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Book Details
Abstract
Coagulation and Flocculation in Water and Wastewater Treatment provides a comprehensive account of coagulation and flocculation techniques and technologies in a single volume covering theoretical principles to practical applications. Thoroughly revised and updated since the 1st Edition it has been progressively modified and increased in scope to cater for the requirements of practitioners involved with water and wastewater treatment. A thorough gamut of treatment scenarios is attempted, including turbidity, color and organics removal, including the technical aspects of enhanced coagulation. The effects of temperature and ionic content are described as well as the removal of specific substances such as arsenic and phosphorus. Chemical phosphorus removal is dealt with in detail, Rapid mixing for efficient coagulant utilization, and flocculation are dealt with in specific chapters. Water treatment plant waste sludge disposal is dealt with in considerable detail, in an Appendix devoted to this subject. Invaluble for water scientists, engineers and students of this field, Coagulation and Flocculation in Water and Wastewater Treatment is a convenient reference handbook in the form of numerous examples and appended information.
Table of Contents
| Section Title | Page | Action | Price |
|---|---|---|---|
| Contents | vi | ||
| Preface | xii | ||
| 1 Introduction | 1 | ||
| 1.1 General | 1 | ||
| 1.2 Stability and Destabilization | 3 | ||
| 1.3 Definitions | 5 | ||
| 1.4 Performance Criteria | 6 | ||
| 1.5 Summary | 7 | ||
| 1.6 References | 8 | ||
| 2 Colloids and interfaces | 9 | ||
| 2.1 Introduction | 9 | ||
| 2.2 Origin of Surface Charge | 13 | ||
| 2.3 Effect of Surface Charge | 14 | ||
| 2.4 Adsorption | 14 | ||
| 2.5 Inner Part of Electrical Double Layer | 17 | ||
| 2.6 Diffuse Part of Electrical Double Layer | 18 | ||
| 2.6.1 Assumptions | 18 | ||
| 2.6.2 Distribution of Potential with Distance from the Charged Surface | 20 | ||
| 2.6.3 Thickness of Double Layer | 22 | ||
| 2.6.4 Effect of Ionic Strength on Double Layer | 24 | ||
| 2.6.5 Effect of Nature of Counter Ions | 25 | ||
| 2.7 Stern's Model of Complete Double Layer | 25 | ||
| 2.8 Colloid Stability in Terms of the Double Layer | 26 | ||
| 2.8.1 Energy of Interaction Between Particles | 26 | ||
| 2.8.2 Theoretical Optimal Concentration of Electrolyte Required for Destabilization | 28 | ||
| 2.8.3 Schulze–Hardy Rule | 29 | ||
| 2.9 Electrokinetic Measurements | 29 | ||
| 2.9.1 Introduction | 29 | ||
| 2.10 References | 30 | ||
| 3 Coagulants | 31 | ||
| 3.1 Introduction | 31 | ||
| 3.2 Metal Coagulants | 32 | ||
| 3.2.1 Commonly Used Metal Coagulants | 32 | ||
| 3.2.2 Chemistry of Metal Coagulants | 42 | ||
| 3.3 Polymers | 50 | ||
| 3.3.1 General | 50 | ||
| 3.3.2 Activated Silica | 51 | ||
| 3.3.3 Natural Polyelectrolytes | 52 | ||
| 3.3.4 Synthetic Polymers | 56 | ||
| 3.4 References | 69 | ||
| 4 Treatment with metal coagulants | 72 | ||
| 4.1 Introduction | 72 | ||
| 4.2 Destabilization of Hydrophobic Colloids | 75 | ||
| 4.2.1 Extent of Hydrolysis and Adsorption | 75 | ||
| 4.2.2 Effect of Coagulant Dosage | 75 | ||
| 4.2.3 Effect of Colloid Concentration | 77 | ||
| 4.2.4 Effect of pH | 80 | ||
| 4.3 Destabilization of Hydrophilic Colloids | 86 | ||
| 4.4 Removal of Natural Organic Matter | 87 | ||
| 4.4.1 Organic Color | 87 | ||
| 4.4.2 Enhanced Coagulation | 98 | ||
| 4.5 Pathogen Removal | 113 | ||
| 4.5.1 Removal of Giardia and Cryptosporidium | 113 | ||
| 4.5.2 Virus Removal | 114 | ||
| 4.6 Effect of Anions | 116 | ||
| 4.6.1 General | 116 | ||
| 4.6.2 Effect of Sulfate | 117 | ||
| 4.6.3 Effect of Phosphate | 118 | ||
| 4.7 Chemical Phosphorus Removal in Wastewater Treatment | 120 | ||
| 4.7.1 General | 120 | ||
| 4.7.2 Mechanisms of Chemical Phosphorus Removal | 124 | ||
| 4.7.3 Applications of Chemical Phosphorus Removal | 138 | ||
| 4.8 Wastewater Treatment by Coagulation | 152 | ||
| 4.9 Arsenic Removal | 159 | ||
| 4.10 Staged Coagulation and Sequencing | 161 | ||
| 4.11 Effects of Preozonation | 169 | ||
| 4.12 Effects of Temperature | 171 | ||
| 4.13 Residual Aluminum | 173 | ||
| 4.14 References | 176 | ||
| 5 Treatment with polymers | 186 | ||
| 5.1 Introduction | 186 | ||
| 5.2 Mechanisms of Destabilization | 187 | ||
| 5.2.1 General | 187 | ||
| 5.2.2 The Bridging Mechanism | 188 | ||
| 5.2.3 The Electrostatic Patch Mechanism | 192 | ||
| 5.3 Polyelectrolytes as Primary Coagulants | 194 | ||
| 5.3.1 General | 194 | ||
| 5.3.2 Turbidity Removal Using Polyelectrolytes | 196 | ||
| 5.3.3 Organics Removal Using Polyelectrolytes | 200 | ||
| 5.3.4 Removal of Microorganisms Using Polyelectrolytes | 204 | ||
| 5.4 Polyelectrolytes as Flocculant Aids | 206 | ||
| 5.4.1 Polymers as Filter Aids | 210 | ||
| 5.5 Polymers as Sludge Conditioners | 211 | ||
| 5.6 References | 214 | ||
| 6 Rapid mixing | 219 | ||
| 6.1 Introduction | 219 | ||
| 6.2 Requirements for Rapid Mixing Devices | 220 | ||
| 6.2.1 General | 220 | ||
| 6.2.2 Comparison of Back-Mix and Plug-Flow Reactors | 222 | ||
| 6.2.3 Velocity Gradient Requirements | 225 | ||
| 6.2.4 Rapid Mixer Retention Time | 226 | ||
| 6.2.5 Tapered Rapid Mix Velocity Gradient | 227 | ||
| 6.2.6 Coagulant Feed Concentration | 227 | ||
| 6.2.7 Sequence of Chemical Addition | 228 | ||
| 6.3 Design of Rapid Mixing Devices | 228 | ||
| 6.3.1 General | 228 | ||
| 6.3.2 Back-mix Reactors | 229 | ||
| 6.3.3 In-line Mixers without Controlled Velocity Gradient | 229 | ||
| 6.3.4 In-line Mixers With Controlled Velocity Gradient | 235 | ||
| 6.4 References | 238 | ||
| 7 Flocculation | 240 | ||
| 7.1 Introduction | 240 | ||
| 7.2 Perikinetic Flocculation | 241 | ||
| 7.3 Orthokinetic Flocculation | 243 | ||
| 7.3.1 Theoretical Development | 243 | ||
| 7.3.2 Working Equation | 249 | ||
| 7.3.3 Flocculation Reactors in Series | 250 | ||
| 7.3.4 Adequacy of G and GT as Design Parameters | 250 | ||
| 7.3.5 Experimental Determination of Flocculation Parameters | 252 | ||
| 7.4 Design of Flocculation Basins | 253 | ||
| 7.4.1 General | 253 | ||
| 7.4.2 Types of Flocculation Chambers and Devices | 254 | ||
| 7.4.3 Short-Circuiting in Flocculation Reactors | 267 | ||
| 7.4.4 Compartmentalization | 268 | ||
| 7.4.5 Combined Flocculation–Sedimentation Basins | 270 | ||
| 7.4.6 Transfer of Flocculated Water | 274 | ||
| 7.5 References | 276 | ||
| 8 Testing and control of coagulation and flocculation | 279 | ||
| 8.1 Introduction | 279 | ||
| 8.2 Optimizing Primary Coagulant Type, Dosage and pH | 280 | ||
| 8.2.1 General | 280 | ||
| 8.2.2 Apparatus | 281 | ||
| 8.2.3 Chemical Solutions | 282 | ||
| 8.2.4 Criteria Describing Process Performance | 285 | ||
| 8.2.5 Jar Test Procedure | 289 | ||
| 8.2.6 Analysis of Results | 291 | ||
| 8.3 Using the Jar Test to Evaluate Settling | 293 | ||
| 8.4 Evaluating Flocculant Aids | 296 | ||
| 8.4.1 General | 296 | ||
| 8.4.2 Initial Choice of Flocculant Aid | 296 | ||
| 8.4.3 Preparation of Polyelectrolyte Solutions | 297 | ||
| 8.4.4 Experimental Procedure | 298 | ||
| 8.5 Evaluating Sludge Conditioners | 299 | ||
| 8.5.1 General | 299 | ||
| 8.5.2 Experimental Procedures | 299 | ||
| 8.6 Optimizing Flocculation Parameters | 304 | ||
| 8.6.1 General | 304 | ||
| 8.6.2 Apparatus | 306 | ||
| 8.6.3 Experimental Procedure | 308 | ||
| 8.6.4 Analysis of Data | 312 | ||
| 8.7 Control Systems for Coagulation | 315 | ||
| 8.7.1 Introduction | 315 | ||
| 8.7.2 Electrokinetic Measurements | 315 | ||
| 8.7.3 Monitoring Floc Formation | 323 | ||
| 8.7.4 Data-Driven Control Systems | 327 | ||
| 8.8 References | 332 | ||
| Appendix: Processing and Disposal of Coagulant Sludges | 338 | ||
| A.1 Introduction | 338 | ||
| A.2 Production of Water Plant Residuals | 341 | ||
| A.2.1 Estimating Sludge Quantities | 341 | ||
| A.2.2 Alternative Coagulants and Dosage Reduction | 344 | ||
| A.2.3 Sludge Characteristics | 345 | ||
| A.2.4 Sludge Conditioning | 347 | ||
| A.3 Filter Backwash | 353 | ||
| A.4 Sludge Lagoons | 357 | ||
| A.5 Sludge Drying Beds | 360 | ||
| A.6 Mechanical Thickening and Dewatering | 365 | ||
| A.6.1 Sludge Thickening | 365 | ||
| A.6.2 Sludge Dewatering | 373 | ||
| A.7 Coagulant Recovery | 380 | ||
| A.8 Sludge Disposal | 388 | ||
| A.8.1 Introduction | 388 | ||
| A.8.2 Disposal to Municipal Sewers | 390 | ||
| A.8.3 Land Application of Water Plant Sludge | 393 | ||
| A.9 References | 394 | ||
| Index | 401 |