The effect of triazoloazepine bromide with biocidal activity on microbial copper corrosion

Abstract

The study deals with the effect of triazoloazepine bromide with biocidal activity against sulfate-reducing bacteria on microbial copper corrosion in neutral water–salt Postgate “B” medium with the enrichment culture of bacteria, isolated from the biofilm, formed on the metal surfaces of sewage treatment facilities. It has been established that the studied substance also inhibits the growth of iron-reducing bacteria, denitrifying bacteria and ammonifying bacteria, which ensure the stable growth of the most numerous and aggressive constituent of the enrichment culture – sulfate-reducing bacteria. It has been demonstrated that triazoloazepine bromide increases the redox potential of the corrosive medium by up to 170 mV. This enables the change of enzymatic reactions direction and considerable inhibition of sulfate-reducing activity of the enrichment culture bacteria. The morphology of the copper coupons surface after the exposure to the corrosive medium with bacterial sulfate-reduction has been examined. It has been defined that without triazoloazepine bromide the biofilm is a chaotic accumulation of bacteria in the polymeric matrix. In the presence of triazoloazepine bromide, only individual bacteria can be observed in the corrosive medium on the surface of the biofilm, which has a loose structure. It has been estimated that triazoloazepine bromide decreases the rate of microbial copper corrosion by a factor of 11.7.