title: SMX degradation by ozonation and UV radiation: a kinetic study.
abstract: The rate constants of sulfamethoxazole (SMX) degradation by ozonation and UV(254) radiation were investigated under various parameters including influent ozone gas concentration, initial SMX concentration, UV light intensity, ionic strength, water quality in terms of varying anions (bicarbonate, sulfate and nitrate), humic acid (HA) and pH. The results indicated that the removal of SMX by ozonation and UV(254) radiation fitted well to a pseudo first-order kinetic model and the rate constants were in the range of (0.9-9.8)×10(-3) and (1.7-18.9)×10(-3) s(-1), respectively. The second-order rate constants of SMX with ozone (ko(3)), under varying operational parameters, were also determined and varied in the range of (0.60-3.38)±0.13×10(5)M(-1) s(-1). In addition, SMX degradation through UV pretreatment followed by ozonation in the presence of HA was proved to be an effective method which can remove SMX with a low ozone dose. The results suggested that ozonation of SMX was more affected by concentration of influent ozone gas, alkalinity, and HA, while incident UV light intensity, pH, and HA were the dominant factors influencing UV degradation of SMX.
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, School of Municipal & Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China.
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Liu
authors.forename: Temesgen
authors.initials: T
authors.lastname: Garoma
authors.forename: Zhonglin
authors.initials: Z
authors.lastname: Chen
authors.forename: Lili
authors.initials: L
authors.lastname: Wang
authors.forename: Youxian
authors.initials: Y
authors.lastname: Wu
mesh_terms: D000890:Anti-Infective Agents / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D006812:Humic Substances / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D009994:Osmolar Concentration; D010126:Ozone / Q000737:chemistry; D010782:Photolysis; D013420:Sulfamethoxazole / Q000737:chemistry*; D014466:Ultraviolet Rays; D014865:Waste Disposal, Fluid; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification; D060753:Water Quality
chemical_list: D000890:Anti-Infective Agents; D006812:Humic Substances; D014874:Water Pollutants, Chemical; D010126:Ozone; D013420:Sulfamethoxazole