Enhanced in-situ mobilization and biodegradation of phenanthrene from soil by a solvent/surfactant system

Laboratory experiments were conducted to investigate the use of paraffin oil as a nontoxic solvent in enhancing the mobilization and biodegradation of a PAH, phenanthrene, in wet soil. As the oil is not miscible with water, a surfactant was added to stabilize the oil/water emulsion. The aqueous solubility of phenanthrene was greater in the presence of the oil/surfactant mixture than when surfactant was used alone. Similarly, a soil column experiment showed that phenanthrene mobilization from the soil was poor when only surfactant was added and was enhanced when the same amount of surfactant was mixed with paraffin oil. Both the oil/surfactant mixture and the surfactant alone had a similar enhancing effect on the rate of biodegradation of the mobilized phenanthrene.