title: Photosensitized degradation of bisphenol A involving reactive oxygen species in the presence of humic substances.
abstract: The photodegradation of endocrine disrupter bisphenol A (BPA) in the presence of natural humic substances (HS) under simulated solar irradiation was studied. BPA underwent slow direct photolysis in neutral pure water, but rapid photosensitized degradation in four kinds of HS, following pseudo-first-order reaction. Reactive oxygen species (ROS) formed from HS were determined, including OH, (1)O(2) and H(2)O(2). The enhancement of BPA degradation by adding Fe(III) was primarily attributed to the oxidation of OH produced from photo-Fenton-like reaction. And the joint effects of HS and nitrate ions coexisting on BPA degradation appeared to depend on respective concentration levels. The effects of dissolved oxygen suggested that the energy transfer between excited state of SRFA and NOFA likely occurred, while the abstraction of phenolic hydrogen atom to reactive triplet state of NOHA possibly took place. Based on the structural analyses of main intermediates and degradation products of BPA detected by GC-MS, the possible photodegradation pathways were proposed, involving the alky cleavage, alkyl oxidation and OH addition. This study gave a better understanding for the photochemical transformation of BPA induced by ROS generated from natural water composition under sunlight irradiation.
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093, PR China.
authors.forename: Manjun
authors.initials: M
authors.lastname: Zhan
authors.forename: Xi
authors.initials: X
authors.lastname: Yang
authors.forename: Qiming
authors.initials: Q
authors.lastname: Xian
authors.forename: Lingren
authors.initials: L
authors.lastname: Kong
mesh_terms: D001559:Benzhydryl Compounds; D001578:Benzopyrans / Q000528:radiation effects*; D006812:Humic Substances / Q000528:radiation effects*; D006861:Hydrogen Peroxide / Q000737:chemistry; D017665:Hydroxyl Radical / Q000737:chemistry; D007501:Iron / Q000737:chemistry; D007700:Kinetics; D009566:Nitrates; D010100:Oxygen / Q000737:chemistry; D010636:Phenols / Q000737:chemistry* / Q000528:radiation effects*; D010782:Photolysis; D013472:Sunlight; D013481:Superoxides / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000528:radiation effects*; D000098826:Bisphenol A Compounds
chemical_list: D001559:Benzhydryl Compounds; D001578:Benzopyrans; D006812:Humic Substances; D006861:Hydrogen Peroxide; D017665:Hydroxyl Radical; D007501:Iron; D009566:Nitrates; D010100:Oxygen; D010636:Phenols; D013481:Superoxides; D014874:Water Pollutants, Chemical; C006780:bisphenol A; D000098826:Bisphenol A Compounds; C005023:fulvic acid