title: Evaluation of the treatment performance of a multistage ozone/hydrogen peroxide process by decomposition by-products.
abstract: The performance of a multistage ozone/hydrogen peroxide (O3/H2O2) process was evaluated with respect to total organic carbon (TOC) removal of waste waters. An aqueous humic acid solution (5.2 mgC l(-1) as TOC) and a sand filtered secondary sewerage effluent (5.6mgC l(-1) as TOC) were used as model waste waters. Appropriate range of hydrogen peroxide (H2O2) dose at each stage depended upon the components of the tested solutions that changed as the process proceeded. Higher hydrogen peroxide dose was required at later stages in which low reactivity compounds with hydroxyl radical (HO*), low molecular fatty acids, were predominant. And, oxalic acid concentration related to H2O2 demand at later stages. This was assumed that the slow decomposition of oxalic acid was rate-determining step for TOC removal after its accumulation. Also, it is important to maintain dissolved ozone at low concentration for efficient TOC removal because rapid ozone consumption is required for the rapid formation of hydroxyl radical (HO*).
authors.affiliation: Research Center for Environmental Quality Control, Kyoto University, Otsu, Shiga, Japan. kosaka@biwa.eqc.kyoto-u.ac.jp
authors.forename: K
authors.initials: K
authors.lastname: Kosaka
authors.forename: H
authors.initials: H
authors.lastname: Yamada
authors.forename: K
authors.initials: K
authors.lastname: Shishida
authors.forename: S
authors.initials: S
authors.lastname: Echigo
authors.forename: R A
authors.initials: RA
authors.lastname: Minear
authors.forename: H
authors.initials: H
authors.lastname: Tsuno
authors.forename: S
authors.initials: S
authors.lastname: Matsui
mesh_terms: D002244:Carbon / Q000378:metabolism; D005374:Filtration; D006812:Humic Substances / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000737:chemistry*; D017665:Hydroxyl Radical / Q000737:chemistry; D019815:Oxalic Acid / Q000737:chemistry; D016877:Oxidants / Q000737:chemistry*; D010083:Oxidants, Photochemical / Q000737:chemistry*; D010126:Ozone / Q000737:chemistry*; D012722:Sewage / Q000737:chemistry*; D014865:Waste Disposal, Fluid
chemical_list: D006812:Humic Substances; D016877:Oxidants; D010083:Oxidants, Photochemical; D012722:Sewage; D017665:Hydroxyl Radical; D010126:Ozone; D002244:Carbon; D019815:Oxalic Acid; D006861:Hydrogen Peroxide