1
|
Song L, Lin L, Wei W, Zhang S, Wan L, Lou Z, Yu J, Xu X. Zero-valent iron-peroxydisulfate as synergistic co-milling agents for enhanced mechanochemical destruction of 2,4-dichlorophenol: Coupling reduction with oxidation. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 345:118571. [PMID: 37421725 DOI: 10.1016/j.jenvman.2023.118571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2023] [Revised: 06/30/2023] [Accepted: 07/02/2023] [Indexed: 07/10/2023]
Abstract
Mechanochemical (MC) remediation with zero-valent iron (ZVI) as co-milling agent enables the non-combustion and solvent-free disposal of solid halogenated organic pollutants (HOPs) via solid-phase reaction, but suffers from incomplete dechlorination (especially for less chlorinated chemicals). Herein, a reduction-oxidation coupling strategy using ZVI and peroxydisulfate as synergistic (ZVI-PDS) co-milling agents was investigated, with 2,4-dichlorophenol (2,4-DCP) as probe contaminant. By revisiting the MC destruction process of 2,4-DCP by ZVI, the contribution of both reductive and oxidative routes is confirmed, and the inefficient •OH generation is addressed. With ball-to-material and reagent-to-pollutant mass ratios of 30:1 and 13:1, respectively, ZVI-PDS achieves higher dechlorination ratio (86.8%) for 2,4-DCP within 5 h, outcompeting sole ZVI (40.3%) or PDS (33.9%), due to the accumulation of numerous SO4•-. As suggested by a two-compartment kinetic model, the optimal ZVI/PDS molar ratio of 4:1 is determined, which balances the relative contribution of reductive/oxidative routes and leads to a maximum mineralization efficiency of 77.4%. The analysis on product distribution verifies the generation of dechlorinated, ring-opening and minor coupling products (with low acute toxicity). This work validates the necessity to couple reduction with oxidation in MC destruction for solid HOPs, and may provide information on reagent formulation.
Collapse
Affiliation(s)
- Ludi Song
- Collaborative Innovation Center of Yangtze River Delta Region Green Pharmaceuticals, Zhejiang University of Technology, Hangzhou, 310014, China; College of Environment, Zhejiang University of Technology, Hangzhou, 310014, China
| | - Lvren Lin
- College of Environment, Zhejiang University of Technology, Hangzhou, 310014, China
| | - Wenjia Wei
- College of Environment, Zhejiang University of Technology, Hangzhou, 310014, China
| | - Shengkun Zhang
- Department of Environmental Engineering, Zhejiang University, Hangzhou, 310058, China
| | - Lei Wan
- Department of Environmental Engineering, Zhejiang University, Hangzhou, 310058, China
| | - Zimo Lou
- Collaborative Innovation Center of Yangtze River Delta Region Green Pharmaceuticals, Zhejiang University of Technology, Hangzhou, 310014, China; College of Environment, Zhejiang University of Technology, Hangzhou, 310014, China.
| | - Jianming Yu
- Collaborative Innovation Center of Yangtze River Delta Region Green Pharmaceuticals, Zhejiang University of Technology, Hangzhou, 310014, China; College of Environment, Zhejiang University of Technology, Hangzhou, 310014, China.
| | - Xinhua Xu
- Department of Environmental Engineering, Zhejiang University, Hangzhou, 310058, China.
| |
Collapse
|
2
|
Ge X, Hashmi MZ, Lin S, Qi Z, Yu Y, An T. Emission characteristics of (halogenated) polycyclic aromatic hydrocarbons during printed circuit board combustion and estimated emission intensity of a typical e-waste dismantling site in South China. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 334:122162. [PMID: 37429487 DOI: 10.1016/j.envpol.2023.122162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 06/28/2023] [Accepted: 07/07/2023] [Indexed: 07/12/2023]
Abstract
The pollution of polycyclic aromatic hydrocarbons (PAHs) and halogenated PAHs (Cl/Br-PAHs) caused by electronic waste dismantling activities have attracted considerable attention. The present study investigated the emissions and formation of PAHs and Cl/Br-PAHs based on the combustion of printed circuit boards simulating electronic waste dismantling process. The emission factor of ΣPAHs was 648 ± 56 ng/g, which was much lower than that of ΣCl/Br-PAHs (8.80 × 104 ± 9.14 × 103 ng/g). From 25 to 600 °C, the emission rate of ΣPAHs reached a sub-peak of 7.39 ± 1.85 ng/(g•min) at 350 °C, then increased gradually with the fastest rate of 19.9 ± 21.8 ng/(g•min) at 600 °C, whereas that of ΣCl/Br-PAHs was the fastest at 350 °C with a rate of 597 ± 106 ng/(g•min), then decreased gradually. The present study suggested that the formation pathways of PAHs and Cl/Br-PAHs are by de novo synthesis. Low molecular weight PAHs were readily partitioned into gas and particle phases, whereas high molecular weight fused PAHs were only detected in oil phase. However, the proportion of Cl/Br-PAHs in particle and oil phases were different from that of gas phase, whereas similar to that of the total emission. In addition, PAH and Cl/Br-PAH emission factors were used to estimate the emission intensity of pyrometallurgy project in Guiyu Circular Economy Industrial Park, and it was shown that approximately 1.30 kg PAHs and 176 kg Cl/Br-PAHs would be emitted annually. This study revealed that Cl/Br-PAHs would be formed by de novo synthesis, and for the first time provided the emission factors of Cl/Br-PAHs during the heat treatment process of printed circuit board, as well as estimated the contribution of pyrometallurgy, a new electronic waste recovery technology, to environmental Cl/Br-PAH pollution, which provides potential scientific information for governmental decision-making on the control of Cl/Br-PAHs.
Collapse
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
| | | | - Shuo Lin
- 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
| | - Zenghua Qi
- 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
| |
Collapse
|
3
|
Hu D, Zeng X, Lin Y, Chen Y, Chen W, Jia Z, Lin J. High Value-Added Reutilization of Waste-Printed Circuit Boards Non-Metallic Components in Sustainable Polymer Composites. Molecules 2023; 28:6199. [PMID: 37687027 PMCID: PMC10489137 DOI: 10.3390/molecules28176199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 08/16/2023] [Accepted: 08/21/2023] [Indexed: 09/10/2023] Open
Abstract
The reutilization non-metallic components from a waste-printed circuit board (WPCB) has become one of the most significant bottlenecks in the comprehensive reuse of electronic wastes due to its low value and complex compositions, and it has received great attention from scientific and industrial researchers. To effectively address the environmental pollution caused by inappropriate recycling methods, such as incineration and landfill, extensive efforts have been dedicated to achieving the high value-added reutilization of WPCB non-metals in sustainable polymer composites. In this review, recent progress in developing sustainable polymer composites based on WPCB non-metallic components was systematically summarized. It has been demonstrated that the WPCB non-metals can serve as a promising reinforcing and functional fillers to significantly ameliorate some of the physical and chemical properties of polymer composites, such as excellent mechanical properties, enhanced thermal stability, and flame retardancy. The recovery strategies and composition of WPCB non-metals were also briefly discussed. Finally, the future potentials and remaining challenges regarding the reutilization of WPCB non-metallic components are outlined. This work provides readers with a comprehensive understanding of the preparation, structure, and properties of the polymer composites based on WPCB non-metals, providing significant insights regarding the high value-added reutilization of WPCB non-metals of electronic wastes.
Collapse
Affiliation(s)
- Dechao Hu
- School of Materials Science and Hydrogen Energy, Foshan University, Foshan 528000, China; (D.H.)
| | - Xianghong Zeng
- School of Materials Science and Hydrogen Energy, Foshan University, Foshan 528000, China; (D.H.)
| | - Yinlei Lin
- School of Materials Science and Hydrogen Energy, Foshan University, Foshan 528000, China; (D.H.)
| | - Yongjun Chen
- Key Lab of Guangdong High Property and Functional Macromolecular Materials, School of Materials Science and Engineering, South China University of Technology, Guangzhou 510640, China
| | - Wanjuan Chen
- School of Materials Science and Hydrogen Energy, Foshan University, Foshan 528000, China; (D.H.)
| | - Zhixin Jia
- Key Lab of Guangdong High Property and Functional Macromolecular Materials, School of Materials Science and Engineering, South China University of Technology, Guangzhou 510640, China
| | - Jing Lin
- Research Center of Flexible Sensing Materials and Devices, School of Applied Physics and Materials, Wuyi University, Jiangmen 529020, China
| |
Collapse
|
4
|
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. THE SCIENCE OF THE TOTAL ENVIRONMENT 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] [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.
Collapse
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
| |
Collapse
|
5
|
Liang J, Wang R, Liu H, Xie D, Tao X, Zhou J, Yin H, Dang Z, Lu G. Unintentional formation of mixed chloro-bromo diphenyl ethers (PBCDEs), dibenzo-p-dioxins and dibenzofurans (PBCDD/Fs) from pyrolysis of polybrominated diphenyl ethers (PBDEs). CHEMOSPHERE 2022; 308:136246. [PMID: 36044966 DOI: 10.1016/j.chemosphere.2022.136246] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2022] [Revised: 08/23/2022] [Accepted: 08/25/2022] [Indexed: 06/15/2023]
Abstract
This study presents the comprehensive investigation for formation pathways of chloro-bromo-mixed products from the pyrolysis of polybrominated diphenyl ethers (PBDEs). In the study, a total of 23 PBDEs with bromination levels from mono-to deca-were selected. Each PBDE standard was sealed in the glass vial and then heated under 450 °C in the muffle furnace to simulate the pyrolysis process. The results demonstrated that PBDEs in the glass vials can unintentionally transform into chloro-bromo diphenyl ethers (PBCDEs) and dibenzo-p-dioxin and dibenzofurans (PBCDD/Fs) during the pyrolysis process. Atmosphere pressure gas chromatography (APGC) coupled with high-resolution mass spectrometry (HRMS) was used to identify these pyrolysis products, which demonstrated that all investigated nPBDEs (n represents the number of bromine substituents) can unintentionally transform into Cl1-(n-1)BDEs, Cl2-(n-2)BDEs, Cl1-(n-1)BDFs, and Cl1-(n-3)BDDs, while some nPBDEs can transform into Cl1-(n-2)PBDD/Fs during pyrolysis. Experimental phenomena assisted with density functional theory (DFT) calculations reveal that Cl atom can substitute at C-Br rather than C-H, and Cl1-(n-1)BDEs can be easily generated by Cl atom attacking at C-Br sites with low energy barriers (3.66-11.9 kcal/mol). In addition, nPBDEs with lower bromination levels are more favorable to generate Cl1-(n-1)BDEs than those with higher bromination levels. Further DFT calculations suggest that PBDEs are preferentially first transformed into Cl1-(n-1)BDEs, then subsequentially transform into PBCDD/Fs. We believe the results of this study can greatly improve our understanding of the transformation mechanism from PBDEs to cholo-bromo-mixed products in thermal treatment processes and provide new insight into controlling the emission of toxic cholo-bromo-mixed products.
Collapse
Affiliation(s)
- Jiahao Liang
- School of Environment and Energy, South China University of Technology, Guangzhou, 510006, China
| | - Rui Wang
- South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou, 510655, China.
| | - He Liu
- South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou, 510655, China
| | - Danping Xie
- South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou, 510655, China
| | - Xueqin Tao
- College of Resources and Environment, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, China
| | - Jiangmin Zhou
- College of Life and Environmental Sciences, Wenzhou University, Wenzhou, 325035, China
| | - Hua Yin
- School of Environment and Energy, South China University of Technology, Guangzhou, 510006, China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou, 510006, China
| | - Zhi Dang
- School of Environment and Energy, South China University of Technology, Guangzhou, 510006, China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou, 510006, China; Guangdong Provincial Key Lab of Solid Wastes Pollution Control and Recycling, South China University of Technology, Guangzhou, 510006, China
| | - Guining Lu
- School of Environment and Energy, South China University of Technology, Guangzhou, 510006, China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou, 510006, China.
| |
Collapse
|
6
|
Yang S, Sun X, Jiang Y, Wu S, Zhao D. Mechanochemical destruction and mineralization of solid-phase hexabromocyclododecane assisted by microscale zero-valent aluminum. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 824:153864. [PMID: 35176362 DOI: 10.1016/j.scitotenv.2022.153864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 02/09/2022] [Accepted: 02/09/2022] [Indexed: 06/14/2023]
Abstract
Hexabromocyclododecane (HBCD) has been listed in Annex A of the Stockholm Convention as a persistent and bio-accumulative chemical. While HBCD is often present in the solid form for its low solubility, cost-effective technologies have been lacking for the degradation of solid-phase HBCD. In this work, mechanochemical (MC) destruction of high-energy ball milling was employed for direct destruction of solid-phase HBCD, where a strong reducer, microscale zero-valent aluminum (mZVAl), was used as the co-milling agent. The new mZVAl-assisted MC process achieved complete debromination and mineralization of HBCD within 3 h milling. The optimal operating parameters were determined, including the milling atmosphere, the milling speed, the mZVAl-to-HBCD molar ratio, and the ball-to-mZVAl mass ratio. Fourier transform infrared spectrometry and Raman analyses revealed that the organic structures of HBCD were destroyed and organic bromine was completely converted into inorganic bromide, accompanied by the generation of amorphous and graphite carbon. Analysis of the milled samples by GC-MS demonstrated the absence of obvious organic matter after MC treatment, also indicating the complete degradation and conversion of HBCD to inorganic compounds. Further X-ray photoelectron spectroscopic analysis indicates that the fresh surface of mZVAl was generated upon the MC treatment, and Al(0) served as a strong reducing agent (e-donor) for reductive debromination and destruction of the carbon skeleton. The mZVAl-assisted MC milling appears promising as a non-combustion approach for effective destruction and carbonization/mineralization of solid-phase HBCD or potentially other persistent organic pollutants.
Collapse
Affiliation(s)
- Shiying Yang
- Key Laboratory of Marine Environment and Ecology, Ministry of Education, Qingdao 266100, China; Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering (MEGE), Qingdao 266100, China; College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China.
| | - Xinrong Sun
- Key Laboratory of Marine Environment and Ecology, Ministry of Education, Qingdao 266100, China; College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China
| | - Yuting Jiang
- College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China
| | - Sui Wu
- College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China
| | - Dongye Zhao
- Department of Civil and Environmental Engineering, 238 Harbert Engineering Center, Auburn University, Auburn, AL 36849, USA.
| |
Collapse
|
7
|
Die Q, Yang J, Wang J, Wang J, Yang Y, Huang Q, Zhou Q. Occurrence and formation pathways analysis of PBDD/Fs from 2,4,6-tribromophenol under thermal reaction conditions. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2022; 235:113449. [PMID: 35358919 DOI: 10.1016/j.ecoenv.2022.113449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Revised: 03/17/2022] [Accepted: 03/20/2022] [Indexed: 06/14/2023]
Abstract
Polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs) are highly toxic and persistent compounds that provoke a wave of publicity. Bromophenols are important precursors for forming PBDD/Fs, and their reaction path has always been a research hotspot. In this study, the formation characteristic of PBDD/Fs from 2,4,6-TBP were studied. The yields of 2,3,7,8-substituted PBDD/Fs and 2,4,6,8-TBDF for the different thermal products ranged from 0.067 to 10.3 ng/g and 0.207-9.68 ng/g, respectively. The effects of adding Cu, Fe, and Sb2O3 were investigated and found to be more inclined to accelerate the formation of ortho-substituted PBDD/Fs than 2,3,7,8-PBDD/Fs. The formation pathways of 2,3,7,8-substituted PBDD/Fs and 2,4,6,8-TBDF were also proposed. 2,4,6,8-TBDF is generated in the C-C coupling reactions of some radical intermediates from the debromination of 2,4,6-TBP. The 2,3,7,8-PBDD/Fs are produced through more complex debromination, bromine substitution, and bromine rearrangement reactions. In addition, various catalytic effects on PBDD/F formation pathways were found, and the catalytic effect of Cu by the Ullmann reaction was the highest, while bromophenol oxidation by Fe was the highest. These results proved that both 2,3,7,8-substituted and non-2,3,7,8-substituted PBDD/Fs would be generated from 2,4,6-TBP, and the effects of the catalyst on the Br substituted position of 2,3,7,8-substituted PBDD/Fs were much lower than the Br-substituted position on bromophenol.
Collapse
Affiliation(s)
- Qingqi Die
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Jinzhong Yang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Jianyuan Wang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Jian Wang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Yufei Yang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Qifei Huang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Qi Zhou
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
| |
Collapse
|
8
|
Takaya Y, Xiao Y, Tsunazawa Y, Córdova M, Tokoro C. Mechanochemical degradation treatment of TBBPA: A kinetic approach for predicting the degradation rate constant. ADV POWDER TECHNOL 2022. [DOI: 10.1016/j.apt.2022.103469] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
9
|
Wang H, Hao R, Nie L, Zhang X, Zhang Y. Pollution characteristics and risk assessment of air multi-pollutants from typical e-waste dismantling activities. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 294:118630. [PMID: 34871645 DOI: 10.1016/j.envpol.2021.118630] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 12/01/2021] [Accepted: 12/02/2021] [Indexed: 06/13/2023]
Abstract
This study investigated the characteristics of air multi-pollutants emitted during typical electronic waste (e-waste) dismantling processes and assessed their risks to the environment and human health. Concentrations of total volatile organic compounds (TVOCs), polybrominated diphenyl ethers (PBDEs), and polycyclic aromatic hydrocarbons (PAHs) in a typical e-waste dismantling workshop were 137 μg/m3, 135 ng/m3 and 42 ng/m3, respectively, which were lower than those without emission control measures. The partial removal of pollutants due to the emission control measures also decreased the ozone formation potential and non-cancer risk of volatile organic compounds (VOCs). In the workshop, the lifetime cancer risk (LCR) of VOCs (8.1 × 10-5) was close to the recommended values. Conversely, the LCR of PAHs (3.6 × 10-5) and the total exposure index of PBDEs (19 ng/d) were remarkably lower than the recommended values of 10-3 and that without emission control measures, respectively. Meanwhile, the concentrations of TVOCs, polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs), PBDEs, and PAHs in the outlet were approximately 10-30 times higher than those in the workshop. In addition, the LCR of TVOCs within a 5-km radius area remained higher than the accepted value (10-6), and the inhalation exposure risk of PCDD/Fs within a 20-km radius area was five times higher than the recommended value. Therefore, the emissions from e-waste recycling processes should be considered as an important source of air pollution, and more efficient control measures should be taken in the future.
Collapse
Affiliation(s)
- Hailin Wang
- Beijing Key Laboratory for VOCs Pollution Prevention and Treatment Technology Application, Beijing Municipal Research Institute of Environment Protection, Beijing, 100037, China
| | - Run Hao
- Beijing Key Laboratory for VOCs Pollution Prevention and Treatment Technology Application, Beijing Municipal Research Institute of Environment Protection, Beijing, 100037, China
| | - Lei Nie
- Beijing Key Laboratory for VOCs Pollution Prevention and Treatment Technology Application, Beijing Municipal Research Institute of Environment Protection, Beijing, 100037, China
| | - Xin Zhang
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 101408, China; Yanshan Earth Critical Zone and Surface Fluxes Research Station, University of Chinese Academy of Sciences, Beijing, 101408, China.
| | - Yuanxun Zhang
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 101408, China; Yanshan Earth Critical Zone and Surface Fluxes Research Station, University of Chinese Academy of Sciences, Beijing, 101408, China
| |
Collapse
|
10
|
Song A, Li H, Liu M, Peng P, Hu J, Sheng G, Ying G. Polybrominated dibenzo-p-dioxins/furans (PBDD/Fs) in soil around municipal solid waste incinerator: A comparison with polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs). ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 293:118563. [PMID: 34838709 DOI: 10.1016/j.envpol.2021.118563] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 11/05/2021] [Accepted: 11/19/2021] [Indexed: 06/13/2023]
Abstract
Polybrominated dibenzo-p-dioxins/furans (PBDD/Fs) and polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) share similar toxicities and thermal origins, e.g., municipal solid waste incinerator (MSWI). Recently, PBDD/Fs from MSWI attracted rising concern because their important precursors, i.e., brominated flame retardants (BFRs), were frequently found in various wastes for landfill or MSWI feedstock. So far, however, little is known about PBDD/Fs and their associated risks in the vicinal environments of MSWI. Here we analyzed PBDD/Fs and PCDD/Fs in 29 soil samples collected around a multiyear large-scale MSWI, and compared their spatial distributions, sources and risks. PBDD/Fs demonstrated comparable concentrations and toxic equivalent quantities (TEQs) to PCDD/Fs in these samples. Spatially, both the concentrations of PBDD/Fs and PCDD/Fs decreased outwards from the MSWI, and exhibited significant linear correlations with the distances from the MSWI in the southeast downwind soil, suggesting the influence of the MSWI on its vicinal soil environment. However, the existence of other dioxin sources concealed its influence beyond 6 km. PBDD/Fs in the soils were characterized by highly-brominated PBDFs, especially Octa-BDF, and their sources were diagnosed as the MSWI and diesel exhaust; PCDD/Fs, however, were dominated by highly-chlorinated PCDDs, particularly Octa-CDD, and were contributed individually or jointly by the MSWI, automobile exhaust and pentachlorophenol (PCP)/Na-PCP. The non-carcinogenic risks of dioxins in all the soil samples were acceptable, but their carcinogenic risks in 17% of the samples were unacceptable. These samples were all located close to the MSWI and highways, therefore, the land use of these two high-risk zones should be cautiously planed.
Collapse
Affiliation(s)
- Aimin Song
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Huiru Li
- SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou, 510006, China; School of Environment, South China Normal University, Guangzhou, 510006, China.
| | - Mingyang Liu
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ping'an Peng
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China; University of Chinese Academy of Sciences, Beijing, 100049, China; CAS Center for Excellence in Deep Earth Science, Guangzhou, 510640, China; Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou, 510640, China
| | - JianFang Hu
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China
| | - Guoying Sheng
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China
| | - Guangguo Ying
- SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou, 510006, China; School of Environment, South China Normal University, Guangzhou, 510006, China
| |
Collapse
|
11
|
Chen K, Huang T, Zhang X, Liu X, Huang Y, Wang L, Zhao Y, Gao H, Tao S, Liu J, Jian X, Gusev A, Ma J. The footprint of dioxins in globally traded pork meat. iScience 2021; 24:103255. [PMID: 34755094 PMCID: PMC8564055 DOI: 10.1016/j.isci.2021.103255] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 08/30/2021] [Accepted: 10/08/2021] [Indexed: 11/29/2022] Open
Abstract
The bioaccumulation of polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs), known as dioxins, in fatty meat is one of primary pathways of entry into the human body, but levels of human exposure to dioxins in fatty meat subject to global trade are unknown. We show high dioxin estimated dietary intake (EDI) via pork consumption in Europe, the United States, and China, owing to stronger dioxin environmental contamination and high pork consumption in these countries. The dioxin risk transfer embodied in pork trade is mostly significant in high-latitude countries and regions of Canada, Russia, and Greenland because these regions with low dioxin environmental levels import large amounts of pork meat from more severely dioxin-contaminated Europe and the United States. We demonstrate that global pig feed trading decreases the exposure of pork consumers to dioxins via the import of feed from countries with low dioxin environmental contamination by pig breeding countries.
Collapse
Affiliation(s)
- Kaijie Chen
- Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - Tao Huang
- Key Laboratory for Environmental Pollution Prediction and Control, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000, China
| | - Xiaodong Zhang
- Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - Xinrui Liu
- Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - Yufei Huang
- Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - Linfei Wang
- Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - Yuan Zhao
- Key Laboratory for Environmental Pollution Prediction and Control, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000, China
| | - Hong Gao
- Key Laboratory for Environmental Pollution Prediction and Control, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000, China
| | - Shu Tao
- Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - Junfeng Liu
- Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - Xiaohu Jian
- Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - Alexey Gusev
- Meteorological Synthesizing Centre-East, Convention on Long-Range Transboundary Air Pollution, Moscow, Russia
| | - Jianmin Ma
- Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China.,Key Laboratory for Environmental Pollution Prediction and Control, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000, China
| |
Collapse
|
12
|
Recovery of Ag, Au, and Pt from Printed Circuit Boards by Pressure Leaching. RECYCLING 2021. [DOI: 10.3390/recycling6040067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Reclamation of printed circuit boards (PCBs) to recover metals is gaining growing attention due to minerals being non-renewable resources. Currently, metals extraction from PCBs through an efficient and green method is still under investigation. The present investigation concerns the recycling of printed circuit boards using hydrometallurgical processes. First, the basic metals (Cu, Ni, Zn and Fe) were separated using a sulfuric acid solution at moderate temperatures. The remaining solids were characterized by SEM-EDS, whereby a high content of precious metals (Au, Ag and Pt) was observed. In the second stage, solids were leached with a solution of HCl and NaClO in a 1-L titanium reactor with varied oxygen pressure (0.2, 0.34 and 0.55 MPa), temperature (40, 50 and 80 °C) and concentration of HCl (2 and 4 M), obtaining extractions above 95% at [HCl] = 4 M, P = 0.34 MPa and T = 40 °C. The extraction increased depending on the concentration of HCl. Eh–pH diagrams for Ag–Cl–H2O, Au–Cl–H2O and Pt–Cl–H2O were constructed to know the possible species in the solution.
Collapse
|
13
|
Yang Y, Zheng M, Yang L, Jin R, Li C, Liu X, Liu G. Profiles, spatial distributions and inventory of brominated dioxin and furan emissions from secondary nonferrous smelting industries in China. JOURNAL OF HAZARDOUS MATERIALS 2021; 419:126415. [PMID: 34166953 DOI: 10.1016/j.jhazmat.2021.126415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 06/08/2021] [Accepted: 06/14/2021] [Indexed: 06/13/2023]
Abstract
Nonferrous metallurgical processes are important sources of carcinogenic polybrominated dibenzo-p-dioxin and dibenzofuran (PBDD/Fs) that transport globally. Studies on the profiles, spatial distributions and inventory of PBDD/F emissions into the atmosphere from nonferrous metallurgical plants are needed for better source control. In this study, field investigations on PBDD/F emissions from typical nonferrous metallurgical plants were conducted to characterize the PBDD/F profiles and derive their emission factors. Based on the PBDD/F profiles, diagnostic ratios of PBDD/Fs for secondary copper, zinc and lead smelting were proposed for identifying the potential sources of PBDD/Fs in environment. The PBDD/F emission factors for the secondary copper, lead, and zinc smelting plants were 0.71, 1.65, and 1.54 μg toxic equivalents/t, respectively. The estimated annual input of PBDD/Fs into atmosphere by secondary nonferrous metallurgical plants in China was 212.4 g by mass and 3511.3 mg by toxic equivalents, which is of significance for further evolving a global inventory. The spatial distribution of PBDD/F emissions from nonferrous metallurgical plants in China was mapped. Larger amounts of PBDD/Fs were emitted in the southeastern coastal region and northern China than elsewhere in China.
Collapse
Affiliation(s)
- Yuanping Yang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Minghui Zheng
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China; School of Environment, Hangzhou Institute for Advanced Study, UCAS, Hangzhou 310000, China
| | - Lili Yang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Rong Jin
- School of Environment, Hangzhou Institute for Advanced Study, UCAS, Hangzhou 310000, China
| | - Cui Li
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaoyun Liu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Guorui Liu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China; School of Environment, Hangzhou Institute for Advanced Study, UCAS, Hangzhou 310000, China.
| |
Collapse
|
14
|
Dismantling of Printed Circuit Boards Enabling Electronic Components Sorting and Their Subsequent Treatment Open Improved Elemental Sustainability Opportunities. SUSTAINABILITY 2021. [DOI: 10.3390/su131810357] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
This critical review focuses on advanced recycling strategies to enable or increase recovery of chemical elements present in waste printed circuit boards (WPCBs). Conventional recycling involves manual removal of high value electronic components (ECs), followed by raw crushing of WPCBs, to recover main elements (by weight or value). All other elements remain unrecovered and end up highly diluted in post-processing wastes or ashes. To retrieve these elements, it is necessary to enrich the waste streams, which requires a change of paradigm in WPCB treatment: the disassembly of WPCBs combined with the sorting of ECs. This allows ECs to be separated by composition and to drastically increase chemical element concentration, thus making their recovery economically viable. In this report, we critically review state-of-the-art processes that dismantle and sort ECs, including some unpublished foresight from our laboratory work, which could be implemented in a recycling plant. We then identify research, business opportunities and associated advanced retrieval methods for those elements that can therefore be recovered, such as refractory metals (Ta, Nb, W, Mo), gallium, or lanthanides, or those, such as the platinum group elements, that can be recovered in a more environmentally friendly way than pyrometallurgy. The recovery methods can be directly tuned and adapted to the corresponding stream.
Collapse
|
15
|
Yang L, Liu G, Shen J, Wang M, Yang Q, Zheng M. Environmental characteristics and formations of polybrominated dibenzo-p-dioxins and dibenzofurans. ENVIRONMENT INTERNATIONAL 2021; 152:106450. [PMID: 33684732 DOI: 10.1016/j.envint.2021.106450] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 12/23/2020] [Accepted: 02/04/2021] [Indexed: 06/12/2023]
Abstract
Polybrominated dibenzo-p-dioxins and furans (PBDD/Fs) are emerging persistent organic pollutants (POPs) that have similar or higher toxicities than the notorious dioxins. Toxicities, formation mechanisms, and environmental fates of PBDD/Fs are lacking because accurate quantification, especially of higher brominated congeners, is challenging. PBDD/F analysis is difficult because of photolysis and thermal degradation and interference from polybrominated diphenyl ethers. Here, literatures on PBDD/F analysis and environmental occurrences are reviewed to improve our understanding of PBDD/F environmental pollution and human exposure levels. Although PBDD/Fs behave similarly to dioxins, different congener profiles between PBDD/Fs and dioxins in the environment indicates their different sources and formation mechanisms. Herein, potential sources and formation mechanisms of PBDD/Fs were critically discussed, and current knowledge gaps and future directions for PBDD/F research are highlighted. An understanding of PBDD/F formation pathways will allow for development of synergistic control strategies for PBDD/Fs, dioxins, and other dioxin-like POPs.
Collapse
Affiliation(s)
- Lili Yang
- 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
| | - Guorui Liu
- 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; School of Environment, Hangzhou Institute for Advanced Study, UCAS, Hangzhou 310000, China; College of Resource and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jia Shen
- 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
| | - Minxiang Wang
- 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
| | - Qiuting Yang
- 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
| | - Minghui Zheng
- 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; School of Environment, Hangzhou Institute for Advanced Study, UCAS, Hangzhou 310000, China; Institute of Environment and Health, Jianghan University, Wuhan 430056, China.
| |
Collapse
|
16
|
Shen J, Yang L, Liu G, Zhao X, Zheng M. Occurrence, profiles, and control of unintentional POPs in the steelmaking industry: A review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 773:145692. [PMID: 33940761 DOI: 10.1016/j.scitotenv.2021.145692] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 02/02/2021] [Accepted: 02/03/2021] [Indexed: 06/12/2023]
Abstract
The steelmaking industry is an important source of unintentionally produced persistent organic pollutants (UP-POPs). This review summarizes the emission levels, characteristics, and formation mechanisms of UP-POPs, including halogenated dioxins, polychlorinated biphenyls, polychlorinated naphthalenes, and penta- and hexa- chlorobenzenes in the steelmaking industry to improve our understanding of the emissions of UP-POPs from the steelmaking industry. The factors influencing UP-POP formation during the iron ore sintering (IOS) process are also reviewed. The raw materials and temperature during the steelmaking process are important factors influencing UP-POP generation. Raw materials containing plastics, paints, cutting oil, rubber, and iron from electronic waste recycling can contribute to high emissions of UP-POPs during steelmaking processes. Electrostatic precipitator dust contains chlorine, carbon, and metals, which are usually recycled as a component of the raw material, and could also promote dioxin formation and emissions from IOS. Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) are easily formed in high concentrations at temperatures in the range of 200 °C-650 °C. This review also provides a comprehensive summary of the UP-POP emission limits in the steel industry worldwide and the best available techniques and environmental practices for UP-POP emission reduction. The information in this review will be useful for the reduction of UP-POPs in the steelmaking process.
Collapse
Affiliation(s)
- Jia Shen
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Geology and Environment, Xi'an University of Science and Technology, Xi'an 710054, China
| | - Lili Yang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
| | - Guorui Liu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; School of Environment, Hangzhou Institute for Advanced Study, UCAS, Hangzhou 310000, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Xiaoguang Zhao
- College of Geology and Environment, Xi'an University of Science and Technology, Xi'an 710054, China
| | - Minghui Zheng
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; School of Environment, Hangzhou Institute for Advanced Study, UCAS, Hangzhou 310000, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100190, China
| |
Collapse
|
17
|
Kumar A, Holuszko ME, Janke T. Analysis of rejects from waste printed circuit board processing as an alternative fuel for the cement industry. WASTE MANAGEMENT & RESEARCH : THE JOURNAL OF THE INTERNATIONAL SOLID WASTES AND PUBLIC CLEANSING ASSOCIATION, ISWA 2021; 39:841-848. [PMID: 32907519 DOI: 10.1177/0734242x20952847] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Waste Printed circuit boards (PCBs) are one of the most valuable and recycled components of electronic waste due to the presence of precious metals such as copper, silver, gold and palladium. The rejects of the PCB recycling process, named non-metal fraction (NMF) have continuously been sent to landfills. Several researchers have proposed alternative use of NMF as secondary materials such as fillers in composites or as adsorbent. This study is focused on the potential application of the PCB recycling rejects as waste-derived fuel or alternative fuel in the cement industry. Approximately 2 million metric tonnes (Mt) of this waste was produced in 2014 globally and estimated to reach 6.5 million Mt in 2050. The presence of high organic matter in the NMF renders it useful as an alternative fuel. The organic content of the NMF could also potentially be increased using gravity separation and thus increasing its net calorific value. The study showed that the NMF could provide up to 21 MJ kg-1 of heating value with low heavy metal and ash concentration. A comparison with other waste-derived fuel sources is also presented in the paper.
Collapse
Affiliation(s)
- Amit Kumar
- NBK Institute of Mining Engineering, University of British Columbia, Vancouver, BC, Canada
| | - Maria E Holuszko
- NBK Institute of Mining Engineering, University of British Columbia, Vancouver, BC, Canada
| | - Travis Janke
- Ronin8 Technologies Limited, Vancouver, BC, Canada
| |
Collapse
|
18
|
Wu D, Qi J, Li Q, Chen J, Chen Y, Chen J. Extreme Exposure Levels of PCDD/Fs Inhaled from Biomass Burning Activity for Cooking in Typical Rural Households. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:7299-7306. [PMID: 34014073 DOI: 10.1021/acs.est.1c00469] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), emitted during biomass combustion, are carcinogenic chemicals. The association between indoor biomass burning and PCDD/Fs inhalation exposure levels is still poorly understood. This study first reports direct measurement of personal exposure to PCDD/Fs in real-world households with wood combustion. In homes where biomass burning is used for cooking, toxic equivalent quantity (TEQ) PCDD/Fs concentrations were found to be 545 ± 251 fg I-TEQ/m3 in kitchens, with levels of 4.5-, 6.9-, and 13.3-fold higher than those in living rooms (122 ± 92 fg I-TEQ/m3), bedrooms (79 ± 27 fg I-TEQ/m3), and ambient air (41 ± 15 fg I-TEQ/m3), respectively. PCDD/Fs exposure levels in populations using biomass fuels for cooking (353 ± 110 fg I-TEQ/m3) were 4.3-fold higher than those in the control groups (82 ± 32 fg I-TEQ/m3). Additionally, the average cancer risks for biomass cooking person were approximately 3.1-fold higher than those in factory workers. Overall, residents of household that use biomass fuels for cooking have the highest known risk of PCDD/Fs exposure. These results highlight that aiming to mitigate the PCDD/Fs exposure risk in the general population, the focus of dioxin emission source control measures should shift from industrial sectors to residential biomass combustion.
Collapse
Affiliation(s)
- Di Wu
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China
| | - Juan Qi
- School of Chemical Engineering, Xuzhou College of Industrial Technology, Xuzhou 221140, China
| | - Qing Li
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China
- Shanghai Institute of Eco-Chongming (SIEC), No. 3663 Northern Zhongshan Road, Shanghai 200062, China
| | - Jiping Chen
- Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Yingjun Chen
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China
- Shanghai Institute of Eco-Chongming (SIEC), No. 3663 Northern Zhongshan Road, Shanghai 200062, China
| | - Jianmin Chen
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China
| |
Collapse
|
19
|
Abstract
Resource Recovery from Waste Electronics has emerged as one of the most imperative processes due to its pressing challenges all over the world. The Printed Circuit Board (PCB) is one of the typical E-waste components that comprise large varieties of metals and nonmetals. Urban Mining of these metals has received major attention all over the world. The existing treatment procedures used extensively for the resource extraction are hydrometallurgy and pyro-metallurgy and crude recycling practices in the informal sector. However, these methods are prone to cause secondary pollutants with certain drawbacks. Also, the existing informal recycling procedures resulted in insignificant occupational health hazards and severe environmental threats. The application of biotechnology is extensively exploited for metal extraction and emerged as one of the sustainable and eco-friendly tools. However, a limited field-scale study is prevailing in the realm of resource recovery from E-waste using bioleaching method. Hence, the application of bioleaching requires more attention and technical know-how in developing countries to curtail crude practices. The application of bioleaching in E-waste, including its available methods, kinetics mechanism associated opportunities, and barriers, have been discussed in this paper. A glance of E-waste management in India and the menace of 95% crude E-waste recycling are also elaborated. The incentives toward profit, socio-economic, and environmentally sustainable approaches have been delineated based on critical analysis of the available literature.
Collapse
Affiliation(s)
- Shashi Arya
- Technology Development Centre (TDC), CSIR-National Environmental Engineering Research Institute (CSIR-NEERI) , Nagpur, India.,Technology Development Centre (TDC), Academy of Scientific and Innovative Research (AcSIR) , Ghaziabad, India
| | - Sunil Kumar
- Technology Development Centre (TDC), CSIR-National Environmental Engineering Research Institute (CSIR-NEERI) , Nagpur, India
| |
Collapse
|
20
|
Plastic Recycling Practices in Vietnam and Related Hazards for Health and the Environment. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18084203. [PMID: 33921067 PMCID: PMC8071425 DOI: 10.3390/ijerph18084203] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Revised: 04/02/2021] [Accepted: 04/08/2021] [Indexed: 11/17/2022]
Abstract
Waste plastic today is a global threat. The rapid increase in global production and use has led to increasing quantities of plastics in industrial and municipal waste streams. While in industrialized countries plastic waste is taken up by a waste management system and at least partly recycled, in low-income countries adequate infrastructure to collect and treat waste adequately is often not in place. This paper analyzes how plastic waste is handled in Vietnam, a country with a fast-growing industry and growing consumption. The recycling of plastic waste typically takes place in an informal context. To demonstrate this in more detail, two rural settlements—so-called craft villages—are taken as case studies. Technologies and processes for plastic recycling are described and related risks for human health and the environment are shown, as well as the potential for the improvement of this situation.
Collapse
|
21
|
Das P, Gabriel JCP, Tay CY, Lee JM. Value-added products from thermochemical treatments of contaminated e-waste plastics. CHEMOSPHERE 2021; 269:129409. [PMID: 33388566 DOI: 10.1016/j.chemosphere.2020.129409] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 12/14/2020] [Accepted: 12/20/2020] [Indexed: 06/12/2023]
Abstract
The rise of electronic waste (e-waste) generation around the globe has become a major concern in recent times and its recycling is mostly focused on the recovery of valuable metals, such as gold, silver, and copper, etc. However, e-waste consists of a significant weight fraction of plastics (25-30%) which are either discarded or incinerated. There is a growing need for recycling of these e-waste plastics. The majority of them are made from high-quality polymers (composites), such as acrylonitrile butadiene styrene (ABS), high impact polystyrene (HIPS), polycarbonate (PC), polyamide (PA), polypropylene (PP) and epoxies. These plastics are often contaminated with hazardous materials, such as brominated flame retardants (BFRs) and heavy metals (such as Pb and Hg). Under any thermal stress (thermal degradation), the Br present in the e-waste plastics produces environmentally hazardous pollutants, such as hydrogen bromide or polybrominated diphenyl ethers/furans (PBDE/Fs). The discarded plastics can lead to the leaching of toxins into the environment. It is important to remove the toxins from the e-waste plastics before recycling. This review article gives a detailed account of e-waste plastics recycling and recovery using thermochemical processes, such as extraction (at elevated temperature), incineration (combustion), hydrolysis, and pyrolysis (catalytic/non catalytic). A basic framework of the existing processes has been established by reviewing the most interesting findings in recent times and the prospects that they open in the field recycling of e-waste plastics.
Collapse
Affiliation(s)
- Pallab Das
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, Singapore, 637459, Singapore.
| | | | - Chor Yong Tay
- School of Materials Science and Engineering, Nanyang Technological University, N4.1, 50 Nanyang Avenue, Singapore, 639798, Singapore; School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore, 637551, Singapore
| | - Jong-Min Lee
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, Singapore, 637459, Singapore.
| |
Collapse
|
22
|
Fernandes AR, Falandysz J. Polybrominated dibenzo-p-dioxins and furans (PBDD/Fs): Contamination in food, humans and dietary exposure. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 761:143191. [PMID: 33160676 DOI: 10.1016/j.scitotenv.2020.143191] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 10/15/2020] [Accepted: 10/16/2020] [Indexed: 05/11/2023]
Abstract
Polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs) have been recognised as environmental pollutants for decades but their occurrence in food has only recently been reported. They elicit the same type of toxic response as analogous polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) with similar potencies and effects, and share similar origins - inadvertent production during combustion and occurrence as by-products in industrial chemicals. Surprisingly, PBDD/Fs have received considerably less attention than PCDD/Fs, perhaps because determination requires a higher degree of analytical competence, a result of the higher adsorptivity and lability associated with carbon-bromine bonding. For most populations, the principal exposure pathway is dietary intake. The PBDD/F toxicity arising from occurrence in foods has often been expressed as toxic equivalents (TEQs) using the same scheme developed for PCDD/Fs. This approach is convenient, but resulting TEQ estimates are more uncertain, given the known differences in response for some analogous congeners and also the different patterns of PBDD/F occurrence confirmed by the newer data. Further studies to consolidate potency factors would help to refine TEQ estimates. Characteristically, most foods and human tissues show more frequent and higher PBDF concentrations relative to PBDDs, reflecting major source patterns. Occurrence in food ranges from <0.01 to several thousand pg/g (or up to 0.3 pg TEQ/g whole weight) which is comparable to PCDD/F occurrence (ΣPBDD/F TEQs are underestimated as not all relevant congeners are included). Plant based foods show higher PBDD/F: PCDD/F TEQ ratios. Reported PBDD/F dietary intakes suggest that some population groups, particularly young children, may exceed the revised tolerable weekly intake for dioxin-like contaminants (2 pg TEQ/kg bw/week), even for mean consumption estimated with lower bound data. It is evident that the omission of PBDD/Fs from the TEQ scheme results in a significant underestimation of the cumulative toxicity and associated risk arising from this mode of action.
Collapse
Affiliation(s)
- Alwyn R Fernandes
- School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ, UK.
| | - Jerzy Falandysz
- University of Gdańsk, Environmental Chemistry and Ecotoxicology, 80-308 Gdańsk, Poland
| |
Collapse
|
23
|
Kojima Y, Fujimori T, Goto A, Shiota K, Kunisue T, Takaoka M. Bromination of Carbon and Formation of PBDD/Fs by Copper Bromide in Oxidative Thermal Process. JOURNAL OF HAZARDOUS MATERIALS 2021; 403:123878. [PMID: 33264949 DOI: 10.1016/j.jhazmat.2020.123878] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 08/12/2020] [Accepted: 08/29/2020] [Indexed: 06/12/2023]
Abstract
Brominated aromatic compounds are unintentionally generated during various thermal processes, including municipal solid waste incineration, electric-waste open burning, and secondary copper smelting. Copper (Cu) plays an important role in the formation of brominated aromatic compounds. In the present study, the thermochemical behaviors of Cu and Br in model samples, including copper bromide (CuBr2) and activated carbon, were studied using in situ X-ray absorption near-edge structure (XANES) and thermogravimetry. Quantification of polybrominated dibenzo-p-dioxins/furans (PBDD/Fs) was also conducted by gas chromatograph-high resolution mass spectrometer. Three key reactions were identified: (i) the reduction of CuBr2 to CuBr (room temperature to 300 °C), (ii) the generation of Br bonded with aromatic carbon (150-350 °C), and (iii) the oxidation of copper (>350 °C). Maximum amounts of PBDD/Fs were found in residual solid phase after heating at 300 °C. The analytical results indicated the direct bromination of aromatic carbon by the debromination of copper bromides (I, II) and that CuBr and CuO acted as catalysts in the oxidation of the carbon matrix. The bromination mechanisms revealed in this study are essential to the de novo formation of PBDD/Fs and other brominated aromatic compounds.
Collapse
Affiliation(s)
- Yusuke Kojima
- Department of Environmental Engineering, Graduate School of Engineering, Kyoto University, Katsura, Nisikyo-ku, Kyoto 615-8540, Japan
| | - Takashi Fujimori
- Department of Environmental Engineering, Graduate School of Engineering, Kyoto University, Katsura, Nisikyo-ku, Kyoto 615-8540, Japan; Department of Global Ecology, Graduate School of Global Environmental Studies, Japan.
| | - Akitoshi Goto
- Center for Marine Environmental Studies (CMES), Ehime University, Bunkyo-cho 2-5, Matsuyama 790-8577, Japan
| | - Kenji Shiota
- Department of Environmental Engineering, Graduate School of Engineering, Kyoto University, Katsura, Nisikyo-ku, Kyoto 615-8540, Japan
| | - Tatsuya Kunisue
- Center for Marine Environmental Studies (CMES), Ehime University, Bunkyo-cho 2-5, Matsuyama 790-8577, Japan
| | - Masaki Takaoka
- Department of Environmental Engineering, Graduate School of Engineering, Kyoto University, Katsura, Nisikyo-ku, Kyoto 615-8540, Japan; Department of Global Ecology, Graduate School of Global Environmental Studies, Japan
| |
Collapse
|
24
|
Gao R, Liu B, Zhan L, Guo J, Zhang J, Xu Z. Catalytic effect and mechanism of coexisting copper on conversion of organics during pyrolysis of waste printed circuit boards. JOURNAL OF HAZARDOUS MATERIALS 2021; 403:123465. [PMID: 32846256 DOI: 10.1016/j.jhazmat.2020.123465] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 06/30/2020] [Accepted: 07/14/2020] [Indexed: 06/11/2023]
Abstract
Pyrolysis is a promising technology for recycling organic materials from waste printed circuit boards (WPCBs). Nevertheless, the generated organic bromides are toxic and urgently needed to be removed. The coexisting copper (Cu) of WPCBs has potential performance on debromination. However, the catalytic effect and mechanism of Cu on pyrolysis process and products were still unclear. To clarify the in-situ catalysis of Cu, the analysis on kinetics and pyrolysis products was performed. The results showed that Cu can change the mechanism function of pyrolysis, which reduced the apparent activation energy (Ea). The mechanism function of Cu-coated WPCBs was obtained by Šesták-Berggren model and expressed as: dαdt=1.65×107×1-α-1.30α6.09-ln1-α-6.03exp-202.45KJ/molRT. Product analysis suggested that Cu promoted the conversion of organic bromides to Br2 and HBr. During the process of pyrolysis, bromide atoms interacted with Cu to form coordination compound, which can weaken the strength of C-Br bond and generate bromide free radical (Br*). Besides, Cu can promote the conversion of aromatic-Br to Br2 as the catalyst for Ullmann cross-coupling reaction. Therefore, the presence of Cu was beneficial to pyrolysis. This work provided the theoretical basis for the improvement and application of pyrolysis technology.
Collapse
Affiliation(s)
- Ruitong Gao
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, PR China
| | - Binyang Liu
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, PR China
| | - Lu Zhan
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, PR China
| | - Jie Guo
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, PR China
| | - Jie Zhang
- Instrumental Analysis Center, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, PR China
| | - Zhenming Xu
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, PR China.
| |
Collapse
|
25
|
Shen X, Yang Q, Shen J, Yang L, Wang M, Yang Y, Liu G. Characterizing the emissions of polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs) from electric arc furnaces during steel-making. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2021; 208:111722. [PMID: 33396053 DOI: 10.1016/j.ecoenv.2020.111722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 11/09/2020] [Accepted: 11/23/2020] [Indexed: 06/12/2023]
Abstract
The amount of steel produced using electric arc furnaces (EAFs) has been increasing in recent years. In this study, stack gases from EAFs in steelmaking plants were analyzed to determine if they are also dominant sources of polybrominated dibenzo-p-dioxin and dibenzofuran (PBDD/F) emissions in China. Isotope dilution high-resolution gas chromatography high-resolution mass spectrometry for qualitative and quantitative analysis of PBDD/F congeners revealed that the mean PBDD/F mass concentrations were 271.1-9467.8 pg Nm-3 for the preheating stages (PS) of three EAF plants and that the corresponding toxic equivalents (TEQs) were 10.8-971.2 pg TEQ Nm-3. The PBDD/F mass concentration from the smelting stage (SS) at plant E3 was 261.9 pg Nm-3 (4.5 pg TEQ Nm-3). The PBDD/F emission factors (EF) during the preheating stage for the three plants were 0.0356-1.51 μg TEQ t-1, and the EF was 0.0359 μg TEQ t-1 during the E3 smelting stage. PBDD/Fs were found to contribute 2.39-67.85% to the total mass and 2.84-57.68% to the total dioxin TEQ. These wide fluctuations were caused by differences in the composition of feeding materials and the working temperature of bag filters. Overall, the results indicate that PBDD/F emissions from EAF steelmaking should receive increased attention. The PBDD/F congener patterns among the three EAF plants were variable, possibly because of differences in raw materials. The results presented herein will facilitate assessment of the contribution of EAFs to total PBDD/F emissions in China and investigations of PBDD/F emissions at different stages of steelmaking processes using EAFs.
Collapse
Affiliation(s)
- Xuejing Shen
- Central Iron & Steel Research Institute, Beijing 100081, China
| | - Qiuting Yang
- Central Iron & Steel Research Institute, Beijing 100081, China; 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
| | - Jia Shen
- 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
| | - Lili Yang
- 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
| | - Minxiang Wang
- 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
| | - Yuanping Yang
- 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
| | - Guorui Liu
- 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; School of Environment, Hangzhou Institute for Advanced Study, UCAS, Hangzhou, China.
| |
Collapse
|
26
|
Liang J, Lu G, Wang R, Tang T, Huang K, Jiang F, Yu W, Tao X, Yin H, Dang Z. The formation pathways of polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs) from pyrolysis of polybrominated diphenyl ethers (PBDEs): Effects of bromination arrangement and level. JOURNAL OF HAZARDOUS MATERIALS 2020; 399:123004. [PMID: 32502858 DOI: 10.1016/j.jhazmat.2020.123004] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2020] [Revised: 05/19/2020] [Accepted: 05/20/2020] [Indexed: 06/11/2023]
Abstract
This study presents comprehensive formation pathways of polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs) from the pyrolysis of polybrominated diphenyl ethers (PBDEs). A total of 23 PBDE congeners, from mono- to hepta- brominated, were selected to conduct the pyrolysis experiments. The results suggest that n-PBDEs (where n means the number of bromine substituents) can transform into n/(n-1) PBDFs and (n-1)/(n-2) PBDDs as long as they meet certain structural requirement. One single PBDE congener can only transform (if possible) specific PBDF or PBDD based on their specific brominated arrangement by direct/oxygen bridge connecting the two ortho-carbon atoms. Among all selected BDEs, we found that only 2,2',4,4',5,5'-hexaBDE (BDE-153) can transform into 2,3,7,8-tetraBDD, which is most toxic congener among these group of compounds. When the degree of bromination increased, the yield of polybromobenzene increased, while that of the PBDD/Fs decreased, suggesting that the higher PBDEs favors to break the ether bond to form polybromobenzene, while the lower PBDEs favor transformation into PBDD/Fs. We proposed that the results in this study greatly improved our understanding on the transformation of PBDD/Fs from PBDEs in the pyrolysis process.
Collapse
Affiliation(s)
- Jiahao Liang
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Guining Lu
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou 510006, China.
| | - Rui Wang
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Ting Tang
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Kaibo Huang
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Fengyu Jiang
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Wenjie Yu
- School of Environmental Science and Engineering, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, China
| | - Xueqin Tao
- School of Environmental Science and Engineering, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, China
| | - Hua Yin
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou 510006, China
| | - Zhi Dang
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou 510006, China
| |
Collapse
|
27
|
Liu R, Ma S, Yu Y, Li G, Yu Y, An T. Field study of PAHs with their derivatives emitted from e-waste dismantling processes and their comprehensive human exposure implications. ENVIRONMENT INTERNATIONAL 2020; 144:106059. [PMID: 32882668 DOI: 10.1016/j.envint.2020.106059] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 08/01/2020] [Accepted: 08/14/2020] [Indexed: 05/24/2023]
Abstract
Extensive electronic waste (e-waste) recycling might be an important emission source of polycyclic aromatic hydrocarbons (PAHs) mixture, which might induce negative effects on the employees. In the present work, atmospheric pollution patterns of PAHs and their derivatives were determined in five different workshops to dismantle waste printed circuit boards (WPCBs) via thermal treatment. The results showed that mass concentrations of PAHs, chlorinated PAHs (ClPAHs), brominated PAHs (BrPAHs), oxy-PAHs (OPAHs) as well as carbazole (CBZ) were ranged from 1.53 × 104-2.02 × 105, 32.3-364, 8.29-1.13 × 103, 923-1.39 × 104 and 225-1.95 × 103 pg·m-3, respectively. Electric heating furnaces (EHF) workshops emitted relatively higher contaminants than other disposal sectors. OPAHs was found to be the most predominant derivatives of PAHs with 9,10-anthraquinone (83.0%) has the absolute superior in EHFTV, while benzo(a)anthracene-7,12-dione (>45.0%) was found to be the highest congener in other workshops, respectively. 9,10-Cl2Phe exhibited the largest contributions to the ΣClPAHs whereas the composition profiles of BrPAHs varied among five workshops. In addition to direct chlorination of parent PAHs, thermal degradation of halogenated flame retardants incorporated into plastic materials might dominate the generation of Cl/BrPAHs from e-waste dismantling activities. The specific isomeric ratios of BrPAHs (3-BrFlu/1-BrPyr and 1-BrPyr/3-BrFlu) might be used to discriminate other emission sources from pyrolysis of WPCBs. However, their specific application as novel tracers for source identification should be further verified with more studies. The emitted PAHs mixture with their derivatives in all dismantling workshops posed carcinogenic risks to these dismantling workers via inhalation, particularly the workshop using electric heating furnaces to treat router. Nevertheless, new loadings of PAHs derivatives observed from e-waste dismantling activities, as well as their comprehensive health risk assessment provides us with a fresh perspective on the source appointment and potential adverse consequences of PAHs. More attention needs to be paid to the potential carcinogenic risks of exposure to PAHs and their derivatives from e-waste dismantling processes.
Collapse
Affiliation(s)
- Ranran Liu
- Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China
| | - Shengtao Ma
- Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China; Synergy Innovation Institute of GDUT, Shantou 515100, China
| | - Yangyi Yu
- Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China
| | - Guiying Li
- Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China; Synergy Innovation Institute of GDUT, Shantou 515100, China
| | - Yingxin Yu
- Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China
| | - Taicheng An
- Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China.
| |
Collapse
|
28
|
Chen J, Wang W, Zhai S, Sun P, Wu Z. The positive effect of Ca2+ on cryptomelane-type octahedral molecular sieve (K-OMS-2) catalysts for chlorobenzene combustion. J Colloid Interface Sci 2020; 576:496-504. [DOI: 10.1016/j.jcis.2020.04.071] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 04/04/2020] [Accepted: 04/18/2020] [Indexed: 11/30/2022]
|
29
|
Guo J, Patton L, Wang J, Xu Z. Fate and migration of polybrominated diphenyl ethers in a workshop for waste printed circuit board de-soldering. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:30342-30351. [PMID: 32451903 DOI: 10.1007/s11356-019-06735-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 10/10/2019] [Indexed: 06/11/2023]
Abstract
Polybrominated diphenyl ethers (PBDEs) are released from the recycling process of PBDE-containing waste printed circuit board (WPCB), but studies on the mechanism of PBDE emission and migration are limited. In this study, PBDE concentrations in particulate matter (PM), dust, and fumes collected in a pilot-scale workshop for the WPCB de-soldering process were measured, and PBDE emission after gas treatment was estimated. The results showed that the mean concentrations of ∑8PBDEs in TSP and PM2.5 in the workshop were 20.3 ng/m3 (24.7 μg/g) and 16.1 ng/m3 (115 μg/g), respectively. In practice, the fumes containing gaseous and particulate PBDEs were treated by the combination of alkaline solution absorption and activated carbon adsorption. Compared to PBDE concentration in workshop floor dust (2680 ng/g), PBDE concentrations in solution scum (68,000 ng/g) and hood inside dust (20,200 ng/g) were condensed. The concentrations of ∑6PBDEs at the stack outlet (416 pg/m3) after gas treatment were lower than those in the stack pipe (1310 pg/m3) and hood inside (7440 pg/m3). The PBDEs in fumes were removed through physical adsorption of alkaline solution and activated carbon, and solution scum constituted the main mass discharges of PBDEs. The emission factor of PBDEs at the stack outlet was 47.3 ng ∑6PBDEs/kg WPCB. As a result, the WPCB de-soldering process is an important source of PBDE pollution, and gas treatment of solution absorption and activated carbon adsorption can reduce PBDE emission to some extent.
Collapse
Affiliation(s)
- Jie Guo
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, People's Republic of China
- Guangdong Provincial Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou, 510632, China
| | - Luorong Patton
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, People's Republic of China
| | - Jianbo Wang
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, People's Republic of China
| | - Zhenming Xu
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, People's Republic of China.
| |
Collapse
|
30
|
|
31
|
Ismail H, Hanafiah MM. A review of sustainable e-waste generation and management: Present and future perspectives. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2020; 264:110495. [PMID: 32250915 DOI: 10.1016/j.jenvman.2020.110495] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 03/22/2020] [Accepted: 03/23/2020] [Indexed: 06/11/2023]
Abstract
Studies on sustainable management of waste from electrical and electronic equipment (or e-waste) have gained increasing attention from researchers around the world in recent years, with investigations into various aspects of e-waste management were investigated. Studies on e-waste generation by previous papers have been reviewed to provide an overview of the current research progress and recommendations for future research. The relevant existing studies were collected from various databases. Using content analysis, three main aspects of the existing studies were evaluated: the distribution and trends of the publications, the scope and boundaries of the studies, and the current research practices and research applications. Although there was a significant increasing trend of the amount of research on the evaluation of e-waste generation, however, the number of publications based on the countries of origin was still small. Another limitation was found related to the differences in the selection of research subjects and the level of analysis resulted in variations in the scopes and boundaries of the existing studies. Various other research areas were investigated further based on their research findings, but the analysis of various methodological aspects was complicated due to the increasing number of newly developed methodologies and the lack of comprehensive and up-to-date reviews on this research area. Additionally, there was also a need to evaluate emerging and/or older technology, which led electrical appliances to be overlooked. We found that comprehensive and up-to-date reviews of the methodological aspects of e-waste generation are still lacking. Based on the research gaps and limitations discussed, recommendations for future research were made.
Collapse
Affiliation(s)
- Haikal Ismail
- Department of Earth Sciences and Environment, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600, UKM Bangi, Selangor, Malaysia; School of Technology Management and Logistics, College of Business, Universiti Utara Malaysia, 06010, Sintok, Kedah, Malaysia
| | - Marlia M Hanafiah
- Department of Earth Sciences and Environment, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600, UKM Bangi, Selangor, Malaysia; Centre for Tropical Climate Change System, Institute of Climate Change, Universiti Kebangsaan Malaysia, 43600, UKM Bangi, Selangor, Malaysia.
| |
Collapse
|
32
|
Dai Q, Xu X, Eskenazi B, Asante KA, Chen A, Fobil J, Bergman Å, Brennan L, Sly PD, Nnorom IC, Pascale A, Wang Q, Zeng EY, Zeng Z, Landrigan PJ, Bruné Drisse MN, Huo X. Severe dioxin-like compound (DLC) contamination in e-waste recycling areas: An under-recognized threat to local health. ENVIRONMENT INTERNATIONAL 2020; 139:105731. [PMID: 32315892 DOI: 10.1016/j.envint.2020.105731] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 04/07/2020] [Accepted: 04/07/2020] [Indexed: 02/05/2023]
Abstract
Electrical and electronic waste (e-waste) burning and recycling activities have become one of the main emission sources of dioxin-like compounds (DLCs). Workers involved in e-waste recycling operations and residents living near e-waste recycling sites (EWRS) are exposed to high levels of DLCs. Epidemiological and experimental in vivo studies have reported a range of interconnected responses in multiple systems with DLC exposure. However, due to the compositional complexity of DLCs and difficulties in assessing mixture effects of the complex mixture of e-waste-related contaminants, there are few studies concerning human health outcomes related to DLC exposure at informal EWRS. In this paper, we have reviewed the environmental levels and body burdens of DLCs at EWRS and compared them with the levels reported to be associated with observable adverse effects to assess the health risks of DLC exposure at EWRS. In general, DLC concentrations at EWRS of many countries have been decreasing in recent years due to stricter regulations on e-waste recycling activities, but the contamination status is still severe. Comparison with available data from industrial sites and well-known highly DLC contaminated areas shows that high levels of DLCs derived from crude e-waste recycling processes lead to elevated body burdens. The DLC levels in human blood and breast milk at EWRS are higher than those reported in some epidemiological studies that are related to various health impacts. The estimated total daily intakes of DLCs for people in EWRS far exceed the WHO recommended total daily intake limit. It can be inferred that people living in EWRS with high DLC contamination have higher health risks. Therefore, more well-designed epidemiological studies are urgently needed to focus on the health effects of DLC pollution in EWRS. Continuous monitoring of the temporal trends of DLC levels in EWRS after actions is of highest importance.
Collapse
Affiliation(s)
- Qingyuan Dai
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, China
| | - Xijin Xu
- Laboratory of Environmental Medicine and Developmental Toxicology, Shantou University Medical College, China
| | - Brenda Eskenazi
- School of Public Health, University of California, Berkeley, USA
| | | | - Aimin Chen
- Department of Biostatistics, Epidemiology and Informatics, University of Pennsylvania, USA
| | - Julius Fobil
- School of Public Health, University of Ghana, Ghana
| | - Åke Bergman
- Department of Environmental Science, Stockholm University, Sweden; Department of Science and Technology, Örebro University, Sweden; College of Environmental Science and Engineering, Tongji University, China
| | - Lesley Brennan
- Department of Obstetrics and Gynaecology, University of Alberta, Canada
| | - Peter D Sly
- Child Health Research Centre, University of Queensland, Australia
| | | | - Antonio Pascale
- Department of Toxicology, University of the Republic, Uruguay
| | - Qihua Wang
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, China
| | - Eddy Y Zeng
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, China
| | - Zhijun Zeng
- Laboratory of Environmental Medicine and Developmental Toxicology, Shantou University Medical College, China
| | | | - Marie-Noel Bruné Drisse
- Department of Environment, Climate Change and Health, World Health Organization, Geneva, Switzerland
| | - Xia Huo
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, China.
| |
Collapse
|
33
|
Tan Q, Liu L, Yu M, Li J. An innovative method of recycling metals in printed circuit board (PCB) using solutions from PCB production. JOURNAL OF HAZARDOUS MATERIALS 2020; 390:121892. [PMID: 31883733 DOI: 10.1016/j.jhazmat.2019.121892] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 12/11/2019] [Accepted: 12/12/2019] [Indexed: 06/10/2023]
Abstract
Waste printed circuit boards (WPCBs) have both a potentially high resource value and hazardous drawbacks. Meanwhile, large quantities of corrosive waste solutions are generated in PCB production. Existing methods for recycling metals in WPCBs produce high yields but unfortunately produce secondary pollution. In this study, to minimize these disadvantages, a win-win innovative recycling method for WPCBs was developed using waste solutions that are generated in PCB production. Both of the waste solutions - waste tin stripping solution (WTSS) and waste etching solution (WES) - had an enormous capacity to extract Pb, Sn, and Cu. It was suggested that 1 L of WTSS was potentially capable for dissolving solder from 3.6 to 7.2 kg of WPCBs under room temperature, while WES was capable for Cu leaching from 0.13-0.35 kg of WPCBs. Compared with conventional leaching solutions, it was demonstrated that approximately 1 kW h of electricity could be saved from the recycling process when WTSS and WES were used to recycle only 1 kg of WPCBs. The proposed approach can be expected to significantly reduce energy consumption for recycling metals from WPCBs, without additional waste solution generated, and to increase the potential value of WTSS and WES, as they can facilitate the recycling process.
Collapse
Affiliation(s)
- Quanyin Tan
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Lili Liu
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Miao Yu
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China; College of Humanities and Urban - Rural Development, Beijing University of Agriculture, Beijing 100096, China
| | - Jinhui Li
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
| |
Collapse
|
34
|
Xiu FR, Li Y, Qi Y. Efficient low-temperature debromination and high selectivity products recovery from brominated epoxy resin waste by subcritical water-urea treatment. WASTE MANAGEMENT (NEW YORK, N.Y.) 2020; 109:171-180. [PMID: 32408100 DOI: 10.1016/j.wasman.2020.05.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 05/01/2020] [Accepted: 05/01/2020] [Indexed: 06/11/2023]
Abstract
In this study, a subcritical water-urea (SubCW-urea) process was developed for the treatment of brominated epoxy resin powder (BRP) waste. The SubCW-urea process had two significant advantages: efficient low-temperature debromination and highly selective products recovery. The NH3 and CO2 released from urea in the SubCW medium had a prominent enhancement effect on the decomposition and debromination of BRP waste when the SubCW temperature was below 300 °C. The debromination efficiency of SubCW-urea treatment was significantly enhanced in comparison with that of SubCW-NH3 and single SubCW treatments. The debromination efficiency of BRP could reach 38.21%, 85.3%, and 99.92% at 200 °C, 250 °C, and 300 °C, respectively. The debromination rate constant of BRP in SubCW-urea, SubCW-NH3, and single SubCW system was 0.1363, 0.1254, and 0.0146 min-1, respectively. No brominated chemical compound could be detected in the oil phase products when the treatment temperature was higher than 250 °C. The decomposition products of BRP waste could be easily regulated by controlling the treatment temperature of SubCW-urea. 2-bromo-phenol with the purity of 72.5% could be selectively prepared from BRP by SubCW-urea process at 200 °C. The purity of the recovered phenol could reach as high as 81.5% at 250 °C. The selectivity of the products decreased greatly at 300 °C due to the secondary reactions. The SubCW-urea process has an application prospect in the safe treatment of BRP waste with the aim of high-efficiency debromination and high selectivity products recovery at low temperature.
Collapse
Affiliation(s)
- Fu-Rong Xiu
- College of Geology and Environment, Xi'an University of Science and Technology, Xi' an 710054, China; Shaanxi Provincial Key Laboratory of Geological Support for Coal Green Exploitation, Xi'an 710054, China.
| | - Yifan Li
- College of Geology and Environment, Xi'an University of Science and Technology, Xi' an 710054, China
| | - Yingying Qi
- College of Geology and Environment, Xi'an University of Science and Technology, Xi' an 710054, China; Shaanxi Provincial Key Laboratory of Geological Support for Coal Green Exploitation, Xi'an 710054, China
| |
Collapse
|
35
|
Gollakota ARK, Gautam S, Shu CM. Inconsistencies of e-waste management in developing nations - Facts and plausible solutions. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2020; 261:110234. [PMID: 32148304 DOI: 10.1016/j.jenvman.2020.110234] [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: 10/21/2019] [Revised: 01/31/2020] [Accepted: 02/01/2020] [Indexed: 06/10/2023]
Abstract
Electronic and electrical equipment (EEE) became an integral part of daily life and had an immense influence on the economy. The skyrocketing demand, progressive technologies, and high dependency resulted in inconceivable utilization of EEE. However, these scientific expansions shortened the life span of EEE, thereby generating massive volumes of waste electronic and electrical equipment (WEEE). On a global perspective, Oceania generates a per capita of 17.3 kg/inh (inhabitants), followed by Europe 16.6 kg/inh, America 11.6 kg/inh, Asia 4.2 kg/inh and the least contribution by Africa 1.9 kg/inh. As known, EEE comprises complex metallic and non-metallic fractions causing severe discrepancies within the ecosystem, endangering the living species; if not dealt with properly. Thus, there is a pressing need of immediate addressal on the effective e-waste management strategies both from developed and developing countries. On the spin side, the separation of the precious fractions from the EEE on the end-of-life may be a twin dimensional strategy of economic addition, and plummeting the alarming level threats to ecology. However, these menaces are well tackled by the developed countries to some extent by the stringent law enactments, establishing proper recycling facilities, and trading to the underdeveloped and developing nations. But, the majority of the developing and under developed nations lacks the statutes, gaps in policy making, socio-economic-cultural barriers, technology, and the appropriate treatment facilities. In addition, the review identified ten major shortfalls (10L's) refraining the effective e-waste management, especially in the developing and under developed nations. Among which, integration of the formal and informal sectors, mandated network registry, stringent law enforcements, regulated transboundary movements, manufacturers responsibility, consumer awareness and improved eco designs, investing on effective recycling facilities, and improved disposal facilities holds the key. Further, replacing the traditional and conventional procedures with the futuristic and eco-friendly approaches such as chelation, inducing ionic liquids, integrated processes or hybrid technologies, micro factories, photo catalysis, and green adsorption will substantially harness the current barriers of the e-waste management. Finally, the present review will be a thorough glancing for the future research of e-waste management of meso-micro-macro scales.
Collapse
Affiliation(s)
- Anjani R K Gollakota
- Department of Safety, Health, & Environmental Engineering, National Yunlin University of Science and Technology, Douliou, Yunlin County, 64002, Taiwan, ROC
| | - Sneha Gautam
- Department of Civil Engineering, Karunya Institute of Technology and Sciences, Coimbatore, Tamil Nadu, 641114, India.
| | - Chi-Min Shu
- Department of Safety, Health, & Environmental Engineering, National Yunlin University of Science and Technology, Douliou, Yunlin County, 64002, Taiwan, ROC.
| |
Collapse
|
36
|
Qin S, Sun P, Wu Z, Liu W, Yang C. Foam fractionation for effectively recovering copper from the discarded printed circuit board of personal computer. SEP SCI TECHNOL 2020. [DOI: 10.1080/01496395.2020.1743312] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- Shaojie Qin
- School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin, China
| | - Pengkun Sun
- School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin, China
| | - Zhaoliang Wu
- School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin, China
| | - Wei Liu
- School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin, China
| | - Chunyan Yang
- National-Local Joint Engineering Laboratory for Energy Conservation in Chemical Process Integration and Resources Utilization, School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin, China
| |
Collapse
|
37
|
Xing M, Li Y, Zhao L, Song X, Fu Z, Du Y, Huang X. Swelling-enhanced catalytic degradation of brominated epoxy resin in waste printed circuit boards by subcritical acetic acid under mild conditions. WASTE MANAGEMENT (NEW YORK, N.Y.) 2020; 102:464-473. [PMID: 31743837 DOI: 10.1016/j.wasman.2019.11.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 11/08/2019] [Accepted: 11/10/2019] [Indexed: 06/10/2023]
Abstract
Waste printed circuit boards (WPCBs) contain a large amount of brominated epoxy resins (BERs), which may cause environmental problems. However, BERs degradation under mild conditions is challenging due to the good thermal and chemical stabilities of BERs. This study proposes a mild and efficient method that uses subcritical acetic acid (220 °C-260 °C, 2.6-3.6 MPa) to decompose BERs. BERs swell quickly at 200 °C and are thoroughly decomposed into bisphenol A and phenol at 220 °C when the acetic acid mass concentration and holding time are fixed at 49.90% and 1 h, respectively. Experimental results show that subcritical acetic acid has excellent swelling and catalytic degradation effects on BERs. The quick swelling of BERs allows the free migration of the catalyst in the epoxy network and thus significantly enhances the catalytic degradation effect. Therefore, BERs can be thoroughly decomposed by subcritical acetic acid under mild conditions. Temperature and acetic acid concentration are the major parameters that control the resin degradation rate. Bromine-free oil phase products are obtained at ≥240 °C. The possible decomposition pathway of BERs in subcritical acetic acid is also investigated. Most of the bromine is transformed into HBr and enriched in the aqueous phase. In conclusion, the proposed mild method could be used as a novel practical and industrial procedure for the degradation and debromination of BERs.
Collapse
Affiliation(s)
- Mingfei Xing
- Institute of Resource and Environment, Henan Polytechnic University, Jiaozuo 454000, Henan, China.
| | - Yu Li
- Institute of Resource and Environment, Henan Polytechnic University, Jiaozuo 454000, Henan, China
| | - Lei Zhao
- Zhengzhou Quality and Technical Supervision and Inspection Center, Zhengzhou 450006, Henan, China
| | - Xiaoyan Song
- College of Geosciences and Engineering, North China University of Water Resources and Electric Power, Zhengzhou 450046, Henan, China
| | - Zegang Fu
- Institute of Resource and Environment, Henan Polytechnic University, Jiaozuo 454000, Henan, China
| | - Yajie Du
- Institute of Resource and Environment, Henan Polytechnic University, Jiaozuo 454000, Henan, China
| | - Xingyu Huang
- Institute of Resource and Environment, Henan Polytechnic University, Jiaozuo 454000, Henan, China; School of Environment Science and Spatial Informatics, China University of Mining and Technology, Xuzhou 221116, Jiangsu, China.
| |
Collapse
|
38
|
Guo J, Luo X, Tan S, Ogunseitan OA, Xu Z. Thermal degradation and pollutant emission from waste printed circuit boards mounted with electronic components. JOURNAL OF HAZARDOUS MATERIALS 2020; 382:121038. [PMID: 31450210 DOI: 10.1016/j.jhazmat.2019.121038] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2019] [Revised: 08/15/2019] [Accepted: 08/17/2019] [Indexed: 06/10/2023]
Abstract
Waste printed circuit boards mounted with electronic components (WPCB-ECs) are generated from electronic waste dismantling and recycling process. Air-borne pollutants, including particulate matter (PM) and volatile organic compounds (VOCs), can be released during thermal treatment of WPCB-CEs. In this study, organic substances from WPCB-ECs were pyrolyzed by both thermo-gravimetric analysis (TGA) and in a quartz tube furnace. We discovered that board resin and solder coating were degraded in a one-stage process, whereas capacitor scarfskin and wire jacket had two degradation stages. Debromination of brominated flame retardants occurred, and HBr and phenol were the main products during TGA processing of board resin. Dehydrochlorination occurred, and HCl, benzene and toluene were detected during the pyrolysis of capacitor scarfskin. Benzene formation was found only in the first degradation stage (272-372 °C), while toluene was formed both in the two degradation stages. PM with bimodal mass size distributions at diameters of 0.45-0.5 and 4-5 μm were emitted during heating WPCB-ECs. The PM number concentrations were highest in the size ranges of 0.3-0.35 μm and 1.6-2 μm. The research produced new data on pollutant emissions during thermal treatment of WPCB-ECs, and information on strategies to prevent toxic exposures that compromise the health of recyclers.
Collapse
Affiliation(s)
- Jie Guo
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, People's Republic of China; Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou, 510006, People's Republic of China
| | - Xiaomei Luo
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, People's Republic of China
| | - Shufei Tan
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, People's Republic of China
| | - Oladele A Ogunseitan
- Department of Population Health and Disease Prevention & School of Social Ecology, University of California, Irvine, CA, 92697-3957, USA
| | - Zhenming Xu
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, People's Republic of China.
| |
Collapse
|
39
|
Advanced Recovery Techniques for Waste Materials from IT and Telecommunication Equipment Printed Circuit Boards. SUSTAINABILITY 2019. [DOI: 10.3390/su12010074] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Waste from information technology (IT) and telecommunication equipment (WITTE) constitutes a significant fraction of waste from electrical and electronic equipment (WEEE). The presence of rare metals and hazardous materials (e.g., heavy metals or flame retardants) makes the necessary recycling procedures difficult and expensive. Important efforts are being made for Waste Printed Circuit Board (WPCB) recycling because, even if they only amount to 5–10% of the WITTE weight, they constitute up to 80% of the recovered value. This paper summarizes the recycling techniques applicable to WPCBs. In the first part, dismantling and mechanical recycling techniques are presented. Within the frame of electro-mechanical separation technology, the chain process of shredding, washing, and sieving, followed by one or a combination of magnetic, eddy current, corona electrostatic, triboelectrostatic, or gravity separation techniques, is presented. The chemical and electrochemical processes are of utmost importance for the fine separation of metals coming from complex equipment such as WPCBs. Thermal recycling techniques such as pyrolysis and thermal treatment are presented as complementary solutions for achieving both an extra separation stage and thermal energy. As the recycling processes of WPCBs require adequate, efficient, and ecological recycling techniques, the aim of this survey is to identify and highlight the most important ones. Due to the high economic value of the resulting raw materials relative to the WPCBs’ weight and composition, their recycling represents both a necessary environmental protection action, as well as an economic opportunity.
Collapse
|
40
|
Wang C, Cao Y, Wang H. Copper-based catalyst from waste printed circuit boards for effective Fenton-like discoloration of Rhodamine B at neutral pH. CHEMOSPHERE 2019; 230:278-285. [PMID: 31108438 DOI: 10.1016/j.chemosphere.2019.05.068] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 05/08/2019] [Accepted: 05/09/2019] [Indexed: 06/09/2023]
Abstract
The carbonized waste printed circuit board (c-PCB) was used as novel copper-based catalyst for Fenton-like discoloration of Rhodamine B (RhB). The elemental ingredients, structure and morphology of the catalyst was investigated by multi-techniques. The catalytic activity of c-PCB for RhB discoloration was evaluated in the presence of H2O2, examining the factors of catalyst dosage, H2O2 dosage, solution pH, RhB concentration and temperature. RhB discoloration is improved with increasing catalyst dosage (0-2.0 g L-1), H2O2 dosage (0-0.15 mol L-1), solution pH (4.66-9.36) and temperature (30-50 °C). We found that c-PCB shows excellent catalytic activity for RhB discoloration in a broad pH range. RhB removal of 95.78% is obtained within 6 h at neutral pH (6.70). RhB discoloration is well described by the first-order kinetics, and the activation energy is calculated to be 87 kJ mol-1. The dominant role of OH radical in the c-PCB/H2O2 system is identified by quenching tests. The plausible pathway for RhB discoloration is discussed based on the time-dependent UV-vis spectra. The possible catalytic mechanism in the c-PCB/H2O2 system is also presented. Good reusability of c-PCB is verified by three cycles. This work opens a new strategy of "waste treating waste", facilitating management of hazardous solid wastes and cleaner treatment of textile wastewater.
Collapse
Affiliation(s)
- Chongqing Wang
- School of Chemical Engineering and Energy, Zhengzhou University, Zhengzhou, 450001, China
| | - Yijun Cao
- School of Chemical Engineering and Energy, Zhengzhou University, Zhengzhou, 450001, China.
| | - Hui Wang
- School of Chemistry and Chemical Engineering, Central South University, Changsha, 410083, China
| |
Collapse
|
41
|
Yang L, Zhao Y, Shi M, Zheng M, Xu Y, Li C, Yang Y, Qin L, Liu G. Brominated dioxins and furans in a cement kiln co-processing municipal solid waste. J Environ Sci (China) 2019; 79:339-345. [PMID: 30784457 DOI: 10.1016/j.jes.2018.12.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 12/14/2018] [Accepted: 12/17/2018] [Indexed: 06/09/2023]
Abstract
A field study and theoretical calculations were performed to clarify the levels, profiles, and distributions of polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs) in a cement kiln co-processing solid waste, with a focus on the PBDF formation mechanism. The raw materials contributed greatly to input of PBDD/Fs into the cement kiln. The PBDD/F concentrations in the raw materials were much higher than those in particle samples from different process stages in the cement kiln. The PBDD/F concentrations in the clinkers were 1.40% of the concentrations in the raw materials, which indicated that the high destruction efficiencies for PBDD/Fs by cement kiln. PBDD/F distribution patterns in particle samples collected from different process stages indicated the cement kiln backend was a major site for PBDD/F formation. PBDFs with high levels of halogenation, such as heptabrominated furans (HpBDF), were the dominant contributors to the total PBDD/F concentrations and accounted for 42%-73% of the total PBDD/F concentrations in the particle samples. Our results showed that co-processing of municipal solid waste in a cement kiln may influence the congener profile of PBDD/Fs, especially for the higher halogenated PBDD fraction. In addition, there were significant correlations between the decabromodiphenyl ether and heptabrominated furan concentrations, which is an indicator of transformation from polybrominated diphenyl ethers to PBDD/Fs. Theoretical calculations were performed and demonstrated that elimination of HBr and Br2 from polybrominated diphenyl ethers were the dominant formation pathways for PBDD/Fs. These pathways differed from that for polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs).
Collapse
Affiliation(s)
- Lili Yang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yuyang Zhao
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Miwei Shi
- Hebei Engineering Research Center for Geographic Information Application, Institute of Geographical Sciences, Hebei Academy of Sciences, Shijiazhuang 050051, China
| | - Minghui Zheng
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yang Xu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Cui Li
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yuanping Yang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Linjun Qin
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Guorui Liu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| |
Collapse
|
42
|
Weng X, Long Y, Wang W, Shao M, Wu Z. Structural effect and reaction mechanism of MnO2 catalysts in the catalytic oxidation of chlorinated aromatics. CHINESE JOURNAL OF CATALYSIS 2019. [DOI: 10.1016/s1872-2067(19)63322-x] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
43
|
Guo J, Ji A, Wang J, Ogunseitan OA, Xu Z. Emission characteristics and exposure assessment of particulate matter and polybrominated diphenyl ethers (PBDEs) from waste printed circuit boards de-soldering. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 662:530-536. [PMID: 30699373 DOI: 10.1016/j.scitotenv.2019.01.176] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Revised: 01/14/2019] [Accepted: 01/14/2019] [Indexed: 06/09/2023]
Abstract
Heating processes for the removal of electronic components from waste printed circuit boards (WPCBs) is an important step in the chain of electronic waste recycling, and toxic fumes are generated during the de-soldering process, causing environmental pollution and posing health risks for the workers. This study is aimed to characterize emission and deposition fluxes of respirable particulate matter (PM), and assess exposure of workers to particle-bound polybrominated diphenyl ethers (PBDEs). An electrical low-pressure impactor was used to measure the real-time PM concentrations inside and outside the hood during the WPCBs de-soldering process. The results show that PM mass concentration inside the hood (204 mg/m3) was significantly higher than outside the hood (9.4 mg/m3), representing 95.4% PM removal by the hood. According to the International Commission on Radiological Protection model, the total deposition fluxes of PM in head airways region, tracheobronchial region, and alveolar region were determined as 1930, 74.0, and 123 μg/h, respectively. The deposition flux for coarse particles (2.5-10 μm) in the head airways was the largest (1830 μg/h), accounting for 86.1% of total PM deposited in respiratory system. The ∑8PBDEs concentration in PM10 inside the WPCBs de-soldering workshop was 20,300 pg/m3, and the ∑8PBDEs inhalation exposure for the worker was 1.46 ng/kg/day. This study improves understanding of PM emission mechanisms and provides fundamental data for health assessments during WPCBs de-soldering process.
Collapse
Affiliation(s)
- Jie Guo
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China; Department of Population Health and Disease Prevention & School of Social Ecology, University of California, Irvine, CA 92697-3957, USA
| | - Ang Ji
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Jianbo Wang
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Oladele A Ogunseitan
- Department of Population Health and Disease Prevention & School of Social Ecology, University of California, Irvine, CA 92697-3957, USA
| | - Zhenming Xu
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China.
| |
Collapse
|
44
|
Tue NM, Matsushita T, Goto A, Itai T, Asante KA, Obiri S, Mohammed S, Tanabe S, Kunisue T. Complex Mixtures of Brominated/Chlorinated Diphenyl Ethers and Dibenzofurans in Soils from the Agbogbloshie e-Waste Site (Ghana): Occurrence, Formation, and Exposure Implications. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:3010-3017. [PMID: 30793891 DOI: 10.1021/acs.est.8b06929] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The distribution and toxic equivalents (TEQs) of brominated and chlorinated dibenzo- p-dioxins/dibenzofurans (PBDD/Fs and PCDD/Fs) in soils from Agbogbloshie e-waste site (Ghana) were investigated. The composition of brominated/chlorinated dibenzofurans (PXDFs) and diphenyl ethers (PBDEs, PCDEs, and PXDEs) was examined using two-dimensional gas chromatography-time-of-flight mass spectrometry to elucidate possible formation pathways of dioxins from e-waste recycling. The highest concentrations of PCDD/Fs and PBDD/Fs were found, respectively, in the open burning (1.3-380 ng/g dry weight) and dismantling areas (11-1000 ng/g dry weight) and were comparable to the highest reported for informal e-waste sites. PXDFs and PXDEs were detected at up to the range of hundreds of nanograms per gram. The homologue profiles suggest that PXDFs were formed mainly from PBDFs through successive Br-to-Cl exchange. However, monobromo-PCDFs were also derived from de-novo-generated PCDFs in open burning areas. PBDFs contributed similar or higher TEQs (7.9-5400 pg/g dry weight) compared with PCDD/Fs (6.8-5200 pg/g dry weight), whereas PXDFs were also substantial TEQ contributors in open burning areas. The high TEQs of PBDFs in the dismantling area (120-5200 pg/g dry weight) indicate the need to consider brominated dioxins besides chlorinated dioxins in future studies on health implications for e-waste workers and local residents.
Collapse
Affiliation(s)
- Nguyen Minh Tue
- Center for Marine Environmental Studies (CMES) , Ehime University , 2-5 Bunkyo-cho , Matsuyama 790-8577 , Japan
| | - Takafumi Matsushita
- Center for Marine Environmental Studies (CMES) , Ehime University , 2-5 Bunkyo-cho , Matsuyama 790-8577 , Japan
| | - Akitoshi Goto
- Center for Marine Environmental Studies (CMES) , Ehime University , 2-5 Bunkyo-cho , Matsuyama 790-8577 , Japan
| | - Takaaki Itai
- Center for Marine Environmental Studies (CMES) , Ehime University , 2-5 Bunkyo-cho , Matsuyama 790-8577 , Japan
| | - Kwadwo Ansong Asante
- Center for Marine Environmental Studies (CMES) , Ehime University , 2-5 Bunkyo-cho , Matsuyama 790-8577 , Japan
- CSIR Water Research Institute , P.O. Box AH 38, Achimota, Accra , Ghana
| | - Samuel Obiri
- CSIR Water Research Institute , P.O. Box AH 38, Achimota, Accra , Ghana
| | - Saada Mohammed
- CSIR Water Research Institute , P.O. Box AH 38, Achimota, Accra , Ghana
| | - Shinsuke Tanabe
- Center for Marine Environmental Studies (CMES) , Ehime University , 2-5 Bunkyo-cho , Matsuyama 790-8577 , Japan
| | - Tatsuya Kunisue
- Center for Marine Environmental Studies (CMES) , Ehime University , 2-5 Bunkyo-cho , Matsuyama 790-8577 , Japan
| |
Collapse
|
45
|
Liu K, Yang J, Hou H, Liang S, Chen Y, Wang J, Liu B, Xiao K, Hu J, Deng H. Facile and Cost-Effective Approach for Copper Recovery from Waste Printed Circuit Boards via a Sequential Mechanochemical/Leaching/Recrystallization Process. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:2748-2757. [PMID: 30698959 DOI: 10.1021/acs.est.8b06081] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The recovery of copper (Cu0) from waste printed circuit boards (WPCBs) is a great challenge as a result of its heterogeneous structural properties, with a mixture of metals, epoxy resin, and fiberglass. In this study, a three-step sequential process, including mechanochemical processing, water leaching, and recrystallization, for Cu0 recovery from WPCB powder is reported. Potassium persulfate (K2S2O8), instead of acid/alkali reagents, was employed as the sole reagent in the cupric sulfate (CuSO4) regeneration process. Complete oxidation of Cu0 in the WPCBs to copper oxide (CuO) and CuSO4 was first achieved during mechanochemical processing with K2S2O8 as the solid oxidant, and the K2S2O8 was simultaneously converted to sulfate compounds [K3H(SO4)2] via a solid-solid reaction with epoxy resin (C nH mO y) as the hydrogen donator under mechanical force. The rapid leaching of Cu species in the forms of CuO and CuSO4 was therefore easily realized with pure water as a nontoxic leaching reagent. The kinetics of the leaching process of Cu species was confirmed to follow the shrinking nucleus model controlled by solid-film diffusion. Finally, CuSO4·5H2O was successfully separated by cooling crystallization of the hot saturated solution of sulfate salt [K2Cu(SO4)2·6H2O]. An efficient conversion of Cu0 to CuSO4·5H2O product, for WPCB recycling, was therefore established.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | | | - Huali Deng
- Dongjiang Environmental Protection Company, Limited , Shenzhen , Guangdong 518000 , People's Republic of China
| |
Collapse
|
46
|
Chen B, He J, Xi Y, Zeng X, Kaban I, Zhao J, Hao H. Liquid-liquid hierarchical separation and metal recycling of waste printed circuit boards. JOURNAL OF HAZARDOUS MATERIALS 2019; 364:388-395. [PMID: 30384249 DOI: 10.1016/j.jhazmat.2018.10.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Revised: 10/08/2018] [Accepted: 10/09/2018] [Indexed: 06/08/2023]
Abstract
Waste electrical and electronic equipment is rapidly increasing worldwide, resulting in a large quantity of waste printed circuit boards (WPCBs). There is a great challenge on how to efficiently separate mixed metals in WPCBs, which consists of more than 10 elements including hazardous Cr, Pb and Cd. In this work, based on atomic interactions, a method of liquid-liquid hierarchical separation is developed to separate the mixed metals dissociated from the pyrolyzed WPCBs of mobile phones. The hierarchical separation of L→LFe-rich + LCu,Pb-rich, LCu,Pb-rich→LCu-rich + LPb-rich and LPb-rich→SCu-dendritical + L'Pb-rich produces four immiscible Fe-rich, Cu-rich, Cu-dendritical and Pb-rich substances. The separation rate between these substances can reach more than 96% in a super-gravity field of G = 1000g. Other metals selectively distribute in the four substances. The Fe-rich substance collects Cr, Co, Ni and Si. Almost all of Au and Ag are trapped in the Cu-rich and Cu-dendritical substances. The low-melting-point metals, i.e. Bi, Cd, In and Sn, are located in the Pb-rich substance. This work provides a green shortcut for efficiently separating and recycling overall metals in WPCBs.
Collapse
Affiliation(s)
- Bin Chen
- Institute of Metal Research, Chinese Academy of Sciences, Shenyang, 110016, China; School of Materials Science and Engineering, University of Science and Technology of China, Shenyang, 110016, China
| | - Jie He
- Institute of Metal Research, Chinese Academy of Sciences, Shenyang, 110016, China.
| | - Yaoyao Xi
- Institute of Metal Research, Chinese Academy of Sciences, Shenyang, 110016, China
| | - Xiangfeng Zeng
- Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China
| | - Ivan Kaban
- IFW Dresden, Institute for Complex Materials, Helmholtzstr. 20, Dresden, 01069, Germany
| | - Jiuzhou Zhao
- Institute of Metal Research, Chinese Academy of Sciences, Shenyang, 110016, China.
| | - Hongri Hao
- Institute of Metal Research, Chinese Academy of Sciences, Shenyang, 110016, China
| |
Collapse
|
47
|
Zhan F, Zhang H, Cao R, Fan Y, Xu P, Chen J. Release and Transformation of BTBPE During the Thermal Treatment of Flame Retardant ABS Plastics. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:185-193. [PMID: 30516371 DOI: 10.1021/acs.est.8b05483] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Thermal scenarios inevitably occur during the lifecycle of engineering plastics laden with brominated flame retardants (BFRs). However, little information on the fate of embedded BFRs during the thermal processes is available. In this study, we measured the release and transformation of a typical BFR, 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE), during the thermal treatment of acrylonitrile butadiene styrene (ABS) plastics. The possible thermal scenarios were simulated by varying the heating temperature and atmosphere. The maximum release rate of BTBPE was observed at 350 °C. A release kinetic model was developed to explore the mechanism of BTBPE release while heating ABS. Material-phase diffusion was found to be the rate-determining step during release. According to the developed release model, it was estimated that 0.04-0.17% of embedded BTBPE could be released to air during the industrial processing of ABS plastics. When the heating temperature was ≥350 °C, approximately 15-56% of embedded BTBPE decomposed to bromophenols (BPs) and 1,3,5-tribromo-2-(vinyloxy) benzene (TBVOB), and the decomposition followed a first-order kinetics at 350 °C. Polybrominated dibenzo- p-dioxins and dibenzofurans (PBDD/Fs) were also significantly formed at ≥350 °C from BPs and TBVOB via a precursor mechanism. A higher temperature (≥450 °C) was favorable for the formation of PBDFs.
Collapse
Affiliation(s)
- Faqiang Zhan
- Key Laboratory of Separation Science for Analytical Chemistry , Dalian Institute of Chemical Physics , Chinese Academy of Sciences, Dalian , 116023 , China
- University of Chinese Academy of Sciences , Beijing 100049 , China
| | - Haijun Zhang
- Key Laboratory of Separation Science for Analytical Chemistry , Dalian Institute of Chemical Physics , Chinese Academy of Sciences, Dalian , 116023 , China
| | - Rong Cao
- Key Laboratory of Separation Science for Analytical Chemistry , Dalian Institute of Chemical Physics , Chinese Academy of Sciences, Dalian , 116023 , China
- University of Chinese Academy of Sciences , Beijing 100049 , China
| | - Yun Fan
- Key Laboratory of Separation Science for Analytical Chemistry , Dalian Institute of Chemical Physics , Chinese Academy of Sciences, Dalian , 116023 , China
| | - Pengjun Xu
- National Research Center for Environmental Analysis and Measurement , Beijing 100029 , China
| | - Jiping Chen
- Key Laboratory of Separation Science for Analytical Chemistry , Dalian Institute of Chemical Physics , Chinese Academy of Sciences, Dalian , 116023 , China
| |
Collapse
|
48
|
Ilankoon IMSK, Ghorbani Y, Chong MN, Herath G, Moyo T, Petersen J. E-waste in the international context - A review of trade flows, regulations, hazards, waste management strategies and technologies for value recovery. WASTE MANAGEMENT (NEW YORK, N.Y.) 2018; 82:258-275. [PMID: 30509588 DOI: 10.1016/j.wasman.2018.10.018] [Citation(s) in RCA: 104] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 10/10/2018] [Accepted: 10/11/2018] [Indexed: 05/07/2023]
Abstract
E-waste, or waste generated from electrical and electronic equipment, is considered as one of the fastest-growing waste categories, growing at a rate of 3-5% per year in the world. In 2016, 44.7 million tonnes of e-waste were generated in the world, which is equivalent to 6.1 kg for each person. E-waste is classified as a hazardous waste, but unlike other categories, e-waste also has significant potential for value recovery. As a result it is traded significantly between the developed and developing world, both as waste for disposal and as a resource for metal recovery. Only 20% of global e-waste in 2016 was properly recycled or disposed of, with the fate of the remaining 80% undocumented - likely to be dumped, traded or recycled under inferior conditions. This review paper provides an overview of the global e-waste resource and identifies the major challenges in the sector in terms of generation, global trade and waste management strategies. It lists the specific hazards associated with this type of waste that need to be taken into account in its management and includes a detailed overview of technologies employed or proposed for the recovery of value from e-waste. On the basis of this overview the paper identifies future directions for effective e-waste processing towards sustainable waste/resource management. It becomes clear that there is a strong divide between developed and developing countries with regard to this sector. While value recovery is practiced in centralised facilities employing advanced technologies in a highly regulated industrial environment in the developed world, in the developing world such recovery is practiced in a largely unregulated artisanal industry employing simplistic, labour intensive and environmentally hazardous approaches. Thus value is generated safely in the hi-tech environment of the developed world, whereas environmental burdens associated with exported waste and residual waste from simplistic processing remain largely in developing countries. It is argued that given the breadth of available technologies, a more systematic evaluation of the entire e-waste value chain needs to be conducted with a view to establishing integrated management of this resource (in terms of well-regulated value recovery and final residue disposal) at the appropriately local rather than global scale.
Collapse
Affiliation(s)
- I M S K Ilankoon
- Discipline of Chemical Engineering, School of Engineering, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway, Selangor Darul Ehsan 47500, Malaysia; Global Asia in the 21st Century (GA21) Multidisciplinary Platform, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway, Selangor Darul Ehsan 47500, Malaysia.
| | - Yousef Ghorbani
- Department of Civil, Environmental & Natural Resources Engineering, Luleå University of Technology, SE-971 87 Luleå, Sweden.
| | - Meng Nan Chong
- Discipline of Chemical Engineering, School of Engineering, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway, Selangor Darul Ehsan 47500, Malaysia; Global Asia in the 21st Century (GA21) Multidisciplinary Platform, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway, Selangor Darul Ehsan 47500, Malaysia; Sustainable Water Alliance, Advanced Engineering Platform, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway, Selangor Darul Ehsan 47500, Malaysia
| | - Gamini Herath
- Global Asia in the 21st Century (GA21) Multidisciplinary Platform, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway, Selangor Darul Ehsan 47500, Malaysia; School of Business, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway, Selangor Darul Ehsan 47500, Malaysia
| | - Thandazile Moyo
- Department of Chemical Engineering, University of Cape Town, Rondebosch, South Africa
| | - Jochen Petersen
- Department of Chemical Engineering, University of Cape Town, Rondebosch, South Africa
| |
Collapse
|
49
|
Zhou Y, Liu J. Emissions, environmental levels, sources, formation pathways, and analysis of polybrominated dibenzo-p-dioxins and dibenzofurans: a review. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:33082-33102. [PMID: 30269281 DOI: 10.1007/s11356-018-3307-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Accepted: 09/20/2018] [Indexed: 06/08/2023]
Abstract
Polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs) were labeled potential persistent organic pollutants by the Stockholm Convention and have structures and toxicities similar to those of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), which has caused considerable concern. This article reviews the current available literature on the status, sources, formation pathways, and analysis of PBDD/Fs. PBDD/Fs are widely generated in industrial thermal processes, such as those for brominated flame retardant (BFR) products, e-waste dismantling, metal smelting processes, and waste incineration. PBDD/Fs can form via the following routes: precursor formation, de novo formation, biosynthesis, and natural formation. The levels of PBDD/Fs in the environment and in organisms and humans have increased due to extensive consumption and the increasing inventory of BFRs; thus, the risk of human exposure to PBDD/Fs is expected to be high.
Collapse
Affiliation(s)
- Yanxiao Zhou
- Zhejiang University of Technology, No.18 Chaowang Road, Hangzhou, 310014, Zhejiang, China
| | - Jinsong Liu
- Zhejiang University of Technology, No.18 Chaowang Road, Hangzhou, 310014, Zhejiang, China.
- Zhejiang Environmental Monitoring Center, Hangzhou, 310012, Zhejiang, China.
| |
Collapse
|
50
|
Wang X, He S, Wang G, Wang Y, Cai Y, Chen P, Mei J. Characterization of PBDD/F emissions from simulated polystyrene insulation foam via lab-scale programmed thermal treatment testing. CHEMOSPHERE 2018; 211:926-933. [PMID: 30119024 DOI: 10.1016/j.chemosphere.2018.08.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Revised: 08/02/2018] [Accepted: 08/06/2018] [Indexed: 06/08/2023]
Abstract
Accidental fires and open combustion are regarded as major potential contributors to the environmental release of polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs). The characterization of PBDD/Fs emitted from thermal treatment of simulated polystyrene (PS) foam is reported in this study. PS, hexabromocyclododecane (HBCDD) and metals (or metallic compounds) composed the test samples, which imitated real extruded (XPS) and expanded (EPS) polystyrene thermal insulation foams. Test samples were subjected to thermal treatments under different experimental conditions. This study shows that the temperature, metal (metallic compound) content, and type of atmosphere are the key factors in the formation of congeners and PBDD/Fs during thermal processes. The total yield of polybrominated dibenzofurans (PBDFs) was greater than that of the polybrominated dibenzo-p-dioxins (PBDDs) during the test, and 1,2,3,7,8-PeBDF and 2,3,7,8-TBDF were the predominant congeners emitted during the thermal treatment experiments.
Collapse
Affiliation(s)
- Xiuji Wang
- Analysis Center, Guangdong Medical University, Dongguan 523808, China
| | - Shufen He
- School of Pharmacy, Guangdong Medical University, Dongguan 523808, China
| | - Guanhai Wang
- School of Pharmacy, Guangdong Medical University, Dongguan 523808, China
| | - Yanchun Wang
- School of Pharmacy, Guangdong Medical University, Dongguan 523808, China
| | - Ying Cai
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Pei Chen
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Jun Mei
- School of Pharmacy, Guangdong Medical University, Dongguan 523808, China.
| |
Collapse
|