title: [Photodegradation of naproxen in aqueous systems by UV irradiation: mechanism and toxicity of photolysis products].
abstract: This paper studies the degradation mechanism, the reaction kinetics and the toxicity of photolysis products of naproxen in waters under UV irradiation (120 W mercury lamp) by quenching experiments of reactive oxygen species (ROS), oxygen concentration experiment and toxicity evaluation using Vibrio fischeri bacteria. The results demonstrated that NPX could be degraded effectively by UV irradiation and the photolysis pathways was the sum of the degradation by direct photolysis and self-sensitization via ROS, and the contribution rates of self-sensitized photodegradation were 0.1%, 80.2%, 35.7% via *OH, (1)O2, O2*-, respectively. The effect of oxygen concentration illustrated that dissolved oxygen had an inhibitory effect on the direct photodegradation of NPX, and the higher the oxygen content, the more obvious the inhibitory effect. The toxicity evaluation illustrated the formation of some intermediate products that were more toxic than NPX during the photodegradation of NPX. The process of NPX degradation in all cases could be fitted by the pseudo first-order kinetics model.
authors.affiliation: School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China. cuckoom2009@126.com
authors.forename: Du-juan
authors.initials: DJ
authors.lastname: Ma
authors.forename: Guo-guang
authors.initials: GG
authors.lastname: Liu
authors.forename: Wen-ying
authors.initials: WY
authors.lastname: Lü
authors.forename: Kun
authors.initials: K
authors.lastname: Yao
authors.forename: Li-hua
authors.initials: LH
authors.lastname: Zhou
authors.forename: Cheng-ping
authors.initials: CP
authors.lastname: Xie
mesh_terms: D007700:Kinetics; D009288:Naproxen / Q000302:isolation & purification / Q000528:radiation effects* / Q000633:toxicity; D010782:Photolysis / Q000528:radiation effects*; D014466:Ultraviolet Rays; D014874:Water Pollutants, Chemical / Q000302:isolation & purification / Q000528:radiation effects*
chemical_list: D014874:Water Pollutants, Chemical; D009288:Naproxen