Inactivation of Escherichia coli and coliphage MS-2 by chloramine and copper

Abstract

The efficacy of chloramine in the presence of copper chloride was evaluated for the inactivation of an indicator bacteria Escherichia coli and coliphage MS-2. Both microorganisms were exposed to chloramine with and without copper chloride. Results showed an increase in the inactivation rate of Escherichia coli and MS-2 phage with an increasing concentration of chloramine. To achieve a 99 percent reduction in the number of Escherichia coli, an exposure of 46, 21, 6, and 5 minutes was necessary for 1, 2.5, 5, and 10 mg chloramine/L, respectively. A 99 percent reduction of MS-2 phage occurred after 60 and 25 minutes of exposure to 5 and 10 mg chloramine/L. Chloramine in the presence of copper increased the inactivation rate of Escherichia coli and MS-2 phage. The time needed for 99 percent inactivation of E. coli and MS-2 phage was reduced. Copper increases the inactivation rate of bacteria and viruses by chloramine. (Abstract shortened with permission of author.)