INDUCED SOIL VENTING FOR RECOVERY / RESTORATION OF GASOLINE HYDROCARBONS IN THE VADOSE ZONE

Abstract Induced soil venting can be a rapid, efficient method for the removal of insular and pellicular gasoline trapped in soils following a spill or leak. Evaporation rates of over 50 gasoline hydrocarbon components were measured in laboratory soil column experiments. The effects of soil density, moisture content, particle size, and induced air flow rate were determined. Residual soil saturation by gasoline and soil permeability to air and water were evaluated over the range of soil conditions. Gasoline recovery from soils by soil venting exceeded 99 per cent in all experiments as determined by GC, GC/MS and bulk weight analyses. Sequential volatilization of gasoline components was related to compound vapor pressure and mole fraction variations in the solvent phase with respect to time. Equilibrium and diffusion limitations of the soil venting process are analyzed and discussed. Applications of the column study to in situ soil venting in the field are discussed.