Infectivity reduction efficacy of UV irradiation and peracetic acid-UV combined treatment on MS2 bacteriophage and murine norovirus in secondary wastewater effluent.

Peracetic acid (PAA)is a strong oxidant/bactericide that has been applied in various industries (e.g., food processing, pharmaceuticals, medical device sterilization, etc.)as a disinfectant. There is increasing interest in using PAA for wastewater disinfection because it does not form halogenated byproducts, and no post-treatment quenching is required. Previous studies have demonstrated good efficiency in controlling bacteria in wastewater, but limited information is available for viruses, especially those hosted by mammals (e.g., norovirus). Therefore, a study on the infectivity reduction of murine norovirus (MNV)was undertaken to evaluate the disinfection efficacy of PAA or UV alone and in combination with UV irradiation in undisinfected secondary effluent from a municipal wastewater reclamation facility (MWW)and phosphate buffer solution (PBS)at pH 7. Experiments employing MS2 bacteriophage were also performed in parallel for comparison purposes. MS2 infectivity reduction was found to be lower than MNV infectivity reduction for each condition studied - PAA, PAA + UV, and UV disinfection. These data suggest that MS2 may not be an appropriate surrogate to accurately predict the reduction of MNV infectivity.