水中三氯生的处理方法及主要降解路径研究进展

Research Progress of Triclosan Treatment Methods and Analysis of Main Degradation Pathways

三氯生(TCS)是一种新型污染物,会对生态环境和人体健康造成严重危害,TCS的无害化处理受到广泛关注。该文概述了物理吸附、生物处理、化学还原及化学氧化处理TCS的优缺点,并提出对应的改进方向。同时,汇总分析了不同方法下TCS的主要降解产物,其中2,4-二氯苯酚、氯酚和苯酚是所有方法的共性产物。由此,归纳出TCS在不同处理方法中的主要降解路径:(1)生物处理法利用微生物自身产生的电子穿梭体作为载体,将胞内电子传至胞外受体TCS,最终将TCS还原成含有多个TCS骨架结构的复杂有机物;(2)化学还原法通过逐级加氢还原脱氯作用生成低氯或无氯产物;(3)化学氧化法通过醚键断裂和苯环直接羟基化2条路径生成不同的含氯产物,含氯产物进一步发生氧化开环反应实现脱氯,直至完全矿化。该文的研究成果可为今后TCS绿色无害化处理方法的开发和选择提供一定的借鉴和参考。

Triclosan(TCS)is a new type of pollutant that can cause serious harm to the ecological environment and human health,and the harmless treatment of TCS has received widespread attention.In this study,the advantages and disadvantages of physical adsorption,biological treatment,chemical reduction and chemical oxidation treatment of TCS were summarized,and the corresponding improvement directions were proposed.Meanwhile,the main degradation products of TCS under different methods were summarized and analyzed,among them,2,4-dichlorophenol(2,4-DCP),chlorophenol and phenol were common degradation products during different process methods.Therefore,the main degradation pathways of TCS in different treatment methods include:(1)The biological treatment method uses the electron shuttle produced by the microorganism itself as a carrier to transfer the intracellular electrons to the extracellular receptor TCS,and finally TCS was reduced into a complex organic products containing multiple TCS skeleton structures;(2)The chemical reduction method generates low-chlorine or non-chlorine products through stepwise hydrogenation reduction and dechlorination;(3)The chemical oxidation method generates different chlorine-containing products through two pathways containing of ether bond cleavage and direct hydroxylation of the benzene ring.The chlorine-containing products further undergo ring-opening reaction to achieve dechlorination and complete mineralization.The research results are expected to provide a certain reference for the development and selection of TCS green and harmless treatment methods in the future.