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.
Chapter 17 Microfiltration and Ultrafiltration 1 17.1 UF and MF: cut-off 2 17.2 UF and MF: materials 6 17.2.1 Cellulose acetate 6 17.2.2 Polypropylene 7 17.2.3 Polyacrylonitrile 7 17.2.4 Polyether sulfone/polysulfone 7 17.2.5 Polyvinylidene fluoride 8 17.3 UF and MF: membrane types 8 17.4 UF and MF: implementation of membranes under pressure 11 17.4.1 Horizontal-vertical configuration 13 17.4.2 Submerged membranes 17 17.5 Filtration modes: frontal or tangential 19 17.5.1 Batch operation: filtration-backwash 21 17.5.2 Filtration direction 21 17.6 Sizing parameters: membrane selection 22 17.7 Sizing parameters: horizontal or vertical configuration 25 17.8 Sizing parameters: flow 25 17.8.1 Instantaneous flow and net flow 26 17.8.2 Transmembrane pressure 31 17.8.3 Resistance 33 17.8.4 Permeability 33 17.8.5 Principle of the calculation of the membrane surface and water losses 35 17.8.6 Pre-filters 37 17.9 Operating parameters 37 17.9.1 Evolution of the permeability 37 17.9.2 Clogging 38 17.9.3 Frequency and conditions of hydraulic and chemical backwashing 46 17.9.4 Frequency and conditions of CIP 53 17.9.5 Membrane integrity 56 17.10 MF and UF’s place in a treatment process 62 17.10.1 Turbidity and SS 63 17.10.2 TOC (and UV254) 63 17.10.3 Algae 63 17.10.4 Iron and manganese 63 17.11 Combination of coagulation and UF membranes 71 17.12 Combination of PAC and UF 75 17.13 Performance and guarantees 76 17.13.1 Turbidity 76 17.13.2 Supplier warranty on the life of the membranes 86 17.14 Advantages of MF and UF 87 17.15 Veolia’s experience 87 17.16 Appendix: sheets 92 17.17 References 107 Chapter 18 Nanofiltration and Reverse Osmosis 111 18.1 Membranes 112 18.1.1 Materials 112 18.1.2 Membrane element configurations 115 18.2 Principles of operation and separation 119 18.2.1 Conceptual principle 119 18.2.2 Molecular weight cut-off 124 18.3 Treatment process including high-pressure membranes and parameters to be considered 127 18.3.1 Particulates and SS 127 18.3.2 Particle count 128 18.3.3 Conductivity 128 18.3.4 The SDI or MFI: clogging indices 128 18.3.5 The SDI 128 18.3.6 The MFI 130 18.3.7 Salts and metals 131 18.3.8 Biological clogging 132 18.3.9 Undesirable substances 133 18.3.10 Limit values of compounds at the inlet of high-pressure membranes 133 18.4 Sizing parameters 134 18.4.1 Temperature 134 18.4.2 Implementation configuration 134 18.4.3 Calculation of the osmotic pressure 138 18.4.4 Mass flow diagram 139 18.4.5 Salt passage 140 18.4.6 Concentration factor 140 18.4.7 Hydraulic pressure loss 140 18.4.8 Pressure tubes and number of modules per tube 141 18.5 Chemical conditioning of pre-treated water 143 18.5.1 Calculation of saturation indices and antiscalant dosage 143 18.5.2 Choice and implementation of the antiscalant 146 18.5.3 pH adjustment at the membrane inlet 147 18.5.4 Choice and application of the acid 148 18.5.5 Influence of sulfates 148 18.6 Design and implementation 148 18.6.1 Pre-treatment 148 18.6.2 Treatment processes 149 18.6.3 Membrane station 152 18.6.4 Post-treatment 158 18.6.5 Cleaning units in place 159 18.7 Functional and operating parameters 162 18.7.1 Basic principles 162 18.7.2 Permeability (Lp) 166 18.7.3 Longitudinal pressure drop (ΔPfc) 166 18.7.4 Hydraulic resistance 167 18.7.5 Energy 167 18.7.6 Sdi 168 18.7.7 Chemical cleaning 168 18.7.8 The fate of concentrates and used washing solutions 168 18.7.9 Methods for assessing the impact of concentrate discharges in the natural environment 171 18.8 High-pressure membrane performance 174 18.8.1 Organic matter 175 18.8.2 Pesticides, drug residues, endocrine disruptors and industrial residues 176 18.8.3 Various toxic and undesirable substances 177 18.8.4 Salts 177 18.8.5 Micro-organisms 178 18.8.6 Overall performance 179 18.9 Lifetime warranties 179 18.10 Parameters affecting the performance of NF membranes 180 18.10.1 Taking clogging into account 181 18.11 Monitoring and control parameters: standardization of raw data 182 18.12 Veolia’s experience: examples of treatment processes 184 18.12.1 Surface water No 1 184 18.12.2 Surface water No 2 188 18.12.3 Groundwater No 1 193 18.12.4 Groundwater No 2 195 18.13 References 200 Chapter 19 Desalination by Reverse Osmosis 205 19.1 Characterization of the water to be treated 205 19.1.1 Physical characteristics 207 19.1.2 Chemical composition: ionic content 214 19.1.3 Chemical composition: organic substances 224 19.2 Fields of application 234 19.3 Operating principle of RO 234 19.4 The membranes used in desalination 237 19.5 Sizing parameters 238 19.5.1 Flow 239 19.5.2 Concentration polarization 240 19.5.3 Conversion rate 240 19.5.4 Passage rate and rejection rate in salts 241 19.5.5 Influence of the temperature 242 19.5.6 Determining the number of modules and pressure tubes 243 19.6 Implementation 244 19.6.1 Membranes 244 19.6.2 Pressure tube 245 19.6.3 Pass 246 19.7 Pre-treatment 246 19.7.1 Pre-treatment selection 246 19.7.2 Pre-treatment systems 250 19.8 Pre-chlorination 254 19.8.1 Pre-chlorination and development of micro- and macro-organisms 254 19.8.2 Implementation of chlorination 257 19.8.3 pH adjustment 263 19.8.4 Direct filtration 263 19.8.5 Chemical conditions of implementation 273 19.8.6 Flotation 276 19.8.7 Settling 281 19.8.8 Membranes (UF and MF) 282 19.8.9 Conclusions on pre-treatment with UF membranes 291 19.9 Energy consumption 292 19.9.1 Energy consumption without recovery 292 19.9.2 Energy consumption with recovery 293 19.9.3 Hydraulic exchanger systems 293 19.10 Operating parameters 305 19.10.1 Relationship between conductivity and salt concentration 305 19.10.2 Controlling RO membrane clogging 306 19.11 Performance of RO membranes used in desalination 307 19.11.1 Boron removal 307 19.12 Post-treatment 315 19.12.1 Indicators characterizing the aggressiveness or corrosiveness of the water 317 19.12.2 Application to desalinated water 320 19.12.3 Treatments 322 19.13 Monitoring and control parameters 336 19.13.1 Standardization of raw data 336 19.13.2 Bromates 338 19.14 Veolia’s new processes applied to seawater desalination 339 19.14.1 Flotation with the Spidflow® process 339 19.14.2 Spidflow® filter process applied to seawater desalination 344 19.14.3 BiopROtector 349 19.14.4 Barrel (SIDEM Veolia) 353 19.14.5 Hiprode 355 19.15 Packaged solutions in desalination 358 19.16 Veolia’s experience (HP membranes) 360 19.17 References 374 Index 385 Summaries of other volumes 387
Kader Gaid is a doctor of physical sciences, specifically environmental process engineering. A professor and researcher at the Alger University of Science and Technology Houari Boumédiène (Algeria), he has been an expert in drinking water at the worldwide company Veolia for over 25 years.
