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

[Display omitted] •Molecular simulation confirms that sodium pyrithione (SPT) inhibits iron corrosion.•SPT is found to inhibit planktonic and sessile sulfate reducing bacteria (SRB).•SRB corrosion rate in simulated oilfield produced water is reduced by SPT.•SRB corrosion weight loss data are corroborated by electrochemical measurements. 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.