RONALD DROSTE, PHD, is an Emeritus Professor in the Department of Civil Engineering at the University of Ottawa, and a Fellow of the Canadian Society for Civil Engineering (CSCE).

RONALD GEHR, PHD, is an Associate Professor (Post-retirement) in the Department of Civil Engineering and Applied Mechanics at McGill University and a Fellow of the Canadian Society for Civil Engineering (CSCE).

Acknowledgments XXI

Preface XXIII

Abbreviations and Acronyms Used in the Text XXV

About the Companion Website XXXIII

Section I: Chemistry 1

1 Basic Chemistry 3

1.1 Definitions 3

1.2 The Expression of Concentration 4

1.3 Ions and Molecules in Water 5

1.3.1 Oxidation Number 5

1.4 Balancing Reactions 9

1.5 Oxidation-Reduction Reactions 10

1.6 Equilibrium 12

1.7 Conductivity and Ionic Strength 13

1.7.1 Conductance 14

1.7.2 Ionic Strength 14

1.8 Chemical Kinetics 15

1.8.1 Other Formulations 16

Consecutive or Series 16

Parallel 17

Retardant 17

Autocatalytic 17

Catalysis 18

1.8.2 The Effect of Temperature on Rate of Reaction 19

1.9 Gas Laws 19

1.10 Gas Solubility: Henry's Law 20

1.11 Solubility Product 23

1.12 Complexes 25

1.13 Nuclear Chemistry 27

1.13.1 Radioactivity Units 27

Questions and Problems 30

References 33

2 The Thermodynamic Basis for Equilibrium 35

2.1 Thermodynamic Relations 35

2.1.1 Free Energy 35

Expression of Concentration in Equilibrium Expressions 39

2.1.2 Enthalpy and Temperature Effects on the Equilibrium Constant 42

2.2 Redox Potentials 43

2.2.1 Cell or Couple Potential 46

2.2.2 Oxidation-Reduction Potential and System Potential 48

2.3 Corrosion 49

2.3.1 Microbial Corrosion 51

2.3.2 Corrosion Prevention from External Environmental Factors 52

Galvanic Cathodic Protection 52

Electrolytic (or Impressed Current) Cathodic Protection 53

Questions and Problems 53

References 55

3 Acid-Base Chemistry 57

3.1 pH 57

3.2 Acids and Bases 58

3.2.1 Conjugate Acids and Bases 61

3.3 Equivalents and Normality 61

3.4 Solution of Multiequilibria Systems 62

3.5 Buffers 63

3.5.1 Dilution of a Buffered Solution 65

3.5.2 The Most Effective pH for a Buffer 65

3.6 Acid-Base Titrations 66

3.6.1 Titration of Strong Acids and Bases 66

3.6.2 Titration of Weak Acids and Bases 68

3.6.3 Indicating the Endpoint of an Acid-Base Titration 71

3.7 Natural Buffering of Waters from Carbon Dioxide and Related Compounds 73

3.7.1 Acidity and Alkalinity 74

Questions and Problems 76

References 78

4 Organic and Biochemistry 81

4.1 Carbon 81

4.2 Properties of Organic Compounds 81

4.3 Functional Groups 82

4.4 Types of Organic Compounds 83

4.4.1 Aliphatic Compounds 83

Aldehydes and Ketones 83

Alcohols, Esters, and Ethers 83

4.4.2 Nitrogen-containing Compounds 83

4.5 Aromatic Compounds 84

4.5.1 Compounds of Sulfur 85

4.6 Naturally Occurring Organic Compounds 85

4.6.1 Carbohydrates 85

4.6.2 Proteins 86

4.6.3 Fats and Oils 86

4.7 Biochemistry 86

4.8 Glycolysis 87

4.9 The Tricarboxylic Acid Cycle 88

4.10 Enzyme Kinetics 89

Questions and Problems 91

References 93

5 Analyses and Constituents in Water 95

5.1 Titration 95

5.1.1 Complex and Precipitate Formation Titrations 95

5.1.2 Redox Titrations and Potentiometric Analyses 96

5.1.3 Indicators for Potentiometric Analysis 98

5.2 Colorimetric Analyses 99

5.2.1 The Beer-Lambert Laws for Light Transmittance 99

5.3 Physical Analyses 99

5.3.1 Solids 99

5.3.2 Turbidity and Color 101

5.4 Determination of Organic Matter 102

5.4.1 Chemical Oxygen Demand 103

General Reaction for COD 104

Interferences with the COD Test 105

5.4.2 Biochemical Oxygen Demand 105

Effects of Temperature on BOD Exertion 108

Carbonaceous and Nitrogenous BOD 109

Laboratory Methods for Determining BOD 110

Limitations of the BOD Test for Biological Wastewater Treatment Process Design 110

Analysis of a BOD Progression 111

5.4.3 Total Organic Carbon 113

Questions and Problems 113

References 118

Section II: Microorganisms in Water and Water Quality 119

6 Microbiology 121

6.1 Groups of Microorganisms and the Phylogenetic Tree 121

6.2 Bacteria and Archaea 121

6.2.1 Classification of Bacteria 124

Taxonomy 124

Metabolic Requirements 125

Oxygen Requirements 125

Temperature 126

Salt and Sugar Concentrations 127

pH 127

6.3 Eukaryotes 127

6.3.1 Algae 128

6.3.2 Fungi 129

6.3.3 Protists 129

6.4 Other Microorganisms 130

6.4.1 Viruses and Phages 130

6.4.2 Rotifers 131

6.4.3 Worms 131

6.5 Determining the Growth of Microorganisms 132

6.5.1 Growth of Pure Cultures 132

6.5.2 Growth of Mixed Cultures 135

6.5.3 Viability and Mass in Growing Cultures 136

6.5.4 Enumeration of Microorganisms 136

Plate Counts 136

Practical Considerations in Determining Mean Values 140

6.5.5 Microbial Genomics and Molecular Microbiology Tools 141

Phylogenetic Microbial Community Composition Analysis 141

Functional Analysis 142

Questions and Problems 143

References 145

7 Water, Wastes, and Disease 147

7.1 Agents of Disease 147

7.1.1 Bacterial Pathogens 147

7.1.2 Viral Pathogens 149

7.1.3 Protozoan Pathogens 150

7.1.4 Helminths 150

7.1.5 Insect and Animal Vectors of Disease 153

7.2 Indicator, Test, and Model Microorganisms 153

7.3 Indicators of Fecal Contamination 155

7.4 Indicator Microorganisms 156

7.4.1 Coliforms: Total, Thermotolerant, and E. coli 156

7.4.2 Enterococci 157

7.5 Surrogates 157

7.6 Survival of Microorganisms in the Aquatic Environment 159

7.7 Minimum Infective Dose 162

Questions and Problems 163

References 164

8 Water Constituents and Quality Standards 167

8.1 Toxicity of Elements and Compounds 167

8.2 Contaminants in Water 170

8.2.1 Emerging Contaminants 171

8.2.2 Common Contaminants 173

Aluminum 173

Nitrate 173

Fluoride 173

Detergents 174

8.2.3 Carcinogens 174

8.2.4 Radioactive Constituents 175

8.3 Taste and Odor 176

8.4 Bases for Standards 178

8.4.1 Risk Assessment for Microbial Infection 179

8.4.2 Determination of Carcinogenicity 180

8.4.3 Toxicity Determination 182

8.4.4 Environmental Water Quality Standards 184

8.5 Standards for Drinking Water 184

8.5.1 International Drinking Water Standards 185

8.5.2 US Safe Drinking Water Act 185

8.5.3 Canadian Water Quality Guidelines 186

8.6 Comparison of Drinking Water Standards 187

8.6.1 Microbiological Parameters 187

WHO Guidelines for Microbiological Quality 187

United States Standards for Microbiological Quality 187

Canadian Guidelines for Microbiological Quality 188

8.6.2 Chemical and Physical Qualities 188

8.6.3 Aesthetic Quality 188

8.6.4 Radiological Constituents 188

8.6.5 Other Water Standards 192

8.7 Water Consumption 192

8.8 Canadian Federal Wastewater Quality Guidelines 195

8.9 Wastewater Characteristics 195

Greywater 196

8.10 Wastewater Production 197

Questions and Problems 198

References 200

Section III: Water and Wastewater Treatment 205

9 Water and Wastewater Treatment Operations 207

9.1 Water Treatment Operations 207

Microbial Contaminants 212

Reservoirs 213

9.1.1 Home Water Treatment Units 216

9.2 Wastewater Treatment Unit Operations 216

9.3 Hydraulic Design of Water and Wastewater Treatment Plants 225

Flow in Pressurized Pipes 225

Flow in Open Channels 226

Other Losses 227

Questions and Problems 230

References 232

10 Mass Balances and Hydraulic Flow Regimes 235

10.1 Setup of Mass Balances 235

10.1.1 Mixing Characteristics of Basins 236

10.1.2 Mass Balances for PF Reactors 237

Method I 238

Method II 239

Method III 239

10.1.3 Mass Balances and Reaction for CM Basins 242

10.1.4 Batch Processes 244

10.2 Flow Analysis of CM and PF Reactors 245

10.2.1 Tracer Analysis of Complete Mixed Reactors 245

10.2.2 Tracer Analysis of Plug Flow 247

10.2.3 Complete Mixed Reactors in Series 247

10.2.4 Other Flow Irregularities: Dead Volume and Short-circuiting 248

10.2.5 Typical Flow Characteristics of Basins 249

10.2.6 Measurement of Dispersion 250

10.3 Detention Time in Vessels 250

10.3.1 Average Detention Time 251

10.3.2 The Effects of Flow Recycle on Detention Time 251

10.3.3 The Effects of Recycle on Mixing 253

10.4 Flow and Quality Equalization 253

10.5 System Material Balances 256

Questions and Problems 266

References 271

Section IV: Physical-Chemical Treatment Processes 273

11 Screening and Sedimentation 275

11.1 Screens and Bar Racks 275

11.1.1 Screens for Water Treatment Plants 276

11.1.2 Screens at Wastewater Treatment Plants 277

11.1.3 Microstrainers 277

11.2 Sedimentation 278

11.2.1 Particle Settling Velocity 279

11.3 Grit Chambers 281

11.3.1 Horizontal Flow Grit Chambers 282

Channel with Varying Cross Section 283

Design Notes for a Parabolic Grit Chamber 284

11.3.2 Aerated Grit Chambers 290

11.3.3 Square Tank Degritter 292

11.3.4 Vortex Grit Removal Devices 293

Grit Washing 294

11.4 Type I Sedimentation 294