Surfactant-enhanced soil flushing of petroleum hydrocarbons from unsaturated soils

The recovery of non-aqueous phase liquids (NAPLs) from contaminated aquifers using soil flushing and pump-and-treat technology can be enhanced by the addition of surfactants. Laboratory column studies examined the influence of media pore size distribution (PSD) on the mobilization of m-xylene from unsaturated porous media using a 1% alcohol ethoxylate surfactant solution (Witconol;Experiments utilized glass columns (2.5 cm I.D. x 31 cm) packed with porous media where a three phase system (i.e., air, water and oil) was established. Recovery efficiency was based on the number of pore volumes of flushing solution required to mobilize a fixed percentage of initial contaminant.;A biodegradable surfactant (Hamposyl L-30) was evaluated through a series of column experiments as a flushing agent under unsaturated conditions. The surfactant active ingredient phase was then successfully separated along with m-xylene from effluent samples by acidification. (Abstract shortened by UMI.).