Electrochemical investigation of increased carbon steel corrosion via extracellular electron transfer by a sulfate reducing bacterium under carbon source starvation.

Highlights • D. vulgaris is pre-grown on C1018 carbon steel coupons before the starvation test. • Carbon source starvation weakens the SRB biofilm but still increases weight loss. • Weight loss is 6.6 mg/cm2 for 20% carbon source vs. 3.3 mg/cm2 for 100% after 10 d. • Pit depth and electrochemical measurement data corroborate weight loss trend. • Iron corrosion by SRB belongs to extracellular electron transfer MIC (EET-MIC). Abstract Microbiologically influenced corrosion (MIC) of carbon steel by sulfate reducing bacterium (SRB) Desulfovibrio vulgaris under organic carbon starvation was investigated using electrochemical methods to support weight loss and pitting data. 20% carbon source led to the highest weight loss (6.6 mg/cm2), while 100% had the lowest (3.3 mg/cm2) after 10 days. Linear polarization resistance and electrochemical impedance spectrometry data confirmed the weight loss and pitting data trends. The data in this work support the theory that carbon steel corrosion by SRB is due to electron harvest from extracellular iron oxidation by SRB, which belongs to extracellular electron transfer MIC (EET-MIC). [ABSTRACT FROM AUTHOR]