Parameters which were expected to control the removal process of VOCs from contaminated soil during the SVE operation were studied by means of numerical simulations and laboratory experiments in the project. Experimental results of SVE with soil columns in the laboratory indicated that the removal efficiency of VOCs from soil columns was a complicated function of air flow and the hydrogeometry inside. The partition process between air and the immobile liquid was not an equilibrium one, and the interfacial mass transfer varied with the residual amount of VOCs in the soil. Additional experiments under various conditions should be conducted to obtain further insight into SVE process. Two computer models were developed to study soil air and VOC movement during the SVE process. The first one was an analytical approximate model which could be used for the simulation of air movement in the SVE operation with multiple wells in homogeneous soil media. The second one was a numerical model in three-dimensional geometry which used a finite difference solution scheme. A simple pneumatic pump test was conducted, and part of test data were used for the validation of the simple analytical model.

"May 1991" "EPA/600/2-91/016" PB91-181750 Includes bibliographical references (p. 74-79).