Corrosion Behaviour of Carbon Steel in Sea Water Medium in Presence of P-aeruginosa Bacteria

The present paper aims to investigate on corrosion behaviour of carbon steel in the nutrient-rich simulated sea water medium in presence of Pseudomonas aeruginosa bacteria. Different techniques such as scanning electron microscopy (SEM), visual inspection, X-ray diffraction (XRD) and weight loss measurement were used to characterize the corrosion products and biofilm layer. The SEM results show the formation of filamentous heterogeneous biofilm layer on the steel substrate due to presence of P. aeruginosa bacteria in a medium. The visual inspection preliminary results show the more severe corrosion damages occurred on the steel substrate exposed to bacteria-contained medium compared with the steel substrate immersed in the sterile medium. The weight loss results show that the corrosion rate of steel substrates in bacteria-contained medium was around 1.6 times higher than corrosion rate of steel substrates in sterile medium indicating the aggressive role of bacteria on corrosion acceleration. XRD results show that the corrosion products are composed of FeOOH, FeO, Fe3O4 and FeO center dot Fe2O3 due to metabolism activity of the bacteria. From the present study, it is inferred that bacterium. P. aeruginosa is responsible for severe corrosion of steel substrate in the sea water medium.