多氯联苯微生物厌氧脱氯研究进展

A review on microbial-catalyzed reductive dechlorination of polychlorinated biphenyls

多氯联苯是一种典型的持久性有机污染物,其在环境中的转化归趋备受关注.在厌氧条件下,多氯联苯可以通过微生物脱氯进行降解,该降解方式虽然广泛存在于自然界中,但是受生物地球化学因素的影响较大,调控较为复杂.本文对多氯联苯的厌氧微生物脱氯降解进行综述,讨论了脱氯路径和自然界中8种主要脱氯历程;脱氯微生物及相关的微生物还原脱卤酶;影响脱氯速率、程度和历程的主要物理和地球化学因素(温度、pH和氧化还原水平、碳源、电子受体、电子供体及抑制物).最后分析了多氯联苯厌氧脱氯研究中存在的问题并对其前景进行展望.

Polychlorinated biphenyls（ PCBs） are typical persistent organic pollutants. Their fate in the environment is of great concern. Under anaerobic conditions,certain microorganisms are capable of removing chlorine atoms from PCB molecule. However,although microbial-catalyzed reductive dechlorination is believed to take place in natural sediments,PCB dechlorination activities are influenced by many biogeochemical properties,which make it difficult to control. In this review,dechlorination pathways and eight existing dechlorination processes are discussed,as well as PCB dechlorinating microorganisms, reductive dehalogenases, physical and geochemical factors（ temperature,pH and redox level,available carbon sources,competing electron accepters,supplemented electron donors and inhibitors）. Moreover,difficulties on drawing general conclusions about PCB dechlorination are discussed,as well as the perspective on the application of anaerobic dechlorination in in situ remediation.