Biological corrosion prevention in water and wastewater installations by application of TiO2 nano particles coating

All countries around the world are spending a large amount of their national gross income to prevent corrosion or to cope with effects of that every year which often costs about 1% to 5% of their total national gross product. Microbiologically-influenced corrosion (MIC) is one of corrosion type which includes 40% of corrosion loss. Thus application of new technologies is necessary in order to reduce effects of biological corrosion and facing its effects. Considering the fact that MIC has a large portion of the corrosion damage, this research focused on this type of corrosion.In this research we tried to prevent formation of a biofilm layer which is the major reason of biological corrosion by using TiO2 coating. TiO2 is a photocatalyst material which can produce free hydroxyl radicals and super oxide ion by receiving energy from UV light irradiation. These produced radicals are very strong oxidants which cause oxidation of organic materials, penetration in and deterioration cellular membrane and cause annihilation of microorganisms and at last prevents the biological layer growth. In this research, TiO2 thin films with antibacterial activity were prepared on glass slides (2.5×10cm2) by using sol–gel method. Samples with TiO2 coating and control samples without TiO2 coating, placed in the water containing various kinds of microorganism exposed to UV irradiation. To study the thickness and the amount of biofilm formation the weighting method has been applied. After 30 days monitoring the control samples were covered by biofilm and this layer thickened. After analyzing data, it was shown that the growth of biofilm on the coating samples is fewer than the control samples. So their study shows that using of TiO2 coating is an effective way for prevention MIC.

Keywords:

Microbial Influence Corrosion (MIC) , TiO2 , Biofilm , weighting method