title: Two-stage reduction/subsequent oxidation treatment of 2,2',4,4'-tetrabromodiphenyl ether in aqueous solutions: kinetic, pathway and toxicity.
abstract: The effectiveness of a two-stage reduction/subsequent oxidation (T-SRO) treatment of BDE-47, consisting of Fe-Ag reduction and Fenton-like oxidation, was investigated in this study. As an oxidation-resisting pollutant, BDE-47 (5 mg L(-1)) was difficult to be degraded by homogeneous Fe-Ag/H(2)O(2) system coupled with ultrasound (US) in 30 min. However, when this solution was firstly treated with Fe-Ag/US, the final debrominated product could be rapidly oxidized by the succeeding Fenton-like reactions, resulting in an efficient debromination of BDE-47 and a 100% mineralization of diphenyl ether (DPE). To scrutinize the degradation mechanism, several analytical techniques including HPLC, LC-MS/MS and GC/MS, were employed to monitor the major intermediates and final products. Moreover, luminescent bacteria test showed that the acute toxicity of the original solution (before reduction) was evidently lower than that of Fe-Ag/US reduction-treated solution; no toxicity was detected after Fenton-like oxidation. Evidence for the significance of a T-SRO treatment to decompose BDE-47 was presented.
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093, PR China.
authors.forename: Si
authors.initials: S
authors.lastname: Luo
authors.forename: Shaogui
authors.initials: S
authors.lastname: Yang
authors.forename: Yingang
authors.initials: Y
authors.lastname: Xue
authors.forename: Feng
authors.initials: F
authors.lastname: Liang
authors.forename: Cheng
authors.initials: C
authors.lastname: Sun
mesh_terms: D001419:Bacteria / Q000235:genetics; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D002853:Chromatography, Liquid / Q000379:methods; D004867:Equipment Design; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D055768:Halogenated Diphenyl Ethers / Q000032:analysis* / Q000737:chemistry; D006861:Hydrogen Peroxide / Q000737:chemistry; D007501:Iron / Q000737:chemistry; D007700:Kinetics; D049449:Luminescence; D013058:Mass Spectrometry / Q000379:methods; D010100:Oxygen / Q000737:chemistry*; D010647:Phenyl Ethers / Q000737:chemistry; D011075:Polybrominated Biphenyls; D014867:Water / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis*; D018508:Water Purification / Q000379:methods*
chemical_list: C045076:Fenton's reagent; D055768:Halogenated Diphenyl Ethers; D010647:Phenyl Ethers; D011075:Polybrominated Biphenyls; D014874:Water Pollutants, Chemical; D014867:Water; C511295:2,2',4,4'-tetrabromodiphenyl ether; C031538:phenyl ether; D006861:Hydrogen Peroxide; D007501:Iron; D010100:Oxygen