Geochemical Equilibrium Modeling in Soils and Sediments provides a systematic examination of the application of thermodynamic principles to chemical reactions of elements in soils. Classical thermodynamic concepts are introduced, providing a theoretical foundation. Equilibrium reactions are then discussed element-by-element in order of decreasing average abundance in the solid phase of soils and sediments. Solid phase transitions, dissolution, volatilization, and aqueous speciation are investigated in detail. Each chapter gives the reader greater depth of understanding of these complex systems. Geochemical Equilibrium Modeling in Soils and Sediments represents a modernization of the approach through geochemical modeling, updating thermodynamic data, and focusing on those reactions that are known to occur at the solid-solution interface in soil and sediment environments. Readers are shown how these developments are integrated into geochemical modeling and how to interpret geochemical modeling results. The tools in this book will further allow readers understand the interactions among elements, predict solubility as the physical environment changes, and the means to anticipate chemical and biological lability in response to perturbations.