Membrane Behavior of Clay Soil Barrier Materials

Colorado State University, Fort Collins CO

Investigators

Abstract

The effect of membrane behavior in clay soils is to reduce the contaminant mass flux through the soil relative to the contaminant mass flux that would occur in the absence of membrane behavior. Since the purpose of many clay soil barriers used in waste containment and in situ remediation applications is to restrict the migration of aqueous miscible contaminants, the existence of membrane behavior represents a potentially significant beneficial aspect that presently is not considered in the use of clay soil barriers for such applications. Thus, the goal of the research is to evaluate the significance of membrane behavior of engineered clay soil barrier materials with respect to their use in waste containment and in situ remediation applications. This goal will be achieved by providing sufficient experimental data to evaluate the combined effects of compressibility and salt concentration on the membrane behavior of clay soils that have properties resembling those of barrier materials used in waste containment and in situ remediation applications. The proposed research will advance our present understanding of membrane behavior sufficiently to allow a more rational basis for potentially incorporating membrane behavior into the design of clay soil barriers, such as compacted clay liners, geosynthetic clay liners, and soil-bentonite vertical cutoff walls.