Effect of W–TiO2 composite to control microbiologically influenced corrosion on galvanized steel

• Published in: Applied microbiology and biotechnology 2013-06, Vol.97 (12), p.5615-5625
• Main Authors: Basheer, Rubina, Ganga, G., Chandran, R. Krishna, Nair, G. M., Nair, Meena B., Shibli, S. M. A.
• Format: Article
• Language: English
• Subjects: Alloys - chemistry; Alloys - pharmacology; Analysis; Anti-Bacterial Agents - chemistry; Anti-Bacterial Agents - pharmacology; Antifouling substances; Bacteria; Bacteria - drug effects; Bacteria - growth & development; Bacteria - metabolism; Bacterial Physiological Phenomena; Bacteriological Techniques; Biofilms; Biofilms - drug effects; Biofilms - growth & development; Biomedical and Life Sciences; Biotechnology; Cathodic corrosion; Chemical analysis; Chemical composition; Corrosion; Distilled water; Electrochemistry; Environmental Biotechnology; Galvanized steel; Life Sciences; Metal oxides; Metals; Microbial corrosion; Microbial Genetics and Genomics; Microbiology; Microorganisms; Microscopy, Electron, Scanning; Natural environment; Phenols; Plating; Radiation; Scanning electron microscopy; Seawater; Spectrometry, X-Ray Emission; Steel; Studies; Titanium - chemistry; Titanium - pharmacology; Titanium dioxide; Tungsten - chemistry; Tungsten - pharmacology; Water analysis; X-ray spectroscopy; Zinc
• ISSN: 0175-7598; 1432-0614
• DOI: 10.1007/s00253-012-4389-1

Microorganisms tend to colonize on solid metal/alloy surface in natural environment leading to loss of utility. Microbiologically influenced corrosion or biocorrosion usually increases the corrosion rate of steel articles due to the presence of bacteria that accelerates the anodic and/or cathodic corrosion reaction rate without any significant change in the corrosion mechanism. An attempt was made in the present study to protect hot-dip galvanized steel from such attack of biocorrosion by means of chemically modifying the zinc coating. W–TiO 2 composite was synthesized and incorporated into the zinc bath during the hot-dipping process. The surface morphology and elemental composition of the hot-dip galvanized coupons were analyzed by scanning electron microscopy and energy dispersive X-ray spectroscopy. The antifouling characteristics of the coatings were analyzed in three different solutions including distilled water, seawater, and seawater containing biofilm scrapings under immersed conditions. Apart from electrochemical studies, the biocidal effect of the composite was evaluated by analyzing the extent of bacterial growth due to the presence and absence of the composite based on the analysis of total extracellular polymeric substance and total biomass using microtiter plate assay. The biofilm-forming bacteria formed on the surface of the coatings was cultured on Zobell Marine Agar plates and studied. The composite was found to be effective in controlling the growth of bacteria and formation of biofilm thereafter.