title: Photodegradation of naproxen in water under simulated solar radiation: mechanism, kinetics, and toxicity variation.
abstract: The main objective of this study was to investigate the degradation mechanism, the reaction kinetics, and the evolution of toxicity of naproxen in waters under simulated solar radiation. These criteria were investigated by conducting quenching experiments with reactive oxygen species (ROS), oxygen concentration experiments, and toxicity evaluations with Vibrio fischeri bacteria. The results indicated that the degradation of naproxen proceeds via pseudo first-order kinetics in all cases and that photodegradation included degradation by direct photolysis and by self-sensitization via ROS; the contribution rates of self-sensitized photodegradation were 1.4%, 65.8%, and 31.7% via ·OH, (1)O₂ and O₂(•-), respectively. Furthermore, the oxygen concentration experiments indicated that dissolved oxygen inhibited the direct photodegradation of naproxen, and the higher the oxygen content, the more pronounced the inhibitory effect. The toxicity evaluation illustrated that some of the intermediate products formed were more toxic than naproxen.
authors.affiliation: School of Environmental Science and Engineering, Guangdong University of Technology, No. 100 Waihuan Xi Road, Guangzhou Higher Education Mega Center, Panyu District, Guangzhou, 510006, People's Republic of China.
authors.forename: Dujuan
authors.initials: D
authors.lastname: Ma
authors.forename: Guoguang
authors.initials: G
authors.lastname: Liu
authors.forename: Wenying
authors.initials: W
authors.lastname: Lv
authors.forename: Kun
authors.initials: K
authors.lastname: Yao
authors.forename: Xiangdan
authors.initials: X
authors.lastname: Zhang
authors.forename: Huahua
authors.initials: H
authors.lastname: Xiao
mesh_terms: D048908:Aliivibrio fischeri / Q000187:drug effects; D002851:Chromatography, High Pressure Liquid; D007700:Kinetics; D008826:Microbial Sensitivity Tests; D015394:Molecular Structure; D009288:Naproxen / Q000737:chemistry / Q000528:radiation effects* / Q000633:toxicity; D010100:Oxygen / Q000032:analysis; D010782:Photolysis / Q000528:radiation effects*; D017382:Reactive Oxygen Species / Q000378:metabolism; D013472:Sunlight; D014874:Water Pollutants, Chemical / Q000528:radiation effects*
chemical_list: D017382:Reactive Oxygen Species; D014874:Water Pollutants, Chemical; D009288:Naproxen; D010100:Oxygen