title: Debromination of polybrominated diphenyl ethers by attapulgite-supported Fe/Ni bimetallic nanoparticles: Influencing factors, kinetics and mechanism.
abstract: To enhance the removal efficiency of 2,2',4,4'-tetrabromodiphenylether (BDE47) in aqueous solutions, novel attapulgite-supported Fe/Ni bimetallic nanoparticles (A-Fe/Ni), which were characterized by a core-shell nanoparticle structure and with an average diameter of 20-40 nm, were synthesized for use in BDE47 degradation. The presence of attapulgite in bimetallic systems could reduce Fe/Ni nanoparticle aggregation and enhance their reactivity. BDE47 was degraded with a significant improvement in removal efficiency of at least 96% by A-Fe/Ni that played a reductive role in the reaction. The degradation kinetics of BDE47 by A-Fe/Ni complied with pseudo-first-order characteristics. To better understand the removal mechanism, detailed analyses were performed for several influential parameters. The improved dosage of A-Fe/Ni was found to be beneficial, and higher values of initial concentration, pH, and methanol/water ratio hindered the degradation rate, which, for example, decreased significantly in mixtures with a methanol proportion higher than 50%. The identification of BDE47 degradation products revealed a stepwise debromination from n-bromo-DE to (n-1)-bromo-DE as a possible pathway, wherein the para-Br was more easily eliminated than ortho-Br. Our findings provide insight into the removal mechanism and evidence for polybrominated diphenyl ether debromination by clay-Fe/Ni bimetallic nanoparticles.
authors.affiliation: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; University of the Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Zongtang
authors.initials: Z
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.
authors.forename: Chenggang
authors.initials: C
authors.lastname: Gu
authors.affiliation: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.
authors.forename: Mao
authors.initials: M
authors.lastname: Ye
authors.affiliation: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.
authors.forename: Yongrong
authors.initials: Y
authors.lastname: Bian
authors.affiliation: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; University of the Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Yinwen
authors.initials: Y
authors.lastname: Cheng
authors.affiliation: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.
authors.forename: Xinglun
authors.initials: X
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Song
authors.affiliation: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China. Electronic address: jiangxin@issas.ac.cn.
authors.forename: Xin
authors.initials: X
authors.lastname: Jiang
mesh_terms: D001966:Bromine / Q000737:chemistry*; D052918:Environmental Restoration and Remediation; D055768:Halogenated Diphenyl Ethers / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000737:chemistry*; D007700:Kinetics; D017616:Magnesium Compounds / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D000432:Methanol; D009532:Nickel / Q000737:chemistry*; D010316:Particle Size; D011075:Polybrominated Biphenyls / Q000737:chemistry*; D017655:Silicon Compounds / Q000737:chemistry*; D014867:Water
chemical_list: D055768:Halogenated Diphenyl Ethers; D017616:Magnesium Compounds; D011075:Polybrominated Biphenyls; D017655:Silicon Compounds; D014867:Water; C511295:2,2',4,4'-tetrabromodiphenyl ether; D009532:Nickel; D007501:Iron; D001966:Bromine; C026325:attapulgite; D000432:Methanol
keywords: Attapulgite; Debromination; Kinetics; Polybrominated diphenyl ethers; Supported Fe/Ni nanoparticles