Modeling diffusive Cd and Zn contaminant emissions from soils to surface waters.

Modeling contaminant transport of diffusive contaminants is generally difficult, as most contaminants are located in the top soil where soil properties will vary strongly with depth and often a strong gradient in contaminant concentrations exists. When groundwater periodically penetrates the contaminated layers, stationary models (like most 3D models) cannot adequately describe contaminant transport. Therefore we have combined a hydrological instationary model using a 1D distributed column approach with a simple geochemical model to describe contaminant transport in the soil.