Full Factorial Design on Screening Experiments for Biosurfactant Enhanced Remediation of Hydrophobic Substances in Soil

This paper evaluates the cleaning efficiency of glycolipid-based anionic biosurfactant produced by a local company. Before practical application in removal of oil or other hydrophobic substances from soil, it is necessary to learn the behavior of the biosurfactant across different systems. As process variables, temperature of environment, contact time with dilution of biosurfactant, and concentration of biosurfactant in washing solution were modeled by applying full factorial design. As response variable, cleaning efficiency was obtained experimentally by a set of laboratory tests. Screening design is employed for evaluation of interactions between response variable and process variables. The cleaning efficiency showed various results depending on the initial values of variables. At the upper limit of variables (+ 35 oC temperature of environment, 15 minutes contact time with dilution of biosurfactant, and 0.3 wt% concentration of biosurfactant in washing solution) the cleaning efficiency was 99.32 %. The results showed that all variables had significant effects on the cleaning efficiency at 95 % confidence level.