Corrosion behavior of copper under biofilm of sulfate-reducing bacteria

• Sulfate-reducing bacteria tolerate copper toxicity and adhere to form biofilm.
• Sulfate-reducing bacteria promote localized corrosion of copper.
• Corrosion of copper is related to metabolic activity of sulfate-reducing bacteria.
• Mechanism of copper corrosion induced by sulfate-reducing bacteria is illuminated.

The effect of sulfate-reducing bacteria (SRB) on corrosion behavior of copper was investigated using surface analysis and electrochemical measurements in seawater. Results demonstrated that SRB adhere onto copper surface to form biofilm and that the resulting corrosion product is mainly composed of cuprous sulfide. Cuprous sulfide and EPS are helpful for SRB adhesion on copper by providing a barrier against copper toxicity. In SRB growth cycle, corrosion rate is related to metabolic activity. Especially during exponential growth and stationary phases, SRB metabolism decreases the anodic zone area and promotes localized corrosion of copper.