title: Degradation, metabolism, and bound-residue formation and release of Tetrabromobisphenol A in soil during sequential anoxic-oxic incubation.
abstract: Tetrabromobisphenol A (TBBPA) is one of the most commonly used flame retardants and has become an environmental contaminant worldwide. We studied the fate of (14)C-labeled TBBPA in soil under static anoxic (195 days) and sequential anoxic (125 days)-oxic (70 days) conditions. During anoxic incubation, TBBPA dissipated with a half-life of 36 days, yielding four debromination metabolites: bisphenol A (BPA) and mono-, di-, and tribrominated BPA. At the end of anoxic incubation, all four brominated BPAs completely disappeared, leaving BPA (54% of initial TBBPA) as the sole detectable organic metabolite. TBBPA dissipation was accompanied by trace mineralization (<1.3%) and substantial bound-residue formation (35%), probably owing to chemical binding to soil organic matter. Subsequent oxic incubation was effective in degrading accumulated BPA (half-life 11 days) through mineralization (6%) and bound-residue formation (62%). However, 42% of the anoxically formed bound residues was released as TBBPA and lower brominated BPAs, which were then persistent during oxic incubation. Our results provide the first evidence for release of bound residues during alteration of the redox environment and indicate that sequential anoxic-oxic incubation approaches-considered effective in remediation of environments containing halogenated xenobiotics-do not completely remove xenobiotics from environmental matrices.
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University , Xianlin Avenue 163, 210023 Nanjing, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Liu
authors.forename: Yongfeng
authors.initials: Y
authors.lastname: Wang
authors.forename: Bingqi
authors.initials: B
authors.lastname: Jiang
authors.forename: Lianhong
authors.initials: L
authors.lastname: Wang
authors.forename: Jianqiu
authors.initials: J
authors.lastname: Chen
authors.forename: Hongyan
authors.initials: H
authors.lastname: Guo
authors.forename: Rong
authors.initials: R
authors.lastname: Ji
mesh_terms: D002851:Chromatography, High Pressure Liquid; D013058:Mass Spectrometry; D010100:Oxygen / Q000737:chemistry*; D011075:Polybrominated Biphenyls / Q000737:chemistry* / Q000378:metabolism; D012989:Soil Pollutants / Q000737:chemistry* / Q000378:metabolism
chemical_list: D011075:Polybrominated Biphenyls; D012989:Soil Pollutants; C020806:tetrabromobisphenol A; D010100:Oxygen