Nanoscale zero-valent iron (nZVI) is recognized as a powerful tool for the remediation of groundwater contaminated by chlorinated ethenes (CEs). This long-term field study explored nZVI-driven degradation of CEs supported by electrokinetic (EK) treatment, which positively affects nZVI longevity and migration, and its impact on indigenous bacteria. In particular, the impact of combined nZVI-EK treatment on organohalide-respiring bacteria, ethenotrophs and methanotrophs (all capable of CE degradation) was assessed using molecular genetic markers detecting Dehalococcoides spp., Desulfitobacterium spp., the reductive dehalogenase genes vcrA and bvcA and ethenotroph and methanotroph functional genes. The remediation treatment resulted in a rapid decrease of the major pollutant cis-1,2-dichloroethene (cDCE) by 75% in the affected area, followed by an increase in CE degradation products methane, ethane and ethene. The newly established geochemical conditions in the treated aquifer not only promoted growth of organohalide-respiring bacteria but also allowed for the concurrent presence of vinyl chloride- and cDCE-oxidizing methanotrophs and (especially) ethenotrophs, which proliferated preferentially in the vicinity of an anode where low levels of oxygen were produced. The nZVI treatment resulted in a temporary negative impact on indigenous bacteria in the application well close to the cathode; but even there, the microbiome was restored within 15 days. The nZVI-EK treatment proved highly effective in reducing CE contamination and creating a suitable environment for subsequent biodegradation by changing groundwater conditions, promoting transport of nutrients and improving CE availability to soil and groundwater bacteria.

纳米级零价铁（nZVI）被公认为是补救被氯化乙烯（CEs）污染的地下水的有力工具。这项长期的现场研究探索了电动（EK）处理支持的nZVI驱动的CE降解，这对nZVI的寿命和迁移及其对本地细菌的影响产生了积极影响。尤其是，使用检测Dehalococcoides spp。，Desulfitobacterium spp。，还原性脱卤素酶基因vcrA和bvcA的分子遗传标记评估了nZVI-EK联合治疗对呼吸有机卤化物的细菌，种族营养和甲烷营养（均能降解CE）的影响。以及人类营养和甲烷营养功能基因。补救治疗导致主要污染物的迅速下降顺受灾地区的-1,2-二氯乙烯（cDCE）增长了75％，其次是CE降解产物甲烷，乙烷和乙烯的增加。在处理过的含水层中新建立的地球化学条件不仅促进了吸入有机卤化物的细菌的生长，而且还允许同时存在氯乙烯和cDCE氧化的甲烷营养生物和（尤其是）乙烯营养生物，它们优先在阳极附近扩散，产生了低水平的氧气。nZVI处理对靠近阴极的应用中的本地细菌产生了暂时的负面影响；但即使在那儿，微生物组也能在15天内恢复。nZVI-EK处理被证明在减少CE污染方面非常有效，并通过改变地下水条件为随后的生物降解创造了合适的环境，