Application of Rhamnolipid Biosurfactant for Removing Polychlorinated Biphenyls from Contaminated Soil

Rhamnolipid (RL) was used to study the removing of polychlorinated biphenyls (PCBs) from contaminated soils. The results showed that RL obviously enhanced desorption of PCBs from soils and RL was more effective than POE(6). Pseudomonas strain LB400 was able to grow rapidly in the medium with RL, POE(6) or biphenyl as carbon source. PCBs biodegraded in growing cells were greater than that in resting cells. In growing cells with RL as carbon source, when the incubating time reached 72 h, PCBs Biodegraded was 98.7% and increased by 0.5% compared with that with biphenyl as carbon source. PCBs degraded were the lowest in all kinds of cell systems with POE(6) as carbon source. In the growing cell system, P.LB400 was able to fully utilize RL, so the cell density and PCBs Biodegraded rapidly increased with the increase of the concentration of RL. However, in the resting cell system, RL had negative impact on biodegradation of PCBs.