Environmental Transport Processes

A unique approach to the challenges of complex environmentalsystems

Environmental Transport Processes, Second Edition providesmuch–needed guidance on mass transfer principles in environmentalengineering. It focuses on working with uncontrolled conditionsinvolving biological and physical systems, offering examples fromdiverse fields, including mass transport, kinetics, wastewatertreatment, and unit processes.

This new edition is fully revised and updated, incorporatingmodern approaches and practice problems at the end of chapters,making the Second Edition more concise, accessible, and easy touse.

The book discusses the fundamentals of transport processesoccurring in natural environments, with special emphasis on workingat the biological physical interface. It considers transportand kinetics in terms of systems that involve microorganisms, alongwith in–depth coverage of particles, size spectra, and calculationsfor particles that can be considered either spheres or fractals.The book′s treatment of particles as fractals is especially uniqueand the Second Edition includes a new section on exoelectrogenicbiofilms. It also addresses dispersion in natural and engineeredsystems unlike any other book on the subject.

Readers will learn to tackle with confidence complexenvironmental systems and make transport calculations inheterogeneous environments with mixtures of chemicals.

1. Introduction 1

1.1 Background 1

1.2 Notation for chemical transport 2

1.3 Simplifications for environmental systems 5

1.4 Review of Mass Balances 11

2. Equilibrium Calculations 18

2.1 Introduction 18

2.2 Thermodynamic state functions 20

2.3 Chemical potentials 21

2.4 Gibbs free energy and equilibrium constants 23

2.5 Distribution of chemical based on fugacites 25

3. Diffusive Transport 43

3.1 Introduction 43

3.2 Diffusion 43

3.3 Calculation of molecular diffusion coefficients 45

3.4 Effective diffusion coefficients in porous media 53

3.5 Experimental determination of diffusivities and molecularsize spectra 59

4. The Constitutive Transport Equation 79

4.1 Introduction 79

4.2 Derivation of the general transport equation 80

4.3 Special forms of the general transport equation 81

4.4 Similarity of mass, momentum, and heat dispersion laws84

4.5 Transport relative to moving coordinate systems 86

4.6 Simplified forms of the constitutive transport equation89

4.7 The constitutive transport equation in cylindrical andspherical coordinates 91

5. Concentration Profiles and Chemical Fluxes 95

5.1 Introduction 95

5.2 The three theories of mass transport 95

5.3 Mass transport in radical and cylindrical coordinates usingshell balances 112

6. Mass Transport Correlations: From Theory to Empiricism120

6.1 Definition of a mass transport coefficient 120

6.2 The three theories 121

6.3 Multiple resistances during interphase mass transport125

6.4 Correlations for mass transport coefficients 132

6.5 Transport to spheres 135

7. Kinetics and Mass Transfer 140

7.1 Introduction 140

7.2 Fluid shear and turbulence 141

7.3 Mass transport in steady sheared fluids 145

7.4 Mass transport in turbulent sheared fluids 148

7.5 Shear rates in mixed reactors 149

7.6 Chemical transport in bubbled reactors 158

8. Suspended Unattached and Aggregated Microorganisms167

8.1 Introduction 167

8.2 Chemical transport to cells at rest 167

8.3 Effect of fluid motion on microorganisms 170

8.4 Transport to microbial aggregates 175

8.5 Effectiveness factors for mass transport 184

8.6 Relative uptake factors for mass transport 187

8.7 Differences between the MEC and MFC systems 145

9. Biofilms 194

9.1 Introduction 194

9.2 Transport in the fluid layer above a biofilm 194

9.3 Biofilm kinetics 198

9.4 Modeling completely mixed biofilm reactors: rotationbiological contactors 210

9.5 Modeling plug flow biofilm reactors: packed beds 213

9.6 Modeling wetted wall biofilm reactors: trickling filters215

9.7 Electrogenic biofilms 225

10. Disperson 232

10.1 Introduction 232

10.2 Averaging properties to derive dispersion coefficients inturbulent fluids 235

10.3 Dispersion in nonboundeded turbulent sheared fluids 239

10.4 Longitundinal dispersion coefficients for defined systems244

10.5 Dispersion in porous media 253

11. Rivers, Lakes and Oceans 264

11.1 Introduction 264

11.2 Chemical transport in rivers 265

11.3 Mixing in lakes 273

11.4 Mixing in estuaries 277

11.5 Mixing in the ocean 279

11.6 Operation and assessment of MFCs 181

12. Chemical Transport in Porous Media 292

12.1 Introduction 292

12.2 Porous media hydraulics 292

12.3 Contaminant transport of conservative tracers 295

12.4 Transport with reaction 298

12.5 Transport with chemical adsorption 299

12.6 Formation of gangolia of non–aqueous phase–liquids 306

12.7 Mass transport calculations of chemical fluxes fromNAPL

12.8 ganglia 315

13. Particles and Fractals 331

13.1 Introduction 331

13.2 Particle size spectra 332

13.3 Solid particles and fractal aggregate geometries 336

13.4 Measuring particle size distributions 351

13.5 Calculating fractal dimentions from particle sizedistributions 353

14. Coagluation in Natural and Engineered Systems 362

14.1 Introduction 362

14.2 The general coagulation equations: integral and summationforms 363

14.3 Factors affecting the stability of aquasols 364

14.4 Coagulation kinetics: collision kernels form spheres374

14.5 Fractal coagulation models 388

14.6 Coagulation in the ocean 397

15. Particle Transport in Porous Media 408

15.1 Introduction 408

15.2 A macroscopic particle transport equation 409

15.3 Clean bed filtration theory 411

15.4 Discrete particle size distributions prepared by filtration426

15.5 The dimensionless collision number 432

15.6 Pressure drops in clean bed filters 434

15.7 Particle accumulation in filters 435

15.8 Particle transport in aquifers 437

Appendices 445

1. Notation 445

2. Transport equations 452

3. Chemical properties 453

4. Solutions of differential equations 458

5. References 465

Index 474 

Bruce E. Logan is the Stan and Flora Kappe Professor ofEnvironmental Engineering, Department of Civil and EnvironmentalEngineering at Penn State. He is Director of the Engineering Energy& Environmental Institute and the Hydrogen Energy (H2E) Center.Dr. Logan has won several awards for his research and articles andhas authored Microbial Fuel Cells, also from Wiley.

It also would be useful for people that work with theseissues.  Environmental Transport Processes can be recommendedboth to undergraduate and graduate students seeking to gain a goodcomprehension of environmental
transport processes.   (Environ Earth Science, 19October 2012)