水质控制胶体与界面化学

Preface xi

1. Brief History of Colloid and Interface Chemistry and Basic Concepts

1.1 Origin of the Term “Colloid” 1

1.2 Classifi cation of the Colloidal System 2

1.3 Dispersion Degree and Specifi c Surface Area 4

1.4 Shape of Colloidal Particles 5

1.5 Polydispersity and the Average Size of Colloidal Particles 6

1.6 Colloidal Pollutants in Natural Waters 11

2. Diffusion and Brownian Motion

2.1 Diffusion 13

2.1.1 Fick’s First Law 13

2.1.2 Fick’s Second Law 14

2.2 Brownian Motion 15

2.3 Application of Diffusion 18

2.3.1 Calculation of Radius and Molecular Weight of Spherical Particle 18

2.3.2 Calculation of Axial Ratio of Nonspherical Particle 19

2.3.3 Estimation of Amount of Solvation 20

2.4 Role of Diffusion Theory in Water Treatment and Natural Water 22

3. Sedimentation

3.1 Sedimentation in the Gravity Field 23

3.1.1 Measurement of the Distribution of Particle Sizes by Sedimentation Analysis 24

3.1.2 Sedimentation Equilibrium and Altitude Distribution Law 26

3.2 Sedimentation in Centrifugal Force Field 28

3.2.1 Velocity Method 28

3.2.2 Equilibrium Method 31

3.3 Applications of Sedimentation in Water Treatment 33

4. Osmotic Pressure

4.1 Osmotic Pressure of Ideal Solutions 37

4.2 Osmotic Pressure of Macromolecule Solutions 39

4.3 Donnan Equilibrium and Osmotic Pressure 41

4.4 Measurement of Osmotic Pressure 43

4.4.1 Osmometer 43

4.4.2 Semipermeable Membrane 43

4.4.3 Method of Measurement 45

4.5 Application of Reverse Osmosis in Water Treatment 46

5. Optical Properties

5.1 Light Scattering of Colloid Systems 49

5.2 Rayleigh Equation of Light Scattering 51

5.3 Polarized Components and Space Distribution of Scattered Light 52

5.4 Light Scattering of Large Particles 54

5.5 Light Scattering of Macromolecule Solutions 55

5.5.1 Fluctuation in Density and Concentration 55

5.5.2 Measurement of the Molecular Weight of Polymers 57

5.6 Turbidity of Water 57

6. Rheology Properties

6.1 Basic Concept and Basic Theory 61

6.1.1 Shearing Strain and Shear Rate 61

6.1.2 Newton Equation 62

6.2 Measurement of Viscosity 63

6.2.1 Capillary Flow Method 63

6.2.2 Concentric Rotational Cylinder Method 66

6.3 Viscosity of Dilute Colloidal Solutions 67

6.3.1 Basic Concept 67

6.3.2 Effect of Spherical Particles on the Viscosity of Colloidal Dispersion 68

6.3.3 Effect of Particle Morphology on the Viscosity of Colloidal Solutions 69

6.3.4 Effect of Particle Solvation on the Viscosity of Colloidal Solutions 69

6.3.5 Measuring the Molecular Weight of Polymers and Flocculants in Water Treatment 70

6.4 Rheology Properties of Concentrated Dispersion Systems 73

6.5 Rheology Properties of Sludge Produced in Water Treatment 76

7. Electrical Properties

7.1 Origin of the Surface Charge of Colloids in Natural Waters 80

7.1.1 Isomorphous Replacement Within the Lattice 80

7.1.2 Ionization and Adsorption of Hydrous Oxide Minerals 81

7.1.3 Specifi c Adsorption 82

7.1.4 Ionization and Adsorption of Humic Substances 82

7.1.5 Amphoteric Behavior of Protein 83

7.2 Electrokinetic Phenomena 84

7.2.1 Electrophoresis 84

7.2.2 Electroosmosis 85

7.2.3 Streaming Potential 86

7.2.4 Sedimentation Potential 86

7.3 Model of Electric Double Layer 87

7.3.1 Helmholtz Model of Parallel-Plate Capacitor 87

7.3.2 Gouy–Chapman Model of Diffuse Double Layer 88

7.3.3 Stern Model 94

7.4 Electrokinetic Theory and Experiment 96

7.4.1 Theory and Experiment of Electroosmosis 97

7.4.2 Theory and Experiment of Electrophoresis 101

7.4.3 Theory and Experiment of Streaming Potential 108

7.4.4 Theory and Experiment of Sedimentation Potential 109

7.5 Coagulation Thermodynamics: DLVO Theory of Colloid Stability 110

7.5.1 van der Waals Attractive Energy Between Particles 111

7.5.2 Double Layer Repulsive Energy Between Particles 113

7.5.3 Total Energy of Interaction Between Particles 115

7.5.4 Critical Coagulation Concentration 118

7.6 Kinetics of Coagulation 122

7.6.1 Rate of Perikinetic Coagulation 122

7.6.2 Rate of Orthokinetic Coagulation 126

7.7 Effect of Macromolecules on Colloid Stability 131

7.7.1 Stabilization Effect of Macromolecules 131

7.7.2 Application of Stabilization Effect of Macromolecules in Cooling Water 133

7.7.3 Flocculation Effect of Macromolecules 133

7.8 Coagulation in Natural Waters and Water Treatment 134

8. Surface of Liquid

8.1 Surface Tension and Surface Free Energy 137

8.1.1 Basic Concepts 137

8.1.2 Origination of Surface Tension and Surface Free Energy 138

8.1.3 Surface Tensions of Common Liquids 139

8.1.4 Variation of Surface Tension With Temperature and Pressure 139

8.2 Relation Between Liquid Pressure and Surface Curvature 141

8.3 Relation Between Vapor Pressure of Liquid and Surface Curvature 144

8.4 Contact Angle 146

8.5 Measurement of Surface Tension 146

8.5.1 Capillary Rise Method 146

8.5.2 Ring Method 148

8.6 Cohesion Work and Adhesion Work 149

8.7 Spreading of One Liquid on Another Liquid 150

8.8 Fowkes Theory of Interfacial Tension 152

8.9 Insoluble Monomolecular Film 155

8.9.1 Surface Pressure 155

8.9.2 Various States of Monomolecular Film 156

8.9.3 Application of Surface Film 158

9. Surface of Solution

9.1 Surface Activity 161

9.2 Surface Excess and Gibbs Adsorption Equation 162

9.2.1 Surface Excess 162

9.2.2 Gibbs Adsorption Equation 165

9.2.3 Adsorption at Surface of Solution 167

9.3 Surfactant 169

9.3.1 Characteristics, Chemical Structure, and Classifi cation of Surfactant 169

9.3.2 Formation of Micelles 170

9.3.3 Effect of Micelles on the Property of Solution 172

9.3.4 Dependence of Surfactant Solubility on Temperature 172

9.3.5 Dependence of Surfactant Properties on Its Structure 173

10. Surface of Solids

10.1 Basic Principles 176

10.1.1 Physical Adsorption and Chemical Adsorption 176

10.1.2 Thermodynamics of Adsorption 177

10.2 Adsorption of Gas at a Solid Surface 180

10.2.1 Adsorption Isotherm 180

10.2.2 Langmuir Adsorption Isotherm Equation 181

10.2.3 Freundlich Adsorption Equation 187

10.2.4 Temkin Adsorption Equation 187

10.2.5 BET Equation for Multimolecular Layer Adsorption 188

10.2.6 Polanyi Adsorption Potential Theory and D–R Equation 194

10.2.7 Capillary Condensation and Adsorption Hysteresis 199

10.3 Adsorption from Solution 201

10.3.1 Amount of Adsorption 201

10.3.2 Adsorption Kinetics 204

10.3.3 Pseudofi rst Order Model 205

10.3.4 Pseudosecond Order Model 205

10.3.5 Intraparticle Diffusion Model 206

10.3.6 Elovich Model 207

10.4 Wetting of Solid Surface 207

10.4.1 Measurement of Contact Angle 209

10.4.2 Effect of Surface Roughness on Contact Angle 212

10.4.3 Spreading of Liquid on Solid Surface 213

10.4.4 Wetting and Water Treatment 215

10.5 Measurement of Properties of Adsorbents 216

10.5.1 Measurement of Specifi c Surface Area 216

10.5.2 Measurement of Pore Volume 217

10.5.3 Measurement of Mean Pore Radius 218

10.5.4 Measurement of Pore Radius Distribution 219

10.6 Analysis of the Surface of Adsorbents 221

10.6.1 Analysis of the Surface Morphology of Adsorbents 221

10.6.2 Analysis of the Surface Composition of Adsorbents 222

10.7 Adsorption in Natural Water and Water Treatment 223

11. Emulsion, Foam, and Gel

11.1 Emulsion 227

11.1.1 Formation of Emulsion and Its Type 227

11.1.2 Stabilization and Breaking of Emulsion 229

11.1.3 Applications of Emulsion in Wastewater Treatment 233

11.2 Foam 234

11.2.1 Structure and Formation Condition of Foam 234

11.2.2 Stability of Foam 235

11.2.3 Destruction of Foam 237

11.2.4 Application of Foam in Wastewater Treatment 239

11.3 Gel 240

11.3.1 Basic Concepts 240

11.3.2 Structure of Gel 241

11.3.3 Expansion of Gel 242

11.3.4 Diffusion in Gel 243

11.3.5 Gels in Water Treatment 244

Appendix A

Table A.1 Basic SI Units 247

Table A.2 Derived SI Units 247

Table A.3 Relation of SI Units to Other Common Units 248

Table A.4 Unit Prefi xes 248

Appendix B

Table B.1 Physical Constants 249

Table B.2 Surface Tension of Common Liquids 249

Table B.3 Physicochemical Constants of Water 250

Table B.4 HLB Value of Some Surfactants 252

Appendix C

Table C.1 Common Equations 253

Further Reading 255

Index 257