title: Wastewater disinfection by ozone: main parameters for process design.
abstract: Wastewater disinfection by ozone was investigated at pilot scale on different wastewater effluents. Variations in operating conditions showed that a very low hydraulic retention time (2 min) was sufficient for efficient fecal coliform inactivation, provided a sufficient ozone dose was transferred to the effluent. Therefore, the transferred ozone dose appeared to be the critical parameter for the design of wastewater disinfection. As a consequence, the "Ct" approach commonly applied in drinking water treatment should not be used for wastewater ozonation. Design parameters of ozonation were proposed for two types of regulations, and for effluents of different qualities. It was demonstrated that only with an efficient filtration step one can meet stringent standards such as the California Title 22 criteria. In all cases, viruses were totally inactivated; consequently, viruses do not constitute a limiting factor in wastewater disinfection by ozone. The standard drinking water model failed to match the experimental data obtained on real wastewater effluents. A modified approach was successfully developed, based on the simultaneous consumption of ozone by the microorganisms and the organic matrix.
authors.affiliation: Laboratoire Hydrosciences, MSE, UMR no. 5569, Université Montpellier II, France.
authors.forename: Pei
authors.initials: P
authors.lastname: Xu
authors.forename: Marie-Laure
authors.initials: ML
authors.lastname: Janex
authors.forename: Philippe
authors.initials: P
authors.lastname: Savoye
authors.forename: Arnaud
authors.initials: A
authors.lastname: Cockx
authors.forename: Valentina
authors.initials: V
authors.lastname: Lazarova
mesh_terms: D019149:Bioreactors; D004867:Equipment Design; D005374:Filtration; D010083:Oxidants, Photochemical / Q000737:chemistry*; D010126:Ozone / Q000737:chemistry*; D010865:Pilot Projects; D014865:Waste Disposal, Fluid / Q000379:methods*; D014871:Water Microbiology; D018508:Water Purification / Q000379:methods*; D014881:Water Supply
chemical_list: D010083:Oxidants, Photochemical; D010126:Ozone