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Zhang J, Xu Q, Wang H, Li S. Preparation of hydrothermally solidified materials from waste cathode ray tube panel glass for construction applications. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:57516-57522. [PMID: 35355179 DOI: 10.1007/s11356-022-19920-6] [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: 03/09/2021] [Accepted: 03/22/2022] [Indexed: 06/14/2023]
Abstract
Solidification of cathode ray tube (CRT) panel glass was carried out using a hydrothermal processing method. In this way, the glass powder was first compacted in a mold at 20 MPa, and then hydrothermally cured in an autoclave under saturated steam pressure at 200 ℃ for 6 h. The CRT panel glass was then hydrothermally solidified by the formation of tobermorite (Ca5Si6O16(OH)2·4H2O), which was encouraged by the addition of slaked lime (Ca(OH)2). The strength of solidified specimen heavily depended on the amount of tobermorite formed, with higher concentrations of tobermorite producing commensurately greater mechanical strength. With the addition of Ca(OH)2 at 20-30% by mass, the specimen achieved a bending strength of approximately 16 MPa, which was sufficiently great for using as a construction material. As such, there is cause to believe that the hydrothermal processing method used here may have great potential for resource utilization of CRT panel glass, and the performance of the product is suitable for use as building materials.
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Affiliation(s)
- Jing Zhang
- School of Ecology and Environment, Zhengzhou University, Zhengzhou, 450000, China
| | - Qingbo Xu
- Solid Waste Management Center, Sanmenxia Ecological and Environmental Protection Bureau, Sanmenxia, 472000, China
| | - Haiyang Wang
- School of Ecology and Environment, Zhengzhou University, Zhengzhou, 450000, China
| | - Shunyi Li
- School of Ecology and Environment, Zhengzhou University, Zhengzhou, 450000, China.
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Potential for Use of Recycled Cathode Ray Tube Glass in Making Concrete Blocks and Paving Flags. MATERIALS 2022; 15:ma15041499. [PMID: 35208038 PMCID: PMC8875816 DOI: 10.3390/ma15041499] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 02/08/2022] [Accepted: 02/12/2022] [Indexed: 02/04/2023]
Abstract
The potential to use waste glass, including cathode ray tube (CRT) glass, for making new products or as an admixture to existing ones is being intensively investigated. This kind of research intensified particularly in the period after CRT TV sets and computer monitors were replaced in the market by the advanced technology of thin film transistor (TFT) and liquid crystal display (LCD) screens. Cathode ray tube glass represents a considerable part of electronic waste (e-waste). E-waste globally increases at a far higher rate than other solid waste materials. There is a possibility to recycle cathode ray tube glass and use it in the construction industry. This paper shows the test results of physical and mechanical properties of blocks and paving flags. The reference specimen was made with quartz sand, while the other product employed a combination of quartz sand and ground panel cathode ray tube glass. The glass was ground to the fraction 0.25/1.00 mm, which corresponds to quartz sand fineness. The following tests were performed: shape and dimensions, resistance to freeze/thaw and de-icing salts, water absorption, splitting tensile strength and tensile strength by bending. Special attention was paid to the tests of Böhme wear resistance, slip resistance of the top surface of CRT products using a pendulum, radioactivity and leaching. The texture of the experimental concrete products was observed by SEM (scanning electron microscopy) and analyzed. The results obtained by experimental testing unequivocally show that CRT glass can successfully be used for making concrete blocks and paving flags.
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Wang Y, Xiong Y, Hu C, Yang J, Huang Y. Low-dielectric styrene resins with high mechanical strength and good (re)processability via constructing imine-crosslinked network and introducing small amount of amino molecules. Eur Polym J 2021. [DOI: 10.1016/j.eurpolymj.2021.110780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Xiong Y, Liu L, Hu C, Yang X, Yang J, Huang Y. Reprocessable low-dielectric styrene resins with coordination bonds: the effect of metal centers on low dielectric, mechanical, and reprocessing properties. JOURNAL OF MACROMOLECULAR SCIENCE PART A-PURE AND APPLIED CHEMISTRY 2021. [DOI: 10.1080/10601325.2021.1922087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Yang Xiong
- State Key Laboratory of Environmental-friendly Energy Materials, Southwest University of Science and Technology, Mianyang, China
- School of Materials Science and Engineering, Southwest University of Science and Technology, Mianyang, China
| | - Lili Liu
- School of Materials Science and Engineering, Southwest University of Science and Technology, Mianyang, China
| | - Chengyao Hu
- School of Materials Science and Engineering, Southwest University of Science and Technology, Mianyang, China
| | - Xuping Yang
- School of Materials Science and Engineering, Southwest University of Science and Technology, Mianyang, China
| | - Junxiao Yang
- State Key Laboratory of Environmental-friendly Energy Materials, Southwest University of Science and Technology, Mianyang, China
| | - Yawen Huang
- State Key Laboratory of Environmental-friendly Energy Materials, Southwest University of Science and Technology, Mianyang, China
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Bi H, Zhu H, Zu L, Gao Y, Gao S, Bai Y. Environment-friendly technology for recovering cathode materials from spent lithium iron phosphate batteries. WASTE MANAGEMENT & RESEARCH : THE JOURNAL OF THE INTERNATIONAL SOLID WASTES AND PUBLIC CLEANSING ASSOCIATION, ISWA 2020; 38:911-920. [PMID: 32552572 DOI: 10.1177/0734242x20931933] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The consumption of lithium iron phosphate (LFP)-type lithium-ion batteries (LIBs) is rising sharply with the increasing use of electric vehicles (EVs) worldwide. Hence, a large number of retired LFP batteries from EVs are generated annually. A recovery technology for spent LFP batteries is urgently required. Compared with pyrometallurgical, hydrometallurgical and biometallurgical recycling technologies, physical separating technology has not yet formed a systematic theory and efficient sorting technology. Strengthening the research and development of physical separating technology is an important issue for the efficient use of retired LFP batteries. In this study, spent LFP batteries were discharged in 5 wt% sodium chloride solution for approximately three hours. A specially designed machine was developed to dismantle spent LFP batteries. Extending heat treatment time exerted minimal effect on quality loss. Within the temperature range of 240°C-300°C, temperature change during heat treatment slightly affected mass loss. The change in heat treatment temperature also had negligible effect on the shedding quality of LFP materials. The cathode material and the aluminium foil current collector accounted for a certain proportion in a sieve with a particle size of -1.25 + 0.40 mm. Corona electrostatic separation was performed to separate the metallic particles (with a size range of -1.5 + 0.2 mm) from the nonmetallic particles of crushed spent LFP batteries. No additional reagent was used in the process, and no toxic gases, hazardous solid waste or wastewater were produced. This study provides a complete material recovery process for spent LFP batteries.
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Affiliation(s)
- Haijun Bi
- School of Mechanical Engineering, Hefei University of Technology, People's Republic of China
| | - Huabing Zhu
- School of Mechanical Engineering, Hefei University of Technology, People's Republic of China
| | - Lei Zu
- School of Mechanical Engineering, Hefei University of Technology, People's Republic of China
| | - Yong Gao
- School of Mechanical Engineering, Hefei University of Technology, People's Republic of China
| | - Song Gao
- School of Mechanical Engineering, Hefei University of Technology, People's Republic of China
| | - Yuxuan Bai
- School of Mechanical Engineering, Hefei University of Technology, People's Republic of China
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Feasibility study of recycled CRT glass on elastic and radiation shielding properties used as x-ray and gamma-ray shielding materials. PROGRESS IN NUCLEAR ENERGY 2020. [DOI: 10.1016/j.pnucene.2019.103149] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Qi Y, Xiao X, Lu Y, Shu J, Wang J, Chen M. Cathode ray tubes glass recycling: A review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 650:2842-2849. [PMID: 30373061 DOI: 10.1016/j.scitotenv.2018.09.383] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2018] [Revised: 09/25/2018] [Accepted: 09/29/2018] [Indexed: 06/08/2023]
Abstract
With the rapid development in kinescope technologies, Cathode Ray Tubes (CRTs) now are almost completely replaced by thinner and lighter flat panel displays, such as liquid crystal displays (LCD), plasma display panels (PDP) and light emitting diode (LED) displays. Waste CRT glass contains many poisonous and harmful substances, especially lead. If it is not properly disposed of, it would pose a serious threat to the environment and human health. This paper reviews the existing waste CRT glass recycling technologies, analyses the obstacles that hinder their industrial application, pinpoints its future directions. This paper also points out the academic conflict in the risk of lead contained CRT glass and proposes a basic rule for waste treatment and disposal: the lower risk principle. The results of this study could help to understand waste CRT glass recycling and guide its future research and development.
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Affiliation(s)
- Yaping Qi
- Key Laboratory of Solid Waste Treatment and Resource Recycle (SWUST), Ministry of Education, Mianyang 621010, PR China
| | - Xiang Xiao
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, PR China; Changsha Research Institute of Nonferrous Metallurgy, Changsha 410011, PR China
| | - Yan Lu
- Key Laboratory of Solid Waste Treatment and Resource Recycle (SWUST), Ministry of Education, Mianyang 621010, PR China
| | - Jiancheng Shu
- Key Laboratory of Solid Waste Treatment and Resource Recycle (SWUST), Ministry of Education, Mianyang 621010, PR China
| | - Jianbo Wang
- Key Laboratory of Solid Waste Treatment and Resource Recycle (SWUST), Ministry of Education, Mianyang 621010, PR China
| | - Mengjun Chen
- Key Laboratory of Solid Waste Treatment and Resource Recycle (SWUST), Ministry of Education, Mianyang 621010, PR China.
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Lu X, Ning XA, Chen D, Chuang KH, Shih K, Wang F. Lead extraction from Cathode Ray Tube (CRT) funnel glass: Reaction mechanisms in thermal reduction with addition of carbon (C). WASTE MANAGEMENT (NEW YORK, N.Y.) 2018; 76:671-678. [PMID: 29650298 DOI: 10.1016/j.wasman.2018.04.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Revised: 03/27/2018] [Accepted: 04/06/2018] [Indexed: 06/08/2023]
Abstract
This study quantitatively determined the extraction of lead from CRT funnel glass and examined the mechanisms of thermally reducing lead in the products of sintering Pb-glass with carbon in the pre-heated furnace. The experimentally derived results indicate that a 90.3 wt% lead extraction efficiency can be achieved with 20 wt% of C addition at 950 °C for 3 min under air. The formation of viscous semi-liquid glass blocked the oxygen supply between the interaction of C and Pb-glass, and was highly effective for the extraction of metallic Pb. A maximum of 87.3% lead recover was obtained with a C to Na2CO3 ratio of 1/3 at 1200 °C. The decrease of C/Na2CO3 ratio enhanced the metallic lead recovery by increasing the glass viscosity for effective sedimentation of metallic lead in the bottom. However, with the further increase of temperature and treatment time, re-vitrification of lead back to silicate-glass matrix was detected in both Pb-glass/C and Pb-glass/C/Na2CO3 systems. The findings indicated that with proper controls, using C as an inexpensive reagent can effectively reduce treatment time and energy, which is crucial to a waste-to-resource technology for economically recovering lead from the waste CRT glass.
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Affiliation(s)
- Xingwen Lu
- School of Environmental Science and Engineering and Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China; Department of Civil Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong Special Administrative Region
| | - Xun-An Ning
- School of Environmental Science and Engineering and Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China
| | - Da Chen
- School of Environment, Guangzhou Key Laboratory of Environmental Exposure and Health, and Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou 510632, China
| | - Kui-Hao Chuang
- Department of Safety Health and Environmental Engineering, Central Taiwan University of Science and Technology, Taichung 406, Taiwan, ROC
| | - Kaimin Shih
- Department of Civil Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong Special Administrative Region
| | - Fei Wang
- Department of Civil Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong Special Administrative Region; School of Environment, Guangzhou Key Laboratory of Environmental Exposure and Health, and Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou 510632, China.
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Wang C, Yao D, Liu Y, Wu Y, Shen J. Development of a novel recycling system for waste cathode ray tube funnel glass based on the integration of nanoscale Fe 0 with ball milling. WASTE MANAGEMENT (NEW YORK, N.Y.) 2018; 76:679-686. [PMID: 29643009 DOI: 10.1016/j.wasman.2018.04.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 04/02/2018] [Accepted: 04/04/2018] [Indexed: 06/08/2023]
Abstract
A novel and effective system was developed for recycling cathode ray tube (CRT) funnel glass wastes. Initially, the combination of nanoscale Fe0 with ball milling promoted lead transfer that was strongly encapsulated in the glass inner structure to the surface of funnel glass and/or adhere to iron substance due to the collapse of SiO bonds. This condition enhanced the dissolution of lead in the acid solution. A high lead extraction rate of 97.8% from funnel glass was achieved through nitric acid leaching by optimizing the operational parameters (Fe0/funnel glass mass ratio, 0.5:1; ball milling time; 72 h). Subsequently, lead sulfate, iron hydroxides, and sodium nitrate were gradually recovered from the acid leachate by using three simple operations, namely, sulfation, alkali neutralization, and salt evaporation. Meanwhile, the leaching results of short-term toxicity characteristic leaching (TCLP) and long-term multiple extraction procedures (MEP) clearly demonstrated that the residual high silica products (after acid leaching) had no impact on the environment and could be used to synthesize high value-added zeolites as raw materials. With the addition of Al sources, the complete conversion of high silica residues into high crystalline zeolites with high cation exchange capacity value was realized by applying an alkaline fusion method during the hydrothermal treatment. Furthermore, lead, NO-3, and SO2-4 concentrations of the resulting drainage were considerably lower than the relevant standard for surface water quality. Therefore, the proposed recycling system provided an eco-friendly and feasible technique for complete reutilization of obsolete CRT funnel glass.
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Affiliation(s)
- Chunfeng Wang
- Henan Key Laboratory for Environmental Pollution Control and Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, School of Environment, Henan Normal University, 46 East Jianshe Road, Xinxiang, Henan Province 453007, China; Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
| | - Dan Yao
- Henan Key Laboratory for Environmental Pollution Control and Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, School of Environment, Henan Normal University, 46 East Jianshe Road, Xinxiang, Henan Province 453007, China
| | - Yang Liu
- Henan Key Laboratory for Environmental Pollution Control and Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, School of Environment, Henan Normal University, 46 East Jianshe Road, Xinxiang, Henan Province 453007, China
| | - Yufan Wu
- Henan Key Laboratory for Environmental Pollution Control and Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, School of Environment, Henan Normal University, 46 East Jianshe Road, Xinxiang, Henan Province 453007, China
| | - Jinyou Shen
- Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
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Xing M, Wang J, Fu Z, Zhang D, Wang Y, Zhang Z. Extraction of heavy metal (Ba, Sr) and high silica glass powder synthesis from waste CRT panel glasses by phase separation. JOURNAL OF HAZARDOUS MATERIALS 2018; 347:8-14. [PMID: 29288919 DOI: 10.1016/j.jhazmat.2017.12.046] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 11/23/2017] [Accepted: 12/18/2017] [Indexed: 06/07/2023]
Abstract
In this study, a novel process for the extraction of heavy metal Ba and Sr from waste CRT panel glass and synchronous preparation of high silica glass powder was developed by glass phase separation. CRT panel glass was first remelted with B2O3 under air atmosphere to produce alkali borosilicate glass. During the phase separation process, the glass separated into two interconnected phases which were B2O3-rich phase and SiO2-rich phase. Most of BaO, SrO and other metal oxides including Na2O, K2O, Al2O3 and CaO were mainly concentrated in the B2O3-rich phase. The interconnected B2O3-rich phase can be completely leached out by 5mol/L HNO3 at 90 ℃. The remaining SiO2-rich phase was porous glasses consisting almost entirely of silica. The maximum Ba and Sr removal rates were 98.84% and 99.38% and high silica glass powder (SiO2 purity > 90 wt%) was obtained by setting the temperature, B2O3 added amount and holding time at 1000-1100 ℃, 20-30% and 30 min, respectively. Thus this study developed an potential economical process for detoxification and reclamation of waste heavy metal glasses.
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Affiliation(s)
- Mingfei Xing
- Henan Key Laboratory Cultivation Base of Mine Environmental Protection and Ecological Remediation, Henan Polytechnic University, Jiaozuo 454000, Henan, China; Institute of Resource and Environment, Henan Polytechnic University, Jiaozuo 454000, Henan, China
| | - Jingyu Wang
- Institute of Resource and Environment, Henan Polytechnic University, Jiaozuo 454000, Henan, China
| | - Zegang Fu
- Institute of Resource and Environment, Henan Polytechnic University, Jiaozuo 454000, Henan, China
| | - Donghui Zhang
- Jiaozuo Environmental Protection Agency, Jiaozuo 454000, Henan, China
| | - Yaping Wang
- School of Surveying and Land Information Engineering, Henan Polytechnic University, Jiaozuo 454000, Henan, China.
| | - Zhiyuan Zhang
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
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Hu B, Hui W. Extraction of lead from waste CRT funnel glass by generating lead sulfide - An approach for electronic waste management. WASTE MANAGEMENT (NEW YORK, N.Y.) 2017; 67:253-258. [PMID: 28587804 DOI: 10.1016/j.wasman.2017.05.048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2017] [Revised: 05/22/2017] [Accepted: 05/29/2017] [Indexed: 06/07/2023]
Abstract
Waste cathode ray tube (CRT) funnel glass is the key and difficult points in waste electrical and electronic equipment (WEEE) disposal. In this paper, a novel and effective process for the detoxification and reutilization of waste CRT funnel glass was developed by generating lead sulfide precipitate via a high-temperature melting process. The central function in this process was the generation of lead sulfide, which gathered at the bottom of the crucible and was then separated from the slag. Sodium carbonate was used as a flux and reaction agent, and sodium sulfide was used as a precipitating agent. The experimental results revealed that the lead sulfide recovery rate initially increased with an increase in the amount of added sodium carbonate, the amount of sodium sulfide, the temperature, and the holding time and then reached an equilibrium value. The maximum lead sulfide recovery rate was approximately 93%, at the optimum sodium carbonate level, sodium sulfide level, temperature, and holding time of 25%, 8%, 1200°C, and 2h, respectively. The glass slag can be made into sodium and potassium silicate by hydrolysis in an environmental and economical process.
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Affiliation(s)
- Biao Hu
- School of Management, Tianjin University of Technology, Tianjin, China; School of Environmental Science and Safety Engineering, Tianjin University of Technology, Tianjin, China
| | - Wenlong Hui
- School of Environmental Science and Safety Engineering, Tianjin University of Technology, Tianjin, China.
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Singh N, Li J, Zeng X. Global responses for recycling waste CRTs in e-waste. WASTE MANAGEMENT (NEW YORK, N.Y.) 2016; 57:187-197. [PMID: 27072617 DOI: 10.1016/j.wasman.2016.03.013] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Revised: 02/03/2016] [Accepted: 03/06/2016] [Indexed: 06/05/2023]
Abstract
The management of used cathode ray tube (CRT) devices is a major problem worldwide due to rapid uptake of the technology and early obsolescence of CRT devices, which is considered an environment hazard if disposed improperly. Previously, their production has grown in step with computer and television demand but later on with rapid technological innovation; TVs and computer screens has been replaced by new products such as Liquid Crystal Displays (LCDs) and Plasma Display Panel (PDPs). This change creates a large volume of waste stream of obsolete CRTs waste in developed countries and developing countries will be becoming major CRTs waste producers in the upcoming years. We studied that there is also high level of trans-boundary movement of these devices as second-hand electronic equipment into developing countries in an attempt to bridge the 'digital divide'. Moreover, the current global production of e-waste is estimated to be '41million tonnes per year' where a major part of the e-waste stream consists of CRT devices. This review article provides a concise overview of world's current CRTs waste scenario, namely magnitude of the demand and processing, current disposal and recycling operations.
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Affiliation(s)
- Narendra Singh
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - 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
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Lv J, Yang H, Jin Z, Ma Z, Song Y. Feasibility of lead extraction from waste Cathode-Ray-Tubes (CRT) funnel glass through a lead smelting process. WASTE MANAGEMENT (NEW YORK, N.Y.) 2016; 57:198-206. [PMID: 27211314 DOI: 10.1016/j.wasman.2016.05.010] [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: 02/24/2016] [Revised: 04/14/2016] [Accepted: 05/10/2016] [Indexed: 06/05/2023]
Abstract
A novel and effective process for extracting lead from the hazardous waste Cathode Ray Tubes (CRT) funnel glass is presented. The technological breakthrough of this process is introducing the discarded CRT funnel glass to traditional lead smelting. In this study, the influences of amount of carbon addition, calcium-silicate ratio, temperature, holding time and funnel glass addition on lead extraction efficiency were investigated to determine the optimal operational parameters. With a glass addition of less than 30wt%, a high extraction yield of 97.5% of lead from the mixture of funnel glass and lead slag was successfully obtained by controlling the C/PbO molar ratio, CaO/SiO2 ratio, temperature, treatment time at 0.9, 0.8, 1200°C, 60min, respectively. The main crystalline phases of the residues were calcium silicate slag, and an amorphous glass phase appears at a glass addition more than 30wt%. Thermodynamic calculation shows that the proportion of liquid phase in the slag first increased and then decreased, when the addition of glass is increased, while the viscosity of the slag exhibited a continuous decrease. Thus, based on all the results, it is concluded that the process proposed in this paper is an effective and promising approach for reutilization of obsolete CRT funnel glass.
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Affiliation(s)
- Jianfang Lv
- School of Metallurgy, Northeastern University, Shenyang 110819, Liaoning, China
| | - Hongying Yang
- School of Metallurgy, Northeastern University, Shenyang 110819, Liaoning, China
| | - Zhenan Jin
- School of Metallurgy, Northeastern University, Shenyang 110819, Liaoning, China.
| | - Zhiyuan Ma
- School of Metallurgy, Northeastern University, Shenyang 110819, Liaoning, China
| | - Yan Song
- School of Metallurgy, Northeastern University, Shenyang 110819, Liaoning, China
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Tian XM, Wu YF. Recent development of recycling lead from scrap CRTs: A technological review. WASTE MANAGEMENT (NEW YORK, N.Y.) 2016; 57:176-186. [PMID: 26365873 DOI: 10.1016/j.wasman.2015.09.004] [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: 07/08/2015] [Revised: 09/03/2015] [Accepted: 09/03/2015] [Indexed: 06/05/2023]
Abstract
Cathode ray tubes (CRTs) contain numerous harmful substances with different functions. Lead is found in the funnel glass of CRTs. Improperly treated toxic lead may pose significant risks to human health and the environment. This paper reviews and summarizes existing technological processes on the recycling of lead from waste CRTs, including pyrometallurgy, hydrometallurgy, and product-regeneration. The present situation, advantages, and disadvantages of these techniques are described in detail. Generally, pyrometallurgy shows better practicability in recovery lead from waste CRT than hydrometallurgy and hydrometallurgy, in view of environmental impact, energy-consumption, product formats and safety and maturity of technology. Moreover, the gaps in the existing technologies were identified and recommendations for future research were provided.
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Affiliation(s)
- Xiang-Miao Tian
- Institute of Recycling Economy, Beijing University of Technology, No. 100, Pingleyuan Street, Chaoyang District, Beijing 100124, PR China
| | - Yu-Feng Wu
- Institute of Recycling Economy, Beijing University of Technology, No. 100, Pingleyuan Street, Chaoyang District, Beijing 100124, PR China.
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Mingfei X, Yaping W, Jun L, Hua X. Lead recovery and glass microspheres synthesis from waste CRT funnel glasses through carbon thermal reduction enhanced acid leaching process. JOURNAL OF HAZARDOUS MATERIALS 2016; 305:51-58. [PMID: 26642446 DOI: 10.1016/j.jhazmat.2015.11.032] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Revised: 11/14/2015] [Accepted: 11/17/2015] [Indexed: 06/05/2023]
Abstract
In this study, a novel process for detoxification and reutilization of waste cathode ray tube (CRT) funnel glass was developed by carbon thermal reduction enhanced acid leaching process. The key to this process is removal of lead from the CRT funnel glass and synchronous preparation of glass microspheres. Carbon powder was used as an isolation agent and a reducing agent. Under the isolation of the carbon powder, the funnel glass powder was sintered into glass microspheres. In thermal reduction, PbO in the funnel glass was first reduced to elemental Pb by carbon monoxide and then located on the surface of glass microspheres which can be removed easily by acid leaching. Experimental results showed that temperature, carbon adding amount and holding time were the major parameters that controlled lead removal rate. The maximum lead removal rate was 94.80% and glass microspheres that measured 0.73-14.74μm were obtained successfully by setting the temperature, carbon adding amount and holding time at 1200°C, 10% and 30min, respectively. The prepared glass microspheres may be used as fillers in polymer materials and abrasive materials, among others. Accordingly, this study proposed a practical and economical process for detoxification and recycling of waste lead-containing glass.
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Affiliation(s)
- Xing Mingfei
- Henan Key Laboratory Cultivation Base of Mine Environmental Protection and Ecological Remediation, Henan Polytechnic University, Jiaozuo 454000, Henan, China; Institute of Resource and Environment, Henan Polytechnic University, Jiaozuo 454000, Henan, China.
| | - Wang Yaping
- School of Surveying and Land Information Engineering, Henan Polytechnic University, Jiaozuo 454000, Henan, China
| | - Li Jun
- Institute of Resource and Environment, Henan Polytechnic University, Jiaozuo 454000, Henan, China
| | - Xu Hua
- Mengzhou talents exchange center, Jiaozuo 454000, Henan, China
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16
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Meng W, Wang X, Yuan W, Wang J, Song G. The Recycling of Leaded Glass in Cathode Ray Tube (CRT). ACTA ACUST UNITED AC 2016. [DOI: 10.1016/j.proenv.2016.02.120] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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17
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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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18
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Iniaghe PO, Adie GU. Management practices for end-of-life cathode ray tube glass: Review of advances in recycling and best available technologies. WASTE MANAGEMENT & RESEARCH : THE JOURNAL OF THE INTERNATIONAL SOLID WASTES AND PUBLIC CLEANSING ASSOCIATION, ISWA 2015; 33:947-961. [PMID: 26463115 DOI: 10.1177/0734242x15604212] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Cathode ray tubes are image display units found in computer monitors and televisions. In recent years, cathode ray tubes have been generated as waste owing to the introduction of newer and advanced technologies in image displays, such as liquid crystal displays and high definition televisions, among others. Generation and subsequent disposal of end-of-life cathode ray tubes presents a challenge owing to increasing volumes and high lead content embedded in the funnel and neck sections of the glass. Disposal in landfills and open dumping are anti-environmental practices considering the large-scale contamination of environmental media by the potential of toxic metals leaching from glass. Mitigating such environmental contamination will require sound management strategies that are environmentally friendly and economically feasible. This review covers existing and emerging management practices for end-of-life cathode ray tubes. An in-depth analysis of available technologies (glass smelting, detoxification of cathode ray tube glass, lead extraction from cathode ray tube glass) revealed that most of the techniques are environmentally friendly, but are largely confined to either laboratory scale, or are often limited owing to high cost to mount, or generate secondary pollutants, while a closed-looped method is antiquated. However, recycling in cementitious systems (cement mortar and concrete) gives an added advantage in terms of quantity of recyclable cathode ray tube glass at a given time, with minimal environmental and economic implications. With significant quantity of waste cathode ray tube glass being generated globally, cementitious systems could be economically and environmentally acceptable as a sound management practice for cathode ray tube glass, where other technologies may not be applicable.
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Affiliation(s)
| | - Gilbert U Adie
- Department of Chemistry, University of Ibadan, Ibadan, Nigeria
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19
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Zhao W, Ding L, Gu X, Luo J, Liu Y, Guo L, Shi Y, Huang T, Cheng S. Levels and ecological risk assessment of metals in soils from a typical e-waste recycling region in southeast China. ECOTOXICOLOGY (LONDON, ENGLAND) 2015; 24:1947-1960. [PMID: 26318052 DOI: 10.1007/s10646-015-1532-7] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 08/22/2015] [Indexed: 06/04/2023]
Abstract
Due to the high threat to human health and the ecosystem from metals, the levels and distribution of As, Hg, Cr, Co, Ni, Cu, Zn, Cd, Pb, Mn, V, Sn, Sb, Li and Be in various layers of soil from an e-waste recycling area in Guiyu, China were investigated. The extent of pollution from the metals in soil was assessed using enrichment factors (EFs) and the Nemerow pollution index (P N ). To determine the metals' integrated potential ecological risks, the potential ecological risk index (RI) was chosen. The concentrations of Hg, Ni, Cu, Cd, Pb, Sn and Sb were mainly enriched in the topsoil. EF values (2-5) of the elements Hg, Co, Ni, Zn, Sn, Li and Be revealed their moderate enrichment status in the topsoil, derived from e-waste recycling activities. P N presented a decreasing trend in different layers in the order topsoil (0-20 cm) > deep soil (100-150 cm) > middle soil (50-100 cm) > shallow soil (20-50 cm). With higher potential ecological risk factor (E(i)), Hg and Cd are the main contributors to the potential ecological risk. With respect to the RI, all the values in soil from the study area exceeded 300, especially for the soil at sites S2, S4, S5, S7 and S8, where RI was greater than 600. Therefore, immediate remediation of the contaminated soil is necessary to prevent the release of metals and potential ecological harm.
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Affiliation(s)
- Weituo Zhao
- School of Environmental Studies, China University of Geosciences, Wuhan, 430074, People's Republic of China
| | - Lei Ding
- School of Environmental Studies, China University of Geosciences, Wuhan, 430074, People's Republic of China
| | - Xiaowen Gu
- School of Earth Sciences, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Jie Luo
- School of Environmental Studies, China University of Geosciences, Wuhan, 430074, People's Republic of China
| | - Yunlang Liu
- School of Environmental Studies, China University of Geosciences, Wuhan, 430074, People's Republic of China
| | - Li Guo
- School of Environmental Studies, China University of Geosciences, Wuhan, 430074, People's Republic of China
| | - Yi Shi
- School of Environmental Studies, China University of Geosciences, Wuhan, 430074, People's Republic of China
| | - Ting Huang
- School of Environmental Studies, China University of Geosciences, Wuhan, 430074, People's Republic of China
| | - Shenggao Cheng
- School of Environmental Studies, China University of Geosciences, Wuhan, 430074, People's Republic of China.
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20
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Zhang S, Ding Y, Liu B, Pan D, Chang CC, Volinsky AA. Challenges in legislation, recycling system and technical system of waste electrical and electronic equipment in China. WASTE MANAGEMENT (NEW YORK, N.Y.) 2015; 45:361-373. [PMID: 26059074 DOI: 10.1016/j.wasman.2015.05.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Revised: 05/07/2015] [Accepted: 05/07/2015] [Indexed: 06/04/2023]
Abstract
Waste electrical and electronic equipment (WEEE) has been one of the fastest growing waste streams worldwide. Effective and efficient management and treatment of WEEE has become a global problem. As one of the world's largest electronic products manufacturing and consumption countries, China plays a key role in the material life cycle of electrical and electronic equipment. Over the past 20 years, China has made a great effort to improve WEEE recycling. Centered on the legal, recycling and technical systems, this paper reviews the progresses of WEEE recycling in China. An integrated recycling system is proposed to realize WEEE high recycling rate for future WEEE recycling.
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Affiliation(s)
- Shengen Zhang
- Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083, PR China.
| | - Yunji Ding
- Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083, PR China
| | - Bo Liu
- Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083, PR China.
| | - De'an Pan
- Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083, PR China
| | - Chein-chi Chang
- Department of Engineering and Technical Services, District of Columbia Water and Sewer Authority, Washington, DC 20032, USA
| | - Alex A Volinsky
- Department of Mechanical Engineering, University of South Florida, Tampa, FL 33620, USA
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21
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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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22
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Veit HM, Oliveira ED, Richter G. Thermal processes for lead removal from the funnel glass of CRT monitors. ACTA ACUST UNITED AC 2015. [DOI: 10.1590/0370-44672014680141] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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23
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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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24
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Kasper AC, Gabriel AP, de Oliveira ELB, de Freitas Juchneski NC, Veit HM. Electronic Waste Recycling. ELECTRONIC WASTE 2015. [DOI: 10.1007/978-3-319-15714-6_9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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25
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Wang R, Xu Z. Recycling of non-metallic fractions from waste electrical and electronic equipment (WEEE): a review. WASTE MANAGEMENT (NEW YORK, N.Y.) 2014; 34:1455-69. [PMID: 24726822 DOI: 10.1016/j.wasman.2014.03.004] [Citation(s) in RCA: 107] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2013] [Revised: 03/02/2014] [Accepted: 03/05/2014] [Indexed: 05/25/2023]
Abstract
The world's waste electrical and electronic equipment (WEEE) consumption has increased incredibly in recent decades, which have drawn much attention from the public. However, the major economic driving force for recycling of WEEE is the value of the metallic fractions (MFs). The non-metallic fractions (NMFs), which take up a large proportion of E-wastes, were treated by incineration or landfill in the past. NMFs from WEEE contain heavy metals, brominated flame retardant (BFRs) and other toxic and hazardous substances. Combustion as well as landfill may cause serious environmental problems. Therefore, research on resource reutilization and safe disposal of the NMFs from WEEE has a great significance from the viewpoint of environmental protection. Among the enormous variety of NMFs from WEEE, some of them are quite easy to recycle while others are difficult, such as plastics, glass and NMFs from waste printed circuit boards (WPCBs). In this paper, we mainly focus on the intractable NMFs from WEEE. Methods and technologies of recycling the two types of NMFs from WEEE, plastics, glass are reviewed in this paper. For WEEE plastics, the pyrolysis technology has the lowest energy consumption and the pyrolysis oil could be obtained, but the containing of BFRs makes the pyrolysis recycling process problematic. Supercritical fluids (SCF) and gasification technology have a potentially smaller environmental impact than pyrolysis process, but the energy consumption is higher. With regard to WEEE glass, lead removing is requisite before the reutilization of the cathode ray tube (CRT) funnel glass, and the recycling of liquid crystal display (LCD) glass is economically viable for the containing of precious metals (indium and tin). However, the environmental assessment of the recycling process is essential and important before the industrialized production stage. For example, noise and dust should be evaluated during the glass cutting process. This study could contribute significantly to understanding the recycling methods of NMFs from WEEE and serve as guidance for the future technology research and development.
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Affiliation(s)
- Ruixue Wang
- School of Environmental Science & Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Zhenming Xu
- School of Environmental Science & Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China.
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26
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Li Y, Duan YP, Huang F, Yang J, Xiang N, Meng XZ, Chen L. Polybrominated diphenyl ethers in e-waste: level and transfer in a typical e-waste recycling site in Shanghai, Eastern China. WASTE MANAGEMENT (NEW YORK, N.Y.) 2014; 34:1059-1065. [PMID: 24090830 DOI: 10.1016/j.wasman.2013.09.006] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2013] [Revised: 08/26/2013] [Accepted: 09/05/2013] [Indexed: 06/02/2023]
Abstract
Very few data for polybrominated diphenyl ethers (PBDEs) were available in the electronic waste (e-waste) as one of the most PBDEs emission source. This study reported concentrations of PBDEs in e-waste including printer, rice cooker, computer monitor, TV, electric iron and water dispenser, as well as dust from e-waste, e-waste dismantling workshop and surface soil from inside and outside of an e-waste recycling plant in Shanghai, Eastern China. The results showed that PBDEs were detected in the majority of e-waste, and the concentrations of ΣPBDEs ranged from not detected to 175 g/kg, with a mean value of 10.8 g/kg. PBDEs were found in TVs made in China after 1990. The mean concentrations of ΣPBDEs in e-waste made in Korea, Japan, Singapore and China were 1.84 g/kg, 20.5 g/kg, 0.91 g/kg, 4.48 g/kg, respectively. The levels of ΣPBDEs in e-waste made in Japan far exceed the threshold limit of RoHS (1.00 g/kg). BDE-209 dominated in e-waste, accounting for over 93%. The compositional patterns of PBDEs congeners resembled the profile of Saytex 102E, indicating the source of deca-BDE. Among the samples of dust and surface soil from a typical e-waste recycling site, the highest concentrations of Σ18PBDEs and BDE-209 were found in dust in e-waste, ranging from 1960 to 340,710 ng/g and from 910 to 320,400 ng/g, which were 1-2 orders of magnitude higher than other samples. It suggested that PBDEs released from e-waste via dust, and then transferred to surrounding environment.
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Affiliation(s)
- Yue Li
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Yan-Ping Duan
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
| | - Fan Huang
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Jing Yang
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Nan Xiang
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Xiang-Zhou Meng
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Ling Chen
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
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27
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Lu X, Shih K, Liu C, Wang F. Extraction of metallic lead from cathode ray tube (CRT) funnel glass by thermal reduction with metallic iron. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 47:9972-9978. [PMID: 23915263 DOI: 10.1021/es401674d] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
A novel and effective process of thermal reduction treatment with the addition of metallic iron (Fe(0)) to recover lead from cathode ray tube (CRT) funnel glass is introduced. The key technological breakthrough of this process is the use of a relatively lower temperature and an inexpensive reducing agent to extract the metallic lead. The influences of temperature, the reducing agent content, and the holding time for lead reduction were examined to determine the optimal extraction efficiency. The lead extraction efficiency first increased and then decreased with increasing temperature. The maximum lead extraction efficiency occurred at 700 °C. The growth of crystalline lead first increased significantly with an increase in the Fe content, reaching maximum growth at an Fe addition of 50 wt %. The most effective treatment time was determined to be 30 min, as the vitrification of lead back to the glass matrix occurred under longer treatment times. The experimentally derived results indicate that a 58 wt % lead extraction can be achieved with the optimized operational parameters (50 wt % Fe addition, heating at 700 °C for 30 min) in a single extraction operation.
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Affiliation(s)
- Xingwen Lu
- Department of Civil Engineering, The University of Hong Kong , Pokfulam Road, Hong Kong, Hong Kong SAR, China
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28
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Zhang C, Wang J, Bai J, Guan J, Wu W, Guo C. Recovering lead from cathode ray tube funnel glass by mechano-chemical extraction in alkaline solution. WASTE MANAGEMENT & RESEARCH : THE JOURNAL OF THE INTERNATIONAL SOLID WASTES AND PUBLIC CLEANSING ASSOCIATION, ISWA 2013; 31:759-763. [PMID: 23592759 DOI: 10.1177/0734242x13484188] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
This study evaluates the efficiency of lead (Pb) extraction from cathode ray tube (CRT) funnel glass in strongly alkaline solution using mechanical activation in a ball mill as the chemical breakage and defects formed in the inner structures will contribute to the easy dissolution of the activated Pb glass. The combination of mechanical activation and a chemical leaching process in a single operation (mechano-chemical leaching) is more effective than the mechanical activation and subsequent chemical leaching. More than 97% of Pb in the CRT funnel glass can be extracted with a stirring ball mill leaching process in 5 M sodium hydroxide at 70°C. The diameter of the stainless steel balls as the activation medium is 5 mm; the mass ratio of ball to raw materials is 25:1. Pb powder with a purity of 97% can be obtained by electrowinning from the leaching solution. The Pb-depleted solution can be recycled into the leaching step. After Pb is removed, the solid leaching residues can be used for preparation of foam glass. Thus, a novel hydrometallurgical process for recovering Pb from CRT funnel glass in alkaline solution is proposed.
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Affiliation(s)
- Chenglong Zhang
- School of Urban Development and Environmental Engineering, Shanghai Second Polytechnic University, Shanghai, People's Republic of China.
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