Peter Grathwohl – författare

This text introduces the general principles of diffusion in the subsurface environment and discusses the implications for the fate and transport of contaminants in soils and groundwater. Emphasis is placed on sorption/desorption and the dissolution kinetics of organic contaminants, both of which are limited by the slow speed of molecular diffusion. The book compiles methods for calculating the diffusion coefficients of organic compounds (in aqueous solution or vapour phase) in natural porous media. The author uses analytical solutions of Fick's 2nd law and some simple numerical models to model diffusive transport under various initial and boundary conditions. A number of these models may be solved using spreadsheets. The book examines sorption/desorption rates of organic compounds in various soils and aquifer materials, and also examines the dissolution kinetics of nonaqueous phase liquids in aquifers, in both the trapped residual phase and in pools. The text concludes with a discussion of the impact of slow diffusion processes on soil and groundwater decontamination and the implications of these processes for groundwater risk assessment.

Diffusion in Natural Porous Media: Contaminant Transport, Sorption/Desorption and Dissolution Kinetics introduces the general principles of diffusion in the subsurface environment and discusses the implications for the fate and transport of contaminants in soils and groundwater. Emphasis is placed on sorption/desorption and the dissolution kinetics of organic contaminants, both of which are limited by the slow speed of molecular diffusion. Diffusion in Natural Porous Media: Contaminant Transport, Sorption/Desorption and Dissolution Kinetics compiles methods for calculating the diffusion coefficients of organic compounds (in aqueous solution or vapor phase) in natural porous media. The author uses analytical solutions of Fick's 2nd law and some simple numerical models to model diffusive transport under various initial and boundary conditions. A number of these models may be solved using spreadsheets. The book examines sorption/desorption rates of organic compounds in various soils and aquifer materials, and also examines the dissolution kinetics of nonaqueous phase liquids in aquifers, in both the trapped residual phase and in pools. Diffusion in Natural Porous Media: Contaminant Transport, Sorption/Desorption and Dissolution Kinetics concludes with a discussion of the impact of slow diffusion processes on soil and groundwater decontamination and the implications of these processes for groundwater risk assessment.

Advanced Tools and Models to Improve River Basin Management in Europe in the Context of Climate Change - AquaTerra has developed from an integrated project of the 6th EU RTD Framework Programme that aims to provide the scientific basis for an improved river basin management through a better understanding of the river-sediment-soil-groundwater system as a whole, by integrating both natural and socio-economics aspects at different temporal and spatial scales. This book aims: To provide better understanding of the river-sediment-soil-groundwater system at various temporal and spatial scales To relate expected climate alterations to changes in deposition, mobility and distribution of pollutants in European river basinsTo provide the scientific basis for improved river basin management  To introduce novel tools for water and soil quality monitoring  To show the necessity of integrated modelling frameworks for impact evaluation of pollution as well as climate and land-use changes for definition of long-term management schemes The work illustrates the dynamic behavior of the pathway of pollutants in soils, groundwater, surface water and sediments. It highlights the fundamental importance of integrating knowledge from several combined disciplines on various environmental compartments in order to understand the large number of processes that govern pollutant input, transport and turnover. Results shows that a significant step forward has been made in the development new analytical methods and of process-based numerical models that are capable of making predictions of likely trends and environmental changes to be expected in the near or distant future at the basin-scale. These models can be used e.g. to generate hydrologic scenarios based on climate models and to simulate pollutant distribution and turnover rates from decades to millennia.