title: Inactivation of Bacillus subtilis spores during ozonation in water treatment plant: influence of pre-treatment and consequences for positioning of the ozonation step.
abstract: This study reports on quantitative methodology for rational selection of the ozone injection point within unit processes of conventional drinking water treatment plants to improve disinfection efficiencies. The method is based on the fact that a specific inactivation level of microorganisms is achieved at a unique value of ozone exposures, independent of ozone dose and type of water, and quantitatively described by a Delayed Chick-Watson model (C T(lag): 1.03mgl(-1), k: 1.44mg(-1)lmin(-1)). This study demonstrated this phenomenon by performing the inactivation of Bacillus subtilis (B. subtilis) spores with ozone in various types of water collected from a series of unit processes in a water treatment plant. Simple measurements of the ozone decomposition behavior in waters from each unit process of a water treatment plant can allow the quantitative evaluation of the ozone needed to achieve a required level of inactivation. This methodology will be useful for drinking water treatment plants which intend to improve the disinfection efficiencies of their ozonation process.
authors.affiliation: The Environment Technology Institute Department of Development II, Naewei Bldg., 7F, 6 Euljiro 2-ga, Joong-gu, Seoul 100-844, Republic of Korea.
authors.forename: Yuseung
authors.initials: Y
authors.lastname: Choi
authors.forename: Min
authors.initials: M
authors.lastname: Cho
authors.forename: Yunho
authors.initials: Y
authors.lastname: Lee
authors.forename: Jung
authors.initials: J
authors.lastname: Choi
authors.forename: Jeyong
authors.initials: J
authors.lastname: Yoon
mesh_terms: D001412:Bacillus subtilis / Q000187:drug effects* / Q000502:physiology; D004203:Disinfection / Q000379:methods; D010126:Ozone / Q000737:chemistry*; D011786:Quality Control; D013171:Spores, Bacterial; D014871:Water Microbiology / Q000592:standards; D018508:Water Purification / Q000379:methods*; D014881:Water Supply / Q000592:standards*
chemical_list: D010126:Ozone