Anaerobic Mineralization of Vinyl Chloride in Fe(III)-Reducing, Aquifer Sediments

Within anaerobic aquifer systems, reductive dehalogenation of polychlorinated ethenes commonly results in the accumulation of vinyl chloride, which is highly toxic and carcinogenic to humans. Anaerobic reduction of vinyl chloride is considered to be slow and incomplete. Here, we provide the first evidence for anaerobic oxidation of vinyl chloride under Fe(III)-reducing conditions. Addition of chelated Fe(III) (as Fe−EDTA) to anaerobic aquifer microcosms resulted in mineralization of up to 34% of [1,2-14C]vinyl chloride within 84 h. The results indicate that vinyl chloride can be mineralized under anaerobic, Fe(III)-reducing conditions and that the bioavailability of Fe(III) is an important factor affecting the rates of mineralization.