Page 14 - Fundamentals of Water Treatment Unit Processes : Physical, Chemical, and Biological

Contents xiii

9.9.4 Structure of Polymers................................................................................................................. 220
9.9.4.1 Functional Groups....................................................................................................... 220
9.9.4.2 Monomers ................................................................................................................... 220
9.9.4.3 Polymers ..................................................................................................................... 221
9.9.5 Selection of Polymers................................................................................................................. 221
9.9.5.1 Polymer Screening...................................................................................................... 221
9.9.5.2 Polymer Packaging ..................................................................................................... 223
9.9.5.3 Specification Sheets .................................................................................................... 224
9.9.5.4 Prepared Batches......................................................................................................... 224
9.9.5.5 Feed of Polymer.......................................................................................................... 224
9.9.5.6 Concentration: Convention (Adapted from AWWA B453-96) ................................. 224
Problems............................................................................................................................................................. 226
Acknowledgments .............................................................................................................................................. 228
Glossary.............................................................................................................................................................. 228
References .......................................................................................................................................................... 235

Chapter 10 Mixing ................................................................................................................................................................ 239
10.1 Definitions and Applications ................................................................................................................... 239
10.1.1 Definitions .................................................................................................................................. 239
10.1.1.1 Mixing......................................................................................................................... 239
10.1.1.2 Near-Synonyms........................................................................................................... 239
10.1.2 Application Categories ............................................................................................................... 239
10.1.2.1 Liquid–Solid ............................................................................................................... 239
10.1.2.2 Liquid–Gas.................................................................................................................. 239
10.1.2.3 Immiscible Liquids ..................................................................................................... 239
10.1.2.4 Miscible Liquids ......................................................................................................... 240
10.1.2.5 Fluid Motion ............................................................................................................... 240
10.1.2.6 Pumping and Shear..................................................................................................... 240
10.1.2.7 Examples..................................................................................................................... 240
10.1.3 Mixing as Rate Limiting ............................................................................................................ 240
10.2 History of Mixing.................................................................................................................................... 240
10.2.1 Drinking Water Treatment ......................................................................................................... 240
10.2.1.1 Initial Mixing .............................................................................................................. 240
10.2.1.2 Gas Dissolution........................................................................................................... 241
10.2.2 Wastewater Treatment................................................................................................................ 241
10.2.3 Evolution of Mixing Theory ...................................................................................................... 242
10.2.3.1 Development of Collision Frequency Mathematics ................................................... 242
10.2.3.2 Derivation of G........................................................................................................... 243
10.2.3.3 Modifying Camp and Stein’s G.................................................................................. 243
10.2.3.4 Empirical Parameters .................................................................................................. 243
10.2.3.5 G and u ....................................................................................................................... 243
10.2.4 Technologies of Mixing ............................................................................................................. 244
10.3 Theory of Mixing .................................................................................................................................... 244
10.3.1 Transport Mechanisms ............................................................................................................... 244
10.3.1.1 Advection.................................................................................................................... 245
10.3.1.2 Turbulence .................................................................................................................. 246
10.3.1.3 Transport Regime........................................................................................................ 252
10.3.2 Navier–Stokes Equation ............................................................................................................. 253
10.3.2.1 Mathematics of Navier–Stokes Equation ................................................................... 253
10.3.2.2 Computational Fluid Dynamics.................................................................................. 254
10.3.3 Similitude.................................................................................................................................... 254
10.3.3.1 Dimensionless Numbers ............................................................................................. 255
10.3.3.2 Variables of Impeller–Basin Mixing .......................................................................... 256
10.3.3.3 Experimental Plots...................................................................................................... 256
10.3.3.4 Scale-Up by Fluid Similitude ..................................................................................... 256
10.3.3.5 Scale-Up Dilemma...................................................................................................... 258