Effects of metabolic activity of sulphate‐reducing bacteria on heterogeneous corrosion behaviors of copper in seawater

Abstract

In this paper, wire beam electrode method combined with other analysis methods, that is, electrochemical impedance spectroscopy, scanning electron microscope, and X‐ray photoelectron spectroscopy, was used to investigate effects of metabolic activity of sulphate‐reducing bacteria (SRB) on heterogeneous corrosion behaviors of copper in seawater. Results show that heterogeneous corrosion behaviors of copper are associated with metabolic activity of SRB, that is, the higher metabolic activity of SRB is, the more heterogeneously current of copper distributes. In particularly, on the 5th day of exposure, SRB cells on cathodic and anodic areas display distinct micromorphologies. SRB attach onto corrosion products film surface in anodic area, while they implant in corrosion products film with self‐produced organic nanowires in cathodic area. These organic nanowires may be conductive, and help SRB to obtain electrons from cathodic area directly. The XPS results show that the relative content of corrosion products components on cathodic area is obviously different with that on anodic area when SRB with the high metabolic activity are present.