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Lei M, Tang Y, Zhu L, Tang H. Chemical reductive technologies for the debromination of polybrominated diphenyl ethers: A review. J Environ Sci (China) 2023; 127:42-59. [PMID: 36522073 DOI: 10.1016/j.jes.2022.05.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 05/06/2022] [Accepted: 05/10/2022] [Indexed: 06/17/2023]
Abstract
Polybrominated diphenyl ethers (PBDEs) are widely used as brominated flame retardants, which had attracted amounts of attention due to their harmful characteristics of high toxicity, environmental persistence and potential bioaccumulation. Many chemical reductive debromination technologies have been developed for the debromination of PBDEs, including photolysis, photocatalysis, electrocatalysis, zero-valent metal reduction, chemically catalytic reduction and mechanochemical method. This review aims to provide information about the degradation thermodynamics and kinetics of PBDEs and summarize the degradation mechanisms in various systems. According to the comparative analysis, the rapid debromination to generate bromine-free products in an electron-transfer process, of which photocatalysis is a representative one, is found to be relatively difficult, because the degradation rate of PBDEs depended on the Br-rich phenyl ring with the lowest unoccupied molecular orbital (LUMO) localization. On the contrary, the complete debromination occurs easily in other systems with active hydrogen atoms as the main reactive species, such as chemically catalytic reduction systems. The review provides the knowledge on the chemical reductive technique of PBDEs, which would greatly help not only clarify the degradation mechanism but also design the more efficient system for the rapid and deep debromination of PBDEs in the future.
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Affiliation(s)
- Ming Lei
- College of Resources and Environmental Science, South-Central Minzu University, Wuhan 430074, China
| | - Yao Tang
- College of Resources and Environmental Science, South-Central Minzu University, Wuhan 430074, China
| | - Lihua Zhu
- School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
| | - Heqing Tang
- College of Resources and Environmental Science, South-Central Minzu University, Wuhan 430074, China.
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Sun B, Li Q, Zheng M, Su G, Lin S, Wu M, Li C, Wang Q, Tao Y, Dai L, Qin Y, Meng B. Recent advances in the removal of persistent organic pollutants (POPs) using multifunctional materials:a review. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 265:114908. [PMID: 32540566 DOI: 10.1016/j.envpol.2020.114908] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2019] [Revised: 04/30/2020] [Accepted: 05/28/2020] [Indexed: 06/11/2023]
Abstract
Persistent organic pollutants (POPs) have gained heightened attentions in recent years owing to their persistent property and hazard influence on wild life and human beings. Removal of POPs using varieties of multifunctional materials have shown a promising prospect compared with conventional treatments. Herein, three main categories, including thermal degradation, electrochemical remediation, as well as photocatalytic degradation with the use of diverse catalytic materials, especially the recently developed prominent ones were comprehensively reviewed. Kinetic analysis and underlying mechanism for various POPs degradation processes were addressed in detail. The review also systematically documented how catalytic performance was dramatically affected by the nature of the material itself, the structure of target pollutants, reaction conditions and treatment techniques. Moreover, the future challenges and prospects of POPs degradation by means of multiple multifunctional materials were outlined accordingly. Knowing this is of immense significance to enhance our understanding of POPs remediation procedures and promote the development of novel multifunctional materials.
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Affiliation(s)
- Bohua Sun
- Key Laboratory of Environmental Nanotechnology and Health Effects, State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco- Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Qianqian Li
- Key Laboratory of Environmental Nanotechnology and Health Effects, State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco- Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Minghui Zheng
- Key Laboratory of Environmental Nanotechnology and Health Effects, State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco- Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Guijin Su
- Key Laboratory of Environmental Nanotechnology and Health Effects, State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco- Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Shijing Lin
- College of Chemical Engineering, Beijing Institute of Petrochemical Technology, Beijing, 102617, PR China
| | - Mingge Wu
- Key Laboratory of Environmental Nanotechnology and Health Effects, State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco- Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Chuanqi Li
- Key Laboratory of Environmental Nanotechnology and Health Effects, State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco- Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Qingliang Wang
- Key Laboratory of Environmental Nanotechnology and Health Effects, State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco- Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yuming Tao
- Key Laboratory of Environmental Nanotechnology and Health Effects, State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco- Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Lingwen Dai
- Key Laboratory of Environmental Nanotechnology and Health Effects, State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco- Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yi Qin
- Key Laboratory of Environmental Nanotechnology and Health Effects, State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco- Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Bowen Meng
- Key Laboratory of Environmental Nanotechnology and Health Effects, State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco- Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China
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Lei M, Guo S, Wang Z, Zhu L, Tang H. Ultrarapid and Deep Debromination of Tetrabromodiphenyl Ether over Noble-Metal-Free Cu/TiO 2 Nanocomposites under Mild Conditions. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:11743-11751. [PMID: 30207447 DOI: 10.1021/acs.est.8b03202] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Fast and deep debromination of polybrominated diphenyl ethers (PBDEs) under mild conditions is a challenge in the field of pollution control. A strategy was developed to achieve it by exploiting Cu/TiO2 composites as a noble-metal-free catalyst. Toward the debromination of 2,2',4,4'-tetrabromodiphenyl ether (BDE47) as a typical PBDE, the use of Cu/TiO2 as a catalyst and hydrazine hydrate (N2H4·H2O) as a reducing agent yielded a degradation removal of 100% and a debromination efficiency of 87.7% in 3 s. A complete debromination of BDE47 at 1500 mg L-1 was possible by successively adding N2H4·H2O. A debromination pathway involving active H atom species was proposed for the catalytic transfer hydrogenation (CTH) of PBDEs according to the identified degradation intermediates. A mechanism was further clarified by density functional theory calculations: electrons are delivered from N2H4·H2O to the metallic Cu atom via a coordination of N in N2H4·H2O with Cu atoms. The electron-trapped Cu atom interacts with adsorbed BDE47 to form a transition complex, and then the debromination of this complex occurs on the surface of Cu nanoparticles due to the hydrogen donation of N2H4·H2O through the CTH process. The new method provides a highly efficient method to remove brominated pollutants.
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Affiliation(s)
- Ming Lei
- Key Laboratory of Catalysis and Materials Science of the State Ethnic Affairs Commission and Ministry of Education, College of Resources and Environmental Science , South-Central University for Nationalities , Wuhan 430074 , People's Republic of China
| | - Shun Guo
- School of Chemistry and Chemical Engineering , Huazhong University of Science and Technology , Wuhan 430074 , People's Republic of China
| | - Zhiying Wang
- Key Laboratory of Catalysis and Materials Science of the State Ethnic Affairs Commission and Ministry of Education, College of Resources and Environmental Science , South-Central University for Nationalities , Wuhan 430074 , People's Republic of China
| | - Lihua Zhu
- School of Chemistry and Chemical Engineering , Huazhong University of Science and Technology , Wuhan 430074 , People's Republic of China
| | - Heqing Tang
- Key Laboratory of Catalysis and Materials Science of the State Ethnic Affairs Commission and Ministry of Education, College of Resources and Environmental Science , South-Central University for Nationalities , Wuhan 430074 , People's Republic of China
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Martin ET, McGuire CM, Mubarak MS, Peters DG. Electroreductive Remediation of Halogenated Environmental Pollutants. Chem Rev 2016; 116:15198-15234. [DOI: 10.1021/acs.chemrev.6b00531] [Citation(s) in RCA: 115] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Erin T. Martin
- Department
of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Caitlyn M. McGuire
- Department
of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | | | - Dennis G. Peters
- Department
of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
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Huang A, Zhang Z, Wang N, Zhu L, Zou J. Green mechanochemical oxidative decomposition of powdery decabromodiphenyl ether with persulfate. JOURNAL OF HAZARDOUS MATERIALS 2016; 302:158-165. [PMID: 26474378 DOI: 10.1016/j.jhazmat.2015.09.072] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Revised: 09/20/2015] [Accepted: 09/30/2015] [Indexed: 06/05/2023]
Abstract
A method was developed for efficiently degrading powdery decabromodiphenyl ether (BDE209) by using mechanochemical (MC) activation of persulfate (PS). Characteristic Raman spectra of BDE209 corresponding to CBr and CO bonds were decreased in intensity and finally disappeared as the MC reaction proceeded. The BDE209 removal was influenced by the molar ratio of PS to BDE209, the mass ratio of milling ball to reaction mixtures, the ball size, and the ball rotation speed. Under optimal conditions, the new method could achieve a complete degradation, debromination and mineralization of BDE209 within 3h of milling. However, the degradation removal (or debromination efficiency) was decreased to only 51.7% (15.6%) and 67.8% (31.5%) for the use of CaO and peroxymonosulfate, respectively. The analyses of products demonstrated that once the degradation was initiated, BDE209 molecules were deeply debrominated and fully mineralized in the MC-PS system. The strong oxidizing ability of this system was due to the reactive sulfate radicals generated from the MC-enhanced activation of PS, which was confirmed with electron spin resonance spectroscopy. Because no toxic low brominated polybrominated diphenyl ethers were accumulated as byproducts, the proposed MC oxidative degradation method will have promising applications in the treatment of solid BDE209 at high concentrations.
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Affiliation(s)
- Aizhen Huang
- College of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, PR China
| | - Zhimin Zhang
- College of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, PR China
| | - Nan Wang
- College of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, PR China
| | - Lihua Zhu
- College of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, PR China.
| | - Jing Zou
- School of Chemistry and Environmental Engineering, Wuhan Institute of Technology, Wuhan 430073, PR China
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Mao R, Zhao X, Qu J. Electrochemical Reduction of Bromate by a Pd Modified Carbon Fiber Electrode: Kinetics and Mechanism. Electrochim Acta 2014. [DOI: 10.1016/j.electacta.2014.03.170] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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7
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Rotko G, Romańczyk PP, Kurek SS. Reductive debromination of decabromodiphenyl ether yields brominated dibenzofurans in a Pschorr-type cyclisation. Electrochem commun 2013. [DOI: 10.1016/j.elecom.2013.10.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
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8
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Kinetics of electrochemical dechlorination of 2-chlorobiphenyl on a palladium-modified nickel foam cathode in a basic medium: From batch to continuous reactor operation. Electrochim Acta 2013. [DOI: 10.1016/j.electacta.2013.07.207] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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9
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Cao H, He M, Han D, Li J, Li M, Wang W, Yao S. OH-initiated oxidation mechanisms and kinetics of 2,4,4'-Tribrominated diphenyl ether. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 47:8238-8247. [PMID: 23855483 DOI: 10.1021/es400088v] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
2,4,4'-Tribromodiphenyl ether (BDE-28) was selected as a typical congener of polybrominated diphenyl ethers (PBDEs) to examine its fate both in the atmosphere and in water solution. All the calculations were obtained at the ground state. The mechanism result shows that the oxidations between BDE-28 and OH radicals are highly feasible especially at the less-brominated phenyl ring. Hydroxylated dibrominated diphenyl ethers (OH-PBDEs) are formed through direct bromine-substitution reactions (P1∼P3) or secondary reactions of OH-adducts (P4∼P8). Polybrominated dibenzo-p-dioxins (PBDDs) resulting from o-OH-PBDEs are favored products compared with polybrominated dibenzofurans (PBDFs) generated by bromophenols and their radicals. The complete degradation of OH adducts in the presence of O2/NO, which generates unsaturated ketones and aldehydes, is less feasible compared with the H-abstraction pathways by O2. Aqueous solution reduces the feasibility between BDE-28 and the OH radical. The rate constant of BDE-28 and the OH radical is determined to be 1.79 × 10(-12) cm(3) molecule(-1) s(-1) with an atmospheric lifetime of 6.7 days.
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Affiliation(s)
- Haijie Cao
- Environment Research Institute, Shandong University, Jinan 250100, PR China
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10
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He Z, Sun J, Wei J, Wang Q, Huang C, Chen J, Song S. Effect of silver or copper middle layer on the performance of palladium modified nickel foam electrodes in the 2-chlorobiphenyl dechlorination. JOURNAL OF HAZARDOUS MATERIALS 2013; 250-251:181-189. [PMID: 23454456 DOI: 10.1016/j.jhazmat.2013.02.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Revised: 01/08/2013] [Accepted: 02/01/2013] [Indexed: 06/01/2023]
Abstract
To enhance the activity of chemi-deposited palladium/nickel foam (Pd/Ni) electrodes used for an electrochemical dechlorination process, silver or copper was deposited electrochemically onto the nickel foam substrate (to give Ag/Ni or Cu/Ni) before the chemical deposition of palladium. The physicochemical properties of the resulting materials (Pd/Ni, Pd/Ag/Ni and Pd/Cu/Ni) were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), and their electrochemical catalytic activities were evaluated by monitoring the electrochemical dechlorination of 2-chlorobiphenyl (2-CB) in strongly alkaline methanol/water solution. The results show that the Pd/Ag/Ni and Pd/Cu/Ni electrodes had consistently higher electrocatalytic activities and current efficiencies (CEs) compared with the untreated Pd/Ni electrode. The Pd/Ag/Ni electrode exhibited the highest activity. The dechlorination was also studied as a function of Pd loading, the Ag or Cu interlayer loadings, and the current density. The Pd loading and the interlayer loadings both had positive effects on the dechlorination reaction. Increasing the current density increased the reaction rate but reduced the CE. The improvement of the electrocatalytic activities of the Pd/Ni electrode by applying the interlayer of Ag or Cu resulted from the enlargement of the effective surface area of the electrode and the adjustment of the metal-H bond energy to the appropriate value, as well as the effective adsorption of 2-CB on Ag. Moreover, the high catalytic activity of the Pd/Ag/Ni electrode was maintained after six successive cyclic experiments, whereas Pd/Cu/Ni electrodes deactivate severely under the same conditions.
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Affiliation(s)
- Zhiqiao He
- College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310032, People's Republic of China
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11
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KUROBOSHI M, IDEI H, HARA N, KOKUI Y, TANAKA H. Electroreduction of Aryl Halides Loaded on Palladium-Immobilized Activated Carbon. ELECTROCHEMISTRY 2013. [DOI: 10.5796/electrochemistry.81.359] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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12
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Li J, Liu H, Cheng X, Xin Y, Xu W, Ma Z, Ma J, Ren N, Li Q. Stability of Palladium-Polypyrrole-Foam Nickel Electrode and Its Electrocatalytic Hydrodechlorination for Dichlorophenol Isomers. Ind Eng Chem Res 2012. [DOI: 10.1021/ie3021522] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | | | | | - Yanjun Xin
- School of Resource
and Environment, Qingdao Agricultural University, Qingdao 266109, P. R. China
| | | | - Zhenpeng Ma
- School of Resource
and Environment, Qingdao Agricultural University, Qingdao 266109, P. R. China
| | | | | | - Qing Li
- Department of Pathology
and Cell Biology, Columbia University, Broadway, New York 10027, United States
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Luo S, Yang S, Xue Y, Liang F, Sun C. Two-stage reduction/subsequent oxidation treatment of 2,2',4,4'-tetrabromodiphenyl ether in aqueous solutions: kinetic, pathway and toxicity. JOURNAL OF HAZARDOUS MATERIALS 2011; 192:1795-1803. [PMID: 21807460 DOI: 10.1016/j.jhazmat.2011.07.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2010] [Revised: 05/29/2011] [Accepted: 07/04/2011] [Indexed: 05/31/2023]
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.
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Affiliation(s)
- Si Luo
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093, PR China
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Li MC, Bao DD, Ma CA. Studies on electrochemical hydrodebromination mechanism of 2,5-dibromobenzoic acid on Ag electrode by in situ FTIR spectroscopy. Electrochim Acta 2011. [DOI: 10.1016/j.electacta.2011.01.115] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Granelli L, Eriksson J, Athanasiadou M, Bergman Å. Reductive debromination of nonabrominated diphenyl ethers by sodium borohydride and identification of octabrominated diphenyl ether products. CHEMOSPHERE 2011; 82:839-846. [PMID: 21122890 DOI: 10.1016/j.chemosphere.2010.11.022] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2010] [Revised: 11/03/2010] [Accepted: 11/05/2010] [Indexed: 05/30/2023]
Abstract
A method was developed to study reductive transformation of highly brominated diphenyl ethers (BDEs). The method development is a part of a broader project where it will be used to determine the susceptibility of environmental pollutants to reductive conditions, in an attempt to create a scheme for determination of chemical's persistence. This paper focuses on identification of octabrominated diphenyl ether transformation products from reductive debromination of the three nonabrominated diphenyl congeners (nonaBDE), BDE-206, -207 and -208. Sodium borohydride was used to explore the reductive debromination of the nonaBDEs. The transformation products were collected at two time-points and identified products were quantified by GC-MS. The reduction of the nonaBDEs lead primarily to debrominated products, mainly octaBDEs. The three nonabrominated DEs gave isomer-related transformation product patterns. BDE-207 and BDE-208 showed a propensity for ortho-debromination in the initial reaction step, while no discrimination between initial debromination positions was seen for BDE-206. All three nonabrominated DEs displayed a preferred initial debromination on the fully brominated DE ring.
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Affiliation(s)
- Lisa Granelli
- Environmental Chemistry Unit, Department of Materials and Environmental Chemistry, Stockholm University, SE-10691 Stockholm, Sweden.
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An T, Chen J, Li G, Ding X, Sheng G, Fu J, Mai B, O'Shea KE. Characterization and the photocatalytic activity of TiO2 immobilized hydrophobic montmorillonite photocatalysts. Catal Today 2008. [DOI: 10.1016/j.cattod.2008.08.024] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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17
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Electrocatalytic reduction of 2-chlorobiphenyl in contaminated water using palladium-modified electrode. Sep Purif Technol 2008. [DOI: 10.1016/j.seppur.2008.05.025] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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18
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Konstantinov A, Bejan D, Bunce NJ, Chittim B, McCrindle R, Potter D, Tashiro C. Electrolytic debromination of PBDEs in DE-83 technical decabromodiphenyl ether. CHEMOSPHERE 2008; 72:1159-1162. [PMID: 18472139 DOI: 10.1016/j.chemosphere.2008.03.046] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2007] [Revised: 03/18/2008] [Accepted: 03/19/2008] [Indexed: 05/26/2023]
Abstract
Electrochemical debromination of the commercial decabromodiphenyl ether flame retardant DE-83 in partly aqueous tetrahydrofuran (THF) solution gave lower brominated congeners by sequential loss of bromine atoms. Hydrodebromination was most facile for the most heavily brominated congeners. It involves initial electron transfer and proton transfer from water, rather than hydrogen atom abstraction from THF, as shown by experiments with deuterated water. The product distribution from electrolysis involves preferential loss of bromine meta- and para- to the ether linkage, comparable with the products of metabolism of BDE-209 in various organisms. Significantly, the environmentally relevant congeners BDE-47, BDE-99, and BDE-154 were not major products of debromination of BDE-209 by the electron transfer mechanism.
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Tomilov AP, Turygin VV, Kaabak LV. Studies in the field of electrochemistry of organic compounds in 2000–2006. RUSS J ELECTROCHEM+ 2007. [DOI: 10.1134/s1023193507100023] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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20
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Yang B, Yu G, Shuai D. Electrocatalytic hydrodechlorination of 4-chlorobiphenyl in aqueous solution using palladized nickel foam cathode. CHEMOSPHERE 2007; 67:1361-7. [PMID: 17141295 DOI: 10.1016/j.chemosphere.2006.10.046] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2006] [Revised: 10/07/2006] [Accepted: 10/10/2006] [Indexed: 05/12/2023]
Abstract
The electrocatalytic hydrodechlorination of 4-chlorobiphenyl on palladized nickel foam with high porous structure in an aqueous solution containing MeOH, bromide of hexadecyltrimethylammonium (CTAB), sodium acetate, and acetic acid were investigated in a membrane-separated flow-through cell. The Pd/Ni foam electrode was prepared by electroless deposition method, on which the Pd particles dispersed finely over Ni foam surface indicated by SEM-EDX analysis. The effects of current density, organic cosolvent, initial concentration, temperature, and flow rate on the hydrodechlorination of 4-chlorobiphenyl were examined. Methanol was among the best cosolvents and was used in preferential concentration of 50 vol%. Moderate current density (e.g., 2.23 mA cm(-2)), relatively high initial concentration, temperature, and flow rate were beneficial to improve the hydrodechlorination of 4-chlorobiphenyl. The current efficiencies for the conversion of 1mM 4-MCB decreased with increasing current density and range from 37.2% at 0.74 mA cm(-2) to 14.1% at 5.21 mA cm(-2) after 20 min electrolysis cut. Under the optimized conditions, 1mM of 4-MCB could be removed rapidly with the rate of 94.6% after 2h electrolysis, which gave current efficiencies and energy consumptions in range of 8.1-24.6% and 1.7-5.2 kW h kg(-1), respectively.
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Affiliation(s)
- Bo Yang
- Department of Environmental Science and Engineering, POPs Research Centre, Tsinghua University, Beijing 100084, PR China
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Electrochemical hydrodechlorination of 4-chlorobiphenyl in aqueous solution with the optimization of palladium-loaded cathode materials. Electrochim Acta 2006. [DOI: 10.1016/j.electacta.2006.07.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Niu J, Shen Z, Yang Z, Long X, Yu G. Quantitative structure-property relationships on photodegradation of polybrominated diphenyl ethers. CHEMOSPHERE 2006; 64:658-65. [PMID: 16343592 DOI: 10.1016/j.chemosphere.2005.10.051] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2005] [Accepted: 10/27/2005] [Indexed: 05/05/2023]
Abstract
By partial least squares (PLS) regression, quantitative structure-property relationship (QSPR) models were developed for photodegradation rates (k(p)) and quantum yields (Phi) of polybrominated diphenyl ethers (PBDEs) in methanol/water (8:2), and photodegradation rates in pure methanol by UV light in the sunlight region, respectively. Quantum chemical descriptors computed by PM3 Hamiltonian were used as predictor variables. The cross-validated Q(cum)(2) values for three optimal QSPR models of PBDEs are above 0.90 (remarkably higher 0.50), indicating good predictive abilities for logk(p) and logPhi values of PBDEs. The QSPR results show that logk(p) values of PBDEs in methanol/water (8:2) and in pure methanol are governed by different molecular structural descriptors, respectively, which implies that photodegradation rates of PBDEs are affected by the characteristics of solution in which it takes place.
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Affiliation(s)
- Junfeng Niu
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, PR China.
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