Wastewater treatment
Ravindra, P. N.
Wastewater treatment - Banglore ISTE-Working Professionals Learning Project (AICTE Project) 2007 - xvi,299p. - ISTE-WPLP learing material series .
CONTENTS FOREWORD i PREFACE iii 1 WASTEWATER 1 1.1 Wastewater 1 1.1.1 Wastewater Composition 1 1.1.2 Pollution 2 1.1.3 Contaminants 3 1.1.4 Wastewater Sources 4 1.2 Pollution Parameters 5 1.2.1 Biochemical Oxygen Demand 5 1.2.2 Chemical Oxygen Demand 8 1.2.3 Chlorides 9 1.2.4 pH (Potential Hydrogen) 10 1.2.5 Ammonia Nitrogen 12 1.2.6 Nitrite 13 1.2.7 Nitrate 13 1.2.8 Phosphate 14 1.2.9 Phosphorus 14 1.2.10 Solids 15 1.2.11 Sulphates 17 1.2.12 Temperature 17 1.2.13 Total Organic Carbon 18 1.3 Wastewater Characteristics 18 1.3.1 Physical Characteristics 19 1.3.2 Chemical Characteristics 19 1.3.3 Biological Characteristics 21 1.4 Wastewater Classification 22 1.5 Effluent Standards 23 1.6 Risk Assessment 26 2 WASTEWATER TREATMENT 28 2.1 Introduction 28 2.1.1 Objectives of Treatment 28 2.1.2 Process Train 29 2.1.3 Wastewater Processing 31 2.1.4 Wastewater Management 32 2.2 Process Mechanisms 33 2.2.1 Physical Treatment 36 2.2.2 Chemical Treatment 36 2.2.3 Biological Treatment 40 2.3 Unit Operations and Processes 42 2.3.1 Unit Operations 42 2.3.2 Unit Processes 43 2.4 Reactors 43 2.4.1 Plug Flow Reactor 44 2.4.2 Arbitrary Flow Reactor 44 2.4.3 Batch Reactor 44 2.4.4 Complete-Mix Reactor 45 2.4.5 Fluidised Bed Reactor 46 2.4.6 Packed-Bed Reactor 46 2.5 Specific Treatments 47 2.5.1 Nitrification 47 2.5.2 Denitrification 48 2.5.3 Dilution 49 2.5.4 Low Cost Treatment 50- 2.5.5 Natural Treatment System 50 2.5.6 Wastewater Disinfection 50 2.6 Treatment System 51 2.6.1 Plant Layout 51 2.6.2 Process Analysis 52 2.6.3 Process Variables 52 2.6.4 Process Condition 52 2.6.5 Process Control 53 2.6.6 Wastewater Treatment Plant Cost 55 2.7 Preventive Maintenance 56 2.8 Hydraulic Design 57 2.8.1 Flow in Pressurized Pipes 58 2.8.2 Flow in Open Channels 60 2.8.3 Other Losses 61 2.9 Wastewater Recycling 63 3 PRELIMINARY AND PRIMARY TREATMENT UNITS 64 3.1 Introduction 64 3.2 Preliminary Treatment Units 64 3.2. Bar Racks 64 3.2.2 Screen 65 3.2.3 Drum Screen 67 3.2.4 Screenings 68 3.3 Grit Chamber 68 3.3.1 Constant Velocity Grit Channel 69 3.3.2 Detritor 70 3.3.3 Classifier 71 3.3.4 Aerated Grit Chamber 72 3.3.5 Vortex Grit Separator 73 3.3.6 Centrifugal Grit Chamber 74 3.3.7 Cyclone Grit Separator 74 3.4 Comminution 74 3.5 Grease and Oil Removal 74 3.5.1 Grease and Oil Trap 75 3.5.2 Skimming Tank 76 3.6 Equalisation 77 3.7 Preaeration 79 3.8 Primary Treatment Units 80 3.8.1 Presedimentation Tank 80 3.8.2 Primary Clarification 80 3.8.3 Primary Effluent 82 3.9 ImhoffTank 82 3.10 Septic Tank 83 3.11 Soak Pit 84 4 SEDIMENTATION 86 4.1 Introduction 86 4.1.1Sedimentation 86 4.1.2 Particle Settling Velocity 87 4.2 Settling Regimes 89 4.2.1 Type 1 Sedimentation 90 4.2.2 Type 2 Sedimentation: Flocculent Settling 93 4.2.3 Sizing the Basin 96 4.2.4 Type 3 Sedimentation: Zone Settling 96 4.2.5 Analysis of Zone Sedimentation - 99 4.2.6 Type 4 Sedimentation: Compression Settling 100 4.3 Sedimentation Tank 100 4.3.1 Clarifier Operation 101 4.3.2 Clarifier Design 102 4.3.3 Secondary Clarifier 102 4.3.4 Tube and Lamella Clarifiers 103 5 BIOLOGICAL TREATMENT PROCESSES 106 5.1 Introduction 106 5.2 Microorganism 106 5.2.1 Bacteria 108 5.2.2 Algae 110 5.2.3 Fungi 111 5.2.4 Protozoa and Rotifers 111 5.2.5 Prokaryotes 112 5.2.6 Eukaryotes 112 5.3 Biological Treatment 113 5.3.1 Metabolism 114 5.3.2 Microbiology 114 5.3.3 Microbial Flocculation 115 5.3.4 Growth of Microbes 115 5.3.5 Microbial Growth Curve 116 5.4 Identification and Enumeration of Microbes 118 5.5 Principles of Biological Treatment 120 5.5.1 Aerobic Biological Process 122 5.5.2 Anaerobic Biological Process 123 5.6 Biological Treatment Systems 125 5.6.1 Activated Sludge Process 126 5.6.2 Trickling Filter 127 5.6.3 Rotating Biological Contactors 129 5.6.4 Sequencing Batch Reactor 131 5.6.5 Biological Fluidised Bed 133 5.6.6 Upflow Anaerobic Sludge Blanket Reactor 135 5.7 Combined Aerobic Process 136 5.8 Package Treatment Units 137 5.9 Process Ponds 139 6 ACTIVATED SLUDGE PROCESS 141 6.1 Introduction 141 6.1.1 Activated Sludge 141 6.1.2 Mean Cell Residence Time 143 6.1.3 Mixed Liquor Suspended Solids 144 6.1.4 Sludge Volume Index 144 6.2 Activated Sludge Process 146 6.2.1 Aeration 148 6.2.2 Surface Aerator 150 6.2.3 Submerged Aerators 152 6.2.4 Floating Aerators 153 6.2.5 Diffused Aeration 154 6.2.6 Conventional Activated Sludge Process 155 6.2.6 Bulking of Sludge 156 6.3 Modifications of Activated Sludge Process 156 6.3.1 Composite Activated Sludge Reactor 157 6.3.2 Complete Mix Activated Sludge Process 158 6.3.3 Contact Stabilisation Process 158 6.3.4 Extended Aeration Process 159 6.3.5 Oxidation Ditch 160 6.3.6 Plug Flow Activated Sludge Process 161 6.3.7 Pure Oxygen Activated Sludge Process 162 6.3.8 Step Aeration Process 163 6.3.9 Tapered Aeration Process 163 6.3.10 Deep Shaft Process 164 6.3.11 Anaerobic Anoxic Oxic Process 165 6.3.12 Anaerobic Oxic Process 166 6.3.13 Powder Activated Carbon Activated Sludge Process 167 7 DVANCED WASTEWATER TREATMENT 168 7.1 Introduction 168 7.1.1 Advanced Wastewater Treatment 168 7.1.2 Tertiary Treatment 169 7.2 Specific Processes 170 7.2.1 Biological Nitrification 170 7.2.2 Biological Denitrification 171 7.2.3 Biological Phosphorus Removal 173 7.2.4 Enhanced Nitrogen Removal 173 7.2.5 Phosphorus Precipitation 176 7.2.6 Enhanced Phosphorus Uptake 178 7.2.7 Biological Aerated Filter 179 7.2.8 Biological Filtration 180 7.2.9 Ammonia Stripping 181 7.3 Advanced Biological Processes 182 7.3.1 Bardenpho Process 182 7.3.2 Virginia Initiative Process 184 7.3.3 PhoStrip Process 185 7.3.4 Phoredox Process 185 7.4 Adsorption Process 186 7.4.1 Activated Carbon 187 7.4.2 Granular Activated Carbon 189 7.5 Recent Advanced Processes 191 7.5.1 Membrane Bioreactor 191 7.5.2 Membrane Filtration Process 192 7.5.3 Reverse Osmosis 194 8 NATURAL TREATMENT SYSTEM 198 8.1 Introduction 198 8.2 Natural Treatment Systems 198 8.2.1 Land Application 198 8.2.2 Lagoon 200 8.3 Sewage Farming 201 8.3.1 Surface Irrigation System 201 8.3.2 Root Zone Flow System 205 8.3.3 Reed Bed Treatment 205 8.4 Oxidation Pond 206 8.5 Facultative Pond 207 8.6 Maturation Pond 208 8.7 Anaerobic Pond 208 8.8 Wetland 209 8.8.1 Natural Wetlands 210 8.8.2 Constructed Wetlands 210 8.9 Composting 211 8 RESIDUAL MANAGEMENT 213 9.1 Introduction 213 9.1.1 Sludge 213 9.1.2 Wastewater Sludge Treatment 214 9.2 Sludge Processing 215 9.2.1 Pretreatment and Storage of Sludge 215 9.2.2 Sludge Conditioning 217 9.3 Sludge Stabilisation 218 9.3.1 Chemical Stabilisation 218 9.3.2 Stabilisation by Aerobic Digestion 219 9.3.3 Stabilisation by Anaerobic Digestion220 9.3.4 Anaerobic Digester 222 9.3.5 Role of Mixing 224 9.4 Sludge Chemical Conditioning 224 9.5 Thermal Stabilisation 226 9.6 Sludge Dewatering Operations 227 9.6.1 Sludge Thickener 227 9.6.2 Vacuum Filtration 229 9.6.3 Rotary Vacuum Filtration 231 9.6.4 Wet Air Oxidation 231 9.6.5 Flotation Thickening 232 9.6.6 Recessed Plate Press 232 9.6.7 Belt Filter Press 233 9.6.8 Filter Plate Press 234 9.7 Sludge Pasteurisation Process 235 9.8 Sludge Incineration 237 9.8.1 Multiple Hearth Incinerator 238 9.8.2 Fluidised Bed Incinerator 239 9.9 Land Spreading 240 9.10 Sludge Lagoon 241 9.11 Gravity Dewatering 241 9.11.1 Sludge Thickening 241 9.11.2 Sludge Drying Beds 242 9.11.3 Leachate 245 9.12 Centrifugal Thickening 245 9.12.1 Solid Bowl Centrifuge 246 9.12.2 Nozzle Bowl Centrifuge 247 9.12.3 Basket Centrifuge 248 10 MEMBRANE TREATMENT SYSTEMS 249 10.1 Introduction 249 10.2 Membrane 249 10.3 Membrane Separation Technology 250 10.4 Process Management of Membrane Systems 252 10.4.1 Dead-End Filtration 252 10.4.2 Cross-Flow Filtration 253 10.5 Membrane Modules 253 10.5.1 Tubular Membranes 255 10.5.2 Capillary Membranes 255 10.5.3 Hollow Fibre Membranes 256 10.5.4 Spiral Membranes 256 10.5.5 Pillow-Shaped Membranes 256 10.6 Types of Membranes 257 10.6.1 Microporous Membranes 257 10.6.2 Homogeneous Membranes 257 10.6.3 Asymmetric Membranes 257 10.6.4 Electrically Charged Membranes 258 10.6.5 Liquid Membranes 258 10.7 Membrane Separation Processes 258 10.7.1 Reverse Osmosis 258 10.7.2 Nanofiltration 259 10.7.3 Ultrafiltration 259 10.7.4 Microfiltration 261 10.7.5 Electrodialysis 262 10.7.6 Pervaporation 263 10.8 Membrane Fouling 263 10.9 Membrane Spectrum 264 References 267 Glossary 268 Abbreviations 294
8189731130
628.3 / RAV
Wastewater treatment - Banglore ISTE-Working Professionals Learning Project (AICTE Project) 2007 - xvi,299p. - ISTE-WPLP learing material series .
CONTENTS FOREWORD i PREFACE iii 1 WASTEWATER 1 1.1 Wastewater 1 1.1.1 Wastewater Composition 1 1.1.2 Pollution 2 1.1.3 Contaminants 3 1.1.4 Wastewater Sources 4 1.2 Pollution Parameters 5 1.2.1 Biochemical Oxygen Demand 5 1.2.2 Chemical Oxygen Demand 8 1.2.3 Chlorides 9 1.2.4 pH (Potential Hydrogen) 10 1.2.5 Ammonia Nitrogen 12 1.2.6 Nitrite 13 1.2.7 Nitrate 13 1.2.8 Phosphate 14 1.2.9 Phosphorus 14 1.2.10 Solids 15 1.2.11 Sulphates 17 1.2.12 Temperature 17 1.2.13 Total Organic Carbon 18 1.3 Wastewater Characteristics 18 1.3.1 Physical Characteristics 19 1.3.2 Chemical Characteristics 19 1.3.3 Biological Characteristics 21 1.4 Wastewater Classification 22 1.5 Effluent Standards 23 1.6 Risk Assessment 26 2 WASTEWATER TREATMENT 28 2.1 Introduction 28 2.1.1 Objectives of Treatment 28 2.1.2 Process Train 29 2.1.3 Wastewater Processing 31 2.1.4 Wastewater Management 32 2.2 Process Mechanisms 33 2.2.1 Physical Treatment 36 2.2.2 Chemical Treatment 36 2.2.3 Biological Treatment 40 2.3 Unit Operations and Processes 42 2.3.1 Unit Operations 42 2.3.2 Unit Processes 43 2.4 Reactors 43 2.4.1 Plug Flow Reactor 44 2.4.2 Arbitrary Flow Reactor 44 2.4.3 Batch Reactor 44 2.4.4 Complete-Mix Reactor 45 2.4.5 Fluidised Bed Reactor 46 2.4.6 Packed-Bed Reactor 46 2.5 Specific Treatments 47 2.5.1 Nitrification 47 2.5.2 Denitrification 48 2.5.3 Dilution 49 2.5.4 Low Cost Treatment 50- 2.5.5 Natural Treatment System 50 2.5.6 Wastewater Disinfection 50 2.6 Treatment System 51 2.6.1 Plant Layout 51 2.6.2 Process Analysis 52 2.6.3 Process Variables 52 2.6.4 Process Condition 52 2.6.5 Process Control 53 2.6.6 Wastewater Treatment Plant Cost 55 2.7 Preventive Maintenance 56 2.8 Hydraulic Design 57 2.8.1 Flow in Pressurized Pipes 58 2.8.2 Flow in Open Channels 60 2.8.3 Other Losses 61 2.9 Wastewater Recycling 63 3 PRELIMINARY AND PRIMARY TREATMENT UNITS 64 3.1 Introduction 64 3.2 Preliminary Treatment Units 64 3.2. Bar Racks 64 3.2.2 Screen 65 3.2.3 Drum Screen 67 3.2.4 Screenings 68 3.3 Grit Chamber 68 3.3.1 Constant Velocity Grit Channel 69 3.3.2 Detritor 70 3.3.3 Classifier 71 3.3.4 Aerated Grit Chamber 72 3.3.5 Vortex Grit Separator 73 3.3.6 Centrifugal Grit Chamber 74 3.3.7 Cyclone Grit Separator 74 3.4 Comminution 74 3.5 Grease and Oil Removal 74 3.5.1 Grease and Oil Trap 75 3.5.2 Skimming Tank 76 3.6 Equalisation 77 3.7 Preaeration 79 3.8 Primary Treatment Units 80 3.8.1 Presedimentation Tank 80 3.8.2 Primary Clarification 80 3.8.3 Primary Effluent 82 3.9 ImhoffTank 82 3.10 Septic Tank 83 3.11 Soak Pit 84 4 SEDIMENTATION 86 4.1 Introduction 86 4.1.1Sedimentation 86 4.1.2 Particle Settling Velocity 87 4.2 Settling Regimes 89 4.2.1 Type 1 Sedimentation 90 4.2.2 Type 2 Sedimentation: Flocculent Settling 93 4.2.3 Sizing the Basin 96 4.2.4 Type 3 Sedimentation: Zone Settling 96 4.2.5 Analysis of Zone Sedimentation - 99 4.2.6 Type 4 Sedimentation: Compression Settling 100 4.3 Sedimentation Tank 100 4.3.1 Clarifier Operation 101 4.3.2 Clarifier Design 102 4.3.3 Secondary Clarifier 102 4.3.4 Tube and Lamella Clarifiers 103 5 BIOLOGICAL TREATMENT PROCESSES 106 5.1 Introduction 106 5.2 Microorganism 106 5.2.1 Bacteria 108 5.2.2 Algae 110 5.2.3 Fungi 111 5.2.4 Protozoa and Rotifers 111 5.2.5 Prokaryotes 112 5.2.6 Eukaryotes 112 5.3 Biological Treatment 113 5.3.1 Metabolism 114 5.3.2 Microbiology 114 5.3.3 Microbial Flocculation 115 5.3.4 Growth of Microbes 115 5.3.5 Microbial Growth Curve 116 5.4 Identification and Enumeration of Microbes 118 5.5 Principles of Biological Treatment 120 5.5.1 Aerobic Biological Process 122 5.5.2 Anaerobic Biological Process 123 5.6 Biological Treatment Systems 125 5.6.1 Activated Sludge Process 126 5.6.2 Trickling Filter 127 5.6.3 Rotating Biological Contactors 129 5.6.4 Sequencing Batch Reactor 131 5.6.5 Biological Fluidised Bed 133 5.6.6 Upflow Anaerobic Sludge Blanket Reactor 135 5.7 Combined Aerobic Process 136 5.8 Package Treatment Units 137 5.9 Process Ponds 139 6 ACTIVATED SLUDGE PROCESS 141 6.1 Introduction 141 6.1.1 Activated Sludge 141 6.1.2 Mean Cell Residence Time 143 6.1.3 Mixed Liquor Suspended Solids 144 6.1.4 Sludge Volume Index 144 6.2 Activated Sludge Process 146 6.2.1 Aeration 148 6.2.2 Surface Aerator 150 6.2.3 Submerged Aerators 152 6.2.4 Floating Aerators 153 6.2.5 Diffused Aeration 154 6.2.6 Conventional Activated Sludge Process 155 6.2.6 Bulking of Sludge 156 6.3 Modifications of Activated Sludge Process 156 6.3.1 Composite Activated Sludge Reactor 157 6.3.2 Complete Mix Activated Sludge Process 158 6.3.3 Contact Stabilisation Process 158 6.3.4 Extended Aeration Process 159 6.3.5 Oxidation Ditch 160 6.3.6 Plug Flow Activated Sludge Process 161 6.3.7 Pure Oxygen Activated Sludge Process 162 6.3.8 Step Aeration Process 163 6.3.9 Tapered Aeration Process 163 6.3.10 Deep Shaft Process 164 6.3.11 Anaerobic Anoxic Oxic Process 165 6.3.12 Anaerobic Oxic Process 166 6.3.13 Powder Activated Carbon Activated Sludge Process 167 7 DVANCED WASTEWATER TREATMENT 168 7.1 Introduction 168 7.1.1 Advanced Wastewater Treatment 168 7.1.2 Tertiary Treatment 169 7.2 Specific Processes 170 7.2.1 Biological Nitrification 170 7.2.2 Biological Denitrification 171 7.2.3 Biological Phosphorus Removal 173 7.2.4 Enhanced Nitrogen Removal 173 7.2.5 Phosphorus Precipitation 176 7.2.6 Enhanced Phosphorus Uptake 178 7.2.7 Biological Aerated Filter 179 7.2.8 Biological Filtration 180 7.2.9 Ammonia Stripping 181 7.3 Advanced Biological Processes 182 7.3.1 Bardenpho Process 182 7.3.2 Virginia Initiative Process 184 7.3.3 PhoStrip Process 185 7.3.4 Phoredox Process 185 7.4 Adsorption Process 186 7.4.1 Activated Carbon 187 7.4.2 Granular Activated Carbon 189 7.5 Recent Advanced Processes 191 7.5.1 Membrane Bioreactor 191 7.5.2 Membrane Filtration Process 192 7.5.3 Reverse Osmosis 194 8 NATURAL TREATMENT SYSTEM 198 8.1 Introduction 198 8.2 Natural Treatment Systems 198 8.2.1 Land Application 198 8.2.2 Lagoon 200 8.3 Sewage Farming 201 8.3.1 Surface Irrigation System 201 8.3.2 Root Zone Flow System 205 8.3.3 Reed Bed Treatment 205 8.4 Oxidation Pond 206 8.5 Facultative Pond 207 8.6 Maturation Pond 208 8.7 Anaerobic Pond 208 8.8 Wetland 209 8.8.1 Natural Wetlands 210 8.8.2 Constructed Wetlands 210 8.9 Composting 211 8 RESIDUAL MANAGEMENT 213 9.1 Introduction 213 9.1.1 Sludge 213 9.1.2 Wastewater Sludge Treatment 214 9.2 Sludge Processing 215 9.2.1 Pretreatment and Storage of Sludge 215 9.2.2 Sludge Conditioning 217 9.3 Sludge Stabilisation 218 9.3.1 Chemical Stabilisation 218 9.3.2 Stabilisation by Aerobic Digestion 219 9.3.3 Stabilisation by Anaerobic Digestion220 9.3.4 Anaerobic Digester 222 9.3.5 Role of Mixing 224 9.4 Sludge Chemical Conditioning 224 9.5 Thermal Stabilisation 226 9.6 Sludge Dewatering Operations 227 9.6.1 Sludge Thickener 227 9.6.2 Vacuum Filtration 229 9.6.3 Rotary Vacuum Filtration 231 9.6.4 Wet Air Oxidation 231 9.6.5 Flotation Thickening 232 9.6.6 Recessed Plate Press 232 9.6.7 Belt Filter Press 233 9.6.8 Filter Plate Press 234 9.7 Sludge Pasteurisation Process 235 9.8 Sludge Incineration 237 9.8.1 Multiple Hearth Incinerator 238 9.8.2 Fluidised Bed Incinerator 239 9.9 Land Spreading 240 9.10 Sludge Lagoon 241 9.11 Gravity Dewatering 241 9.11.1 Sludge Thickening 241 9.11.2 Sludge Drying Beds 242 9.11.3 Leachate 245 9.12 Centrifugal Thickening 245 9.12.1 Solid Bowl Centrifuge 246 9.12.2 Nozzle Bowl Centrifuge 247 9.12.3 Basket Centrifuge 248 10 MEMBRANE TREATMENT SYSTEMS 249 10.1 Introduction 249 10.2 Membrane 249 10.3 Membrane Separation Technology 250 10.4 Process Management of Membrane Systems 252 10.4.1 Dead-End Filtration 252 10.4.2 Cross-Flow Filtration 253 10.5 Membrane Modules 253 10.5.1 Tubular Membranes 255 10.5.2 Capillary Membranes 255 10.5.3 Hollow Fibre Membranes 256 10.5.4 Spiral Membranes 256 10.5.5 Pillow-Shaped Membranes 256 10.6 Types of Membranes 257 10.6.1 Microporous Membranes 257 10.6.2 Homogeneous Membranes 257 10.6.3 Asymmetric Membranes 257 10.6.4 Electrically Charged Membranes 258 10.6.5 Liquid Membranes 258 10.7 Membrane Separation Processes 258 10.7.1 Reverse Osmosis 258 10.7.2 Nanofiltration 259 10.7.3 Ultrafiltration 259 10.7.4 Microfiltration 261 10.7.5 Electrodialysis 262 10.7.6 Pervaporation 263 10.8 Membrane Fouling 263 10.9 Membrane Spectrum 264 References 267 Glossary 268 Abbreviations 294
8189731130
628.3 / RAV