Evaluation of surfactant and biosurfactant mixture usefulness in oil removal from soil, based on physicochemical studies and flushing experiments

Surface activity and wetting properties of nonionic surfactant Rokanol NL6, biosurfactant JBR 425 and their mixtures were investigated. On the basis of these investigations, the ability of both surfactants to remove the synthetic base oil (PAO 6) from sand was evaluated. Surfactants solutions were applied in soil flushing in column and in batch experiments. Column tests with the solutions of Rokanol NL6 and JBR 425 gave very poor results (25% oil removal), while washing in batch tests was much more efficient and the oil removal reached even 95%. The mixtures of both surfactants gave better results than those obtained for single compounds.