Subsurface pollutant transport

This chapter focuses on an evaluation of pollutant transport modeling in subsurface soils with an emphasis on the level at which these models represent actual physical conditions at the site. The physical and chemical interaction mechanisms that govern the transport of organic and inorganic pollutants in the subsurface environment are examined. Single-rate and multirate mass transfer processes for an accurate evaluation of pollutant transport, fate, and remedial measures are discussed. For both saturated and unsaturated subsurface materials, pollutant transport modeling of soluble and nonsoluble pollutants using the second postulate of irreversible thermodynamics are presented. Laboratory experimental methods used to determine sorption characteristics are examined. A variety of analytical models for transport equations are used to elaborate on the level of complexity of the problems under investigation. Finally, because of the unpredictability of variables included in the mathematical modeling of pollutant transport phenomena, stochastic modeling is briefly discussed.