Pollutants in Porous Media

A. Modeling of Pollutants Transport.- Introductory Comments.- 1. Tracing Parcels of Water and Solutes in Unsaturated Zones.- 1.1 Introduction.- 1.2 Convective Transport by Simple Flows.- 1.2.1 Movement of Water in Unsaturated Soils.- 1.2.2 Movement of Solutes in Unsaturated Soils.- 1.2.3 Detailed Analysis of Constant Flux Absorption.- 1.2.4 Relative Speeds of Wetting and Solute Fronts.- 1.2.5 Drainage to a Deep Water Table.- 1.3 Convective Transport by Complex Flows.- 1.3.1 Structured Media.- 1.3.2 Secondary Flows Induced by Density Variations.- 1.3.3 Unstable Wetting Fronts.- 1.4 Conclusions.- References.- 2. Solute Transport in Soil at Field Scale.- 2.1 Introduction.- 2.2 Basic Concepts of Stochastic Modeling.- 2.3 Succinct Review of Previous Work.- 2.4 Conclusions and Outline of Future Investigations.- References.- 3. Migration of Organic Fluids Immiscible with Water in the Unsaturated Zone.- 3.1 Introduction.- 3.2 Multiphase Flow.- 3.3 Physical Characteristics.- 3.4 The Migration of the Immiscible Phase.- 3.5 Migration of Dissolved Components.- 3.6 The Migration of Gas Components.- 3.7 Microbial Degradation.- 3.8 Migration in Fissured Media.- 3.9 Conditions in the Unsaturated (Porous) Zone.- 3.10 Measures After Spills of Organic Liquids.- 3.11 Practical Investigations.- 3.12 Cooperative Research.- 3.13 Conclusions.- References.- B. Behavior of Inorganic Chemicals.- Introductory Comments.- 4. Pollution of the Unsaturated Zone with Nitrate.- 4.1 Introduction.- 4.2 Nitrate as a Pollutant.- 4.3 Sources.- 4.4 Behavior.- 4.5 Movement.- 4.6 Possible Solutions.- References.- 5. Behavior of Phosphates in the Unsaturated Zone.- 5.1 Introduction.- 5.2 Equilibrium Models Based on Adsorption Isotherms.- 5.3 Solubility Equilibrium.- 5.4 The Kinetic Approach.- 5.5 Conclusions.- References.- 6. Unsaturated Zone Pollution by Heavy Metals.- 6.1 Introduction.- 6.2 Abundance.- 6.3 Contamination of Groundwater by Heavy Metals.- 6.4 Solubility.- 6.5 Complexation.- 6.6 Colloidal Solutions of Heavy Metals.- 6.7 Precipitation and Coprecipitation.- 6.8 Adsorption and Ion Exchange.- 6.9 Radioactive Decay.- 6.10 Biochemical Processes.- 6.11 Gas Exchange.- 6.12 Filtration.- References.- 7. Effect of Acid Rain on Soil and Groundwater in Sweden.- 7.1 Introduction.- 7.2 Acidification of Precipitation and Surface Water.- 7.2.1 Precipitation.- 7.2.2 Surface Water.- 7.3 Acidification of Soil and Groundwater.- 7.3.1 Terrestrial Water Flow, Especially in Moraine Terrain.- 7.3.2 Acidification Processes.- 7.3.3 Processes in Podzols.- 7.3.4 Sulfate Behavior in Soils.- 7.3.5 Behavior of Soil Solutions as Affected by Soil Acidification.- 7.3.6 Acidification of Soil.- 7.3.7 Acid Groundwater.- 7.3.8 Changes of the Chemistry of Groundwater.- 7.4 Modeling the Acidification.- References.- 8. Heavy Metal Pollution of Natural Surface Soils Due to Long-Distance Atmospheric Transport.- 8.1 Introduction.- 8.2 Atmospheric Pollution in Norway.- 8.3 Heavy Metals in Norwegian Surface Soils.- 8.4 Conclusions.- References.- C. Behavior of Organic Compounds.- Introductory Comments.- 9. Chemical Nature and Reactivities of Soil Organic Polymers.- 9.1 Introduction.- 9.2 The Genesis of Humus Materials.- 9.2.1 Humification by Biological Processes.- 9.2.2 Humification by Chemical Processes.- 9.3 Structures of Humus Substances.- 9.3.1 Extraction and Fractionation of Humus Substances.- 9.3.2 Structural Information from Degradative Procedures.- 9.3.3 Structural Information from Nondegradative Procedures.- 9.3.4 Sizes and Shapes of Humus Substances.- 9.4 Practical Applications of Information from Structural Studies of Humus Substances.- References.- 10. Behavior of Pesticides in the Unsaturated Zone. Adsorption and Transport Phenomena.- 10.1 Introduction.- 10.2 Adsorption.- 10.2.1 General Considerations.- 10.2.2 Some Published Experimental Results.- 10.3 Transport Phenomena.- 10.3.1 Transport with Flow of the Soil Solution.- 10.3.2 Molecular Diffusion.- 10.4 Conclusion.- References.- 11. Nonbiological Degradation of Pesticides in the Unsaturated Zone.- 11.1 Introduction.- 11.2 Properties of the Solid-Liquid Interface Affecting Pesticide Degradation.- 11.3 Importance of Surface-Catalyzed Degradation Processes in the Unsaturated Zone.- 11.4 Factors Affecting Surface-Induced Pesticide Degradation.- 11.5 Conclusion.- References.- 12. The Effect of Solid Organic Components of Sewage on Some Properties of the Unsaturated Zones.- 12.1 Introduction.- 12.2 Composition of Organic Solid Components of Sewage.- 12.3 Physical Effects of Organic Solids.- 12.3.1 Waste Waters.- 12.3.2 Sewage Sludges.- 12.4 Chemical Effects of Organic Solids.- 12.4.1 Enrichment by Chemicals.- 12.4.2 Changes in pH and Total Salt Content.- 12.4.3 Effect on the Exchange Complex and Dissolution-Precipitation Processes.- References.- D. Biological Processes.- Introductory Comments.- 13. Biochemical Processes in Unsaturated Zones.- 13.1 Introduction.- 13.2 Substrates for Microbial Growth.- 13.3 Microbial Metabolites in Relation to Plant Growth.- 13.4 Microbial Effects on Soil Structure.- 13.5 Nutrient Cycles.- 13.6 Pollutant/Microorganism Interactions.- 13.7 Conclusion.- References.- 14. Pathogenic Bacteria and Viruses in the Unsaturated Zone.- 14.1 Introduction.- 14.2 Persistence of Bacteria and Viruses.- 14.3 Transport Processes.- 14.4 Filtration Processes.- References.- E. Unsaturated Zone and Groundwater: Pollution Sources.- Introductory Comments.- 15. Agricultural Pollutants and Groundwater Quality.- 15.1 Introduction.- 15.2 Application Rates.- 15.3 Movement to Groundwater.- 15.3.1 Water Movement.- 15.3.2 Adsorption and Degradation.- 15.4 Results.- 15.4.1 Nitrates.- 15.4.2 Pesticides.- 15.5 Case Study.- References.- 16. Nitrogen Presence in Groundwater as Affected by the Unsaturated Zone.- 16.1 Introduction.- 16.2 Geohydrological and Historical Background of the Coastal Plain Aquifer.- 16.3 Nitrogen in the Coastal Plain Aquifer.- 16.4 Nitrogen Sources.- 16.4.1 Exhaustive Sources.- 16.4.2 Continuous Sources.- 16.5 Nitrogen Stored in the Unsaturated Zone.- 16.6 Processes Modifying Nitrogen Storage in the Unsaturated Zone.- 16.7 The Unsaturated-Saturated Interface.- 16.8 Nitrogen in Groundwater.- References.- 17. Prevention of Groundwater Pollution on a National Scale: Israel as a Case Study.- 17.1 Introduction.- 17.2 Wastes and Potential Pollutants.- 17.2.1 Physical Background.- 17.2.2 The Potential Pollutant Load.- 17.3 Plans and Trends in Land Disposal.- 17.3.1 Agricultural Wastes.- 17.3.2 Wastewater Treatment.- 17.3.3 Solid Waste Disposal.- 17.4 Discussion.- References.- F. Unsaturated Zone and Groundwater: Pollution Control.- Introductory Comments.- 18. Wastewater Renovation in Rapid Infiltration Systems.- 18.1 Introduction.- 18.2 Basin Management.- 18.3 Quality Improvement.- 18.4 Flushing Meadows Project.- 18.5 23rd Avenue Project.- 18.6 Identification of Trace Organics.- 18.7 Removal of Trace Organics in the Unsaturated Zone.- 18.8 Other Organic Micropollutants.- 18.9 Conclusions.- References.- 19. Use of Soil-Aquifer System for Effluent Purification and Reuse.- 19.1 Introduction.- 19.2 The Effluent Recharge Operation in the Dan Region Project.- 19.3 Effluent Purification in the Soil-Aquifer System.- 19.4 Conclusion.- References.- 20. Utilization of the Buffering Properties of the Unsaturated Zone in Groundwater Quality Management on a Regional Scale: The Coastal Aquifer of Israel as a Case Study.- 20.1 Introduction.- 20.2 Systems Approach to Groundwater Quality Management.- 20.3 The Integrated Single-Cell Model.- 20.4 Large-Scale Sewage Reclamation for Irrigation - Risk Assessment of Possible Groundwater Contamination by Toxic Species.- 20.4.1 Recycling Schemes and Their Simulation.- 20.4.2 Assessment of Possible Risks and Related Protection Measures.- 20.4.3 Sensitivity Analyses.- References.