Applied Contaminant Transport Modeling


Book Description

Applied Contaminant Transport Modeling Theory and Practice Chunmiao Zheng and Gordon D. Bennett The design of remedial systems for groundwater contamination requires a thorough understanding of how various interacting processes — advection, dispersion, and chemical reactions — influence the movement and fate of contaminants. Solute transport simulation provides an ideal vehicle to synthesize these controlling processes, evaluate their interactions, and test the effectiveness of remedial measures. Applied Contaminant Transport Modeling is the first complete resource designed to provide clear coverage of the basic principles of solute transport simulation — including the theory behind the most common numerical techniques for solving transport equations, and step-by-step guidance on the development and use of field-scale models. Written by two experts with extensive practical experience in the field, Applied Contaminant Transport Modeling clearly explains: Factors controlling the transport and fate of solutes in the subsurface —g including advective and dispersive transport and chemical reaction — and the equations governing these processes Development of mathematical models of solute transport regimes and representative analytical solutions to the transport equation Particle tracking as a practical tool for solving many types of field problems Development of Eulerian-Lagrangian methods for solving advection-dispersion-reaction equations Step-by-step development and application of solute transport models — emphasizing problem formulation, model setup, parameter selection, calibration, and sensitivity analysis Sources of uncertainty in transport simulation, and methods of evaluating and managing uncertainty Applied Contaminant Transport Modeling presents detailed case histories illustrating how hydrologists, geologists, chemists, and environmental engineers apply transport models in real-life situations, including landfills, hazardous waste sites, and contaminated aquifers. An optional diskette designed to accompany the text provides software to help the reader explore the concepts and techniques presented in the text and gain hands-on experience in transport simulation. Driven by growing concern over groundwater quality and the rapid dissemination of computer technology, solute transport simulation has become an essential means of evaluating and solving groundwater contamination and remediation problems. Applied Contaminant Transport Modeling provides you with the tools to master this significant field of study.




Modeling Groundwater Flow and Contaminant Transport


Book Description

In many parts of the world, groundwater resources are under increasing threat from growing demands, wasteful use, and contamination. To face the challenge, good planning and management practices are needed. A key to the management of groundwater is the ability to model the movement of fluids and contaminants in the subsurface. The purpose of this book is to construct conceptual and mathematical models that can provide the information required for making decisions associated with the management of groundwater resources, and the remediation of contaminated aquifers. The basic approach of this book is to accurately describe the underlying physics of groundwater flow and solute transport in heterogeneous porous media, starting at the microscopic level, and to rigorously derive their mathematical representation at the macroscopic levels. The well-posed, macroscopic mathematical models are formulated for saturated, single phase flow, as well as for unsaturated and multiphase flow, and for the transport of single and multiple chemical species. Numerical models are presented and computer codes are reviewed, as tools for solving the models. The problem of seawater intrusion into coastal aquifers is examined and modeled. The issues of uncertainty in model input data and output are addressed. The book concludes with a chapter on the management of groundwater resources. Although one of the main objectives of this book is to construct mathematical models, the amount of mathematics required is kept minimal.




Characterization, Modeling, Monitoring, and Remediation of Fractured Rock


Book Description

Fractured rock is the host or foundation for innumerable engineered structures related to energy, water, waste, and transportation. Characterizing, modeling, and monitoring fractured rock sites is critical to the functioning of those infrastructure, as well as to optimizing resource recovery and contaminant management. Characterization, Modeling, Monitoring, and Remediation of Fractured Rock examines the state of practice and state of art in the characterization of fractured rock and the chemical and biological processes related to subsurface contaminant fate and transport. This report examines new developments, knowledge, and approaches to engineering at fractured rock sites since the publication of the 1996 National Research Council report Rock Fractures and Fluid Flow: Contemporary Understanding and Fluid Flow. Fundamental understanding of the physical nature of fractured rock has changed little since 1996, but many new characterization tools have been developed, and there is now greater appreciation for the importance of chemical and biological processes that can occur in the fractured rock environment. The findings of Characterization, Modeling, Monitoring, and Remediation of Fractured Rock can be applied to all types of engineered infrastructure, but especially to engineered repositories for buried or stored waste and to fractured rock sites that have been contaminated as a result of past disposal or other practices. The recommendations of this report are intended to help the practitioner, researcher, and decision maker take a more interdisciplinary approach to engineering in the fractured rock environment. This report describes how existing tools-some only recently developed-can be used to increase the accuracy and reliability of engineering design and management given the interacting forces of nature. With an interdisciplinary approach, it is possible to conceptualize and model the fractured rock environment with acceptable levels of uncertainty and reliability, and to design systems that maximize remediation and long-term performance. Better scientific understanding could inform regulations, policies, and implementation guidelines related to infrastructure development and operations. The recommendations for research and applications to enhance practice of this book make it a valuable resource for students and practitioners in this field.




Freshwater Microplastics


Book Description

This book is open access under a CC BY 4.0 license. This volume focuses on microscopic plastic debris, also referred to as microplastics, which have been detected in aquatic environments around the globe and have accordingly raised serious concerns. The book explores whether microplastics represent emerging contaminants in freshwater systems, an area that remains underrepresented to date. Given the complexity of the issue, the book covers the current state-of-research on microplastics in rivers and lakes, including analytical aspects, environmental concentrations and sources, modelling approaches, interactions with biota, and ecological implications. To provide a broader perspective, the book also discusses lessons learned from nanomaterials and the implications of plastic debris for regulation, politics, economy, and society. In a research field that is rapidly evolving, it offers a solid overview for environmental chemists, engineers, and toxicologists, as well as water managers and policy-makers.




A Basic Introduction to Pollutant Fate and Transport


Book Description

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.




Mixing in Inland and Coastal Waters


Book Description

This book is an outgrowth of research contributions and teaching experiences by all the authors in applying modern fluid mechanics to problems of pollutant transport and mixing in the water environment. It should be suitable for use in first year graduate level courses for engineering and science students, although more material is contained than can reasonably be taught in a one-year course, and most instructors will probably wish to cover only selected potions. The book should also be useful as a reference for practicing hydraulic and environmental engineers, as well as anyone involved in engineering studies for disposal of wastes into the environment. The practicing consulting or design engineer will find a thorough explanation of the fundamental processes, as well as many references to the current technical literature, the student should gain a deep enough understanding of basics to be able to read with understanding the future technical literature evolving in this evolving field.




Diffusion Models of Environmental Transport


Book Description

Fate and transport models are critical components in the determination of the exposure to and risk from hazardous contaminants. Analytical models are preferable because they are generally more accessible, more reliable, and require fewer computational resources. Surprisingly, until today, only a limited number of analytical models have been accessible in the literature. Now, there is Diffusion Models of Environmental Transport, which provides more than 40 analytical models of diffusion and advective-diffusion in one, two, and three layer systems, subject to a wide range of boundary and initial conditions. This text illustrates applications to contaminant transport in sediments and soils, including porewater and vapor transport, and also provides Mathcad spreadsheets to aid in the use of these models. The authors supply complete details of the solutions to the models for those who wish for a deeper understanding. For others, who do not have the time or the need, the solutions themselves are ready to be picked up and used. Reible and Choy use their 20-plus years of cumulative experience to create a thorough exploration of fate and transport models. This comprehensive text furnishes an invaluable reference for students and environmental professionals.




Integrated Environmental Modeling


Book Description

Table of Contents Preface Chapter 1 Introduction to Modeling the Transport and Transformation of Contaminants in the Environment Chapter 2 Nature of Environnemental Polluants Chapter 3 Inter-Media Contaminant Transfer: Equilibrium Analysis Chapter 4 Kinetics of Inter-media Chapter 5 Transport Fundamentals Chapter 6 Overview of Numerical Methods in Environmental Modeling Chapter 7 Overview of Probabilistic Methods and Tools for Modeling Chapter 8 Models of Transport in Air Chapter 9 Models of Transport in Individual Media: Soil and Groundwater Chapter 10 Models of Transport in Surface Water Chapter 11 Atmospheric Transformation and Loss Processes Chapter 12 Modeling Chemical Transformations in Water Chapter 13 Exposure and Risk Assessment Chapter 14 Tools for Evaluation, Analysis and Optimization of Environmental Models Index.







Models in Environmental Regulatory Decision Making


Book Description

Many regulations issued by the U.S. Environmental Protection Agency (EPA) are based on the results of computer models. Models help EPA explain environmental phenomena in settings where direct observations are limited or unavailable, and anticipate the effects of agency policies on the environment, human health and the economy. Given the critical role played by models, the EPA asked the National Research Council to assess scientific issues related to the agency's selection and use of models in its decisions. The book recommends a series of guidelines and principles for improving agency models and decision-making processes. The centerpiece of the book's recommended vision is a life-cycle approach to model evaluation which includes peer review, corroboration of results, and other activities. This will enhance the agency's ability to respond to requirements from a 2001 law on information quality and improve policy development and implementation.