1,2,3-三氯丙烷降解机制与污染场地修复技术研究进展

Advances in degradation mechanisms of 1,2,3-trichloropropane and remediation technology of contaminated sites

摘要:

1,2,3-三氯丙烷 (1,2,3-trichloropropane，1,2,3-TCP) 是一种人工合成的脂肪族氯代烃，在工、农业生产中得到广泛应用。1,2,3-TCP作为环氧氯丙烷工业生产的中间产物，可作为前体物质用于生产土壤熏蒸剂、有机溶剂等。因其环境持久性、迁移性和生态毒性，国内外机构逐渐开始关注该有机氯污染物的环境归趋、生态健康风险和环境管控。当前，1,2,3-TCP污染物的降解与场地修复仍然是研究热点，但是对于1,2,3-TCP降解转化机制尚缺乏深入研究与总结。鉴于此，文中在讨论1,2,3-TCP的来源、环境污染、生态效应及物理化学降解方法与技术等的基础上，进一步综述了1,2,3-TCP的微生物降解与修复机制 (如好氧共代谢降解、厌氧降解等)；重点讨论了地下水等厌氧环境中1,2,3-TCP的厌氧微生物降解转化途径与机制，并从热力学角度论证了厌氧条件下1,2,3-TCP作为电子受体被有机卤呼吸微生物利用并降解的可行性；最后，对1,2,3-TCP污染场地原位生物修复进行了总结并对未来研究发展方向进行了展望。

Abstract:

1,2,3-trichloropropane (TCP) is an industrially synthesized aliphatic chlorinated hydrocarbon and an intermediate product in the industrial production of epichlorohydrin, which can be used as a precursor for the manufacture of soil fumigant and organic solvents. Due to its biological toxicity, environmental persistence and strong environmental migration ability, 1,2,3-TCP is listed as an emerging organochlorine pollutant in the environment and regulated by many international organizations. Currently, the degradation of 1,2,3-TCP and the remediation of 1,2,3-TCP-contaminated sites receive great attention, but the degradation mechanism of 1,2,3-TCP has not been summarized in depth. This article discussed the origin of 1,2,3-TCP, its environmental impact and ecological effects, and the physical and chemical degradation techniques. This was followed by summarizing the degradation mechanisms of 1,2,3-TCP (e.g., aerobic co-biodegradation, anaerobic biodegradation). Specially, the pathways and mechanisms of microbial biodegradation and transformation of 1,2,3-TCP in anoxic environments (e.g., groundwater) were thoroughly reviewed. The feasibility of using 1,2,3-TCP as an electron acceptor by organohalide-respiring bacteria under anoxic conditions was predicted based on thermodynamic analysis. Last but not least, in situ bioremediation of 1,2,3-TCP contaminated sites was summarized, and prospects for future research were discussed.