A bromo,nitmpropanediolhsofbiazolone blend (BNPD/ISO) was evaluated in an industrial cooling system to awes its performance and potential man alternative to the oxidizing biocide program (gasous chlorine) currently in use. Finding effective alternatives to gaseous chlorine is important became of safety and handling issues. Furthermore, chlorine has the aasociated problems of increasing cooling water corrosion rates, degradation of wood cooling structures, impaired efficacy at high PH. and sensitivity to organics and reducing agenta in the water. The goals of Ods study were two-fold: First to determine whether BNPD/ISO could be used as a chlorine alternative in an industrial system with equal or better
performance at economically viable use Ievels Second, to develop rapid, effective monitoring for nonoxidizing biocides in this system that would maximize useful application information without consuming large quantities of time and effort. The BNPD/ISO blend controlled the planktonic and sessile microbes in the cooling system. The solution to mcmitoriog nonoxiduing blocides was determined to be ATP technology. ATP monitoring methodology waa compared to standard microbiological field monitoring methods. ATP monitoring provided real-time data and waa found to be an excellent monitor of nonoxidizing biocide efficacy. ATF methodology performed equally well in the presence of chlorine. Results of the effects of biocide on microbes were obtained within one hour after feeding the biocide. The total time needed to process the samples and obtain results was less than ten minutes. Field application data and results are discussed.
Keywords: nonoxidizing biocide, monitoring, ATF technology, chlorine alternative, planktonic bacteria, sessile bacteria, biofilm