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Rathna R, Varjani S, Nakkeeran E. Recent developments and prospects of dioxins and furans remediation. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2018; 223:797-806. [PMID: 29986327 DOI: 10.1016/j.jenvman.2018.06.095] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2018] [Revised: 06/10/2018] [Accepted: 06/30/2018] [Indexed: 05/18/2023]
Abstract
Rapid urbanization and industrialization of anthropogenic activities have exerted immense pressure on the environment. Polyhalogenated organic compounds, especially dioxins and furans are regarded as ubiquitously persistent environmental pollutants in the ecosystem. The recalcitrant nature of dioxins and furans induce toxicity in both humans and wildlife. Dioxins and furans are generated by defective technological chemical processes that occur during the manufacture of herbicides and pesticides, use of fertilizers, bleaching of paper and wood pulp and incomplete combustion process. However, incineration and incomplete combustion of solid waste are the main cause for the discharge of dioxins and furans to the environment. During incineration and incomplete combustion, noxious flue gas and ashes are released into the atmosphere and contaminate the soil and water systems; thereby affecting the ecology. According to World Health Organization fact sheet 2016, more than 90% of human exposure to dioxins is through the food chain, especially from dairy products, seafood and meat. These pollutants are mutagenic, carcinogenic, immunotoxic and teratogenic for lower and higher forms of life i.e. microorganisms to humans. This review describes the sources of dioxins and furans pollution, hazardous effects on the ecosystem and recent techniques to minimize and treat dioxins and furans contaminants in the environment. This paper also previews the significance of conventional and latest remediation techniques prevailing around the globe for treating dioxins and furans entry into the ecosystem.
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Affiliation(s)
- Ravichandran Rathna
- Research Laboratory, Department of Biotechnology, Sri Venkateswara College of Engineering (Autonomous), Sriperumbudur Tk, 602 117, Tamil Nadu, India
| | - Sunita Varjani
- Gujarat Pollution Control Board, Sector-10A, Gandhinagar, 382 010, Gujarat, India
| | - Ekambaram Nakkeeran
- Research Laboratory, Department of Biotechnology, Sri Venkateswara College of Engineering (Autonomous), Sriperumbudur Tk, 602 117, Tamil Nadu, India.
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52
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Completely separating metals and nonmetals from waste printed circuit boards by slurry electrolysis. Sep Purif Technol 2018. [DOI: 10.1016/j.seppur.2018.04.069] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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53
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Wang WL, Meng Q, Xue Y, Weng X, Sun P, Wu Z. Lanthanide perovskite catalysts for oxidation of chloroaromatics: Secondary pollution and modifications. J Catal 2018. [DOI: 10.1016/j.jcat.2018.07.022] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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54
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Duan C, Han J, Zhao S, Gao Z, Qiao J, Yan G. The stripping effect of using high voltage electrical pulses breakage for waste printed circuit boards. WASTE MANAGEMENT (NEW YORK, N.Y.) 2018; 77:603-610. [PMID: 29891416 DOI: 10.1016/j.wasman.2018.06.003] [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: 01/02/2018] [Revised: 03/15/2018] [Accepted: 06/03/2018] [Indexed: 06/08/2023]
Abstract
In this study, high voltage electrical pulses were utilized to process waste printed circuit boards to cost effectively liberate metal and nonmetal materials. Relative mass ωiand particles content ηiindexes were defined to assess the stripping effect produced by high voltage electrical pulses breakage. For relative mass level in the 0-10% range, in the -6+3 mm fraction, particles content accounted for 84.84% of the total particles, while the mechanical crushing only occupied 8.84%. Voltage and pulse experiments were carried out to investigate the crushing effect of high voltage electrical pulse breakage for printed circuit boards. It was found that when the voltage and pulse number was at 160 kV and 300, the stripping rate of copper was 98.56% and 92.58% in the -25+13 mm fraction respectively. The measured bending strength of the material revealed the selective crushing effect of high voltage electrical pulses in the different material interfaces. A liberation mechanism was elaborated by using the energy band theory, and a process model was utilized to reveal the mode of crushing. Furthermore, the microscopic appearance of the resulting product confirmed that copper underwent high-temperature melting, while the resin was decomposed during the crushing process. Compared to conventional mechanical crushing process, high voltage electrical pulses can better liberate metal-bearing than mechanical comminution technology.
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Affiliation(s)
- Chenlong Duan
- Key Laboratory of Coal Processing and Efficient Utilization of Ministry of Education, School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou 221116, China.
| | - Jun Han
- Key Laboratory of Coal Processing and Efficient Utilization of Ministry of Education, School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou 221116, China
| | - Shen Zhao
- Key Laboratory of Coal Processing and Efficient Utilization of Ministry of Education, School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou 221116, China
| | - Zhonglin Gao
- Key Laboratory of Coal Processing and Efficient Utilization of Ministry of Education, School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou 221116, China
| | - Jinpeng Qiao
- Key Laboratory of Coal Processing and Efficient Utilization of Ministry of Education, School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou 221116, China
| | - Guanghui Yan
- Key Laboratory of Coal Processing and Efficient Utilization of Ministry of Education, School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou 221116, China
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55
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Soler A, Conesa JA, Iñiguez ME, Ortuño N. Pollutant formation in the pyrolysis and combustion of materials combining biomass and e-waste. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 622-623:1258-1264. [PMID: 29890593 DOI: 10.1016/j.scitotenv.2017.12.068] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 12/05/2017] [Accepted: 12/06/2017] [Indexed: 06/08/2023]
Abstract
Combustion and pyrolysis runs at 850°C were carried out in a laboratory scale horizontal reactor with different materials combining biomass and waste electrical and electronic equipment (WEEE). Analyses are presented of the carbon oxides, light hydrocarbons, polycyclic aromatic hydrocarbons (PAHs), polychlorinated benzenes (ClBzs), polychlorinated phenols (ClPhs), polybrominated phenols (BrPhs), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). Results showed that gas emissions were mainly composed of CO and CO2; the high level of CO found in the pyrolytic runs was easily transformed into CO2 by reaction with oxygen. The total amount of light hydrocarbons emitted was higher in the samples containing WEEE, methane being the most abundant light hydrocarbon in all the runs. However, the presence of WEEE reduced the emission of PAHs which decreased with the increase of the oxygen. The total amount of BrPhs increased in the decomposition of the samples containing WEEE, reaching its maximum in pyrolysis runs. Emission of PCDD/Fs was enhanced in pyrolytic conditions and easily decreased in the presence of oxygen.
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Affiliation(s)
- Aurora Soler
- Department of Chemical Engineering, University of Alicante, P.O. Box 99, E-03080 Alicante, Spain
| | - Juan A Conesa
- Department of Chemical Engineering, University of Alicante, P.O. Box 99, E-03080 Alicante, Spain.
| | - María E Iñiguez
- Department of Chemical Engineering, University of Alicante, P.O. Box 99, E-03080 Alicante, Spain
| | - Nuria Ortuño
- Department of Chemical Engineering, University of Alicante, P.O. Box 99, E-03080 Alicante, Spain
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56
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Li TY, Zhou JF, Wu CC, Bao LJ, Shi L, Zeng EY. Characteristics of Polybrominated Diphenyl Ethers Released from Thermal Treatment and Open Burning of E-Waste. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:4650-4657. [PMID: 29600707 DOI: 10.1021/acs.est.8b00780] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Primitive processing of e-waste potentially releases abundant organic contaminants to the environment, but the magnitudes and mechanisms remain to be adequately addressed. We conducted thermal treatment and open burning of typical e-wastes, that is, plastics and printed circuit boards. Emission factors of the sum of 39 polybrominated diphenyl ethers (∑39PBDE) were 817-1.60 × 105 ng g-1 in thermal treatment and nondetected-9.14 × 104 ng g-1, in open burning. Airborne particles (87%) were the main carriers of PBDEs, followed by residual ashes (13%) and gaseous constituents (0.3%), in thermal treatment, while they were 30%, 43% and 27% in open burning. The output-input mass ratios of ∑39PBDE were 0.12-3.76 in thermal treatment and 0-0.16 in open burning. All PBDEs were largely affiliated with fine particles, with geometric mean diameters at 0.61-0.83 μm in thermal degradation and 0.57-1.16 μm in open burning from plastic casings, and 0.44-0.56 and nondetected- 0.55 μm, from printed circuit boards. Evaporation and reabsorption may be the main emission mechanisms for lightly brominated BDEs, but heavily brominated BDEs tend to affiliate with particles from heating or combustion. The different size distributions of particulate PBDEs in emission sources and adjacent air implicated a noteworthy redisposition process during atmospheric dispersal.
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Affiliation(s)
- Ting-Yu Li
- School of Environment and Guangdong Key Laboratory of Environmental Pollution and Health , Jinan University , Guangzhou 510632 , China
| | - Jun-Feng Zhou
- School of Environment and Guangdong Key Laboratory of Environmental Pollution and Health , Jinan University , Guangzhou 510632 , China
| | - Chen-Chou Wu
- School of Environment and Guangdong Key Laboratory of Environmental Pollution and Health , Jinan University , Guangzhou 510632 , China
| | - Lian-Jun Bao
- School of Environment and Guangdong Key Laboratory of Environmental Pollution and Health , Jinan University , Guangzhou 510632 , China
| | - Lei Shi
- School of Environment and Guangdong Key Laboratory of Environmental Pollution and Health , Jinan University , Guangzhou 510632 , China
| | - Eddy Y Zeng
- School of Environment and Guangdong Key Laboratory of Environmental Pollution and Health , Jinan University , Guangzhou 510632 , China
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57
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Bjurlid F, Dam M, Hoydal K, Hagberg J. Occurrence of polybrominated dibenzo-p-dioxins, dibenzofurans (PBDD/Fs) and polybrominated diphenyl ethers (PBDEs) in pilot whales (Globicephala melas) caught around the Faroe Islands. CHEMOSPHERE 2018; 195:11-20. [PMID: 29248748 DOI: 10.1016/j.chemosphere.2017.12.044] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Revised: 12/07/2017] [Accepted: 12/08/2017] [Indexed: 06/07/2023]
Abstract
Blubber from Faroese pilot whales (Globicephala melas) was analysed for brominated dioxins PBDD/Fs, with a subset also analysed for chlorinated dioxins, PCDD/Fs. The studied individuals were restricted to juvenile male whales sampled in the Faroe Islands during the period 1997-2013. Among the PBDD/Fs, the furans were predominant, although the relative abundance of various congeners differed between samples. Furans accounted for, on average, 79% of the ∑PBDD/Fs in the samples, with 1,2,3,4,6,7,8-HpBDF the most abundant congener, found in half of the analysed pilot whales. The concentration range for ∑PBDD/Fs among the samples was 0.080-71 pg/g l.w. (lipid weight), and the sum of toxic equivalents ranged from 0.0039 to 4.7 pg TEQ/g l.w. No relationship was found between PBDD/Fs and PCDD/Fs. In addition, 20 pilot whale samples from the period 2010-2013 were analysed for PBDEs. Several PBDE congeners were found in all of the sampled pilot whales, and at noticeably higher levels than PBDD/Fs and PCDD/Fs. The ∑PBDEs ranged from 140 to 1900 ng/g l.w., with BDE #47 the most abundant congener detected in the samples. Results from the present study were then compared with data from previous studies on pilot wales to investigate temporal trends between 1986 and 2013. The comparison indicated that PBDE concentrations in juvenile males have decreased from 1996 to the latest observations in 2013. No relationship between the concentration levels of PBDD/Fs and PBDEs in the sampled pilot whales could be identified, which indicates possible differences in the metabolism of, or exposure to, PBDEs and PBDD/Fs.
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Affiliation(s)
- F Bjurlid
- MTM Research Centre, School of Science and Technology, Örebro University, SE 701 82, Örebro, Sweden.
| | - M Dam
- Environment Agency, Traðagøta 38, FO-165, Argir, Faroe Islands
| | - K Hoydal
- Environment Agency, Traðagøta 38, FO-165, Argir, Faroe Islands
| | - J Hagberg
- MTM Research Centre, School of Science and Technology, Örebro University, SE 701 82, Örebro, Sweden; Department of Occupational and Environmental Medicine, Faculty of Medicine and Health, Örebro University, SE-701 85, Örebro, Sweden
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58
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Kang H, Shao Q, Guo X, Galaska A, Liu Y, Guo Z. Separation and Recovery of Copper Foil and Fabric from Waste Printed Circuit Boards by Decomposing Brominated Epoxy Resin Using Near Critical Water. ACTA ACUST UNITED AC 2018. [DOI: 10.30919/espub.es.180312] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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59
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Bjurlid F, Kärrman A, Ricklund N, Hagberg J. Occurrence of brominated dioxins in a study using various firefighting methods. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 599-600:1213-1221. [PMID: 28514839 DOI: 10.1016/j.scitotenv.2017.05.087] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 05/10/2017] [Accepted: 05/10/2017] [Indexed: 06/07/2023]
Abstract
The use of different firefighting methods influences how fast a fire is extinguished and how fast the temperature drops in the area affected by the fire. These differences may also influence the formation of harmful pollutants during firefighting of an accidental fire. The aim was to study occurrence of brominated dibenzo-p-dioxins and furans (PBDD/Fs) in gas and soot during five fire scenarios resembling a small apartment fire and where different firefighting methods were used. Samples of gas and soot were taken both during the buildup of the fire and during the subsequent extinguishing of the fire while using different firefighting methods (nozzle, compressed air foam system, cutting extinguisher) and an extinguishing additive. New containers equipped with identical sets of combustible material were used for the five tests. The use of different firefighting methods and extinguishing additive induced variations in concentration and congener profiles of detected PBDD/Fs. The concentration range of ∑PBDD/Fs in gas was 4020-18,700pg/m3, and in soot 76-4092pg/m2. PBDFs were the predominant congeners and 1,2,3,4,6,7,8-HpBDF was the most abundant congener. Chlorinated dibenzo-p-dioxins and furans (PCDD/Fs) were also monitored. The PBDD/Fs contributed with in average 97% to the total (PCDD/Fs plus PBDD/Fs) toxic equivalents, in soot and gas. During extinguishing, the shorter time the temperature was around 300°C, the lower occurrence of PBDD/Fs. In the study the firefighting methods showed a difference in how effectively they induced a temperature decrease below 300°C in the fire zone during quenching, where cutting extinguishing using additive and the compressed air foam system showed the fastest drop in temperature.
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Affiliation(s)
- Filip Bjurlid
- MTM Research Centre, School of Science and Technology, Örebro University, SE, 701 82 Örebro, Sweden.
| | - Anna Kärrman
- MTM Research Centre, School of Science and Technology, Örebro University, SE, 701 82 Örebro, Sweden
| | - Niklas Ricklund
- Department of Occupational and Environmental Medicine, Faculty of Medicine and Health, Örebro University, SE, 701 85 Örebro, Sweden
| | - Jessika Hagberg
- MTM Research Centre, School of Science and Technology, Örebro University, SE, 701 82 Örebro, Sweden; Department of Occupational and Environmental Medicine, Faculty of Medicine and Health, Örebro University, SE, 701 85 Örebro, Sweden
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60
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Wang Y, He J, Wang S, Luo C, Yin H, Zhang G. Characterisation and risk assessment of polycyclic aromatic hydrocarbons (PAHs) in soils and plants around e-waste dismantling sites in southern China. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2017; 24:22173-22182. [PMID: 28791539 DOI: 10.1007/s11356-017-9830-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 07/24/2017] [Indexed: 06/07/2023]
Abstract
Environmental pollution due to primitive e-waste dismantling activities has been intensively investigated over the last decade in the south-eastern coastal region of China. In the present study, we investigated the distribution and composition of polycyclic aromatic hydrocarbons (PAHs) in soils and plants around e-waste recycling sites in Longtang, Guangdong province, South China. The results indicated that PAH concentrations in rhizosphere soil and non-rhizosphere soil were in the range of 133 to 626 ng/g and 60 to 816 ng/g, respectively, while PAH levels in plant tissue were 96 to 388 ng/g in shoots and 143 to 605 ng/g in roots. PAHs were enriched in rhizosphere soils in comparison with non-rhizosphere soils. The concentrations of PAHs in plant tissues varied greatly among plant cultivars, indicating that the uptake of PAHs by plants is species-dependent. Different profiles of PAHs in the soil and the corresponding plant tissue implied that PAH uptake and translocation by plants were selective.The total daily intakes of PAHs and carcinogenic PAHs through vegetables at the e-waste recycling site were estimated to be 99 and 22 ng/kg/day, respectively, suggesting that potential health risks associated with the consumption of contaminated vegetables should not be ignored.
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Affiliation(s)
- Yujie Wang
- School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou, 510006, China
| | - Jiexin He
- School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou, 510006, China
| | - Shaorui Wang
- Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China.
| | - Chunling Luo
- Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China.
| | - Hua Yin
- College of Environment and Energy, South China University of Technology, Guangzhou, 510006, China
| | - Gan Zhang
- Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China
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61
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Xu P, Tao B, Zhou Z, Fan S, Zhang T, Liu A, Dong S, Yuan J, Li H, Chen J, Huang Y. Occurrence, composition, source, and regional distribution of halogenated flame retardants and polybrominated dibenzo-p-dioxin/dibenzofuran in the soils of Guiyu, China. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2017; 228:61-71. [PMID: 28511039 DOI: 10.1016/j.envpol.2017.05.024] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2016] [Accepted: 05/08/2017] [Indexed: 06/07/2023]
Abstract
Guiyu, China, is well-known for the crude disposal of electronic waste (EW) and severe persistent organic pollutants (POPs). Therefore, in this study, the occurrence, composition, and source of polybrominated diphenyl ethers (PBDEs), 2,2',4,4',5,5'-hexabromobiphenyl (BB153), some novel brominated flame retardants (NBFRs), Dechlorane Plus (DP) and polybrominated dibenzo-p-dioxins/dibenzofurans (PBDD/Fs) in farmland soils covering Guiyu were studied. In EW disposal area soils, PBDEs were the most abundant FRs, with concentrations of 13-1014 ng g-1. The primary PBDE sources were technical Penta- and Deca-BDE mixtures in northern and southern Guiyu, respectively. The levels of BB153 were relatively low, possibly because it has been banned in the 1970s. The concentrations of hexabromobenzene (HBB) were 0.048-3.3 ng g-1, while pentabromoethylbenzene (PBEB) was almost not detected in the soils. Two alternatives to commercial PBDEs, decabromodiphenyl ethane (DBDPE) and 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE), were the primary NBFRs, with concentrations of 1.8-153 ng g-1 and 0.43-15 ng g-1, respectively. DP was another primary FR, with concentrations of 0.57-146 ng g-1. Moreover, syn-DP and anti-DP isomers were not stereoselectively decomposed during the EW disposal process and were therefore present in their original fractions in the soils. The levels of PBDD/Fs in EW disposal area soils were 2.5-17 pg TEQ g-1. 1,2,3,4,6,7,8-HpBDF and OBDF were the dominant congeners, mainly derived from processing, pyrolysis and combustion of BFRs. The regional distribution of pollutants was shown to be related to the disposal manner of EW, with their open thermal disposal tending to release more highly brominated compounds such as BDE209, DBDPE, and 1,2,3,4,6,7,8-HpBDF. Additionally, some riverbank sites were heavily polluted because of nearby point sources, downwind Simapu (SMP) town without EW disposal activity was also contaminated by these pollutants.
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Affiliation(s)
- Pengjun Xu
- National Research Center for Environmental Analysis and Measurement, 1 South Yuhui Road, Chaoyang District, Beijing 100029, China; Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Shahekou District, Dalian 116023, China; University of Chinese Academy of Sciences, 19 A Yuquan Road, Shijingshan District, Beijing 100049, China; Dalian University of Technology, 2 Linggong Road, Ganjingzi District, Dalian 116024, China
| | - Bu Tao
- Hebei Agricultural University, 289 Lingyusi Street, Baoding 071001, China
| | - Zhiguang Zhou
- National Research Center for Environmental Analysis and Measurement, 1 South Yuhui Road, Chaoyang District, Beijing 100029, China
| | - Shuang Fan
- National Research Center for Environmental Analysis and Measurement, 1 South Yuhui Road, Chaoyang District, Beijing 100029, China
| | - Ting Zhang
- National Research Center for Environmental Analysis and Measurement, 1 South Yuhui Road, Chaoyang District, Beijing 100029, China
| | - Aimin Liu
- National Research Center for Environmental Analysis and Measurement, 1 South Yuhui Road, Chaoyang District, Beijing 100029, China
| | - Shuping Dong
- National Research Center for Environmental Analysis and Measurement, 1 South Yuhui Road, Chaoyang District, Beijing 100029, China
| | - Jingli Yuan
- Dalian University of Technology, 2 Linggong Road, Ganjingzi District, Dalian 116024, China
| | - Hong Li
- Beijing Chaoyang District Environmental Protection Monitoring Center, 5 South Nongzhan Road, Chaoyang District, Beijing 100125, China
| | - Jiping Chen
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Shahekou District, Dalian 116023, China.
| | - Yeru Huang
- National Research Center for Environmental Analysis and Measurement, 1 South Yuhui Road, Chaoyang District, Beijing 100029, China.
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62
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Pan W, Fu J, Zhang A. Theoretical study on the formation mechanism of pre-intermediates for PXDD/Fs from 2-Bromophenol and 2-Chlorophenol precursors via radical/molecule reactions. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2017; 225:439-449. [PMID: 28302335 DOI: 10.1016/j.envpol.2017.03.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Revised: 02/13/2017] [Accepted: 03/02/2017] [Indexed: 06/06/2023]
Abstract
This study investigates reaction pathways for the formation of pre-PXDD/F intermediates via a radical/molecule mechanism. Thermodynamic and kinetic parameters for the combination reactions of 2-bromophenol (2-BP) and 2-chlorophenol (2-CP) precursors with key radical species including the phenoxy radicals, the phenyl radicals and the phenoxyl diradicals were calculated in detail. The couplings of phenoxy radicals with 2-B(C)P tend to produce pre-PXDD intermediates of halogenated o-phenoxyphenol. The combinations of phenyl and phenoxyl diradicals with 2-B(C)P produce two types of structures, i.e., dihydroxybiphenyl and o-phenoxyphenyl, which exclusively act as prestructures of PXDFs. These condensation reactions, especially those involving the phenyl C atom sites in phenyl and phenoxyl diradicals, are proven to be both thermodynamically and kinetically favorable and are nearly comparable with the corresponding steps involved in the radical/radical reactions. Most importantly, reactions of phenyl and phenoxyl diradicals with halogenated phenols solely lead to the formation of PXDFs, which to some extent provides a plausible explanation for the high PXDF-to-PXDD ratios in the real environment. Therefore, our study reveals the pivotal role of the radical/molecule mechanism in homogeneous gas-phase PXDD/F formation, especially in PXDF formation. The present results fill in a knowledge gap that has hitherto existed regarding dioxin formation and improve our understanding of PXDD/F formation characteristics in the environment.
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Affiliation(s)
- Wenxiao Pan
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China
| | - Jianjie Fu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100190, PR China
| | - Aiqian Zhang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100190, PR China.
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63
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Mei J, Wang X, Xiao X, Cai Y, Tang Y, Chen P. Characterization and inventory of PBDD/F emissions from deca-BDE, polyethylene (PE) and metal blends during the pyrolysis process. WASTE MANAGEMENT (NEW YORK, N.Y.) 2017; 62:84-90. [PMID: 28215971 DOI: 10.1016/j.wasman.2017.02.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Revised: 01/30/2017] [Accepted: 02/03/2017] [Indexed: 06/06/2023]
Abstract
The thermal treatment of waste electrical and electronic equipment (WEEE) is regarded as the largest potential contributor to the environmental release of polybrominated dibenzo-p-dioxins/dibenzofurans (PBDD/Fs). Herein, the pyrolysis of decabromodiphenyl ether (deca-BDE), polyethylene (PE) and metal blends was conducted to investigate the emission characteristics of PBDD/Fs at different thermal treatment conditions. The total yield of polybrominated dibenzo-p-dioxins (PBDDs) was less than that of polybrominated dibenzofurans (PBDFs) during the pyrolysis of the PE matrix and metal blends. 2,3,7,8-TBDF and 1,2,3,7,8-PBDF were the dominant congeners emitted from the pyrolysis. Temperature, presence of oxygen and type of added metal were the critical influencing factors for the PBDD/F formation rates and speciation in the pyrolysis process.
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Affiliation(s)
- Jun Mei
- School of Pharmacy, Guangdong Medical University, Dongguan 523808, China
| | - Xiuji Wang
- Analysis Center of Guangdong Medical University, Dongguan 523808, China
| | - Xiao Xiao
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Ying Cai
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Yuhui Tang
- 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
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64
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Ning C, Lin CSK, Hui DCW, McKay G. Waste Printed Circuit Board (PCB) Recycling Techniques. Top Curr Chem (Cham) 2017; 375:43. [PMID: 28353257 DOI: 10.1007/s41061-017-0118-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2016] [Accepted: 01/31/2017] [Indexed: 10/19/2022]
Abstract
With the development of technologies and the change of consumer attitudes, the amount of waste electrical and electronic equipment (WEEE) is increasing annually. As the core part of WEEE, the waste printed circuit board (WPCB) is a dangerous waste but at the same time a rich resource for various kinds of materials. In this work, various WPCB treatment methods as well as WPCB recycling techniques divided into direct treatment (landfill and incineration), primitive recycling technology (pyrometallurgy, hydrometallurgy, biometallurgy and primitive full recovery of NMF-non metallic fraction), and advanced recycling technology (mechanical separation, direct use and modification of NMF) are reviewed and analyzed based on their advantages and disadvantages. Also, the evaluation criteria are discussed including economic, environmental, and gate-to-market ability. This review indicates the future research direction of WPCB recycling should focus on a combination of several techniques or in series recycling to maximize the benefits of process.
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Affiliation(s)
- Chao Ning
- Chemical and Biomolecular Engineering Department, The Hong Kong University of Science and Technology, Hong Kong SAR, Hong Kong
| | - Carol Sze Ki Lin
- School of Energy and Environment, The City University of Hong Kong, Tat Chee Avenue, Hong Kong SAR, Hong Kong
| | - David Chi Wai Hui
- Chemical and Biomolecular Engineering Department, The Hong Kong University of Science and Technology, Hong Kong SAR, Hong Kong
| | - Gordon McKay
- Chemical and Biomolecular Engineering Department, The Hong Kong University of Science and Technology, Hong Kong SAR, Hong Kong. .,College of Science and Engineering, Hamad bin Khalifa University, Education City, Qatar Foundation, Doha, Qatar.
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65
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Zeng X, Yang C, Chiang JF, Li J. Innovating e-waste management: From macroscopic to microscopic scales. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 575:1-5. [PMID: 27723459 DOI: 10.1016/j.scitotenv.2016.09.078] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Revised: 09/08/2016] [Accepted: 09/10/2016] [Indexed: 06/06/2023]
Abstract
Waste electrical and electronic equipment (WEEE or e-waste) has become a global problem, due to its potential environmental pollution and human health risk, and its containing valuable resources (e.g., metals, plastics). Recycling for e-waste will be a necessity, not only to address the shortage of mineral resources for electronics industry, but also to decline environmental pollution and human health risk. To systematically solve the e-waste problem, more attention of e-waste management should transfer from macroscopic to microscopic scales. E-waste processing technology should be significantly improved to diminish and even avoid toxic substance entering into downstream of material. The regulation or policy related to new production of hazardous substances in recycled materials should also be carried out on the agenda. All the findings can hopefully improve WEEE legislation for regulated countries and non-regulated countries.
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Affiliation(s)
- Xianlai Zeng
- Key Laboratory for Solid Waste Management and Environment Safety, School of Environment, Tsinghua University, Beijing 100084, China
| | - Congren Yang
- Key Laboratory for Solid Waste Management and Environment Safety, School of Environment, Tsinghua University, Beijing 100084, China
| | - Joseph F Chiang
- Department of Chemistry and Biochemistry, State University of New York College at Oneonta, Oneonta, NY 13820, USA.
| | - Jinhui Li
- Key Laboratory for Solid Waste Management and Environment Safety, School of Environment, Tsinghua University, Beijing 100084, China.
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66
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Martin ET, McGuire CM, Mubarak MS, Peters DG. Electroreductive Remediation of Halogenated Environmental Pollutants. Chem Rev 2016; 116:15198-15234. [DOI: 10.1021/acs.chemrev.6b00531] [Citation(s) in RCA: 115] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Erin T. Martin
- Department
of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Caitlyn M. McGuire
- Department
of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | | | - Dennis G. Peters
- Department
of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
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67
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Li Q, Li L, Su G, Huang X, Zhao Y, Li B, Miao X, Zheng M. Synergetic inhibition of PCDD/F formation from pentachlorophenol by mixtures of urea and calcium oxide. JOURNAL OF HAZARDOUS MATERIALS 2016; 317:394-402. [PMID: 27318736 DOI: 10.1016/j.jhazmat.2016.05.090] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Revised: 05/15/2016] [Accepted: 05/30/2016] [Indexed: 06/06/2023]
Abstract
Chlorophenols are structurally similar to PCDD/Fs and have been considered as highly potential precursors for PCDD/Fs formation. The suppressing effects of PCDD/F formation from pentachlorophenol (PCP) were investigated on various mass ratios of CaO and urea. The total concentration of 2,3,7,8-PCDD/Fs, mostly dominated by OCDD, was determined to be 48.58-10186ng/mg in inhibitor-reaction systems, being much lower than that in blank reaction system (75654ng/mg). Interestingly, compared with pure CaO and urea reaction system, the concentration and TEQ of formed 2,3,7,8-PCDD/Fs in mixed urea/CaO reaction system were lower, especially with 5-20% urea reaction systems being respectively at decrease by 96.5-99.4% and 99.2-99.7%. The suppression efficiency of TEQ in 5-20% urea reaction systems could be always approximately 100% under 250-350°C. These results suggested that mixed inhibitors, especially 5-20% urea inhibitors, have a synergetic inhibition effect for PCDD/Fs formation from PCP. Mixed inhibitor generated several intermediates, involving CO2, H2O, NH3, Ca(OH)2, CaCO3, HNCO, biuret and ammelide. The complex between PCP and Ca, N-doped species, lower chlorinated phenols and benzenediol, and organic acids were also determined. Synergetic inhibition mechanism may be attributed to accelerated facilitation of acid-base reaction and N doping. The decomposition of PCP itself also contributes to prevent PCDD/Fs formation.
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Affiliation(s)
- Qianqian Li
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Liewu Li
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Guijin Su
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Xinchen Huang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yanhui Zhao
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Binke Li
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xue Miao
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Minghui Zheng
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
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68
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Liu K, Zhang Z, Zhang FS. Advanced degradation of brominated epoxy resin and simultaneous transformation of glass fiber from waste printed circuit boards by improved supercritical water oxidation processes. WASTE MANAGEMENT (NEW YORK, N.Y.) 2016; 56:423-430. [PMID: 27287009 DOI: 10.1016/j.wasman.2016.05.022] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Revised: 05/11/2016] [Accepted: 05/21/2016] [Indexed: 06/06/2023]
Abstract
This work investigated various supercritical water oxidation (SCWO) systems, i.e. SCWO1 (only water), SCWO2 (water+H2O2) and SCWO3 (water+H2O2/NaOH), for waste printed circuit boards (PCBs) detoxification and recycling. Response surface methodology (RSM) was applied to optimize the operating conditions of the optimal SCWO3 systems. The optimal reaction conditions for debromination were found to be the NaOH of 0.21g, the H2O2 volume of 9.04mL, the time of 39.7min, maximum debromination efficiency of 95.14%. Variance analysis indicated that the factors influencing debromination efficiency was in the sequence of NaOH>H2O2>time. Mechanism studies indicated that the dissociated ions from NaOH in supercritical water promoted the debromination of brominated epoxy resins (BERs) through an elimination reaction and nucleophilic substitution. HO2, produced by H2O2 could induce the oxidation of phenol ring to open (intermediates of BERs), which were thoroughly degraded to form hydrocarbons, CO2, H2O and NaBr. In addition, the alkali-silica reaction between OH(-) and SiO2 induced the phase transformation of glass fibers, which were simultaneously converted into anorthite and albite. Waste PCBs in H2O2/NaOH improved SCWO system were fully degraded into useful products and simultaneously transformed into functional materials. These findings are helpful for efficient recycling of waste PCBs.
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Affiliation(s)
- Kang Liu
- Department of Solid Waste Treatment and Recycling, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhiyuan Zhang
- Department of Solid Waste Treatment and Recycling, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Fu-Shen Zhang
- Department of Solid Waste Treatment and Recycling, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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69
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Wang J, Guo J, Xu Z. An environmentally friendly technology of disassembling electronic components from waste printed circuit boards. WASTE MANAGEMENT (NEW YORK, N.Y.) 2016; 53:218-24. [PMID: 27026495 DOI: 10.1016/j.wasman.2016.03.036] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Revised: 01/19/2016] [Accepted: 03/18/2016] [Indexed: 05/28/2023]
Abstract
Electronic components (ECs) disassembling from waste printed circuit boards (WPCBs) is the first and essential step in WPCBs recycling chain. Over the past decades, primitive methods like simply heating WPCBs on a coal-heated plate to melt solders are dominated in practice, causing serious environmental pollution and also putting a real threat to the human health. In order to solve this problem, in this article, an automatic system in pilot-scale for ECs disassembling from WPCBs is designed, manufactured, and investigated. This system contains two parts: ECs automatic disassembly and off-gas purification. Meanwhile, WPCBs from television (i.e., TV-WPCBs) and personal computer (i.e., PC-WPCBs) are used for disassembling tests, respectively. When the disassembling temperature, rotating speed, and incubation time are 265±5°C, 10rpm, and 8min, respectively, the solder can be completely removed from both TV-WPCBs and PC-WPCBs. No pollutant is discharged from this system. Finally, the disassembling procedures for ECs from both TV-WPCBs and PC-WPCBs are suggested to promote WPCBs disassembling in an environment-friendly way, without threaten the environment and human health.
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Affiliation(s)
- Jianbo Wang
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, People's Republic of China
| | - Jie Guo
- 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.
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70
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Liu WJ, Tian K, Jiang H, Yu HQ. Lab-scale thermal analysis of electronic waste plastics. JOURNAL OF HAZARDOUS MATERIALS 2016; 310:217-225. [PMID: 26937868 DOI: 10.1016/j.jhazmat.2016.02.044] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Revised: 01/20/2016] [Accepted: 02/20/2016] [Indexed: 06/05/2023]
Abstract
In this work, we experimentally revealed the thermochemical decomposition pathway of Decabromodiphenyl ethane (DBDPE) and tetrabromobisphenol A (TBBPA) containing electronic waste plastics using an online thermogravimetric-fourier transform infrared-mass spectroscopy (TG-FTIR-MS) system, a high resolution gas chromatography/high resolution mass (HRGC-MS) spectroscopy, and a fixed-bed reactor. We found the distribution and species of produced bromides can be easily controlled by adjusting pyrolytic temperature, which is particularly crucial to their recycle. From the analysis of the liquid and solid phase obtained from the fixed-bed reactor, we proposed that the Br radicals formed during the pyrolysis process may be captured by organic species derived from the depolymerization of plastics to form brominated compounds or by the inorganic species in the plastics, and that these species remained in the char residue after pyrolysis. Our work for the first time demonstrates intramolecular oxygen atoms play a pivotal role in the formation of PBDD/Fs that pyrolysis of oxygen-free BFRs is PBDD/Fs-free, whereas pyrolysis of oxygen-containing BFRs is PBDD/Fs-reduced.
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Affiliation(s)
- Wu-Jun Liu
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science and Technology of China, Hefei 230026, China
| | - Ke Tian
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science and Technology of China, Hefei 230026, China
| | - Hong Jiang
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science and Technology of China, Hefei 230026, China.
| | - Han-Qing Yu
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science and Technology of China, Hefei 230026, China
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71
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Xiao X, Hu J, Peng P, Chen D, Bi X. Characterization of polybrominated dibenzo-p-dioxins and dibenzo-furans (PBDDs/Fs) in environmental matrices from an intensive electronic waste recycling site, South China. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2016; 212:464-471. [PMID: 26952275 DOI: 10.1016/j.envpol.2016.02.029] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Revised: 02/10/2016] [Accepted: 02/16/2016] [Indexed: 06/05/2023]
Abstract
Information on environmental distribution and human exposures of polybrominated dibenzo-p-dioxins and dibenzo-furans (PBDDs/Fs) are little reported. In the present study, workshop dust, soil and sediment samples from Longtang and Shijiao, the intensive e-waste recycling sites within Qingyuan City, southern China, were collected and analyzed following the standard method. PBDD/F concentrations (sum of eight 2378-substituted PBDD/F congeners) in different environmental matrices were in the range of 122-4667 ng kg(-1) dry wt (dw) for workshop dust, 19.6-3793 ng kg(-1) dw for the top soils, and 527 ng kg(-1) dw for the surface sediment, which were substantially higher than those of reference sites. The long-distance transport of PBDDs/Fs also impacted the adjacent areas. Contribution of the most two toxic congeners (2,3,7,8-TBDD and 1,2,3,7,8-PeBDD) to the total toxic equivalent quantity (TEQ) increased significantly from "source" (dust) to "sink" (sediment). Dismantling and open burning were the two procedures contributing relatively higher level PBDDs/Fs to the atmosphere, while acid leaching would contaminate soils and waters directly. The estimated daily intakes of eight PBDD/F congeners via soil/dust ingestion and dermal absorption for local residents were higher than those contributed by seventeen PCDD/F congeners in the same set of samples. Children and e-waste processing workers were the most affected groups by the low-tech recycling activities there.
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Affiliation(s)
- Xiao Xiao
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jianfang Hu
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China.
| | - Ping'an Peng
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China
| | - Deyi Chen
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xinhui Bi
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China
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72
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Chen M, Ogunseitan OA, Wang J, Chen H, Wang B, Chen S. Evolution of electronic waste toxicity: Trends in innovation and regulation. ENVIRONMENT INTERNATIONAL 2016; 89-90:147-154. [PMID: 26854858 DOI: 10.1016/j.envint.2016.01.022] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Revised: 01/01/2016] [Accepted: 01/27/2016] [Indexed: 06/05/2023]
Abstract
Rapid innovation in printed circuit board, and the uncertainties surrounding quantification of the human and environmental health impacts of e-waste disposal have made it difficult to confirm the influence of evolving e-waste management strategies and regulatory policies on materials. To assess these influences, we analyzed hazardous chemicals in a market-representative set of Waste printed circuit boards (WPCBs, 1996-2010). We used standard leaching tests to characterize hazard potential and USEtox® to project impacts on human health and ecosystem. The results demonstrate that command-and-control regulations have had minimal impacts on WPCBs composition and toxicity risks; whereas technological innovation may have been influenced more by resource conservation, including a declining trend in the use of precious metals such as gold. WPCBs remain classified as hazardous under U.S. and California laws because of excessive toxic metals. Lead poses the most significant risk for cancers; zinc for non-cancer diseases; copper had the largest potential impact on ecosystem quality. Among organics, acenaphthylene, the largest risk for cancers; naphthalene for non-cancer diseases; pyrene has the highest potential for ecotoxicological impacts. These findings support the need for stronger enforcement of international policies and technology innovation to implement the strategy of design-for-the-environment and to encourage recovery, recycling, and reuse of WPCBs.
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Affiliation(s)
- Mengjun Chen
- Key Laboratory of Solid Waste Treatment and Resource Recycle (SWUST), Ministry of Education, Southwest University of Science and Technology, 59 Qinglong Road, Mianyang 621010, China; Program in Public Health and School of Social Ecology, University of California, Irvine, CA 92697, USA.
| | - Oladele A Ogunseitan
- Program in Public Health and School of Social Ecology, University of California, Irvine, CA 92697, USA.
| | - Jianbo Wang
- Key Laboratory of Solid Waste Treatment and Resource Recycle (SWUST), Ministry of Education, Southwest University of Science and Technology, 59 Qinglong Road, Mianyang 621010, China
| | - Haiyan Chen
- Key Laboratory of Solid Waste Treatment and Resource Recycle (SWUST), Ministry of Education, Southwest University of Science and Technology, 59 Qinglong Road, Mianyang 621010, China
| | - Bin Wang
- Key Laboratory of Solid Waste Treatment and Resource Recycle (SWUST), Ministry of Education, Southwest University of Science and Technology, 59 Qinglong Road, Mianyang 621010, China
| | - Shu Chen
- Key Laboratory of Solid Waste Treatment and Resource Recycle (SWUST), Ministry of Education, Southwest University of Science and Technology, 59 Qinglong Road, Mianyang 621010, China
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73
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Zhang M, Buekens A, Li X. Brominated flame retardants and the formation of dioxins and furans in fires and combustion. JOURNAL OF HAZARDOUS MATERIALS 2016; 304:26-39. [PMID: 26546701 DOI: 10.1016/j.jhazmat.2015.10.014] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Revised: 10/01/2015] [Accepted: 10/09/2015] [Indexed: 06/05/2023]
Abstract
The widespread use and increasing inventory of brominated flame retardants (BFRs) have caused considerable concern, as a result of BFRs emissions to the environment and of the formation of both polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs) and mixed polybromochloro-dibenzo-p-dioxins and dibenzofurans (PBCDD/Fs or PXDD/Fs). Structural similarities between PBDD/Fs and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) suggest the existence of comparable formation pathways of both PBDD/Fs and PCDD/Fs, yet BFRs also act as specific precursors to form additional PBDD/Fs. Moreover, elementary bromine (Br2) seems to facilitate chlorination by bromination of organics, followed by Br/Cl-exchange based on displacement through the more reactive halogen. Overall, PBDD/Fs form through three possible pathways: precursor formation, de novo formation, and dispersion of parts containing BFRs as impurities and surviving a fire or other events. The present review summarises the formation mechanisms of both brominated (PBDD/Fs) and mixed dioxins (PXDD/Fs with X=Br or Cl) from BFRs, recaps available emissions data of PBDD/Fs and mixed PXDD/Fs from controlled waste incineration, uncontrolled combustion sources and accidental fires, and identifies and analyses the effects of several local factors of influence, affecting the formation of PBDD/Fs and mixed PXDD/Fs during BFRs combustion.
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Affiliation(s)
- Mengmei Zhang
- State key laboratory of clean energy utilisation, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou, China
| | - Alfons Buekens
- State key laboratory of clean energy utilisation, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou, China; Formerly with Chemical Engineering department, Vrije Universiteit Brussel, Brussels, Belgium
| | - Xiaodong Li
- State key laboratory of clean energy utilisation, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou, China.
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74
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Wang M, Liu G, Jiang X, Li S, Liu W, Zheng M. Formation and emission of brominated dioxins and furans during secondary aluminum smelting processes. CHEMOSPHERE 2016; 146:60-67. [PMID: 26706932 DOI: 10.1016/j.chemosphere.2015.11.109] [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: 07/28/2015] [Revised: 11/20/2015] [Accepted: 11/26/2015] [Indexed: 06/05/2023]
Abstract
Secondary aluminum smelting (SAl) processes have previously been found to be important sources of polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs). It is crucial that the key factors that influence the formation and emission of PBDD/Fs are identified to allow techniques for decreasing PBDD/F emissions during SAl processes to be developed. In this study, stack gas samples were collected from four typical secondary aluminum smelters that used different raw materials, and the samples were analyzed to allow differences between PBDD/F emissions from different SAl plants to be assessed. The composition of the raw materials was found to be one of the key factors influencing the amounts of PBDD/Fs emitted. The PBDD/F emission factors (per tonne of aluminum produced) for the plants using 100% (Plant1), 80% (Plant2), and 50% (Plant3) dirty aluminum scrap in the raw material feed were 180, 86, and 14 μg t(-1), respectively. The amounts of PBDD/Fs emitted at different stages of the smelting process (feeding-fusion, refining, and casting) were compared, and the feeding-fusion stage was found to be the main stage in which PBDD/Fs were formed and emitted. Effective aluminum scrap pretreatments could significantly decrease PBDD/F emissions. Much higher polybrominated dibenzofuran concentrations than polybrominated dibenzo-p-dioxin concentrations were found throughout the SAl process. The more-brominated congeners (including octabromodibenzo-p-dioxin, octabromodibenzofuran, heptabromodibenzo-p-dioxins, and heptabromodibenzofurans) were the dominant contributors to the total PBDD/F concentrations. The results could help in the development of techniques and strategies for controlling PBDD/F emissions during metallurgical processes.
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Affiliation(s)
- Mei 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
| | - 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.
| | - Xiaoxu Jiang
- 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
| | - Sumei Li
- 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
| | - Wenbin 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
| | - 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
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75
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Fujimori T, Itai T, Goto A, Asante KA, Otsuka M, Takahashi S, Tanabe S. Interplay of metals and bromine with dioxin-related compounds concentrated in e-waste open burning soil from Agbogbloshie in Accra, Ghana. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2016; 209:155-63. [PMID: 26686056 DOI: 10.1016/j.envpol.2015.11.031] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2015] [Revised: 11/12/2015] [Accepted: 11/19/2015] [Indexed: 05/25/2023]
Abstract
Open burning of electronic waste (e-waste) releases various metals and organohalogen compounds in the environment. Here we investigated the interplay of metals (Cu, Pb, Zn, Fe, Co, and Sr) and bromine (Br) in the formation of dioxin-related compounds (DRCs), including polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (DL-PCBs), as well as non-regulated DRCs such as polybrominated dibenzo-p-dioxins/furans (PBDD/Fs) and their monobrominated PCDD/Fs in soils sampled from open burning e-waste sites at Agbogbloshie in Accra, Ghana. The predominant DRCs were PBDFs, PCDFs, PCDDs, and DL-PCBs. Statistical analyzes, X-ray absorption spectroscopy, and the PCDF/PCDD ratio suggested possible formation paths of PCDD/Fs and DL-PCBs by catalytic behaviors of copper chlorides (CuCl, CuCl2, and Cu2(OH)3Cl) and thermal breakdown of polyvinyl chloride. Predominant formation of brominated furans may be derived from electron transfer from intermediates of PBDE to copper, Cu(II) → Cu(I). Lead chloride also contributed to generate DRCs and may become highly bioaccessible through the open burning of e-waste. The main zinc species (ZnCl2 and ZnS) suggested a possible relationship to generate DRCs and specific zinc source such as tire burning. Cu, Pb, Zn, and Br contained in various e-wastes, wires/cables, plastics, and tires strongly influenced generation of many DRCs.
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Affiliation(s)
- Takashi Fujimori
- Department of Global Ecology, Graduate School of Global Environmental Studies, Kyoto University, Katsura, Nisikyo-ku, Kyoto, 615-8540, Japan; Department of Environmental Engineering, Graduate School of Engineering, Kyoto University, Katsura, Nisikyo-ku, Kyoto, 615-8540, Japan
| | - Takaaki Itai
- Center for Marine Environmental Studies (CMES), Ehime University, Bunkyo-cho 2-5, Matsuyama, Ehime 790-8577, Japan.
| | - Akitoshi Goto
- Center for Marine Environmental Studies (CMES), Ehime University, Bunkyo-cho 2-5, Matsuyama, Ehime 790-8577, Japan
| | - Kwadwo A Asante
- Center for Marine Environmental Studies (CMES), Ehime University, Bunkyo-cho 2-5, Matsuyama, Ehime 790-8577, Japan; CSIR Water Research Institute, PO Box AH 38, Achimota, Accra, Ghana
| | - Masanari Otsuka
- Center for Marine Environmental Studies (CMES), Ehime University, Bunkyo-cho 2-5, Matsuyama, Ehime 790-8577, Japan; Ehime Prefectural Institute of Public Health and Environmental Science, 8-234 Sanban-cho, Matsuyama 790-0003, Japan
| | - Shin Takahashi
- Center for Marine Environmental Studies (CMES), Ehime University, Bunkyo-cho 2-5, Matsuyama, Ehime 790-8577, Japan; Department of Environmental Conservation, Ehime University, Matsuyama 790-8577, Japan
| | - Shinsuke Tanabe
- Center for Marine Environmental Studies (CMES), Ehime University, Bunkyo-cho 2-5, Matsuyama, Ehime 790-8577, Japan
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Tue NM, Goto A, Takahashi S, Itai T, Asante KA, Kunisue T, Tanabe S. Release of chlorinated, brominated and mixed halogenated dioxin-related compounds to soils from open burning of e-waste in Agbogbloshie (Accra, Ghana). JOURNAL OF HAZARDOUS MATERIALS 2016; 302:151-157. [PMID: 26474377 DOI: 10.1016/j.jhazmat.2015.09.062] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Revised: 09/21/2015] [Accepted: 09/27/2015] [Indexed: 05/19/2023]
Abstract
Although complex mixtures of dioxin-related compounds (DRCs) can be released from informal e-waste recycling, DRC contamination in African e-waste recycling sites has not been investigated. This study examined the concentrations of DRCs including chlorinated, brominated, mixed halogenated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs, PBDD/Fs, PXDD/Fs) and dioxin-like polychlorinated biphenyls (DL-PCBs) in surface soil samples from the Agbogbloshie e-waste recycling site in Ghana. PCDD/F and PBDD/F concentrations in open burning areas (18-520 and 83-3800 ng/g dry, respectively) were among the highest reported in soils from informal e-waste sites. The concentrations of PCDFs and PBDFs were higher than those of the respective dibenzo-p-dioxins, suggesting combustion and PBDE-containing plastics as principal sources. PXDFs were found as more abundant than PCDFs, and higher brominated analogues occurred at higher concentrations. The median total WHO toxic equivalent (TEQ) concentration in open burning soils was 7 times higher than the U.S. action level (1000 pg/g), with TEQ contributors in the order of PBDFs>>PCDD/Fs>PXDFs. DRC emission to soils over the e-waste site as of 2010 was estimated, from surface soil lightness based on the correlations between concentrations and lightness, at 200mg (95% confidence interval 93-540 mg) WHO-TEQ over three years. People living in Agbogbloshie are potentially exposed to high levels of not only chlorinated but also brominated DRCs, and human health implications need to be assessed in future studies.
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Affiliation(s)
- Nguyen Minh Tue
- 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
| | - Shin Takahashi
- Center for Marine Environmental Studies (CMES), Ehime University, 2-5 Bunkyo-cho, Matsuyama 790-8577, Japan; Center of Advanced Technology for the Environment, Faculty of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama 790-8566, 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. AH 38, Achimota, Accra, Ghana
| | - Tatsuya Kunisue
- Center for Marine Environmental Studies (CMES), Ehime University, 2-5 Bunkyo-cho, Matsuyama 790-8577, Japan
| | - Shinsuke Tanabe
- Center for Marine Environmental Studies (CMES), Ehime University, 2-5 Bunkyo-cho, Matsuyama 790-8577, Japan
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77
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Awasthi AK, Zeng X, Li J. Comparative Examining and Analysis of E-waste Recycling in Typical Developing and Developed Countries. ACTA ACUST UNITED AC 2016. [DOI: 10.1016/j.proenv.2016.07.065] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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78
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Polybrominated Diphenyl Ethers (PBDEs) Emitted from Heating Machine for Waste Printed Wiring Boards Disassembling. ACTA ACUST UNITED AC 2016. [DOI: 10.1016/j.proenv.2016.02.094] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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79
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Duan H, Hu J, Tan Q, Liu L, Wang Y, Li J. Systematic characterization of generation and management of e-waste in China. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2016; 23:1929-1943. [PMID: 26408118 DOI: 10.1007/s11356-015-5428-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Accepted: 09/14/2015] [Indexed: 06/05/2023]
Abstract
Over the last decade, there has been much effort to promote the management of e-waste in China. Policies have been affected to prohibit imports and to control pollution. Research has been conducted in laboratories and on large-scale industrial operations. A subsidy system to support sound e-waste recycling has been put in place. However, the handling of e-waste is still a concern in China and the issue remains unresolved. There has been relatively little work to follow up this issue or to interpret continuing problems from the perspective of sustainable development. This paper first provides a brief overview of conventional and emerging environmental pollution in Chinese "famous" e-waste dismantling areas, including Guiyu in Guangdong and Wenling in Zhejiang. Environmentalists have repeatedly proven that these areas are significantly polluted. Importing and backyard recycling are decreasing but are ongoing. Most importantly, no work is being done to treat or remediate the contaminated environmental media. The situation is exacerbated by the rising tide of e-waste generated by domestic update of various electronics. This study, therefore, employs a Sales Obsolescence Model approach to predict the generation of e-waste. When accounting for weight, approximately 8 million tons of e-waste will be generated domestically in 2015, of which around 50% is ferrous metals, followed by miscellaneous plastic (30%), copper metal and cables (8%), aluminum (5%), and others (7%). Of this, 3.6% will come from scrap PCBs and 0.2% from lead CRT glass. While more and more end-of-life electronics have been collected and treated by formal or licensed recyclers in China in terms of our analysis, many of them only have dismantling and separation activities. Hazardous e-wastes, including those from PCBs, CRT glass, and brominated flame retardant (BFR) plastics, have become problematic and probably flow to small or backyard recyclers without environmentally sound management. Traditional technologies are still being used to recover precious metals--such as cyanide method of gold hydrometallurgy--from e-waste. While recovery rates of precious metals from e-waste are above 50%, it has encountered some challenges from environmental considerations. Worse, many critical metals contained in e-waste are lost because the recovery rates are less than 1%. On the other hand, this implies that there is opportunity to develop the urban mine of the critical metals from e-waste.
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Affiliation(s)
- Huabo Duan
- College of Civil Engineering, Shenzhen University, 518060, Shenzhen, China.
| | - Jiukun Hu
- Dongjiang Environmental Co., Ltd., 518057, Shenzhen, China
| | - Quanyin Tan
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, 100084, Beijing, China
| | - Lili Liu
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, 100084, Beijing, China
| | - Yanjie Wang
- Dongjiang Environmental Co., Ltd., 518057, Shenzhen, China
| | - Jinhui Li
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, 100084, Beijing, China.
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80
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Saeed A, Altarawneh M, Dlugogorski BZ. Formation of mixed halogenated dibenzo-p-dioxins and dibenzofurans (PXDD/Fs). CHEMOSPHERE 2015; 137:149-156. [PMID: 26159067 DOI: 10.1016/j.chemosphere.2015.06.054] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Revised: 05/27/2015] [Accepted: 06/11/2015] [Indexed: 06/04/2023]
Abstract
This contribution investigates mechanistic and kinetic parameters pertinent to formation of mixed dibenzo-p-dioxins and dibenzofurans (PXDD/Fs) from the condensation reactions involving 2-chlorophenoxy (2-CPxy) and 2-bromophenoxy (2-BPxy) radicals. Keto-ether structures act as direct intermediates for the formation of DD, 1-MCDD, 1-MBDD, 1-B,6-CDD and 1-B,9-CDD molecules. Likewise, diketo adducts initiate the formation of 4-MCDF, 4-MBDF and 4-B,6-CDF compounds through interconversion and rearrangement reactions. As formation mechanisms of halogenated dibenzo-p-dioxins and dibenzofurans from precursors of brominated and chlorinated phenols are insensitive to substitution at meta and para sites, our mechanistic and kinetic analysis of reactions involving 2-BPxy and 2-CPxy should also apply to higher halogenated phenoxy radicals.
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Affiliation(s)
- Anam Saeed
- School of Engineering and Information Technology, Murdoch University, 90 South Street, Murdoch, WA 6150, Australia
| | - Mohammednoor Altarawneh
- School of Engineering and Information Technology, Murdoch University, 90 South Street, Murdoch, WA 6150, Australia.
| | - Bogdan Z Dlugogorski
- School of Engineering and Information Technology, Murdoch University, 90 South Street, Murdoch, WA 6150, Australia
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81
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Systematic characterization of generation and management of e-waste in China. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2015. [PMID: 26408118 DOI: 10.1007/s11356-015-5428-0)] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 09/29/2022]
Abstract
Over the last decade, there has been much effort to promote the management of e-waste in China. Policies have been affected to prohibit imports and to control pollution. Research has been conducted in laboratories and on large-scale industrial operations. A subsidy system to support sound e-waste recycling has been put in place. However, the handling of e-waste is still a concern in China and the issue remains unresolved. There has been relatively little work to follow up this issue or to interpret continuing problems from the perspective of sustainable development. This paper first provides a brief overview of conventional and emerging environmental pollution in Chinese "famous" e-waste dismantling areas, including Guiyu in Guangdong and Wenling in Zhejiang. Environmentalists have repeatedly proven that these areas are significantly polluted. Importing and backyard recycling are decreasing but are ongoing. Most importantly, no work is being done to treat or remediate the contaminated environmental media. The situation is exacerbated by the rising tide of e-waste generated by domestic update of various electronics. This study, therefore, employs a Sales Obsolescence Model approach to predict the generation of e-waste. When accounting for weight, approximately 8 million tons of e-waste will be generated domestically in 2015, of which around 50% is ferrous metals, followed by miscellaneous plastic (30%), copper metal and cables (8%), aluminum (5%), and others (7%). Of this, 3.6% will come from scrap PCBs and 0.2% from lead CRT glass. While more and more end-of-life electronics have been collected and treated by formal or licensed recyclers in China in terms of our analysis, many of them only have dismantling and separation activities. Hazardous e-wastes, including those from PCBs, CRT glass, and brominated flame retardant (BFR) plastics, have become problematic and probably flow to small or backyard recyclers without environmentally sound management. Traditional technologies are still being used to recover precious metals--such as cyanide method of gold hydrometallurgy--from e-waste. While recovery rates of precious metals from e-waste are above 50%, it has encountered some challenges from environmental considerations. Worse, many critical metals contained in e-waste are lost because the recovery rates are less than 1%. On the other hand, this implies that there is opportunity to develop the urban mine of the critical metals from e-waste.
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82
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A Novel Designed Bioreactor for Recovering Precious Metals from Waste Printed Circuit Boards. Sci Rep 2015; 5:13481. [PMID: 26316021 PMCID: PMC4551999 DOI: 10.1038/srep13481] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 07/15/2015] [Indexed: 01/31/2023] Open
Abstract
For recovering precious metals from waste printed circuit boards (PCBs), a novel hybrid technology including physical and biological methods was developed. It consisted of crushing, corona-electrostatic separation, and bioleaching. Bioleaching process is the focus of this paper. A novel bioreactor for bioleaching was designed. Bioleaching was carried out using Pseudomonas chlororaphis. Bioleaching experiments using mixed particles of Au and Cu were performed and leachate contained 0.006 mg/L, 2823 mg/L Au(+) and Cu(2+) respectively. It showed when Cu existed, the concentrations of Au were extremely small. This provided the feasibility to separate Cu from Au. The method of orthogonal experimental design was employed in the simulation bioleaching experiments. Experimental results showed the optimized parameters for separating Cu from Au particles were pH 7.0, temperature 22.5 °C, and rotation speed 80 r/min. Based on the optimized parameters obtained, the bioreactor was operated for recovering mixed Au and Cu particles. 88.1 wt.% of Cu and 76.6 wt.% of Au were recovered. The paper contributed important information to recover precious metals from waste PCBs.
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83
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Chen M, Huang J, Ogunseitan OA, Zhu N, Wang YM. Comparative study on copper leaching from waste printed circuit boards by typical ionic liquid acids. WASTE MANAGEMENT (NEW YORK, N.Y.) 2015; 41:142-147. [PMID: 25869844 DOI: 10.1016/j.wasman.2015.03.037] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Revised: 03/19/2015] [Accepted: 03/25/2015] [Indexed: 06/04/2023]
Abstract
Waste printed circuit boards (WPCBs) are attracting increasing concerns because the recovery of its content of valuable metallic resources is hampered by the presence of hazardous substances. In this study, we used ionic liquids (IL) to leach copper from WPCBs. [BSO3HPy]OTf, [BSO3HMIm]OTf, [BSO4HPy]HSO4, [BSO4HMim]HSO4 and [MIm]HSO4 were selected. Factors that affect copper leaching rate were investigated in detail and their leaching kinetics were also examined with the comparison of [Bmim]HSO4. The results showed that all six IL acids could successfully leach copper out, with near 100% recovery. WPCB particle size and leaching time had similar influences on copper leaching performance, while IL acid concentration, hydrogen peroxide addition, solid to liquid ratio, temperature, showed different influences. Moreover, IL acid with HSO4(-) was more efficient than IL acid with CF3SO3(-). These six IL acids indicate a similar behavior with common inorganic acids, except temperature since copper leaching rate of some IL acids decreases with its increase. The results of leaching kinetics studies showed that diffusion plays a more important role than surface reaction, whereas copper leaching by inorganic acids is usually controlled by surface reaction. This innovation provides a new option for recovering valuable materials such as copper from WPCBs.
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Affiliation(s)
- Mengjun Chen
- Key Laboratory of Solid Waste Treatment and Resource Recycle (SWUST), Ministry of Education, Southwest University of Science and Technology, 59 Qinglong Road, Mianyang 621010, China.
| | - Jinxiu Huang
- Key Laboratory of Solid Waste Treatment and Resource Recycle (SWUST), Ministry of Education, Southwest University of Science and Technology, 59 Qinglong Road, Mianyang 621010, China
| | - Oladele A Ogunseitan
- Program in Public Health, Department of Population Health and Disease Prevention, and School of Social Ecology, University of California, Irvine, CA 92697-3957, USA
| | - Nengming Zhu
- Biogas Institute of Ministry of Agriculture, 13 4th Section Renmin South Road, Chengdu 610041, China
| | - Yan-min Wang
- School of Chemistry and Environmental Science, Shaanxi University of Technology, Hanzhong, Shaanxi 723001, China
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84
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Li J, Zeng X, Chen M, Ogunseitan OA, Stevels A. "Control-alt-delete": rebooting solutions for the E-waste problem. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:7095-108. [PMID: 26007633 DOI: 10.1021/acs.est.5b00449] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
A number of efforts have been launched to solve the global electronic waste (e-waste) problem. The efficiency of e-waste recycling is subject to variable national legislation, technical capacity, consumer participation, and even detoxification. E-waste management activities result in procedural irregularities and risk disparities across national boundaries. We review these variables to reveal opportunities for research and policy to reduce the risks from accumulating e-waste and ineffective recycling. Full regulation and consumer participation should be controlled and reinforced to improve local e-waste system. Aiming at standardizing best practice, we alter and identify modular recycling process and infrastructure in eco-industrial parks that will be expectantly effective in countries and regions to handle the similar e-waste stream. Toxicity can be deleted through material substitution and detoxification during the life cycle of electronics. Based on the idea of "Control-Alt-Delete", four patterns of the way forward for global e-waste recycling are proposed to meet a variety of local situations.
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Affiliation(s)
- Jinhui Li
- †State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Xianlai Zeng
- †State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Mengjun Chen
- ‡Key Laboratory of Solid Waste Treatment and Resource Recycle, Ministry of Education, Southwest University of Science and Technology, Mianyang 621010, China
| | - Oladele A Ogunseitan
- §Program in Public Health and School of Social Ecology, University of California, Irvine, California 92697, United States
| | - Ab Stevels
- ∥Design for Sustainability Lab, Delft University of Technology, 3-5655 JL Eindhoven, The Netherlands
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85
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Wittsiepe J, Fobil JN, Till H, Burchard GD, Wilhelm M, Feldt T. Levels of polychlorinated dibenzo-p-dioxins, dibenzofurans (PCDD/Fs) and biphenyls (PCBs) in blood of informal e-waste recycling workers from Agbogbloshie, Ghana, and controls. ENVIRONMENT INTERNATIONAL 2015; 79:65-73. [PMID: 25797584 DOI: 10.1016/j.envint.2015.03.008] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Revised: 03/03/2015] [Accepted: 03/03/2015] [Indexed: 05/23/2023]
Abstract
The formation and environmental release of highly toxic organohalogen compounds associated with informal recycling of waste electric and electronic equipment (e-waste) is a growing problem at e-waste dumps/recycling sites (EWRSs) in many developing countries worldwide. We chose a cross-sectional study design to measure the internal exposure to polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) as well as polychlorinated biphenyls (PCBs) of individuals working on one of the largest EWRSs of Africa, located at Agbogbloshie, Accra, Ghana, and in controls from a suburb of Accra without direct exposure to EWRS activities. In whole blood samples of 21 age matched male exposed individuals (mean age: 24.7 years, SD 6.0) and 21 male controls (mean age: 24.4 years, SD 5.7) 17 PCDD/F congeners were determined. Moreover three indicator PCB congeners (#138, #153 and #180) were measured in blood of 39 exposed (mean age: 27.5 years, SD 11.7) and 19 non-exposed (mean age: 26.8 years, SD 9.7) patients. Besides a health examination, biometric and demographic data, residential and occupational history, occupational exposures and working conditions were recorded using a standardized questionnaire. In the exposed group, median PCDD/F-concentrations were 6.18 pg/g lipid base WHO2005-TEq (range: 2.1-42.7) and significantly higher compared to the control group with 4.60 pg/g lipid base WHO2005-TEq (range: 1.6-11.6). Concentrations were different for 2,3,7,8-TetraCDD, three HexaCDD and all 10 PCDF congeners, indicating a combustion pattern. Using a multivariate regression analysis exposure to EWRS activities was the most important determinant for PCDD/F exposure. Median PCB levels for the indicator congeners #138, #153 and #180 were 0.011, 0.019 and 0.008 μg/l whole blood (ranges: 0.002-0.18, 0.003-0.16, 0.002-0.078) in the exposed group and, surprisingly, significantly higher in the controls (0.037, 0.062 and 0.022; ranges: 0.005-0.46, 0.010-0.46, 0.004-0.21). In a multivariate regression approach e-waste related activities had no positive influence on internal PCB exposure, but rather the time living in Accra. The internal PCB exposure is in particular notable for a country where PCBs have historically never been produced or used. The impact of EWRS activities on organohalogen compound exposure of individuals working at and living in the surroundings of the Agbogbloshie EWRS, and the surprisingly high PCB exposure of people living in Accra not involved in e-waste activities require further investigation.
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Affiliation(s)
- Jürgen Wittsiepe
- Department of Hygiene, Social and Environmental Medicine, Ruhr-University Bochum, Bochum, Germany.
| | - Julius N Fobil
- Department of Biological, Environmental & Occupational Health Sciences, School of Public Health, University of Ghana, P.O. Box LG13, Legon, Ghana
| | - Holger Till
- GIZ-Regional Coordination Unit for HIV & TB (GiZ-ReCHT), P.O. Box 9698, K.I.A. 32, Cantonment Crescent, Cantonment, Accra, Ghana
| | - Gerd-Dieter Burchard
- Clinical Research Unit, Bernhard Nocht Institute for Tropical Medicine, Bernhard-Nocht Str. 74, 20359 Hamburg, Germany; Department of Medicine, Section Infectious Diseases and Tropical Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Michael Wilhelm
- Department of Hygiene, Social and Environmental Medicine, Ruhr-University Bochum, Bochum, Germany
| | - Torsten Feldt
- Clinical Research Unit, Bernhard Nocht Institute for Tropical Medicine, Bernhard-Nocht Str. 74, 20359 Hamburg, Germany; Clinic of Gastroenterology, Hepatology and Infectious Diseases, University Hospital Düsseldorf, Moorenstr. 5, 40225 Düsseldorf, Germany
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86
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Xu Y, Liu J. Recent developments and perspective of the spent waste printed circuit boards. WASTE MANAGEMENT & RESEARCH : THE JOURNAL OF THE INTERNATIONAL SOLID WASTES AND PUBLIC CLEANSING ASSOCIATION, ISWA 2015; 33:392-400. [PMID: 25827846 DOI: 10.1177/0734242x15576024] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The amount of spent electronic and electrical solid wastes (i.e. e-wastes) has increased to a new level with the rapid development of electronic and electrical industries. Management of e-wastes challenges the administrators and researchers. As a major component of the e-waste stream, pollution caused by the spent printed circuit boards has captured increasing attention. Various innovative methods have recently been developed to dispose and reuse these municipal spent printed circuit boards. In this mini-review article, the disposal approaches for spent printed circuit boards are highlighted. The present state and future perspective are also discussed. We hope that this mini-review can promote the extensive understanding and effective disposal of the spent printed circuit boards in the field of solid waste treatment and resources.
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Affiliation(s)
- Yuquan Xu
- Department of Chemical and Materials Engineering, Hefei University, Hefei, China
| | - Junsheng Liu
- Department of Chemical and Materials Engineering, Hefei University, Hefei, China
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87
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Guo J, Zhang R, Xu Z. PBDEs emission from waste printed wiring boards during thermal process. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:2716-2723. [PMID: 25629562 DOI: 10.1021/es5053599] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Polybrominated diphenyl ethers (PBDEs) contained in waste printed wiring board (PWB) matrix and surface dust can be emitted into the air during thermal process, which is widely used to detach the electronic components from the base boards of waste PWB. In this study, PBDEs concentrations in air and dust samples were detected in a PWB-heating workshop, and then heating experiments of PBDEs-containing materials in a quartz tube furnace were performed to investigate the PBDEs emission mechanism. The results showed that the mean concentrations of Σ8PBDEs in PM10 and TSP were 479 and 1670 ng/m(3), respectively. Compared with surface dust collected from waste PWB (15600 ng/g), PBDEs concentrations in dust from the workshop floor (31,100 ng/g), heating machine inside (84,700 ng/g), and the cyclone extractor (317,000 ng/g), were condensed after thermal process. Heating experiments showed that the emission rates of PBDEs from PBDEs-containing dust were obviously higher than those from PWB fragments in the first 1-h time. The cumulative amounts of PBDEs emitted from dust increased rapidly at first, and then leveled off to become asymptotic to the maximum amounts. At the temperature of 300 °C, the PBDEs emission from dust mainly occurred within the first 5 min, and the average emission rates for BDE-28, -47, and -99 among the first 5 min were 1230, 4480, and 1950 ng/(g·min), respectively. During the initial 1-h period, the trends of PBDEs emission from PWB fragments had a linear increase, and the emission rates of penta-BDE (BDE-47, -99, -100) at different temperatures were at a range of 9.75-11.5 ng/(g·min). All the results showed that PBDEs emission from PWB waste happened during thermal process, and management strategies were provided to reduce the occupational exposure level of PBDEs for workers.
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Affiliation(s)
- Jie Guo
- School of Environmental Science and Engineering, Shanghai Jiao Tong University , 800 Dongchuan Road, Shanghai 200240, People's Republic of China
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88
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Ortuño N, Lundstedt S, Lundin L. Emissions of PBDD/Fs, PCDD/Fs and PBDEs from flame-retarded high-impact polystyrene under thermal stress. CHEMOSPHERE 2015; 123:64-70. [PMID: 25550110 DOI: 10.1016/j.chemosphere.2014.10.085] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Revised: 09/25/2014] [Accepted: 10/27/2014] [Indexed: 06/04/2023]
Abstract
The emissions of polybrominated diphenyl ethers (PBDEs), polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs) and their chlorinated analogues (PCDD/Fs) during the thermal treatment of a high impact polystyrene (HIPS) TV casing were investigated. The halogenated compounds were analyzed in the original material and in the gases emitted during its treatment at temperatures between 50 °C and 250 °C. DecaBDE was the primary PBDE in the TV casing, which also contained high levels of PBDFs (ppm range). At the lower treatment temperatures, non-modified PBDEs evaporated from the samples. Conversely, at 200 °C or above, debromination reactions led to the formation of additional tri- through nonaBDE. The formation of new PBDD/Fs was also detected in the gas phase when the plastic was heated to 200 °C or 250 °C, with higher yields of furans than dioxins. This appreciably increased the toxic equivalent (TEQ) levels of the gas phase relative to those seen in the untreated sample. In all cases, the levels and TEQ contributions from PCDD/Fs were negligible compared to those for brominated analogues.
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Affiliation(s)
- Nuria Ortuño
- Department of Chemistry, Umeå University, SE 901 87 Umeå, Sweden.
| | | | - Lisa Lundin
- Department of Chemistry, Umeå University, SE 901 87 Umeå, Sweden.
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89
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Li K, Xu Z. Application of supercritical water to decompose brominated epoxy resin and environmental friendly recovery of metals from waste memory module. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:1761-1767. [PMID: 25582426 DOI: 10.1021/es504644b] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Waste Memory Modules (WMMs), a particular kind of waste printed circuit board (WPCB), contain a high amount of brominated epoxy resin (BER), which may bring a series of environmental and health problems. On the other hand, metals like gold and copper are very valuable and are important to recover from WMMs. In the present study, an effective and environmental friendly method using supercritical water (SCW) to decompose BER and recover metals from WMMs was developed instead of hydrometallurgy or pyrometallurgy simultaneously. Experiments were conducted under external-catalyst-free conditions with temperatures ranging from 350 to 550 °C, pressures from 25 to 40 MPa, and reaction times from 120 to 360 min in a semibatch-type reactor. The results showed that BER could be quickly and efficiently decomposed under SCW condition, and the mechanism was possibly free radical reaction. After the SCW treatments, the glass fibers and metal foils in the solid residue could be easily liberated and recovered, respectively. The metal recovery rate reached 99.80%. The optimal parameters were determined as 495 °C, 33 MPa, and 305 min on the basis of response surface methodology (RSM). This study provides an efficient and environmental friendly approach for WMMs recycling compared with electrolysis, pyrometallurgy, and hydrometallurgy.
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Affiliation(s)
- Kuo Li
- School of Environmental Science and Engineering, Shanghai Jiao Tong University , 800 Dongchuan Road, Shanghai 200240, People's Republic of China
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90
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Li Y, Chen T, Zhang J, Meng W, Yan M, Wang H, Li X. Mass balance of dioxins over a cement kiln in China. WASTE MANAGEMENT (NEW YORK, N.Y.) 2015; 36:130-135. [PMID: 25532674 DOI: 10.1016/j.wasman.2014.11.027] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Revised: 11/27/2014] [Accepted: 11/28/2014] [Indexed: 06/04/2023]
Abstract
The cement production process may be a potential source of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs, "dioxins"), due to the widespread distribution of dioxins and potential precursors in raw materials and to conditions favorable to de novo formation in the heat exchangers. The emission, gas/particle distribution, and mass balance of PCDD/Fs were investigated at a typical state-of-the-art Chinese cement kiln. Input and output inventories were established for three campaigns, including two in normal operation and one while co-processing refuse derived fuel (RDF). Sample analysis from stack gas, cement kiln dust, raw meal, fly dust and clinker for the analysis of PCDD/Fs were reported in this study. Dioxins were also analyzed at various positions in the pre-heater, presenting an adsorption-desorption circulation process of PCDD/Fs. The over-all dioxin mass balance was negative, indicating that this cement kiln is not a source but a sink process of dioxins.
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Affiliation(s)
- Yeqing Li
- Huaxin Environment Engineering Co., Ltd., Wuhan, China
| | - Tong Chen
- State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China.
| | - Jiang Zhang
- Huaxin Environment Engineering Co., Ltd., Wuhan, China
| | - Weijie Meng
- State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China
| | - Mi Yan
- Institute of Energy & Power Engineering, Zhejiang University of Technology, Hangzhou, China
| | | | - Xiaodong Li
- State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China
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91
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Wang J, Xu Z. Disposing and recycling waste printed circuit boards: disconnecting, resource recovery, and pollution control. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:721-733. [PMID: 25525865 DOI: 10.1021/es504833y] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Over the past decades, China has been suffering from negative environmental impacts from distempered e-waste recycling activities. After a decade of effort, disassembly and raw materials recycling of environmentally friendly e-waste have been realized in specialized companies, in China, and law enforcement for illegal activities of e-waste recycling has also been made more and more strict. So up to now, the e-waste recycling in China should be developed toward more depth and refinement to promote industrial production of e-waste resource recovery. Waste printed circuit boards (WPCBs), which are the most complex, hazardous, and valuable components of e-waste, are selected as one typical example in this article that reviews the status of related regulations and technologies of WPCBs recycling, then optimizes, and integrates the proper approaches in existence, while the bottlenecks in the WPCBs recycling system are analyzed, and some preliminary experiments of pinch technologies are also conducted. Finally, in order to provide directional guidance for future development of WPCBs recycling, some key points in the WPCBs recycling system are proposed to point towards a future trend in the e-waste recycling industry.
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92
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Yan X, Liu X, Qi C, Wang D, Lin C. Mechanochemical destruction of a chlorinated polyfluorinated ether sulfonate (F-53B, a PFOS alternative) assisted by sodium persulfate. RSC Adv 2015. [DOI: 10.1039/c5ra15337a] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Persulfate (PS) can be activated by NaOH and the PS–NaOH assisted mechanochemical destruction method is effective for the degradation of F-53B.
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Affiliation(s)
- Xue Yan
- State Key Laboratory of Water Environment Simulation
- School of Environment
- Beijing Normal University
- Beijing 100875
- China
| | - Xitao Liu
- State Key Laboratory of Water Environment Simulation
- School of Environment
- Beijing Normal University
- Beijing 100875
- China
| | - Chengdu Qi
- State Key Laboratory of Water Environment Simulation
- School of Environment
- Beijing Normal University
- Beijing 100875
- China
| | - Dali Wang
- Calcium Carbide Factory
- Jilin Petrochemical Company
- Petro China
- Jilin 132000
- China
| | - Chunye Lin
- State Key Laboratory of Water Environment Simulation
- School of Environment
- Beijing Normal University
- Beijing 100875
- China
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93
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Hadi P, Ning C, Ouyang W, Xu M, Lin CSK, McKay G. Toward environmentally-benign utilization of nonmetallic fraction of waste printed circuit boards as modifier and precursor. WASTE MANAGEMENT (NEW YORK, N.Y.) 2015; 35:236-246. [PMID: 25445263 DOI: 10.1016/j.wasman.2014.09.020] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Revised: 09/22/2014] [Accepted: 09/23/2014] [Indexed: 06/04/2023]
Abstract
Electronic waste, including printed circuit boards, is growing at an alarming rate due to the accelerated technological progress and the shorter lifespan of the electronic equipment. In the past decades, due to the lack of proper economic and environmentally-benign recycling technologies, a major fraction of e-waste generated was either destined to landfills or incinerated with the sole intention of its disposal disregarding the toxic nature of this waste. Recently, with the increasing public awareness over their environment and health issues and with the enaction of more stringent regulations, environmentally-benign recycling has been driven to be an alternative option partially replacing the traditional eco-unfriendly disposal methods. One of the most favorable green technologies has been the mechanical separation of the metallic and nonmetallic fraction of the waste printed circuit boards. Although metallic fraction, as the most profitable component, is used to generate the revenue of the separation process, the nonmetallic fraction (NMF) has been left isolated. Herein, the recent developments in the application of NMF have been comprehensively reviewed and an eco-friendly emerging usage of NMF as a value-added material for sustainable remediation has been introduced.
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Affiliation(s)
- Pejman Hadi
- Chemical and Biomolecular Engineering Department, Hong Kong University of Science and Technology, Clear Water Bay Road, Hong Kong Special Administrative Region
| | - Chao Ning
- Chemical and Biomolecular Engineering Department, Hong Kong University of Science and Technology, Clear Water Bay Road, Hong Kong Special Administrative Region
| | - Weiyi Ouyang
- Chemical and Biomolecular Engineering Department, Hong Kong University of Science and Technology, Clear Water Bay Road, Hong Kong Special Administrative Region
| | - Meng Xu
- Chemical and Biomolecular Engineering Department, Hong Kong University of Science and Technology, Clear Water Bay Road, Hong Kong Special Administrative Region
| | - Carol S K Lin
- School of Energy and Environment, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Hong Kong Special Administrative Region
| | - Gordon McKay
- Chemical and Biomolecular Engineering Department, Hong Kong University of Science and Technology, Clear Water Bay Road, Hong Kong Special Administrative Region; Division of Sustainable Development, College of Science, Engineering and Technology, Hamad bin Khalifa University, Doha, Qatar.
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94
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Zhang K, Huang J, Wang H, Liu K, Yu G, Deng S, Wang B. Mechanochemical degradation of hexabromocyclododecane and approaches for the remediation of its contaminated soil. CHEMOSPHERE 2014; 116:40-45. [PMID: 24613442 DOI: 10.1016/j.chemosphere.2014.02.006] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Revised: 02/03/2014] [Accepted: 02/09/2014] [Indexed: 06/03/2023]
Abstract
Hexabromocyclododecane (HBCD) has been listed in the Stockholm Convention for elimination due to its persistent and accumulative properties. In consideration of its sound disposal, mechanochemical (MC) method was employed using different co-milling reagents. Fe-Quartz was proven to a good reagent for HBCD destruction achieving both good degradation efficiency and high yield of bromide. The absence of organic matters after MC treatment was demonstrated by thermogravimetry and GC-MS analysis, indicating the complete degradation of HCBD and its conversion into inorganic compounds. No obvious intermediates could be detected due to the swift and spontaneous reaction between HBCD and Fe-Quartz. FTIR and Raman spectra further showed that the organic structures in HBCD were broken down while amorphous and graphite carbon were obtained as another final product besides bromide. After the successful destruction of HBCD, approaches to remediate its contaminated soil were also carried out. Fe-Quartz was also proven to be the best reagent for HBCD degradation in Kaolin, while CaO showed better performance for the remediation of HBCD contaminated Krasnozem. For practical application, preliminary experiments are necessary in order to select a suitable co-milling reagent and a proper milling time depending on the differences in soil properties and HBCD concentration.
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Affiliation(s)
- Kunlun Zhang
- State Key Joint Laboratory of Environment Simulation and Pollution Control (SKJLESPC), School of Environment, POPs Research Center, Tsinghua University, Beijing 100084, PR China
| | - Jun Huang
- State Key Joint Laboratory of Environment Simulation and Pollution Control (SKJLESPC), School of Environment, POPs Research Center, Tsinghua University, Beijing 100084, PR China.
| | - Haizhu Wang
- State Key Joint Laboratory of Environment Simulation and Pollution Control (SKJLESPC), School of Environment, POPs Research Center, Tsinghua University, Beijing 100084, PR China
| | - Kai Liu
- State Key Joint Laboratory of Environment Simulation and Pollution Control (SKJLESPC), School of Environment, POPs Research Center, Tsinghua University, Beijing 100084, PR China
| | - Gang Yu
- State Key Joint Laboratory of Environment Simulation and Pollution Control (SKJLESPC), School of Environment, POPs Research Center, Tsinghua University, Beijing 100084, PR China
| | - Shubo Deng
- State Key Joint Laboratory of Environment Simulation and Pollution Control (SKJLESPC), School of Environment, POPs Research Center, Tsinghua University, Beijing 100084, PR China
| | - Bin Wang
- State Key Joint Laboratory of Environment Simulation and Pollution Control (SKJLESPC), School of Environment, POPs Research Center, Tsinghua University, Beijing 100084, PR China
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95
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Ortuño N, Conesa JA, Moltó J, Font R. Pollutant emissions during pyrolysis and combustion of waste printed circuit boards, before and after metal removal. THE SCIENCE OF THE TOTAL ENVIRONMENT 2014; 499:27-35. [PMID: 25173859 DOI: 10.1016/j.scitotenv.2014.08.039] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Revised: 08/09/2014] [Accepted: 08/12/2014] [Indexed: 06/03/2023]
Abstract
The constant increase in the production of electronic devices implies the need for an appropriate management of a growing number of waste electrical and electronic equipment. Thermal treatments represent an interesting alternative to recycle this kind of waste, but particular attention has to be paid to the potential emissions of toxic by-products. In this study, the emissions from thermal degradation of printed circuit boards (with and without metals) have been studied using a laboratory scale reactor, under oxidizing and inert atmosphere at 600 and 850 °C. Apart from carbon oxides, HBr was the main decomposition product, followed by high amounts of methane, ethylene, propylene, phenol and benzene. The maximum formation of PAHs was found in pyrolysis at 850 °C, naphthalene being the most abundant. High levels of 2-, 4-, 2,4-, 2,6- and 2,4,6-bromophenols were found, especially at 600 °C. Emissions of PCDD/Fs and dioxin-like PCBs were quite low and much lower than that of PBDD/Fs, due to the higher bromine content of the samples. Combustion at 600 °C was the run with the highest PBDD/F formation: the total content of eleven 2,3,7,8-substituted congeners (tetra- through heptaBDD/Fs) was 7240 and 3250 ng WHO2005-TEQ/kg sample, corresponding to the sample with and without metals, respectively.
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Affiliation(s)
- Nuria Ortuño
- Chemical Engineering Department, University of Alicante, P.O. Box 99, 03080 Alicante, Spain
| | - Juan A Conesa
- Chemical Engineering Department, University of Alicante, P.O. Box 99, 03080 Alicante, Spain.
| | - Julia Moltó
- Chemical Engineering Department, University of Alicante, P.O. Box 99, 03080 Alicante, Spain
| | - Rafael Font
- Chemical Engineering Department, University of Alicante, P.O. Box 99, 03080 Alicante, Spain
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96
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Separation and recovery of fine particles from waste circuit boards using an inflatable tapered diameter separation bed. ScientificWorldJournal 2014; 2014:843579. [PMID: 25379546 PMCID: PMC4213985 DOI: 10.1155/2014/843579] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Revised: 08/19/2014] [Accepted: 08/27/2014] [Indexed: 11/18/2022] Open
Abstract
Recovering particle materials from discarded printed circuit boards can enhance resource recycling and reduce environmental pollution. Efficiently physically separating and recovering fine metal particles (-0.5 mm) from the circuit boards are a key recycling challenge. To do this, a new type of separator, an inflatable tapered diameter separation bed, was developed to study particle motion and separation mechanisms in the bed's fluid flow field. For 0.5-0.25 mm circuit board particles, metal recovery rates ranged from 87.56 to 94.17%, and separation efficiencies ranged from 87.71 to 94.20%. For 0.25-0.125 mm particles, metal recovery rates ranged from 84.76 to 91.97%, and separation efficiencies ranged from 84.74 to 91.86%. For superfine products (-0.125 mm), metal recovery rates ranged from 73.11 to 83.04%, and separation efficiencies ranged from 73.00 to 83.14%. This research showed that the inflatable tapered diameter separation bed achieved efficient particle separation and can be used to recover fine particles under a wide range of operational conditions. The bed offers a new mechanical technology to recycle valuable materials from discarded printed circuit boards, reducing environmental pollution.
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97
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Hadi P, Xu M, Lin CSK, Hui CW, McKay G. Waste printed circuit board recycling techniques and product utilization. JOURNAL OF HAZARDOUS MATERIALS 2014; 283:234-243. [PMID: 25285997 DOI: 10.1016/j.jhazmat.2014.09.032] [Citation(s) in RCA: 108] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Revised: 09/02/2014] [Accepted: 09/08/2014] [Indexed: 06/03/2023]
Abstract
E-waste, in particular waste PCBs, represents a rapidly growing disposal problem worldwide. The vast diversity of highly toxic materials for landfill disposal and the potential of heavy metal vapors and brominated dioxin emissions in the case of incineration render these two waste management technologies inappropriate. Also, the shipment of these toxic wastes to certain areas of the world for eco-unfriendly "recycling" has recently generated a major public outcry. Consequently, waste PCB recycling should be adopted by the environmental communities as an ultimate goal. This article reviews the recent trends and developments in PCB waste recycling techniques, including both physical and chemical recycling. It is concluded that the physical recycling techniques, which efficiently separate the metallic and nonmetallic fractions of waste PCBs, offer the most promising gateways for the environmentally-benign recycling of this waste. Moreover, although the reclaimed metallic fraction has gained more attention due to its high value, the application of the nonmetallic fraction has been neglected in most cases. Hence, several proposed applications of this fraction have been comprehensively examined.
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Affiliation(s)
- Pejman Hadi
- Chemical and Biomolecular Engineering Department, Hong Kong University of Science and Technology, Clear Water Bay Road, Hong Kong Special Administrative Region
| | - Meng Xu
- Chemical and Biomolecular Engineering Department, Hong Kong University of Science and Technology, Clear Water Bay Road, Hong Kong Special Administrative Region
| | - Carol S K Lin
- School of Energy and Environment, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong Special Administrative Region
| | - Chi-Wai Hui
- Chemical and Biomolecular Engineering Department, Hong Kong University of Science and Technology, Clear Water Bay Road, Hong Kong Special Administrative Region
| | - Gordon McKay
- Chemical and Biomolecular Engineering Department, Hong Kong University of Science and Technology, Clear Water Bay Road, Hong Kong Special Administrative Region; Division of Sustainable Development, College of Science, Engineering and Technology, Hamad Bin Khalifa University, Qatar Foundation, Doha, Qatar.
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98
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Tue NM, Katsura K, Suzuki G, Tuyen LH, Takasuga T, Takahashi S, Viet PH, Tanabe S. Dioxin-related compounds in breast milk of women from Vietnamese e-waste recycling sites: levels, toxic equivalents and relevance of non-dietary exposure. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2014; 106:220-225. [PMID: 24859707 DOI: 10.1016/j.ecoenv.2014.04.046] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Revised: 04/28/2014] [Accepted: 04/29/2014] [Indexed: 06/03/2023]
Abstract
Although informal e-waste recycling sites (EWRSs) are hotspots of both polychlorinated and polybrominated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs and PBDD/Fs), human exposure to the latter has not been studied in details. This study investigated the accumulation levels and profiles of dioxin-related compounds (DRCs) in breast milk samples from women living in two Vietnamese EWRSs and estimated the intake contribution from e-waste-related exposure. Screening results using Dioxin-Responsive Chemically Activated LUciferase gene eXpression assay (DR-CALUX) showed higher dioxin-like (DL) activities in samples from the EWRS Bui Dau than in those from the EWRS Trang Minh and a reference site (2.3-10 vs 1.7-4.8 and 0.60-5.7 pg CALUX-TEQ/g lipid, n=10, 6 and 9, respectively). Chemical analysis results of selected samples show that the WHO-TEQ levels of PCDD/Fs, DL-PCBs and PBDD/Fs in EWRS samples were not significantly higher than in those from the reference site (0.22-7.4 vs 1.1-3.0 pg/g lipid) and within the Vietnamese background range, but women involved in recycling accumulated higher concentrations of PCDFs (13-15 vs 2.3-8.8 pg/g lipid) and PBDFs (1.1-1.5 vs <1.1 pg/g lipid). By comparing the DRC profile in milk of these women with the reported profile in house dust from the same site, dust ingestion was estimated to contribute most of the intake for tetraBDF, 37 per cent to 55 per cent for penta-octaCDFs, but less than twenty per cent for PCDDs and DL-PCBs, and 26 per cent for total WHO-TEQs. The DL activities in some EWRS milk samples were not fully explained by chemical data, suggesting contribution from unidentified compounds. The estimated WHO-TEQ intake doses for breastfed infants (1.3-33 pg/kg/d) mostly exceeded the tolerable value, especially for those living in the EWRSs; and unidentified DRCs might increase further the dioxin-related health risk.
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Affiliation(s)
- Nguyen Minh Tue
- Center for Marine Environmental Studies (CMES), Ehime University, 2-5 Bunkyo-cho, Matsuyama 790-8577, Japan; Centre for Environmental Technology and Sustainable Development (CETASD), Hanoi University of Science, 334 Nguyen Trai, Hanoi, Vietnam
| | - Kana Katsura
- Center for Marine Environmental Studies (CMES), Ehime University, 2-5 Bunkyo-cho, Matsuyama 790-8577, Japan
| | - Go Suzuki
- Center for Material Cycles and Waste Management Research, National Institute for Environmental Studies (NIES), 16-2 Onogawa, Tsukuba 305-8506, Japan
| | - Le Huu Tuyen
- Center for Marine Environmental Studies (CMES), Ehime University, 2-5 Bunkyo-cho, Matsuyama 790-8577, Japan; Centre for Environmental Technology and Sustainable Development (CETASD), Hanoi University of Science, 334 Nguyen Trai, Hanoi, Vietnam
| | - Takumi Takasuga
- Shimadzu Techno-Research, Inc., Nishinokyo-Shimoaicho, Nakagyo-ku, Kyoto, Japan
| | - Shin Takahashi
- Center for Marine Environmental Studies (CMES), Ehime University, 2-5 Bunkyo-cho, Matsuyama 790-8577, Japan; Center of Advanced Technology for the Environment, Faculty of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama 790-8566, Japan.
| | - Pham Hung Viet
- Centre for Environmental Technology and Sustainable Development (CETASD), Hanoi University of Science, 334 Nguyen Trai, Hanoi, Vietnam
| | - Shinsuke Tanabe
- Center for Marine Environmental Studies (CMES), Ehime University, 2-5 Bunkyo-cho, Matsuyama 790-8577, Japan
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99
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Ortuño N, Moltó J, Conesa JA, Font R. Formation of brominated pollutants during the pyrolysis and combustion of tetrabromobisphenol A at different temperatures. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2014; 191:31-37. [PMID: 24792882 DOI: 10.1016/j.envpol.2014.04.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Revised: 03/31/2014] [Accepted: 04/03/2014] [Indexed: 06/03/2023]
Abstract
Tetrabromobisphenol A (TBBPA) is the most widely used brominated flame retardant worldwide. A detailed examination of the degradation products emitted during thermal decomposition of TBBPA is presented in the study. Runs were performed in a laboratory furnace at different temperatures (650 and 800 °C) and in different atmospheres (nitrogen and air). More than one hundred semivolatile compounds have been identified by GC/MS, with special interest in brominated ones. Presence of HBr and brominated light hydrocarbons increased with temperature and in the presence of oxygen. Maximum formation of PAHs is observed at pyrolytic condition at the higher temperature. High levels of 2,4-, 2,6- and 2,4,6- bromophenols were found. The levels of polybrominated dibenzo-p-dioxins and furans have been detected in the ppm range. The most abundant isomers are 2,4,6,8-TeBDF in pyrolysis and 1,2,3,7,8-PeBDF in combustion. These results should be considered in the assessment of thermal treatment of materials containing brominated flame retardants.
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Affiliation(s)
- Nuria Ortuño
- Department of Chemical Engineering, University of Alicante, P.O. Box 99, E 03080 Alicante, Spain
| | - Julia Moltó
- Department of Chemical Engineering, University of Alicante, P.O. Box 99, E 03080 Alicante, Spain
| | - Juan A Conesa
- Department of Chemical Engineering, University of Alicante, P.O. Box 99, E 03080 Alicante, Spain.
| | - Rafael Font
- Department of Chemical Engineering, University of Alicante, P.O. Box 99, E 03080 Alicante, Spain
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100
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Wagoner ER, Baumberger CP, Gerroll BH, Peters DG. Catalytic reduction of 1,2,5,6,9,10-hexabromocyclododecane by nickel(I) salen electrogenerated at vitreous carbon cathodes in dimethylformamide. Electrochim Acta 2014. [DOI: 10.1016/j.electacta.2014.03.162] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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