Sorption of Trichloroethylene by Saponite Clay. (4249)
Authors:
V. Aggarwal - Michigan State Univ.
H. Li - Michigan State Univ.
B.J. Teppen - Michigan State Univ.
Abstract:
Trichloroethylene (TCE) is one of the common pollutants in groundwater and can cause serious health risks even at small concentrations. Cs is often a co-contaminant at DOE sites contaminated with TCE.
Smectite clays have large surface areas, are common in soils, and have high affinities for some organic contaminants, so have a great potential to influence the movement of pollutants entering soils and sediments. The exchangeable cations present near smectite clay surfaces can radically influence the sorption of organic pollutants by soil clays. This research was therefore undertaken to determine the effect of Cs+, and other common interlayer cations, such as K+, and Ca2+, on the sorption of TCE by a reference smectite clay, saponite. Cs-saturated clay sorbed the most TCE, up to 3500 mg/kg, while Ca-saturated sorbed the least. We hypothesize that the stronger sorption of TCE by the Cs-smectite can be attributed to the lower hydration energy and hence smaller hydrated radius of Cs+, which expands the lateral clay surface domains available for sorption. Also, Cs-smectite interlayers are only one or two water layers thick, which may drive capillary condensation of TCE. We conclude that the presence of Cs+ as a co-contaminant can be expected to increase the sorption of TCE by aquifer materials
containing smectites.
Speaker Information: Vaneet Aggarwal, Michigan State University, Department of Crop & Soil Sciences, East Lansing, MI 48824; Phone: (517) 355 0271 x 245; E-mail: [email protected]
Session Information: Tuesday, November 2, 2004, 1:55 PM-4:15 PM Presentation Start: 1:55 PM
