Modeling Chemical Transport in Soils: Natural and Applied Contaminants provides a comprehensive discussion of mathematical models used to anticipate and predict the consequences and fate of natural and applied chemicals. The book evaluates the strengths, weaknesses, and possibilities for application of numerous models used throughout the world. It examines the theoretical support and need for experimental calibration for each model. The book also reviews world literature to discuss such topics as the movement of sorbed chemicals by soil erosion, the movement of reactive and nonreactive chemicals in the subsurface and groundwater, and salt transport in the landscape. Modeling Chemical Transport in Soils: Natural and Applied Contaminants is an important volume for environmental scientists, agricultural engineers, regulatory personnel, farm managers, consultants, and the chemical industry.
During the last four decades, tremendous advances have been made towards the understanding of transport characteristics of contaminants in soils, solutes, and tracers in geological media. Transport & Fate of Chemicals in Soils: Principles & Applications offers a comprehensive treatment of the subject complete with supporting examples of mathematical models that describe contaminants reactivity and transport in soils and aquifers. This approach makes it a practical guide for designing experiments and collecting data that focus on characterizing retention as well as release kinetic reactions in soils and contaminant transport experiments in the laboratory, greenhouse), and in the field. The book provides the basic framework of the principals governing the sorption and transport of chemicalsin soils. It focuses on physical processes such as fractured media, multiregion, multiple porosities, and heterogeneity and effect of scale as well as chemical processes such as nonlinear kinetics, release and desorption hysteresis, multisite and multireaction reactions, and competitive-type reactions. The coverage also includes details of sorption behavior of chemicals with soil matrix surfaces as well the integration of sorption characteristics with mechanisms that govern solute transport in soils. The discussions of applications of the principles of sorption and transport are not restricted to contaminants, but also include nitrogen, phosphorus, and trace elements including essential micronutrients, heavy metals, military explosives, pesticides, and radionuclides. Written in a very clear and easy-to-follow language by a pioneer in soil science, this book details the basic framework of the physical and chemical processes governing the transport of contaminants, trace elements, and heavy metals in soils. Highly practical, it includes laboratory methods, examples, and empirical formulations. The approach taken by the author gives you not only the fundamentals of understanding of reactive chemicals retention and their transport in soils and aquifers, but practical guidance you can put to immediate use in designing experiments and collecting data.
Ground-water contamination due to surface spills or subsurface leakage of hydrocarbon fuels, organic solvents and other immiscible organic liquids is a widespread problem which poses a serious threat to ground-water resources. In order to model the movement of such materials in the subsurface, it is necessary, in general, to consider flow of water, nonaqueous phase liquid (NAPL) and air, and transport of individual chemical components, which may move by convection and dispersion in each phase. A mathematical model was developed for multiphase flow and multicomponent transport in porous media with water, NAPL and air or any subset of these phases. Numerical procedures for solving the system of coupled flow equations, based on various formulations of the governing equations, were compared. Accurate representation of three-phase permeability-saturation-capillary pressure (k-S-P) relations is crucial to model multiphase fluid movement and accurate models for interphase mass partitioning are critical to describe species transport. A detailed physically-based model for hysteresis in three-phase k-S-P relations was described. Simplified models, which consider effects of nonwetting fluid entrapment, were shown to provide a reasonable compromise between accuracy, on the one hand, and efficiency and robustness, on the other. Laboratory studies of light and dense NAPLs in a 1 x 1.5 meter sand tank, involving measurements of water and NAPL pressures and saturations and component concentrations, are described. These studies were used to validate the mathematical model for multiphase flow and transport.
Physical Nonequilibrium in Soils provides cutting-edge knowledge on physical nonequilibrium phenomena in soils, offering unique insight into the complexity of our physical world. With 18 chapters comprising the book, topics cover soil properties fluid properties mechanistic models transfer function geostatistics fractal analysis cellular-automation fluids coupling of physical and chemical nonequilibrium models confirming and quantifying physical nonequilibrium in soils analytical solutions field-scale research environmental impacts.
A uniquely accessible text on environmental modeling designed for both students and industry personnel Pollutant fate and modeling are becoming increasingly important in both regulatory and scientific areas. However,the complexity of the software and models often act as an inhibitor to the advancement of water quality science. A Basic Introduction to Pollutant Fate and Transport fills the need for a basic instructional tool for students and environmental professionals who lack the rigorous mathematical background necessary to derive the governing fate and transport equations. Taking a refreshingly simple approach to the subject that requires only a basic knowledge of algebra and first-year college chemistry, the book presents and integrates all of the aspects of fate and transport, including chemistry, modeling, risk assessment, and relevant environmental legislation; approaching each topic first conceptually before introducing the math necessary to model it. The first half of the book is dedicated to the chemistry and physics behind the fate and transport models, while the second half teaches and reinforces the logical concepts underlying fate and transport modeling. This better prepares students for support jobs in the environmental arena surrounding chemical industry and Superfund sites. Contributing to the book's ease of use are: An extremely user-friendly software program, Fate, which uses basic models to predict the fate and transport of pollutants in lakes, rivers, groundwater, and atmospheric systems The use of "canned" models to evaluate the importance of model parameters and sensitivity analysis A wealth of easy-to-understand examples and problems A chapter on environmental legislation in the United States and Europe A set of lab exercises, as well as a downloadable set of teaching aids A much-needed basic text for contemporary hydrology or environmental chemistry courses and support courses forthe environmental industry, this is a valuable desk reference for educators and industry professionals.
Pesticides in the soil environment - an overview. Pesticide sources to the soil and principles of spray physics. The retention processes: mechanisms. Sorption estimates for modeling. Abiotic transformations in water, sediments, and soil. Biological transformation processes of pesticides. Volatilization and vapor transport processes. Organic chemical transport to Groundwater. Movement of pesticides into surface waters. Modeling pesticide fate in soils. Efficacy of soil-applied pesticides. Impact of pesticides on the environment. Risk/benefit and regulations. Chemical index.
A comprehensive, thoroughly modern approach to environmental quality assessment The only textbook to combine engineering transport fundamentals and equilibrium aquatic chemistry, Environmental Modeling brings a uniquely contemporary perspective to the assessment of environmental quality. Addressing key questions about fate, transport, and long-term effects of chemical pollutants in the environment, this inherently practical text gives readers the important tools they need to develop and solve their own mathematical models. Contains detailed examples from a wide range of crucial water quality areas-conventional pollutants in rivers, eutrophication of lakes, and toxic organic chemicals and heavy metals in both surface and groundwaters Examines current global issues, including atmospheric deposition, hazardous wastes, soil pollution, global change, and more Features over 200 high-quality illustrations, plus skill-building problems in every chapter Fresh in approach and broad in scope, Environmental Modeling is must reading for today's graduate and advanced undergraduate students in environmental sciences and engineering-a rich, invaluable, and superlative new resource.
Physical Nonequilibrium in Soils provides cutting-edge knowledge on physical nonequilibrium phenomena in soils, offering unique insight into the complexity of our physical world. With 18 chapters comprising the book, topics cover soil properties fluid properties mechanistic models transfer function geostatistics fractal analysis cellular-automation fluids coupling of physical and chemical nonequilibrium models confirming and quantifying physical nonequilibrium in soils analytical solutions field-scale research environmental impacts.
Teaches, using simple analytical models how physical, chemical, and biological processes in the subsurface affect contaminant transport Uses simple analytical models to demonstrate the impact of subsurface processes on the fate and transport of groundwater contaminants Includes downloadable modeling tool that provides easily understood graphical output for over thirty models Modeling tool and book are integrated to facilitate reader understanding Collects analytical solutions from many sources into a single volume and, for the interested reader, shows how these solutions are derived from the governing model equations
