AWWA JAW60136

With MS2 coliphage the most commonly used test microbe for ultraviolet (UV) reactor validation in North America, the development of UV dose-response data for MS2 on the bench scale is an integral part of validation testing. In this research, the effects of water quality and sample depth on inactivation of MS2 coliphage were evaluated for 17 filtered waters. The study also compared the inactivation performance of low-pressure (LP) and medium-pressure (MP) lamp types. Study findings indicated that at the UV doses customarily used in water treatment, turbidity and particle count and size do not significantly affect LP and MP disinfection efficiency of seeded MS2 in filtered water. UV light from MP lamps appeared more effective than LP UV for inactivating MS2, but additional research is necessary to determine if MP UV is actually more effective or if the MP dose calculation method needs further refinement. The authors recommend that bench testing performed as part of a biodosimetry reactor validation test protocol set a maximum sample depth of 1 cm, use LP monochromatic UV lamps, and follow accepted irradiance correction methods. UV light irradiation is recognized as a proven method for disinfecting water supplies. This study offers water providers tools to evaluate the use of MS2 coliphage for the bench-scale testing component of UV reactor testing. In addition, research results should help increase utility confidence in the use of MS coliphage for UV reactor validation in filtered waters.