Treatment of crude-oil contaminated soil using biosurfactants

In this research, the effect of Saponin as a bio surfactant for crude-oil removal by the concentration of 10000 and 30000 ppm in a column soil sample was evaluated. The experimental parameters and their value levels investigated were: concentration of surfactant solutions (0.05, 0.1 and 0.2%-mass); pH (7, 9 and 11); Alkali (NaOH) and polymer (Xanthan Gum) (0.6 and 0.1%-mass) and (0.7 and 0.2%-mass) respectively, as additions for optimum results in case of excessive efficiency evaluation. Results showed that the optimum washing condition for pH was found to be 11 for all the surfactant solutions. Optimum concentration of surfactant solution for 10000 ppm pollution was 0.1%-mass and for 30000 ppm pollution 0.2%-mass and crude-oil removal efficiency were 69 and 72% respectively. Alkali and polymer in amount of 0.7 and 0.2%-mass (for NaOH and Xanthan Gum respectively) caused the efficiency mount to 71 and 75%. TPH is used as the criterion for this experiment.   Key words: Soil remediation, crude oil, biosurfactants, Saponin.