Accelerated cathodic reaction in microbial corrosion of iron due to direct electron uptake by sulfate-reducing bacteria

作者：Hendrik Venzlaff, Dennis Enning, Jayendran Srinivasan, Karl J. J. Mayrhofer, Achim Walter Hassel, Friedrich Widdel, Martin Stratmann · 发表于：Corrosion Science · 年份：2012 · DOI：10.1016/j.corsci.2012.09.006 · 被引用次数：500 · 研究领域：Corrosion Behavior and Inhibition、Metal Extraction and Bioleaching、Microbial Fuel Cells and Bioremediation

Microbially influenced iron corrosion by sulfate-reducing bacteria (SRB) is conventionally attributed to the chemical corrosiveness of H2S, facilitated abiotic H+-reduction at deposited FeS, and biological consumption of chemically formed (‘cathodic’) H2. However, recent studies with corrosive SRB indicated direct consumption of iron-derived electrons rather than of H2 as a crucial mechanism. Here, we conducted potentiodynamic measurements with iron electrodes colonized by corrosive SRB. They significantly stimulated the cathodic reaction, while non-corrosive yet H2-consuming control SRB had no effect. Inactivation of the colonizing bacteria significantly reduced current stimulation, thus confirming biological catalysis rather than an abiotic cathodic effect of FeS.