The performance and mechanism of bifunctional biocide sodium pyrithione against sulfate reducing bacteria in X80 carbon steel corrosion

Anti-bacterial and anti-corrosion properties of sodium pyrithione (SPT) were studied using experimental methods and quantum chemical calculations. SPT at 80 mg/L reduced planktonic and sessile sulfate reducing bacteria (SRB) on X80 carbon steel to undetectable levels. The corrosion inhibition efficiency of SPT against microbiologically influenced corrosion exceeded 80% based on weight loss, which was corroborated by electrochemical data. Molecular modeling showed that SPT molecule provided electrons to the unoccupied orbitals of the Fe surface with a large binding energy of SPT on the Fe (1 1 0) plane, which favored SPT adsorption on the carbon steel.