CMC修饰硫化纳米零价铁耦合功能微小菌群对地下水中氯代烃的协同降解机制

针对以往去除地下水中氯代烃“纳米零价铁（nZVI）-微生物”耦合技术存在的nZVI易钝化、易团聚，电子利用率低，及nZVI-单一细菌耦合难以实现氯代烃高效、持续降解问题，本项目可控合成羧甲基纤维素修饰硫化纳米零价铁（CMC-S-nZVI），筛选新型功能微小细菌有机卤化物呼吸细菌（OHRB）和异化铁还原菌（DIRB），优化耦合试验参数，构建CMC-S-nZVI耦合OHRB及DIRB协同降解模拟地下水中典型氯代烃强化去除技术，考察去除性能。借助多种表征手段研究杂化功能材料界面复合结构；采用TEM、FCM分析细菌形貌变化及生长特性；通过气质联用仪等识别降解产物中间物种。进一步借助宏基因组学、宏转录组学和代谢组学多组学关联分析，构建代谢网络图，阐明CMC-S-nZVI耦合功能微小菌群对氯代烃的协同降解机制。本研究将为地下水中氯代烃高效、持续降解提供理论依据和技术支撑，为氯代烃原位修复提供新思路。

In previous “nanoscale zero-valent iron (nZVI)-microorganism” coupling technology, nZVI is easy to passivate, aggregate, and has low electron utilization efficiency, as well as nZVI coupling with single bacterium is difficult to achieve efficient, continuous degradation of chlorinated hydrocarbons in groundwater. This project aims to synthesize controllably carboxymethyl cellulose modified sulfidated nanoscale zero-valent iron (CMC-S-nZVI), and to isolate new functional ultramicrobacteria (organohalide-respiring bacteria and dissimilatory iron reducing bacteria). Then, the coupling experimental parameters are optimized, so as to construct an enhanced removal technology for typical chlorinated hydrocarbons in simulated groundwater through CMC-S-nZVI coupling OHRB and DIRB, and further to investigate its removal performance. Moreover, the interfacial composite structure of hybrid functional material is studied by means of various characterization methods, the morphology and growth characteristics of the ultramicrobacteria are analyzed by TEM and FCM, and the intermediate species of degradation products are explored by gas chromatography-mass spectrometry analysis, etc. Additionally, the metabolic map will be constucted through the association analysis of metagenomics, metabonomics and metabonomics. Finally, the synergistic degradation mechanism of CMC-S-nZVI coupling functional ultramicrobacteria can be clarified. This project will provide theoretical basis and technical support for the efficient and continuous degradation of chlorinated hydrocarbons in groundwater, and offer a new idea for the in situ remediation of chlorinated hydrocarbons.