Chemical-specific representation of air-soil exchange and soil penetration in regional multimedia models

TitleChemical-specific representation of air-soil exchange and soil penetration in regional multimedia models
Publication TypeJournal Article
Year of Publication2003
AuthorsThomas E McKone, Deborah H Bennett
JournalEnvironmental Science and Technology
Volume37
Issue14
Pagination3123-3132
Date Published07/2003
Abstract

In multimedia mass-balance models, the soil compartment is an important sink as well as a conduit for transfers to vegetation and shallow groundwater. Here a novel approach for constructing soil transport algorithms for multimedia fate models is developed and evaluated. The resulting algorithms account for diffusion in gas and liquid components; advection in gas, liquid, or solid phases; and multiple transformation processes. They also provide an explicit quantification of the characteristic soil penetration depth. We construct a compartment model using three and four soil layers to replicate with high reliability the flux and mass distribution obtained from the exact analytical solution describing the transient dispersion, advection, and transformation of chemicals in soil layers with different properties but a boundary condition at the air-soil surface. The soil compartment algorithms can be dynamically linked to other compartments (air, vegetation, ground water, surface water) in multimedia fate models. We demonstrate and evaluate the performance of the algorithms in a model with applications to benzene, benzo(a)pyrene, MTBE, TCDD, and tritium.

DOI10.1021/es0258529