Investigation of the effect of 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one inhibition on the corrosion of carbon steel in Bacillus sp. inoculated artificial seawater

The antibacterial activity and corrosion inhibition effect of 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one is studied for carbon steel immersed in artificial seawater. Results showed that this compound produced a good antibacterial activity against the metal-oxidizing bacteria. Also the electrochemical studies indicated that it totally owned a very good inhibition effect in artificial seawater with and without bacteria. Equivalent circuits have two time constants in the presence of biocide, which suggests that an adsorption layer is produced on the metal surface and thickened by varying the exposure time, as two maxima could be observed in the Bode phase plots after 12 h.

► The corrosion inhibition and antibacterial activity of isothiazolin were studied.
► An efficient inhibitory corrosion effect is showed with increasing concentration.
► The small change in Ecorr, showed that this biocide acts as a mixed-type inhibitor.
► The mechanism of inhibition is creating an adsorption layer on the metal surface.