Biofilm formation on copper and its control by inhibitor/biocide in cooling water environment.

Abstract

The present study has successfully identified the nitrate reducing bacteria present in the cooling water system and also investigated the performance of industrially applied biocide and inhibitor on the bacterial inhibition. In order to carry out the objective of this study, facilities and methods such as 16S rRNA gene sequencing, Lowry assay, SEM, EIS, ICP-MS and weight loss analysis were being utilized. In this study, two out of the five morphologically dis- similar colonies identified through 16S rRNA gene sequencing, namely the Massilia timonae and the Pseudomonas, were being utilized in the biocorrosion study on copper metal. From the surface analysis using SEM demonstrated the phenomenon of biofilm formation on the copper surface. 2-methylbenzimidazole has the addition of methyl group in the diazole ring position of benzimidazole it has create basicity environment and inhibit the metal deterioration. Meanwhile, it is also deducible from the EIS and protein analysis that com- bination of biocide with either of the inhibitors gives rise to better biocorrosion suppression (0.00178 mpy and 0.00171mpy) as compared to the sole effect of either biocide or inhibitor (0.00219 mpy, 0.00162 and 0.00143). Biocorrosion system biocide with MBM was found to exhibit 65% corrosion inhibition efficiency. Moreover, adoption of 2-Methylbenzimidazole seems to display better performance as compared to Multionic 8151, which is adopted in cooling water system.