Rhamnolipid As an Eco-Friendly Corrosion Inhibitor for Microbiologically Influenced Corrosion

The development of sustainable and non-toxic corrosion inhibitors attracts much attentions. Herein, the rhamnolipid (RH) produced by Pseudomonas aeruginosa was found to effectively inhibit the corrosion of X70 carbon steel in simulated seawater. Moreover, RH was verified to protect X70 carbon steel against the microbiologically influenced corrosion (MIC) caused by Bacillus licheniformis, a typical corrosive bacterium. The addition of 0.1% (m/v) RH reduced the corrosion current density by 68.4% in the presence of B. licheniformis compared with untreated condition. The growth of B. licheniformis was significantly inhibited with RH concentration higher than 125 mg/L. The antimicrobial and corrosion inhibition effects make RH suitable for MIC inhibition.