Adsorption and diffusion of pollutants in unsaturated soils

In environmental geotechnics, transportation calculations for un- saturated soils have to account for pore-water suction, air content, presence of colloids, diffusion mechanism and the amount of adsorbed water upon the inner porous surfaces. We develop a new physically based three-component model which uses the balance principles for an immiscible mixture of con- tinua with microstructure; includes phenomena of diffusion, adsorption and chemical reactions; proposes suitable constitutive equations to study the flow of a fluid/contaminant mixture through the soil modeled as an elastic porous solid. We also investigate on the conditions of hyperbolicity of the subsystem describing the liquid mixture.