title: Sodium persulfate-assisted mechanochemical degradation of tetrabromobisphenol A: Efficacy, products and pathway.
abstract: In recent years, activated persulfate (PS) oxidation has been developed as a new advanced oxidation process for the degradation of organic pollutants. On the other hand, the mechanochemical method has exhibited a unique advantage in dealing with chemical wastes. The degradation of tetrabromobisphenol A (TBBPA), a widely used brominated flame retardant (BFR), in wastes has attracted considerable attention. In this study, the efficacy of a CaO-mechanochemical (CaO-MC) treatment system assisted by the addition of PS for the degradation of TBBPA was investigated. Under the optimum reaction conditions with a mole ratio of PS:CaO = 1:4 and less than 12.5% of TBBPA by mass, the degradation and debromination of TBBPA were completed within 2 h, while the mineralization was completed within 4 h. Characterization of the milled sample by XRD revealed that CaSO4 crystallization occurred. The TG results illustrate that there was little organic matter left after 4 h of milling. Raman and FT-IR spectra exhibited the TBBPA destruction process and disappearance of the organic groups. Through analysis by LC/MS/MS, seventeen intermediates were identified. The mechanism of TBBPA degradation by the PS-assisted CaO-MC treatment system was explained from two aspects, the course of crystallization and the degradation of TBBPA by activated PS, and two parallel initiation pathways were proposed.
authors.affiliation: State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China. Electronic address: liuxt@bnu.edu.cn.
authors.forename: Xitao
authors.initials: X
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China.
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Zhang
authors.affiliation: State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, POPs Research Center, Tsinghua University, Beijing 100084, China.
authors.forename: Kunlun
authors.initials: K
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China.
authors.forename: Chengdu
authors.initials: C
authors.lastname: Qi
mesh_terms: D017610:Calcium Compounds / Q000737:chemistry*; D002853:Chromatography, Liquid; D005411:Flame Retardants; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry*; D011075:Polybrominated Biphenyls / Q000737:chemistry*; D017670:Sodium Compounds / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman; D013431:Sulfates / Q000737:chemistry*; D053719:Tandem Mass Spectrometry
chemical_list: D017610:Calcium Compounds; D005411:Flame Retardants; D010087:Oxides; D011075:Polybrominated Biphenyls; D017670:Sodium Compounds; D013431:Sulfates; C016538:lime; C020806:tetrabromobisphenol A; C024625:sodium persulfate
keywords: CaO; Debromination; Mechanochemical; Persulfate; TBBPA