Predicting Fate and Transport of Environmental Impact Chemicals in Soils

Fate and transport of selected environmental impact chemicals (EIC) in both soil liquid and gaseous phases were investigated. The combined effects of organic matter and pH on ionic pesticide sorption, and the combined effects of sorption non-linearity and time-dependency on polycyclic aromatic hydrocarbon (PAH) sorption were measured. Based on the data, useful models were developed to predict pesticide sorption and mobility from soil organic matter content and pH. Also, sorption non-linearity and sorption time-dependency were linked in a model to predict the reduced mobility of PAH in soil systems. Concerning transport parameters, the processes of soil-water retention and water-repellency were linked with the perspective of better describing water permeability and chemical transport in water-repellent soil. Also, new predictive models for the soil-gas diffusion coefficient as related to basic soil physical characteristics and new conceptual models to describe gas transport coefficients and gaseous phase tortuosity as related to the soil pore size distribution were developed and successfully applied and tested