Dual corrosion promotion of pipeline steel in sea mud induced by sulfate reducing bacteria: Bacteria concentration cell and electronic conduction of the biofilms covered sand grains

Abstract

The microbiologically influenced corrosion (MIC) of X80 carbon steel in sea mud by sulfate reducing bacteria (SRB) was investigated and two unique MIC promotion mechanisms in sea mud were identified. For carbon steel at the seawater-mud interface, difference in the concentrations of sessile cells enhanced galvanic effect between the regions in seawater and sea mud, with the carbon steel in sea mud serving as the anode. SRB in sea mud established significant biofilms on sand grains, enabling the SRB attached on sand grains to participate in the biocatalytic cathodic process of MIC by the contact between sand grains and metal.