Microbiologically influenced corrosion of NiZn alloy coatings by Delftia acidovorans bacterium

In this study, Delftia acidovorans was isolated from water treatment pipe system and used to demonstrate microbiologically influenced corrosion of NiZn alloy coatings using electrochemical techniques. The surface morphologies and the corrosion products were determined using scanning electron microscopy (SEM) and energy dispersive X-ray spectra (EDS) analysis. Results showed that when the metabolic activity reached maximum level, corrosion activity of NiZn alloy coatings significantly increased in correlation with Ecorr, Icorr, QCM and Rct. Furthermore, crevice corrosion which has been seen due to bacterial adhesion confirms that D. acidovorans plays an important role in corrosion of NiZn alloy coating.

► Delftia acidovorans isolated from water treatment pipe system.
► Bacterium attached to the alloy coatings.
► Ecorr exhibited cathodic shift.
► Mass loss reached highest value after inoculation.
► Crevice corrosion was observed on the surface due to bacterium.