Page 12 - Fundamentals of Water Treatment Unit Processes : Physical, Chemical, and Biological

Contents xi

8.3.4.2 Rise Velocity of Particle–Bubble ............................................................................... 172
8.3.4.3 Bubble–Particle Ratio ................................................................................................. 174
8.3.4.4 Concentration Expressions.......................................................................................... 174
8.3.5 Materials Balance for Dissolved Gas in Flotation Basin........................................................... 178
8.3.5.1 Mass Balance for Flotation Basin............................................................................... 178
8.3.5.2 Mass Balance Calculations by Spreadsheet................................................................ 179
8.4 Practice .................................................................................................................................................... 180
8.4.1 Design Criteria............................................................................................................................ 180
8.4.1.1 Flotation in Water Treatment...................................................................................... 180
8.4.1.2 Flotation for Sludge Thickening................................................................................. 181
8.4.1.3 Air-to-Solids Ratio...................................................................................................... 181
8.4.2 Pilot Plants.................................................................................................................................. 181
8.4.2.1 Pilot Plant Study ......................................................................................................... 181
8.4.3 Case: Birmingham...................................................................................................................... 182
8.4.4 Equipment................................................................................................................................... 183
Problems............................................................................................................................................................. 184
Acknowledgments .............................................................................................................................................. 186
Glossary.............................................................................................................................................................. 186
References .......................................................................................................................................................... 187

PART III Microscopic Particles

Chapter 9 Coagulation......................................................................................................................................................... 191
9.1 Coagulation In-a-Nutshell........................................................................................................................ 191
9.1.1 Defining Coagulation ................................................................................................................. 191
9.1.1.1 Particles to Be Removed............................................................................................. 191
9.1.1.2 Coagulation................................................................................................................. 191
9.1.1.3 Microflocs ................................................................................................................... 191
9.1.1.4 Rapid-Mix................................................................................................................... 191
9.1.1.5 Flocculation................................................................................................................. 191
9.1.1.6 Themes of Coagulation Theory .................................................................................. 191
9.1.2 Coagulation Practice................................................................................................................... 191
9.1.2.1 Dosage......................................................................................................................... 191
9.1.2.2 Coagulation Effectiveness........................................................................................... 192
9.2 Particles in Ambient Waters.................................................................................................................... 192
9.2.1 Particle Variety........................................................................................................................... 192
9.2.2 Particle Characteristics ............................................................................................................... 192
9.2.2.1 Colloids....................................................................................................................... 192
9.2.2.2 Microscopic Particles.................................................................................................. 192
9.2.2.3 Natural Organic Matter and Color.............................................................................. 194
9.2.2.4 Total Organic Carbon ................................................................................................. 194
9.2.2.5 Turbidity ..................................................................................................................... 194
9.2.2.6 Particle Counts............................................................................................................ 194
9.2.3 Turbidity and Particle Counts in Ambient Waters and Finished Waters................................... 194
9.2.3.1 Spatial Variation in Source Waters Compared with Plant Effluents.......................... 194
9.2.3.2 Seasonal Variation ...................................................................................................... 194
9.3 Chemistry................................................................................................................................................. 194
9.3.1 Chemistry of Coagulation: Evolution of Theory and Practice .................................................. 194
9.3.1.1 Key Innovations.......................................................................................................... 195
9.3.1.2 Color ........................................................................................................................... 196
9.3.1.3 Modern Theory ........................................................................................................... 196
9.3.2 Coagulation Reactions................................................................................................................ 197
9.3.2.1 Metal Ion Reactions with Water................................................................................. 197
9.3.2.2 Two Coagulation Mechanisms ................................................................................... 197