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Ge X, Gao Y, Yang Y, Chen G, Ma S, Hu B, Yu Y, An T. Mixed bromine/chlorine transformation products of tetrabromobisphenol A formed in the combustion of printed circuit boards: Emission characteristics and transformation pathways. Sci Total Environ 2023; 859:160104. [PMID: 36372166 DOI: 10.1016/j.scitotenv.2022.160104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 11/06/2022] [Accepted: 11/06/2022] [Indexed: 06/16/2023]
Abstract
Recently, mixed bromine/chlorine transformation products of tetrabromobisphenol A (ClyBrxBPAs) were found to be possibly related to the thermal treatment processes of electronic wastes. To explore their emission characteristics and formation mechanism, printed circuit board scraps were combusted in a tube furnace, under the temperature from 25 °C to 600 °C. The emission factor of the debromination products of tetrabromobisphenol A (BrxBPAs) was the highest, whereas that of ClyBrxBPAs was the lowest. Among three phases, most of the target compounds were partitioned into the oil and particle phases, and only negligible gaseous 2-BrBPA and bisphenol A were detected. The emission rates of most compounds were fastest at 300 °C, although 2-BrBPA, 2,6-Br2BPA, and 2-Cl-6-BrBPA peaked at 350 °C. Among the chemicals in total emission, 2-BrBPA was the dominant congener in BrxBPAs, whereas 2-Cl-2',6,6'-Br3BPA, 2-Cl-2',6#-Br2BPA, and Σ2Cl1Br1BPAs shared similar proportions in ClyBrxBPAs. Meanwhile, the composition profiles at 300 °C showed that 2,2',6-Br3BPA and 2-Cl-2',6,6'-Br3BPA occupied the largest proportions in BrxBPAs and ClyBrxBPAs, respectively. To reveal the possible transformation pathways, the Gibbs free energy was calculated based on a radical substitution reaction. After "•Br" removal from tetrabromobisphenol A or other BrxBPAs, the intermediate was more easily combined with "•H" than with "•Cl." In addition, the ClyBrxBPA formation via "-•H + •Cl" by BrxBPAs is nonspontaneous, thus limiting the further generation of ClyBrxBPAs. This study not only provides ideas for the study of other mixed halogenated products, but also provides constructive suggestions for environmental source analysis by combining previous research on the occurrence of ClyBrxBPAs in various environmental matrices.
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Affiliation(s)
- Xiang Ge
- Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, PR China; Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Key Laboratory of City Cluster Environmental Safety and Green Development, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, PR China
| | - Yanpeng Gao
- Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, PR China; Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Key Laboratory of City Cluster Environmental Safety and Green Development, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, PR China
| | - Yan Yang
- Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, PR China; Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Key Laboratory of City Cluster Environmental Safety and Green Development, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, PR China.
| | - Guanhui Chen
- Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, PR China; Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Key Laboratory of City Cluster Environmental Safety and Green Development, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, PR China
| | - Shengtao Ma
- Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, PR China; Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Key Laboratory of City Cluster Environmental Safety and Green Development, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, PR China
| | - Beibei Hu
- Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, PR China; Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Key Laboratory of City Cluster Environmental Safety and Green Development, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, PR China
| | - Yingxin Yu
- Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, PR China; Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Key Laboratory of City Cluster Environmental Safety and Green Development, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, PR China
| | - Taicheng An
- Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, PR China; Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Key Laboratory of City Cluster Environmental Safety and Green Development, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, PR China
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