Evaluation of oxidising biocide for biofouling control in cooling water systems

Fouling-induced blockage of process seawater heat exchangers in Madras Atomic Power Station (MAPS) exists in spite of chlorination. A bromine-based biocide (Actibromide) is being used to control fouling in these heat exchangers. Efficacy of this biocide was assessed using biofilms and fouling mussel Modiolus striatulus in the laboratory. Biofilms (48h old) were developed on glass microscopic slides and exposed to O.5mg/L TRO of chlorine and a combination (1:1) of chlorine and actibromide for different contact times. Three different size groups of the fouling mussel M striatulus were also exposed to two concentrations (5mg/L and 9mg/L) of chlorine and the test biocide. The data indicated that chlorine along with actibromide is more effective in killing M. striatulus when compared to chlorine alone. However it is less effective in controlling bacterial films, when compared to chlorine. (author)