土壤还原过程对氯代有机污染物还原脱氯的影响与机制

摘要

自然环境中,大多数氯代有机污染物厌氧还原脱氯反应是与土壤环境中一些生源要素的生物化学还原过程相伴生.有机污染物的种类、生物有效性以及毒性能够显著影响这些生源要素的转化,反过来,土壤中活跃的氧化还原反应也可以显著影响有机污染物的动力学转化过程.本文从氧化还原顺序上综述了反硝化过程、铁还原过程、硫酸盐还原过程和产甲烷过程对氯代有机污染物厌氧还原脱氯过程的影响与作用机制,旨在为氯代有机污染物在厌氧环境中还原脱氯的过程与机理的进一步研究、以及还原脱氯与微生物介导的生源要素氧化还原过程的耦合作用机制的揭示提供参考.%Under anaerobic conditions,reductive dechlorination of chlorinated organic pollutants is thought to be coupled to biogeochemical processes of some biogenic elements in soil.The variety,bio-availability and toxicity of organic pollutants can significantly affect the transformation of the biogeochemical processes.Correspondingly,soil natural active redox processes can also significantly affect the dynamics of organic pollutant transformation.Based on the classical redox reactions sequence,the effects and mechanisms of denitrification process,dissimilatory iron reduction process,sulfate reduction process and methanogenic process on reductive dechlorination of chlorinated organic pollutants were reviewed and discussed in this paper.We also provided reference for the further study to disclose more in-depth mechanism regarding reductive dechlorination and their interaction with the co-occurring natural redox processes in soil under anaerobic environment.