title: Inactivation of MS2 coliphage by UV and hydrogen peroxide: comparison by cultural and molecular methodologies.
abstract: The use of advanced oxidation processes (AOP) are expected to increase for removal of emerging contaminants and pathogens from drinking water. In this study, the performance of a small community ultraviolet light reactor in combination with hydrogen peroxide (H2O2) for MS2 coliphage inactivation with two different flow rate conditions of 1 gal/min (gpm) and 2 gpm was evaluated. Following UV radiation, MS2 showed a reduction of 5.3-5.8 log10 when quantified with cultural plaque counts, whereas corresponding quantitative polymerase chain reaction (qPCR) data showed only a 1.7-2.8 log10 reduction in viral RNA copy number. When H2O2 was added at either 2.5 or 5 ppm with UV at both flow rate conditions, enhanced MS2 inactivation occurred with a more than 7 log10 reduction observed via plaque counts, indicating that all added MS2 had been inactivated, since no plaques were formed after incubation at 37 °C for 24 h. In contrast, qPCR only showed a corresponding 3-4 log10 reduction in viral RNA copy number. This research also sheds light on the inactivation of MS2 with ultraviolet light and in the presence of hydroxyl radicals and provides a practical use of qPCR to detect MS2 concentration following advanced oxidation relative to traditional plaque methodology; however qPCR detection overestimates the true number of infective virus.
authors.affiliation: a Department of Soil, Water, and Environmental Science , University of Arizona , Tucson , Arizona , USA.
authors.forename: Samendra P
authors.initials: SP
authors.lastname: Sherchan
authors.forename: Shane A
authors.initials: SA
authors.lastname: Snyder
authors.forename: Charles P
authors.initials: CP
authors.lastname: Gerba
authors.forename: Ian L
authors.initials: IL
authors.lastname: Pepper
mesh_terms: D006861:Hydrogen Peroxide / Q000494:pharmacology*; D007700:Kinetics; D017909:Levivirus / Q000187:drug effects* / Q000235:genetics / Q000528:radiation effects*; D010084:Oxidation-Reduction; D012367:RNA, Viral / Q000032:analysis; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods*; D014466:Ultraviolet Rays; D014773:Virology / Q000379:methods*; D038301:Virus Inactivation / Q000187:drug effects* / Q000528:radiation effects; D014871:Water Microbiology; D018508:Water Purification / Q000379:methods*
chemical_list: D012367:RNA, Viral; D006861:Hydrogen Peroxide