title: Ozonation and peroxone oxidation of benzophenone-3 in water: effect of operational parameters and identification of intermediate products.
abstract: The goal of this study was to bring forward new data and insights with respect to the effect of operational variables and reaction pathways during ozonation and peroxone oxidation of the UV filter compound benzophenone-3 (BP3) in water. A systematic parameter study, investigating the effect of the ozone inlet concentration, temperature, pH, H(2)O(2) and t-butanol addition in a lab-scale bubble reactor, showed the promising potential of ozonation towards BP3 degradation. pH showed to be a major process parameter, with half-life times (5.1-15.0 min) being more than two times shorter at pH10 compared to neutral and acid conditions. This indicates the important role of hydroxyl radicals as supported by the addition of H(2)O(2) and t-butanol as HO promoter and scavenger, respectively. Ozonation intermediate products were identified by liquid chromatography coupled to quadrupole-time-of-flight mass spectrometry (HPLC-QqTOF-MS/MS). Demethylation and non-selective HO attack proved to be the major reaction mechanisms. Where available, identified intermediates were confirmed using analytical standards, and concentration profiles along the ozonation process were determined through selective targeted MS/MS analysis. Benzophenone-1 (BP1), also being a UV-filter compound, and 2,2'-dihydroxy-4-methoxybenzophenone (DHMB) revealed to be the major BP3 degradation products, showing a maximum concentration at about the half-life time of BP3.
authors.affiliation: Department of Environmental Chemistry, IDAEA-CSIC, Jordi Girona 18-26, 08034 Barcelona, Spain.
authors.forename: Pablo
authors.initials: P
authors.lastname: Gago-Ferrero
authors.forename: Kristof
authors.initials: K
authors.lastname: Demeestere
authors.forename: M
authors.initials: M
authors.lastname: Silvia Díaz-Cruz
authors.forename: Damià
authors.initials: D
authors.lastname: Barceló
mesh_terms: D001577:Benzophenones / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D006861:Hydrogen Peroxide / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D010126:Ozone / Q000737:chemistry*; D053719:Tandem Mass Spectrometry; D013696:Temperature; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D001577:Benzophenones; D014874:Water Pollutants, Chemical; D010126:Ozone; C005290:oxybenzone; D006861:Hydrogen Peroxide