以汽油为底物好氧共代谢三氯乙烯

三氯乙烯(trichloroethylene,TCE)是土壤和地下水中广泛存在的有机污染物,好氧生物降解因可将污染物彻底转化成无毒的终产物,一直受到广泛关注,但是TCE好氧降解需要共代谢底物。首次提出以汽油为底物,选取真养产碱杆菌作为活性降解菌株,对地下水中三氯乙烯的好氧共代谢降解进行了初步研究。分别优化了共代谢底物、底物与TCE浓度比、培养基、pH值、盐度、溶解氧等条件,确定了最佳降解条件。当水中TCE的浓度为1 mg/L时,通过对体系预曝氧气,调节汽油浓度为10 mg/L,pH值为5,降解24 h,TCE的降解率可达66.8%。为修复同时被汽油和TCE污染的场地提供了一个新的研究方向。

Aerobic co-metabolism of trichloroethylene using gasoline as primary substrate

Trichloroethylene(TCE)is a common organic contaminant in soil and groundwater. Aerobic biological degradation has drawn much attention due to the complete transforming of contaminants to non-toxic products. However,the aerobic degradation of TCE needs the co-existence of primary substrates. In the present study,the degradation of TCE was studied using Ralstonia eutropha as the active degradation species and gasoline as primary substrate. It is the first time to use gasoline as the primary substance for TCE degradation. The degradation conditions were optimized on co-metabolism primary substrate,concentration ratio between primary substrate and TCE,culture medium,pH,salt content and dissolved oxygen respectively. In the system of pre-aeration of oxygen,a TCE degradation rate of 66.8% was achieved at TCE concentration of 1 mg/L,gasoline concentration of 10 mg/L,pH of 5,and degradation time of 24 h. The present study provides a novel approach for remediation of contaminated site simultaneously contaminated by gasoline and TCE.