Influence of NaCl concentration on microbiologically influenced corrosion of carbon steel by halophilic archaeon Natronorubrum tibetense.

The influence of NaCl concentration on microbiologically influenced corrosion (MIC) of Q235 carbon steel by the halophilic archaeon Natronorubrum tibetense was investigated by immersion tests and electrochemical measurements. An increase in NaCl concentration from 0 g/mL to 0.1 g/mL promoted the anodic dissolution of carbon steel and accelerated its corrosion, but MIC did not occur. A further increase in NaCl concentration to 0.2 g/mL led to MIC in inoculated medium, and the occurrence of the MIC resulted in further aggravation of carbon steel corrosion. Once the NaCl concentration reached 0.3 g/mL, the high concentration of chloride ions greatly interfered with the adsorption of dissolved oxygen and the attachment of N. tibetense cells to the surface of carbon steel, thus reducing the corrosion rate of carbon steel and inhibiting the MIC.