Information about the concentration, composition, mineralogy, and surface chemical properties of the mobile colloidal phase is critical in understanding the partitioning of contaminants between the aqueous phase and various solid phases, both mobile and immobile, as well as the specific conditions that favor mobile colloid generation and subsequent transport in the environment. As part of the new (modified continuation) regional project entitled "Mineralogical Controls on Colloid Dispersion and Solid-Phase Speciation of Soil Contaminants", the database generated under the current project will be evaluated using multi-factor statistical techniques to develop a model (DISPERSE) for predicting the dispersibility of soils from the Southern Region based on a set of controlling factors which include clay mineralogy and several commonly measured soil chemical parameters, such as pH, CEC, and SAR. The dispersion behavior of a second set of soils from the Southern Region will then be characterized in terms of the dispersion-controlling factors in an attempt to validate the dispersion model. The new project will also evaluate the mineral-contaminant associations for the project soils and a set of common soil contaminants derived from agricultural and industrial activities reflecting a range of chemical properties (i.e. heavy metals, oxyanions, hydrophobic organics, etc.) to improve our understanding of the mechanisms by which mobile soil colloids can facilitate contaminant migration.

Last Modified: September 30, 1998

Document Prepared by:
North Carolina Agricultural Research Service
North Carolina State University