title: Inactivation of Aspergillus flavus in drinking water after treatment with UV irradiation followed by chlorination.
abstract: The disinfection process for inactivating microorganisms at drinking water treatment plants is aimed for safety of drinking water for humans from a microorganism, such as bacteria, viruses, algae, fungi by using chlorination, ozonation, UV irradiation, etc. In the present study, a combination of two disinfectants, UV irradiation followed by chlorination, was evaluated for inactivating Aspergillus flavus under low contact time and low dosage of UV irradiation. The results indicated an inverse correlation between the inactivation of A. flavus by using UV irradiation only or chlorination alone. By using UV radiation, the 2 log10 control of A. flavus was achieved after 30 s of irradiation, while chlorination was observed to be more effective than UV, where the 2 log was achieved at chlorine concentration of 0.5, 1, 2 and 3 mg/l, in contact time of 60, 5, 1 and 1 min, respectively. However, combined use (UV irradiation followed by chlorination) was more effective than using either UV or chlorination alone; 5 s UV irradiation followed by chlorination produced 4 log10 reduction of A. flavus at chlorine concentrations of 2 and 3 mg/l under a contact time of 15 min. The results indicated that efficiency of UV irradiation improves when followed by chlorination at low concentrations.
authors.affiliation: Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; State Key Laboratory of Environmental Sciences, and Key Laboratory of Ministry of Education for Coast and Wetland Ecosystems, School of Life Sciences, Xiamen University, Xiamen 361005, China.
authors.forename: Hamid Mohammad
authors.initials: HM
authors.lastname: Al-Gabr
authors.forename: Tianling
authors.initials: T
authors.lastname: Zheng
authors.forename: Xin
authors.initials: X
authors.lastname: Yu
mesh_terms: D001231:Aspergillus flavus / Q000187:drug effects / Q000528:radiation effects*; D002713:Chlorine / Q000494:pharmacology*; D004203:Disinfection / Q000379:methods; D004305:Dose-Response Relationship, Drug; D004307:Dose-Response Relationship, Radiation; D060766:Drinking Water / Q000382:microbiology*; D054879:Halogenation; D014466:Ultraviolet Rays; D018508:Water Purification / Q000379:methods*
chemical_list: D060766:Drinking Water; D002713:Chlorine
keywords: Aspergillus flavus; Chlorination; Disinfection; UV irradiation