Effects of Ag and Cu ions on the microbial corrosion of 316L stainless steel in the presence of Desulfovibrio sp.
By Unsal, Tuba; Ilhan-Sungur, Esra; Arkan, Simge; Cansever, Nurhan
Published in Bioelectrochemistry
2016
Abstract
Abstract The utilization of Ag and Cu ions to prevent both microbial corrosion and biofilm formation has recently increased. The emphasis of this study lies on the effects of Ag and Cu ions on the microbial corrosion of 316L stainless steel (SS) induced by Desulfovibrio sp. Electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization were used to analyze the corrosion behavior. The biofilm formation, corrosion products and Ag and Cu ions on the surfaces were investigated using scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDS) and elemental mapping. Through circuit modeling, {EIS} results were used to interpret the physicoelectric interactions between the electrode, biofilm and culture interfaces. {EIS} results indicated that the metabolic activity of Desulfovibrio sp. accelerated the corrosion rate of {SS} in both conditions with and without ions. However, due to the retardation in the growth of Desulfovibrio sp. in the presence of Ag and Cu ions, significant decrease in corrosion rate was observed in the culture with the ions. In addition, {SEM} and {EIS} analyses revealed that the presence of the ions leads to the formation on the {SS} of a biofilm with different structure and morphology. Elemental analysis with {EDS} detected mainly sulfide- and phosphorous-based corrosion products on the surfaces.