Merkel B. Groundwater Geochemistry. A Practical Guide to Modeling...2005

Textbook in PDF format

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.
Hydrogeochemical models are dependent on the quality of the chemical analyses, the boundary conditions presumed by the program, theoretical concepts (e.g. calculation of activity coefficients) and the thermodynamic data. Therefore it is vital to check the results critically. For that, a basic knowledge about chemical and thermodynamic processes is required and will be outlined briefly in the following chapters on hydrogeochemical equilibrium (chapter 1.1), kinetics (chapter 1.2),
and transport (chapter 1.3). Chapter 2 gives an overview on standard hydrogeochemical programs, problems and possible sources of error for modeling, and a detailed introduction to run the program PHREEQC, which is used in this book. With the help of examples, practical modeling applications are addressed and specialized theoretical knowledge is extended. Chapter 4 presents the results for the exercises of chapter
3. This book does not aim to replace a textbook but
rather attempts to be a practical guide for beginners at modeling.
Theoretical Background.
Equilibrium reactions.
Kinetics.
Reactive mass transport.
Hydrogeochemical Modeling Programs.
General.
Use of PHREEQC.
Exercises.
Equilibrium reactions.
Reaction kinetics.
Reactive transport.
Solutions.
Equilibrium reactions.
Reaction kinetics.
Reactive transport