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.