Effects of ferrous ion concentration on microbiologically influenced corrosion of carbon steel by sulfate reducing bacterium Desulfovibrio vulgaris

Abstract

Abstract Ferrous ion (Fe2+) in a sulfate reducing bacteria (SRB) culture medium is known to enhance microbiologically influenced corrosion (MIC) of carbon steel, but the underlining mechanism is controversial. This work showed that it was due to better sessile cell growth that was likely attributed to Fe2+ detoxification of H2S. Two hundred ppm (w/w) initial Fe2+ in the ATCC 1249 medium achieved a 4.7 times higher Desulfovibrio vulgaris sessile cell count and 5.0 times higher C1018 carbon steel weight loss, compared to 20\u2009ppm. Linear polarization resistance, electrochemical impedance spectroscopy and potentiodynamic polarization measurements corroborated weight loss and pitting data trends.