生物表面活性剂鼠李糖脂对PCBs污染土壤的修复作用研究

利用生物表面活性鼠李糖脂（RL）洗脱土壤,再通过紫外光预照射与生物降解协同去除洗脱液中的PCBs的组合方法对多氯联苯（PCBs）污染土壤进行修复,旨在研究RL在修复PCBs污染土壤中的作用及其机理。结果表明,RL对PCBs的洗脱具有显著的促进作用,PCBs的总洗脱率与RL的质量浓度呈正相关。当洗脱液中加入2 000 mg.L-1的RL,在3次批洗脱后,人工污染土样和陈化土样的PCBs总洗脱率分别达到了90.1%和47.1%。PCBs降解菌P.LB400在以RL或联苯为碳源的驯化培养基中均能够快速生长。当土壤洗脱液中的PCBs被P.LB400的生长细胞菌液降解时,RL对PCBs的生物降解具有显著的促进作用;而在P.LB400的休眠细胞降解体系中,RL对PCBs的生物降解有一定的抑制作用。紫外光预照射对土壤洗脱液中PCBs的生物降解有一定的促进作用。紫外光预照射和生物降解的耦合有利于提高PCBs的降解速率。

Remediation of soil contaminated by polychlorinated biphenyls with rhamnolipid biosurfactant

The application of rhamnolipid（RL） biosurfactant in the remediation of polychlorinated biphenyls（PCBs）-contaminated soil by a combination of RL washing,photolysis and biodegradation was studied.The results showed that RL obviously enhanced desorption of PCBs from soils,and the total amount of PCBs desorbed increased with increasing RL concentration.When 2 000 mg.L-1 of RL solution was added to the soil,after three batch washes,the total amount of PCBs removed from the laboratory contaminated soil and the field contaminated soil was 90.1% and 47.1%,respectively.Pseudomonas strain LB400 was able to grow rapidly in the medium with RL or biphenyl as carbon source.In the growing cell system,P.LB400 was able to fully utilize RL and PCBs Biodegraded rapidly increased with the increase of the concentration of RL in the soil wash fluid.However,in the resting cell system,RL had negative impact on biodegradation of PCBs.Precedent photolysis was able to improve Biodegradation of PCBs.A combination of UV pre-irradiation and biological treatment was beneficial to increasing degradation rate of PCBs.