To understand hydrochemistry and to analyze natural as well as man-made impacts on aquatic systems, hydrogeochemical models have been used since the 1960’s and more frequently in recent times. Numerical groundwater flow, transport, and geochemical models are important tools besides classical deterministic and analytical approaches. Solving complex linear or non-linear systems of equations, commonly with hundreds of unknown parameters, is a routine task for a PC. Modeling hydrogeochemical processes requires a detailed and accurate water analysis, as well as thermodynamic and kinetic data as input. Thermodynamic data, such as complex formation constants and solubility-products, are often provided as databases within the respective programs. However, the description of surface-controlled reactions (sorption, cation exchange, surface complexation) and kinetically controlled reactions requires additional input data. Unlike groundwater flow and transport models, thermodynamic models, in principal, do not need any calibration. However, considering surface-controlled or kinetically controlled reaction models might be subject to calibration. Typical problems for the application of geochemical models are: • speciation • determination of saturation indices • adjustment of equilibria/disequilibria for minerals or gases • mixing of different waters • modeling the effects of temperature • stoichiometric reactions (e.g. titration) • reactions with solids, fluids, and gaseous phases (in open and closed systems) • sorption (cation exchange, surface complexation) • inverse modeling • kinetically controlled reactions • reactive transport Hydrogeochemical models depend on the quality of the chemical analysis, the boundary conditions presumed by the program, theoretical concepts (e.g.

Groundwater Geochemistry: Fundamentals and Applications to Contamination examines the integral role geochemistry play s in groundwater monitoring and remediation programs, and presents it at a level understandable to a wide audience. Readers of all backgrounds can gain a better understanding of geochemical processes and how they apply to groundwater systems. The text begins with an explanation of fundamental geochemical processes, followed by a description of the methods and tools used to understand and simulate them. The book then explains how geochemistry applies to contaminant mobility, discusses remediation system design, sampling program development, and the modeling of geochemical interactions. This clearly written guide concludes with specific applications of geochemistry to contaminated sites. This is an ideal choice for readers who do not have an extensive technical background in aqueous chemistry, geochemistry, or geochemical modeling. The only prerequisite is a desire to better understand natural processes through groundwater geochemistry.

There remains a lack of understanding of environmental isotopes and their use; students and practitioners typically find the concepts of isotope concentrations and partitioning to be more complicated than for geochemistry. However, this need not be so, if the basics are presented together with geochemistry, using case studies and examples to make the point. This new book presents the basics of environmental isotopes and geochemistry together, with case studies and simple examples that build a real understanding of their use in natural and contaminated groundwater.

Groundwater Geochemistry: Fundamentals and Applications to Contamination examines the integral role geochemistry play s in groundwater monitoring and remediation programs, and presents it at a level understandable to a wide audience. Readers of all backgrounds can gain a better understanding of geochemical processes and how they apply to groundwater systems. The text begins with an explanation of fundamental geochemical processes, followed by a description of the methods and tools used to understand and simulate them. The book then explains how geochemistry applies to contaminant mobility, discusses remediation system design, sampling program development, and the modeling of geochemical interactions. This clearly written guide concludes with specific applications of geochemistry to contaminated sites. This is an ideal choice for readers who do not have an extensive technical background in aqueous chemistry, geochemistry, or geochemical modeling. The only prerequisite is a desire to better understand natural processes through groundwater geochemistry.

This book contains both practical and theoretical aspects of groundwater resources relating to geochemistry. Focusing on recent research in groundwater resources, this book helps readers to understand the hydrogeochemistry of groundwater resources. Dealing primarily with the sources of ions in groundwater, the book describes geogenic and anthropogenic input of ions into water. Different organic, inorganic and emerging contamination and salinity problems are described, along with pollution-related issues affecting groundwater. New trends in groundwater contamination remediation measures are included, which will be particularly useful to researchers working in the field of water conservation. The book also contains diverse groundwater modelling examples, enabling a better understanding of water-related issues and their management. Groundwater Geochemistry: Pollution and Remediation offers the reader: An understanding of the quantitative and qualitative challenges of groundwater resources An introduction to the environmental geochemistry of groundwater resources A survey of groundwater pollution-related issues Recent trends in groundwater conservation and remediation Mathematical and statistical modeling related to groundwater resources Students, lecturers and researchers working in the fields of hydrogeochemistry, water pollution and groundwater will find Groundwater Geochemistry an essential companion.

The difficult struggle to protect our valuable ground-water resources necessarily involves scientists and engineers from many disciplines. To prevail in this effort, these practitioners—including microbiologists, hydrogeologists, geoscientists, and environmental engineers—must have a common understanding of essential ground-water quality issues and problems. That includes a basic grasp of how microorganisms and microbial processes affect the chemistry of ground water in both pristine and chemically stressed aquifer systems. Ground-Water Microbiology and Geochemistry marks the first attempt to bridge the historical lack of communication among these disciplines by detailing—in language that cuts across specialties—the impact of microorganisms and microbial processes on ground-water systems. To bring these diverse practitioners together, the book has been organized in three parts, with each section addressing the information needs of specific disciplines. The first six chapters of Ground-Water Microbiology and Geochemistry provide an overview of microbiology that’s geared to geoscientists who may lack formal training in the field. Here, the book systematically covers the kinds of microorganisms found in subsurface environments, focusing on their growth, metabolism, genetics, and ecology. The second part of the book, which covers four chapters, speaks both to geoscientists and to microbiologists. It offers a hydrologic perspective on how microbial processes affect groundwater geochemistry in pristine systems—an important topic for geochemists since most ground-water reservoirs have not been chemically affected by human activities, and naturally occurring microbial processes have major impacts on water quality. At the same time, Part Two introduces microbiologists to the different classes of ground-water systems, and gives an overview of techniques for sampling subsurface environments. In addition, microbiologists gain an understanding of biogeochemical cycling in ground-water systems—in coverage that’s unique to this book—and of the classic geochemical modeling techniques that are used to study microbial processes. The final three chapters of Ground-Water Microbiology and Geochemistry focus in on microbial processes in contaminated ground-water systems—a topic of central concern to environmental scientists. In this concluding section, microbiologists see how degradation processes depend upon the hydrologic and geochemical environments within which they operate. Having achieved a basic knowledge of microbiological and biochemical concepts from the earlier chapters, geoscientists are fully prepared for this treatment of microbial acclimation and the biodegradation of petroleum hydrocarbons and halogenated compounds. Ground-Water Microbiology and Geochemistry is as graphically impressive as it is far reaching. High-quality, computer-generated illustrations, of particular appeal to visually oriented geoscientists, can be found throughout the book. Equally important is the book’s unusually comprehensive bibliography, which, like the text itself, spans the relevant science and engineering disciplines. The importance of Ground-Water Microbiology and Geochemistry to geoscientists, hydrologists, and environmental scientists has been amply documented. The book should also be required reading for water planners and lawyers involved in environmental issues. It will also serve as a compelling text in upper undergraduate and graduate courses in ground-water chemistry.