Interactively interfacial reaction of iron-reducing bacterium and goethite for reductive dechlorination of chlorinated organic compounds

The interactively interfacial reactions between the iron-reducing bacterium (Shewanella decolorationis, S12) and iron oxide (α-FeOOH) were investigated to determine reductive dechlorination transformation of chlorinated organic compounds (chloroform and pentachlorophenol). The results showed that the interactive system of S12+ α-FeOOH exhibited relatively high dechlorination rate. By comparison, the S12 biotic system alone had no obvious dechlorination, and the α-FeOOH abiotic system showed low dechlorination rate. The enhanced dechlorination of chloroform and pentachlorophenol in the interactive system of S12+α-FeOOH was derived from the promoted generation of adsorbed Fe(II) by S12. A decrease in redox potential of the Fe(III)/Fe(II) couple in the interactive reaction system was determined by cyclic voltammetry. Our results will give new insight into interactively interfacial reaction between iron-reducing bacterium and iron oxides for degradation of chlorinated organic compounds under anaerobic condition.