Spatial and temporal variability of soil physical and soil chemical properties in field soils. Facilities are available to study soil water content, soil water pressure, soil temperature, soil bulk density, soil texture, and soil chemicals. Software is available for two- and three dimensional kriging of the data and to determine the optimum subset of locations at which to take measurement with a minimum loss of accuracy.
Determination of soil hydraulic parameters by inverse procedures and from particle size distributions. Software is available to determine the hydraulic conductivity and water retention relations of both homogeneous and heterogeneous soil profiles based on water content profiles during drainage and known boundary conditions.
Multi-fluid flow involving water, DNAPLs, LNAPLs, and air. Fundamental research in the areas of capillary pressure-saturation and permeability-saturation for both DNAPLs and LNAPLs is being performed. Variables of interest are spreading vs. non-spreading, wetting vs. non-wetting, partial wetting, and interfacial tension. Spills of DNAPLs and LNAPLs are physically simulated in columns and intermediate scale laboratory flow containers for both homogeneous and stratified porous media. More information ?
Surfactant enhanced remediation of contaminated aquifers. Column and intermediate scale laboratory experiments in both saturated and unsaturated, homogeneous and heterogeneous porous media are being performed to improve our understanding of surfactant enhanced remediation through solubilization and mobilization. Issues of interest are the use of a single surfactant vs. the use of cosurfactants, the movement of NAPLs as a result of mobilization and the concomitant contamination of clean aquifer regions, and the development of dense aqueous plumes as a result of dissolution.
Behavior of dense contaminant plumes in groundwater. A considerable amount of research has been conducted in this area. It has been shown that depending on the relative density of the contaminated (dense) plume, the Darcy velocity, and the vertical saturated hydraulic conductivity, a dense plume can be stable or unstable. Unstable plumes contaminate much larger regions of an aquifer and are therefore more difficult to clean up.