 70 Adsorption of As(V) 71 2.7.4.1 Effect of Initial pH 71 2.7.4.2 Isotherm Study 72 2.7.4.3 Determination of Arsenic by FAAS 72 x 3 RESULTS AND DISCUSSION: SORBENTS DEVELOPMENT 73 3.1 Rice Husk Ash as a Source of Silica 73 3.2 Synthesis of Zeolite NaY 75 3.2.1 X-ray Diffraction Technique 75 3.2.2 Infrared Spectroscopy 80 3.2.3 Elemental Analysis 83 3.2.4 Physicochemical Properties 86 3.3 Characterization of Surfactant Modified Zeolite Y 4 88 3.3.1 X-ray Diffraction Technique 88 3.3.2 Infrared Spectroscopy 90 3.3.3 Elemental Analysis 91 3.3.4 Surface Area and Porosity 94 3.3.5 Dispersion Behavior 95 3.3.6 Maximum Adsorption of HDTMA 98 RESULTS AND DISCUSSION: APPLICATION OF SORBENTS 101 4.1 Removal of Cr(III) 101 4.1.1 Kinetic Study 101 4.1.2 Effect of Initial pH 107 4.1.3 Isotherm Study 109 4.2 Removal of Cr(VI) 113 4.2.1 Effect of Initial pH 113 4.2.2 Isotherm Study 116 4.2.3 SMZY-Chromate Structure Study 119 4.3 Removal of Arsenic 4.3.1 4.3.2 122 Preliminary study: Adsorption of Arsenate and Arsenite 122 Removal of Arsenate 125 4.3.2.1 125 Effect of Initial pH xi 4.3.2.2 5 Isotherm Study 127 CONCLUSIONS AND SUGGESTIONS 132 5.1 Conclusions 132 5.2 Suggestions 136 REFERENCES 137 Appendices A - I 148-198 xii LIST OF TABLES TABLE NO. TITLE PAGE 1.1 Element sources in the zeolites and their function 5 1.2 Composition ratio of synthesis Zeolite NaY 10 1.3 The assignments of the main infrared bands for zeolites 22 2.1 The abbreviation of the surfactant modified zeolite Y 60 2.2 Solutions for calibrating flame photometer 62 3.1 Chemical composition of rice husk ash 74 3.2 Zeolite NaY infrared assignments 81 3.3 IR assignments for commercial, synthesized zeolite NaY and zeolite Y (SiO2/Al2O3 4.87) 82 3.4 Percentage amount of major elements contained in the zeolite samples from the first approach 84 3.5 Percentage amount of major elements contained in zeolite samples by XRF technique 84 3.6 The physicochemical properties of the synthesized (ZeoNaY-S) and commercial zeolite NaY (Zeo-NaY-C) 86 3.7 Peak lists of SMZY infrared spectrum 90 3.8 The content of Na2O in the SMZY and their parent zeolite 91 3.9 Elemental data of the SMZY obtained from the CHNS analyzer 93 3.10 Surface area and porosity of the SMZY and unmodified zeolites 94 xiii 3.11 Fitted Langmuir parameters for sorption of HDTMA by synthesized zeolite Y 99 4.1 Values of the pseudo second order model parameters for the adsorption of Cr(III) by synthesized and commercial zeolite NaY 107 4.2 Fitted Langmuir and Freundlich parameters for Cr(III) sorption on SMZY and the unmodified synthesized and commercial zeolite NaY 111 4.3 Fitted Langmuir parameters for sorption of Cr(VI) by SMZY 117 4.4 Values of the adsorption of As(III) and As(V) by SMZY and respective parent zeolite Y 123 4.5 Values of the Langmuir parameters for sorption of As(V) by SMZY 129 xiv LIST OF FIGURES FIGURE NO. 1.1 TITLE PAGE The sodalite cages (truncated octahedral) connected on the hexagonal faces in zeolite Y. The three types of cation sites are shown. 8 1.2 Derivation of Bragg’s law for X-ray diffraction 18 1.3 The illustration of the X-ray powder diffraction method 19 1.4 The structure of hexadecyltrimethyl bromide (HDTMA-Br) 29 1.5 ammonium Schematic diagram of HDTMA micelle formation in solution and admicelle formation on the zeolite surface and the uptake substance onto surfactant modified zeolite 31 1.6 The structure of the anion form of arsenate (a, b, c and d) and the neutral form of arsenite (e) species. 39 3.1 The XRD diffractogram of RHA 73 3.2 Infrared spectrum of rice husk ash 74 3.3 The X-ray diffraction patterns of the product obtained from the synthesis without ageing and seeding technique (NA-NS-Zeo) and the product from the synthesized zeolite Y with ageing but without seeding technique (A-NS-Zeo) 76 The X-ray diffraction pattern of mixed synthesized zeolite NaY (Zeo-NaY-S) via seeding and ageing techniques match up with the sodium aluminum silicate hydrate NaY (Na2Al2Si4.5O13.xH2O) pattern existed in PDF 77 3.4 xv 3.5 The compilation of X-ray diffractograms of the synthesized zeolite NaY 78 The X-ray diffraction pattern of the commercial zeolite NaY 79 3.7 The infrared spectrum of Zeo-NaY-S 80 3.8 The infrared spectrum of Zeo-NaY-C 80 3.9 The illustration of infrared spectrum of zeolite Y (Si/Al = 2.5) in the region from 1250 to 420 cm-1 81 The comparison of the infrared spectrum of synthesized zeolite NaY (Zeo-NaY-S) and rice husk ash (RHA) 83 The XRD patterns of the surfactant modified zeolite Y together with the parent zeolites 89 The comparison of the Na2O amount (mg/g) present in the SMZY and respective unmodified zeolite 92 The comparison of the specific surface area (m2/g), total pore volume (cc/g) and average pore size (วบ) for SMZY and unmodified zeolite Y 95 Photographs show the distribution of SMZY and unmodified zeolite NaY solid particles when added to hexane-water mixture 96 Photographs showing the distribution of SMZY and unmodified zeolite Y solid particles 97 The sorption isotherm plotted of HDTMA onto the synthesized zeolite Y 98 The plotted of 1/qe against 1/Ce where qe is the HDTMA adsorbed at equilibrium (mmol/kg) and Ce is concentration of HDTMA at equilibrium (mmol/L). 99 Schematic diagram of the theoretical HDTMA formation on the zeolite Y structure 100 Sorption kinetics graph for synthesized zeolite NaY from two different initial concentrations of Cr(III) 102 Sorption kinetics graph for commercial zeolite NaY with two different initial concentrations 102 3.6 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 4.1 4.2 xvi 4.3 4.4 4.5 Percentage of the Cr(III) removal by synthesized (ZeoNaY-S) and commercial zeolite NaY with [Cr(III)]initial = 250 mg/L. 103 Percentage of the Cr(III) removal by synthesized (ZeoNaY-S) and commercial zeolite NaY with [Cr(III)]initial = 500 mg/L. 104 The effect of pH on the Cr(III) removal by synthesized and commercial zeolite NaY 108 The adsorption isotherm of Cr(III) sorption on SMZY from the synthesized zeolite NaY together with the unmodified synthesized zeolite NaY 109 The adsorption isotherm of Cr(III) sorption on SMZY from the commercial zeolite NaY together with the unmodified commercial zeolite NaY 110 The adsorption isotherm of Cr(III) sorption on unmodified synthesized and commercial zeolite NaY 110 The Kf (Freundlich constant) values for the adsorption of Cr(III) by SMZY and unmodified zeolite Y 112 4.10 Effect of pH solution on Cr(VI) removal by SMZY 114 4.11 Sorption of Cr(VI) by SMZY and unmodified synthesized zeolite Y 116 Sorption of Cr(VI) by SMZY and unmodified commercial zeolite Y 116 The comparison of the maximum adsorption (Qo) calculated from the Langmuir isotherm model for the sorption of Cr(VI) by SMZY 118 XRD patterns of the unmodified synthesized zeolite NaY (Zeo-NaY-S), SMZY-100-S and after contacting with chromate solution (SMZY-100-S-Chromate) 120 IR spectra of SMZY-100-S and SMZY-100-SChromate 120 IR spectra of unmodified synthesized zeolite NaY (Zeo-NaY-S) and SMZY-100-S-Chromate 121 Schematic diagram for the mechanism of Cr(VI) sorption by SMZY 121 4.6 4.7 4.8 4.9 4.12 4.13 4.14 4.15 4.16 4.17 xvii 4.18 4.19 4.20 4.21 4.22 4.23 4.24 Adsorption of As(III) by the SMZY and unmodified zeolite NaY 123 The adsorption of As(V) species from aqueous solution by SMZY and unmodified zeolite NaY 124 Effect of the initial pH solution in the removal of As(V) by SMZY 125 As(V) sorption from aqueous solution by SMZY-50-S, SMZY-50-C and respective parent zeolite NaY 128 As(V) sorption from aqueous solution by SMZY-100S, SMZY-100-C and respective parent zeolite NaY 128 As(V) sorption from aqueous solution by SMZY-200S, SMZY-200-C and respective parent zeolite NaY 129 Comparison of the maximum adsorption (Qo) value calculated from the Langmuir isotherm model for the As(V) sorption by each of the SMZY 130 xviii LIST OF SYMBOLS °C - Degree Celsius Co - Initial concentration Ce - Equilibrium concentration cm - Centi meter dm - Deci meter g - Gram kg - Kilo gram kV - Kilo Volt L - Liter m - Meter M - Molar mA - Mili ampere meq - Mili equivalent mg - Mili gram min - Minute mL - Mili Liter mm - Mili meter mmol - Mili mol N - Normal nm - Nano meter ppm - Part per million ppb - Part per billion Å - Angstrom μg - Micro gram μL - Micro Liter xix LIST OF ABBREVIATIONS AAS - Atomic Absorption Spectroscopy APHA - American Public Health Association ASTM - American Society for Testing and Materials ATP - Adenosine Tri-Phosphate BET - Brunauer, Emmet, and Teller BTEX - Benzene, Toluene, Ethylene and Xylene CCA - Chromated Copper Arsenate CEC - Cation Exchange Capacity CHNS - Carbon Hydrogen Nitrogen Sulphur CMC - Critical Micelle Concentration CQ - Chloroquin CRM - Certified Reference Materials DDTMA - Decadecyltrimethyl Ammonium DHA - Dehydroabietic Acid ECEC - External Cation Exchange Capacity EPA - Environmental Protection Agency FAAS - Flame Atomic Absorption Spectroscopy FAU - Faujasite FTIR - Fourier Transform Infrared HDTMA - Hexadecyltrimethyl Ammonium ICDD - International Centre for Diffraction Data ICPMS - Inductively Coupled Plasma Mass Spectrometry IEC - Ion Exchange Capacity IR - Infrared LEDs - Light Emitting Diodes xx LOI - Loss on Ignition LTA - Linde Type A MCL - Maximum Contaminant Levels MTDC - Malaysian Technology Development Corporation NAA - Neutron Activation Analysis NIOSH - National Institute for Occupational Safety and Health NMR - Nuclear Magnetic Resonance ODTMA - Octadecyltrimethyl Ammonium OTS - Octadecyltrichlorosilane PCE - Perchloroethylene PDF - Powder Diffraction File PFC - Plug Flow Combustor PTFE - Polytetrafluoroethylene QC - Quality Control R&D - Research and Development RHA - Rice Husk Ash SIRIM - Standards and Industrial Research Institute of Malaysia SMC - Surfactant Modified Clinoptilolite SMZ - Surfactant Modified Zeolite SMZY - Surfactant Modified Zeolite Y TCE - Trichloro Ethylene TDTMA - Tetradecyltrimethyl Ammonium TEA - Tetraethyl Ammonium TOC - Total Organic Carbon UV-Vis - Ultra Violet-Visible WHO - World Health Organization XRD - X-Ray Diffraction XRF - X-Ray Flourescence xxi LIST OF APPENDICES APPENDIX TITLE PAGE A Elemental analysis for the zeolite NaY 148 A-1 Analysis data for the determination of sodium in the zeolite NaY samples by AAS 148 Analysis data for the determination of Al by ICP-MS 149 Analysis data for the determination of loss on ignition (LOI) and the percentage of silica (%SiO2) 150 A-4 X-Ray Fluorescence (XRF) accuracy 150 B Physicochemical Properties of the Zeolite NaY 151 B-1 Surface area and porosity 151 B-2 Determination of the unit cell 152 B-3 Determination of CEC and ECEC 153 C Infrared spectra of SMZY matching with respective parent zeolite 155 Determination of sodium in SMZY and unmodified zeolite Y 158 Surface area and porosity of the surfactant modified zeolite Y 159 Maximum adsorption of HDTMA on the zeolite Y 160 Removal of Cr(III) study 161 A-2 A-3 D E F G xxii G-1 Kinetic study of the Cr(III) uptake by the synthesized and commercial zeolite NaY 161 G-2 Effect of the initial pH for the Cr(III) removal 164 G-3 Isotherm adsorption study of the Cr(III) by modified and unmodified zeolite NaY 168 H Removal of Cr(VI) study 174 H-1 Effect of the initial pH solution on the removal of Cr(VI) by SMZY 174 Isotherm study of the removal of Cr(VI) by SMZY 180 I Removal of arsenic study 192 I-1 Preliminary study of the As(III) and As(V) adsorption by SMZY and unmodified zeolite Y 192 Effect of the initial pH solution on the removal of As(V) by SMZY 193 H-2 I-2 I-3 Isotherm study of the As(V) sorption by SMZY 195 J Presented papers and expected publications from this study 198
