Today, hundreds of millions of people drink contaminated water without knowing it. Yet water treatment technologies can effectively eliminate contamination and can supply urban and rural populations with safe drinking water in a secure way.
For almost two centuries, the huge number of treatments available to guarantee water quality has grown alongside technological progress, the strengthening of industry norms and the reinforcement of consumer expectations. New treatment methods have been developed according to the advancement of knowledge and new sanitary regulations.
This five-volume book sets out to clearly present the variety of treatments available along with their performance, limitations and conditions of use as well as ways to combine them to produce safe drinking water, which is a basic need essential to everyday life.
The author shares his expertise acquired at Veolia, a company that is a world leader in water services and sanitation, desalination of sea water and the recycling of wastewater. Founded in France in 1853 to bring safe water to populations and to protect them from waterborne epidemics which ravaged cities, its history is intertwined with that of water treatment.
Table of Contents
Chapter 20 Calco-carbonic Equilibrium, Correction of Aggressivity and Remineralization 1
20.1 Characteristics of water leading to calco-carbonic equilibrium 2
20.1.1 Chemical equilibria 2
20.1.2 Aggressive water 12
20.1.3 Scaling water 12
20.1.4 Corrosive water 12
20.2 The equilibrium reactions of water’s constituents 15
20.2.1 Equilibrium pH 16
20.2.2 Langelier equation 20
20.3 Hallopeau-Dubin diagram 25
20.4 Indicative criteria to determine the aggressivity or corrosivity of water 29
20.4.1 Indicators of aggressivity: concrete pipelines 29
20.4.2 Corrosivity indicators 32
20.5 The calco-carbonic equilibrium of water 36
20.5.1 Water quality and regulations 38
20.5.2 The correction of aggressivity 38
20.5.3 Aggressivity correction treatments 39
20.6 Remineralization treatments 60
20.6.1 Graphic method 61
20.6.2 Processes for implementing remineralization: chemical reactions in tanks 62
20.7 Characteristics of the various reagents used 85
20.7.1 Lime 85
20.7.2 “Micronized” lime 86
20.7.3 Caustic soda 86
20.7.4 Caustic soda at 50% 87
20.7.5 Caustic soda flakes or grains 87
20.7.6 Sodium carbonate 88
20.7.7 Sodium bicarbonate 89
20.7.8 Calcium carbonate 89
20.7.9 Acticalmag limestone 90
20.7.10 Magno 90
20.7.11 Calcium sulfate 91
20.7.12 Calcium chloride 92
20.7.13 Carbon dioxide 92
20.7.14 Sulfuric acid (90-98%) 93
20.7.15 Hydrochloric acid 94
20.8 References 96
Chapter 21 Disinfection 99
21.1 Microorganisms present in the water 99
21.1.1 Bacteria 99
21.1.2 Indicator microorganisms or test germs 102
21.1.3 Viruses 104
21.1.4 Parasites 105
21.1.5 Micro-algae 107
21.2 Quality of potable water 108
21.2.1 French regulations 108
21.3 General rules of chemical disinfection 110
21.3.1 Disinfection mechanisms 110
21.3.2 The mode of action of chemical disinfectants 111
21.3.3 Inactivation kinetics 112
21.3.4 The notion of Ct 113
21.4 Factors affecting the efficiency of chemical disinfection 117
21.4.1 Contact time 117
21.4.2 Turbidity 118
21.4.3 Presence of oxidizable matter 118
21.4.4 pH 119
21.4.5 Injection mode and injection point 119
21.4.6 Design of the contact tank 119
21.5 Qualities of a good disinfectant 120
21.6 Chlorine disinfection 121
21.6.1 Gaseous chlorine 122
21.6.2 Hypochlorite 124
21.6.3 Chlorine application points 128
21.6.4 Oxidant demand 132
21.6.5 The implementation of chlorination 137
21.6.6 Disinfection performances with chlorine 146
21.6.7 Synthesis of chlorine reactions 148
21.7 Calcium hypochlorite 149
21.8 Chlorine dioxide disinfection 150
21.8.1 Chlorine dioxide preparation 151
21.8.2 Chlorine dioxide performances 155
21.8.3 Dechlorination 157
21.8.4 The advantages of dioxide over chlorine 159
21.8.5 The special case of the use of chlorine dioxide at a station equipped with ozone 160
21.8.6 Advantages and drawbacks of using chlorine dioxide 160
21.9 Chloramination 161
21.9.1 Principle 161
21.9.2 Implementation 163
21.9.3 Performances of monochloramine 164
21.9.4 Dechloramination 165
21.9.5 Advantages and drawbacks of chloramination 166
21.10 Proportion of chlorine in chlorine disinfectants 167
21.11 Disinfection with ozone 168
21.11.1 General remarks on ozone 168
21.11.2 Ozone production 170
21.11.3 Ozone demand 172
21.11.4 The implementation of ozonation 174
21.11.5 Performances of ozone disinfection 181
21.11.6 De-ozonation 183
21.12 Criteria for choosing a chemical disinfection technique 184
21.12.1 Practical implementation of chemical disinfection 184
21.12.2 Comparative efficiency of the main techniques 185
21.13 Another chemical disinfectant used: bromine (Br 2) 187
21.14 Disinfection by ultraviolet radiation 187
21.14.1 General remarks on UV radiation 187
21.14.2 Inactivation mechanisms 189
21.14.3 Lethal dose and inactivation kinetics 190
21.14.4 Implementation 194
21.14.5 UV disinfection design parameters 199
21.14.6 Factors affecting the efficiency of a UV treatment 200
21.14.7 UV radiation performances 204
21.14.8 Photoreactivation 208
21.14.9 Advantages and drawbacks of UV disinfection 209
21.14.10 Conclusions on UV disinfection 209
21.15. Comparative criteria between the various chemical disinfectants 210
21.16 References 212
Chapter 22 Disinfection By-products 217
22.1 General aspects 217
22.2 Reaction by-products 218
22.3 Formation and evolution of chlorination by-products 222
22.4 Kinetics and formation mechanisms 224
22.4.1 Formation kinetics 224
22.4.2 Mechanisms 226
22.4.3 Chlorination of HS 228
22.4.4 Chlorination of carboxylic acids 230
22.4.5 Factors influencing the formation of DBPs 230
22.5 Regulations 238
22.6 Predictive models of CBPs 239
22.7 Removal of THMs and HAAs 240
22.7.1 Aeration 240
22.7.2 Activated carbon 242
22.7.3 Biofiltration 246
22.7.4 High-pressure membranes 246
22.8 The case of nitrosamines and NDMA 247
22.8.1 Nitrosation mechanism with HOCl 247
22.9 Oxidation by-products related to chlorine dioxide 248
22.10 Ozonation by-products 251
22.11 Recommendations 254
22.12 References 255
Chapter 23 Sludge Treatment 261
23.1 Choosing a treatment chain 262
23.2 Characteristics of drinking water sludge 263
23.2.1 The quantity of sludge produced 263
23.2.2 Sludge concentration estimate at different stages of the chain 265
23.2.3 Sludge quality: physical and chemical properties 266
23.3 Handling and storage: shovelable and stackable nature 268
23.4 Different classes of sludge 269
23.4.1 Hydroxide sludge 269
23.4.2 Softening sludge 269
23.4.3 Metal species sludge treatment 270
23.4.4 Biological sludge 270
23.4.5 The case of mixed sludge 270
23.5 Sludge composition depending on the characteristics of raw water 271
23.5.1 Surface water sludge 271
23.5.2 Treatment sludge with coagulants (Fe or Al) 272
23.5.3 Borehole sludge 272
23.6 Thickening of drinking water sludge 273
23.6.1 Function and criteria for choosing a thickener 273
23.6.2 Thickener design 275
23.6.3 Implementation of thickeners 281
23.6.4 Flotation 286
23.7 Drinking water sludge dewatering 288
23.7.1 Plate filter 288
23.7.2 Centrifugation 291
23.7.3 Belt filters 294
23.7.4 Filter bags 295
23.7.5 Drying beds 296
23.7.6 Sludge lagoon treatment 302
23.8 Advantages and drawbacks of the different sludge dewatering treatments 304
23.9 References 305
Chapter 24 The Treatment Chain: Conception and Design 307
24.1 The treatment chain 309
24.2 The definition of a treatment chain 310
24.3 The stages of a treatment chain 313
24.4 The renovation of water treatment plants 315
24.4.1 Adaptation of new goals 316
24.4.2 The choice of treatment technologies 317
24.5 References 324
Chapter 25 The Future of Water 327
25.1 The major elements of the future of water 327
25.2 Will there be enough water? 330
Index 333
Summaries of other volumes 335
