Sulphate reducing bacteria influenced corrosion of a low carbon steel in marine environment: the role of dissolved organic carbon and temperature

Sulphate Reducing Bacteria (SRB) are significant contributors to corrosion in marine environments. The corrosion induced by SRB can be influenced by the concentration of Dissolved Organic Carbon (DOC) in the media. In this study, we experimentally investigated the synergistic effects of DOC, temperature, and exposure time on the corrosion rate and morphology of a low-carbon steel in seawater containing SRB. The results showed that the corrosion rate was inversely proportional to the DOC concentration up to 25 days, but directly proportional for the subsequent 100 days of exposure, up to 125 days. There was no significant effect of temperatures between 15 and 25 °C on the corrosion rate. Localised corrosion activity of the SRB was found to be influenced by the heterogeneity of porous biofilm-corrosion product matrix on the steel surface. • Sulphate Reducing Bacteria (SRB) increased the corrosion rate of carbon steel in seawater at 15 °C and reduced the rate from 20 to 25 °C. • SRB produces biofilm that acts as a barrier against temperature effects on carbon steel corrosion. • SRB influenced corrosion rate is inversely proportional to Dissolved Organic Carbon (DOC) concentration up to 25 days and directly proportional to DOC concentration from 90 to 125 days.