title: Oxidation of bromophenols and formation of brominated polymeric products of concern during water treatment with potassium permanganate.
abstract: The extensive use of bromophenols (BrPs) in industrial products leads to their occurrence in freshwater environments. This study explored the oxidation kinetics of several BrPs (i.e., 2-BrP, 3-BrP, 4-BrP, 2,4-diBrP, and 2,6-diBrP) and potential formation of brominated polymeric products of concern during water treatment with potassium permanganate [Mn(VII)]. These BrPs exhibited appreciable reactivity toward Mn(VII) with the maxima of second-order rate constants (kMn(VII)) at pH near their pKa values, producing bell-shaped pH-rate profiles. The unusual pH-dependency of kMn(VII) was reasonably explained by a tentative reaction model, where the formation of an intermediate between Mn(VII) and dissociated BrP was likely involved. A novel and powerful precursor ion scan (PIS) approach was used for selective detection of brominated oxidation products by liquid chromatography/electrospray ionization-triple quadrupole mass spectrometry. Results showed that brominated dimeric products such as hydroxylated polybrominated diphenyl ethers (OH-PBDEs) and hydroxylated polybrominated biphenyls (OH-PBBs) were readily produced. For instance, 2'-OH-BDE-68, one of the most naturally abundant OH-PBDEs, could be formed at a relatively high yield possibly via the coupling between bromophenoxyl radicals generated from the one-electron oxidation of 2,4-diBrP by Mn(VII). Given the altered or enhanced toxicological effects of these brominated polymeric products compared to the BrP precursors, it is important to better understand their reactivity and fate before Mn(VII) is applied by water utilities for the oxidative treatment of BrP-containing waters.
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology , Harbin 150090, China.
authors.forename: Jin
authors.initials: J
authors.lastname: Jiang
authors.forename: Yuan
authors.initials: Y
authors.lastname: Gao
authors.forename: Su-Yan
authors.initials: SY
authors.lastname: Pang
authors.forename: Qiang
authors.initials: Q
authors.lastname: Wang
authors.forename: Xiaoliu
authors.initials: X
authors.lastname: Huangfu
authors.forename: Yongze
authors.initials: Y
authors.lastname: Liu
authors.forename: Jun
authors.initials: J
authors.lastname: Ma
mesh_terms: D002851:Chromatography, High Pressure Liquid; D002853:Chromatography, Liquid; D054879:Halogenation; D006863:Hydrogen-Ion Concentration; D008962:Models, Theoretical; D010084:Oxidation-Reduction; D010636:Phenols / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D011196:Potassium Permanganate / Q000737:chemistry*; D045483:Rivers / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization; D014874:Water Pollutants, Chemical / Q000032:analysis*; D018508:Water Purification / Q000379:methods*
chemical_list: D010636:Phenols; D011108:Polymers; D014874:Water Pollutants, Chemical; D011196:Potassium Permanganate