AWWA WQTC55151

Numerous studies have been published defining the experimental methodologies to be used when determining disinfection efficacy. However, these studies have focused primarily on reactor design and accurate measurement of the disinfectant in question, with no regard to the effects of production and handling of the microorganisms used in these studies. Bacteriophage MS2 is a single stranded RNA virus that has been used to provide information concerning the performance of water treatment processes such as coagulation, flocculation, filtration and disinfection. Due to the high cost and technical expertise required to assay enteric viruses, the water industry has chosen to use bacterial viruses such as MS2 as surrogates because of their similarity in size, shape and structure to enteric viruses. While MS2 has been used extensively to characterize disinfection processes, consistent methodologies for phage preparation or handling have not been practiced. Methods of bacteriophage production and the age of the organisms when used may significantly effect the sensitivity of the organism to chemical disinfectants. The sensitivity of bacteriophage MS2 to chemical disinfectants such as chlorine may change by several orders of magnitude based upon the age of the phage preparation at the time of the assay. Includes 16 references.