Work

The acceleration of localized copper corrosion by extracellular polymeric substances of sulfate-reducing bacteria

Year: 2025

Type: article

Abstract: Microbial-induced corrosion (MIC) of copper pipelines, especially in sulfate-reducing bacteria (SRB)-rich environments, poses a significant challenge. Despite its importance, the role of SRB-secreted extracellular polymeric substances (EPS) in copper corrosion particularly their time-dependent interactions remains unclear. This knowledge gap limits the development of effective corrosion mitigation strategies . In this study, we investigate the impact of EPS on copper corrosion using electrochemical and surface characterization techniques. Our findings reveal that EPS exhibits a dual role in copper corrosion. During the initial immersion phase (1–3 days), EPS adsorption forms a protective layer, temporarily inhibiting corrosion. In the middle stage (4–8 days), EPS accelerates corrosion by degrading the copper oxide film, as evidenced by a negative shift in the breakdown potential ( E b ). In the final stage (9–14 days), uneven EPS coverage exacerbates localized corrosion . Thus, SRB-secreted EPS initially acts as a corrosion inhibitor but later promotes localized corrosion through oxide film disruption and non-uniform coverage. We systematically investigated the mechanisms of EPS-mediated corrosion inhibition across different immersion periods, identifying the critical transition threshold between the inhibition and promotion phases.

Source: Bioelectrochemistry

DOI: 10.1016/j.bioelechem.2025.108980

Authors: Huixuan Qian, Tianguan Wang, Bo Zhang, Guozhe Meng

Institution: Sun Yat-sen University

Language: English

Topic: Corrosion Behavior and Inhibition

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $3,970

Funders: National Natural Science Foundation of China, National Key Research and Development Program of China