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Vuppaladadiyam SSV, Thomas BS, Kundu C, Vuppaladadiyam AK, Duan H, Bhattacharya S. Can e-waste recycling provide a solution to the scarcity of rare earth metals? An overview of e-waste recycling methods. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 924:171453. [PMID: 38453089 DOI: 10.1016/j.scitotenv.2024.171453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 02/27/2024] [Accepted: 03/01/2024] [Indexed: 03/09/2024]
Abstract
Recycling e-waste is seen as a sustainable alternative to compensate for the limited natural rare earth elements (REEs) resources and the difficulty of accessing these resources. Recycling facilitates the recovery of valuable products and minimizes emissions during their transportation. Numerous studies have been reported on e-waste recycling using various techniques, including thermo-, hydro- and biometallurgical approaches. However, each approach still has technical, economic, social, or environmental limitations. This review highlights the potential of recycling e-waste, including outlining the current unutilized potential of REE recycling from different e-waste components. An in-depth analysis of e-waste generation on a global scale and Australian scenario, along with various hazardous impacts on ecosystem and human health, is reported. In addition, a comprehensive summary of various metal recovery processes and their merits and demerits is also presented. Lifecycle analysis for recovering REEs from e-waste indicate a positive environmental impact when compared to REEs produced from virgin sources. In addition, recovering REEs form secondary sources eliminated ca. 1.5 times radioactive waste, as seen in production from primary sources scenario. The review outcome demonstrates the increasing potential of REE recycling to overcome critical challenges, including issues over supply security and localized dependency.
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Affiliation(s)
| | - Bennet Sam Thomas
- Department of Chemical and Biological Engineering, Monash University, Australia
| | - Chandan Kundu
- Department of Chemical and Biological Engineering, Monash University, Australia
| | | | - Huabo Duan
- School of Environmental Science and Engineering, Huazhong University of Science and Technology (HUST), Wuhan 430074, China
| | - Sankar Bhattacharya
- Department of Chemical and Biological Engineering, Monash University, Australia.
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Behrsing T, Blair VL, Jaroschik F, Deacon GB, Junk PC. Rare Earths-The Answer to Everything. Molecules 2024; 29:688. [PMID: 38338432 PMCID: PMC10856286 DOI: 10.3390/molecules29030688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Revised: 01/24/2024] [Accepted: 01/27/2024] [Indexed: 02/12/2024] Open
Abstract
Rare earths, scandium, yttrium, and the fifteen lanthanoids from lanthanum to lutetium, are classified as critical metals because of their ubiquity in daily life. They are present in magnets in cars, especially electric cars; green electricity generating systems and computers; in steel manufacturing; in glass and light emission materials especially for safety lighting and lasers; in exhaust emission catalysts and supports; catalysts in artificial rubber production; in agriculture and animal husbandry; in health and especially cancer diagnosis and treatment; and in a variety of materials and electronic products essential to modern living. They have the potential to replace toxic chromates for corrosion inhibition, in magnetic refrigeration, a variety of new materials, and their role in agriculture may expand. This review examines their role in sustainability, the environment, recycling, corrosion inhibition, crop production, animal feedstocks, catalysis, health, and materials, as well as considering future uses.
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Affiliation(s)
- Thomas Behrsing
- School of Chemistry, Monash University, Melbourne, VIC 3800, Australia; (T.B.); (V.L.B.); (G.B.D.)
| | - Victoria L. Blair
- School of Chemistry, Monash University, Melbourne, VIC 3800, Australia; (T.B.); (V.L.B.); (G.B.D.)
| | | | - Glen B. Deacon
- School of Chemistry, Monash University, Melbourne, VIC 3800, Australia; (T.B.); (V.L.B.); (G.B.D.)
| | - Peter C. Junk
- College of Science & Engineering, James Cook University, Townsville, QLD 4811, Australia
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3
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Valizadeh S, Lee SS, Choi YJ, Baek K, Jeon BH, Andrew Lin KY, Park YK. Biochar application strategies for polycyclic aromatic hydrocarbons removal from soils. ENVIRONMENTAL RESEARCH 2022; 213:113599. [PMID: 35679906 DOI: 10.1016/j.envres.2022.113599] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2022] [Revised: 05/21/2022] [Accepted: 05/30/2022] [Indexed: 06/15/2023]
Abstract
Polycyclic aromatic hydrocarbons (PAHs) are known as a hazardous group of pollutants in the soil which causes many challenges to the environment. In this study, the potential of biochar (BC), as a carbonaceous material, is evaluated for the immobilization of PAHs in soils. For this purpose, various bonding mechanisms of BC and PAHs, and the strength of bonds are firstly described. Also, the effect of impressive criteria including BC physicochemical properties (such as surface area, porosity, particle size, polarity, aromaticity, functional group, etc., which are mostly the function of pyrolysis temperature), number of rings in PAHs, incubation time, and soil properties, on the extent and rate of PAHs immobilization by BC are explained. Then, the utilization of BC in collaboration with biological tools which simplifies further dissipation of PAHs in the soil is described considering detailed interactions among BC, microbes, and plants in the soil matrix. The co-effect of BC and biological remediation has been authenticated by previous studies. Moreover, recent technologies and challenges related to the application of BC in soil remediation are explained. The implementation of a combined BC-biological remediation method would provide excellent prospects for PAHs-contaminated soils.
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Affiliation(s)
- Soheil Valizadeh
- School of Environmental Engineering, University of Seoul, Seoul, 02504, Republic of Korea
| | - Sang Soo Lee
- Department of Environmental & Energy Engineering, Yonsei University, Wonju, 26493, Republic of Korea
| | - Yong Jun Choi
- School of Environmental Engineering, University of Seoul, Seoul, 02504, Republic of Korea
| | - Kitae Baek
- Department of Environment & Energy (BK21 FOUR) and Soil Environment Research Center, Jeonbuk National University, Jeonju 54896, Republic of Korea
| | - Byong-Hun Jeon
- Department of Earth Resources and Environmental Engineering, Hanyang University, Seoul, 04763, Republic of Korea
| | - Kun-Yi Andrew Lin
- Department of Environmental Engineering, National Chung Hsing University, 250 Kuo-Kuang Road, Taichung, Taiwan
| | - Young-Kwon Park
- School of Environmental Engineering, University of Seoul, Seoul, 02504, Republic of Korea.
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4
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Recovery of Rare-Earth Elements from Printed Circuit Boards by Vacuum Pyrolysis and Multiple Electrostatic Separation. Processes (Basel) 2022. [DOI: 10.3390/pr10061152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The influence of the multi-stage electrostatic separation (ESS) of mechanically treated and magnetically separated waste electronic material and the pyrolysis of the selected ESS fraction on the distribution of metal elements (MEs), elements contained in refractory oxides (EROs), bromine (Br), and rare-earth elements (REEs) contained in waste electronic material was studied. The concentration of MEs, Br, and EROs in the tested samples was determined by X-ray fluorescence analysis, and the concentration of REEs and uranium was determined by inductively coupled plasma mass spectrometry (ICP-MS). The analysis of the distribution of elements during the multi-stage ESS showed that MEs were predominantly distributed in the conductive fraction and Br, EROs, and REEs were distributed in the nonconductive fraction. The nonconductive fraction (NC2) of the two-stage ESS was subjected to a low-temperature vacuum pyrolysis (T = 550 °C, p = 10 mbar). The distribution of pyrolysis products of the NC2 fraction was determined. The main products of the vacuum pyrolysis experiments were the solid residue phase (54.4 wt.%) and oils (35.4 wt.%). It has been proven that pyrolysis can significantly increase the concentration of MEs, EROs, and REEs in raw materials, thereby providing a method for cost-effectively obtaining of REEs from waste printed circuit boards.
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Sustainable Recovery, Recycle of Critical Metals and Rare Earth Elements from Waste Electric and Electronic Equipment (Circuits, Solar, Wind) and Their Reusability in Additive Manufacturing Applications: A Review. METALS 2022. [DOI: 10.3390/met12050794] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The demand for high-efficiency, low-energy consumption materials, with high durability and stability, has led to the rapid increase of the demand and prices of Rare Earth Elements (REE). The REE monopoly of some countries has held the shift of humanity towards sustainability and renewable energy sources back. The isolation, recovery, and recycle of REE from waste electric and electronic equipment (WEEE) constitute the disengagement strategy and can lead to significant economic benefits, via sustainability. The introduction of critical raw materials (RM), derived from WEEE, as additives to filaments used for the synthesis of composite materials, employed by Additive Manufacturing (AM) applications, has tremendous potential for the performance and the commercialization of the final products by adding unique characteristics, such as antibacterial properties, enhanced mechanical and magnetic properties, and thermal and electrical conductivity. The low cost of the recycled RM, the small numbers of process stages, and the inception of a zero-waste paradigm, present its upscalability, with a realistic view to its industrial employment. Although there are many articles in literature that have reviewed WEEE recycle, a comprehensive review on the conditions, parameters, procedure flow charts, and novel properties of the final composite materials with regards to every RM is missing.
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Red Mud as a Secondary Resource of Low-Grade Iron: A Global Perspective. SUSTAINABILITY 2022. [DOI: 10.3390/su14031258] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Managing red mud (RM), a solid waste byproduct of the alumina recovery process, is a serious ecological and environmental issue. With ~150 million tons/year of RM being generated globally, nearly 4.6 billion tons of RM are presently stored in vast waste reserves. RM can be a valuable resource of metals, minor elements, and rare earth elements. The suitability of RM as a low-grade iron resource was assessed in this study. The utilization of RM as a material resource in several commercial, industrial operations was briefly reviewed. Key features of iron recovery techniques, such as magnetic separation, carbothermal reduction, smelting reduction, acid leaching, and hydrothermal techniques were presented. RMs from different parts of the globe including India, China, Greece, Italy, France, and Russia were examined for their iron recovery potential. Data on RM composition, iron recovery, techniques, and yields was presented. The composition range of RMs examined were: Fe2O3: 28.3–63.2 wt.%; Al2O3: 6.9–26.53 wt.%; SiO2: 2.3–22.0 wt.%; Na2O: 0.27–13.44 wt.%; CaO: 0.26–23.8 wt.%; Al2O3/SiO2: 0.3–4.6. Even with a high alumina content and high Al2O3/SiO2 ratios, it was possible to recover iron in all cases, showing the significant potential of RM as a secondary resource of low-grade iron.
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Khanna R, Konyukhov YV, Ikram-Ul-Haq M, Burmistrov I, Cayumil R, Belov VA, Rogachev SO, Leybo DV, Mukherjee PS. An innovative route for valorising iron and aluminium oxide rich industrial wastes: Recovery of multiple metals. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 295:113035. [PMID: 34167061 DOI: 10.1016/j.jenvman.2021.113035] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 05/31/2021] [Accepted: 06/05/2021] [Indexed: 06/13/2023]
Abstract
Several industrial wastes including biomass, fly ashes, red mud, mill scales, water treatment residues, have significant concentrations of metal oxides: Fe2O3, Al2O3, TiO2, SiO2 etc. Several efforts have been made towards recovering metals within these wastes. Rather than recovering one metal at a time, we report a novel approach for simultaneously extracting multiple metals from mixed oxides in a single process step. Using three distinct furnaces/heating regimes, the carbothermic reduction of Fe2O3/Al2O3/SiO2 system was investigated at 1450-1700 °C for up to 2 h over a wide composition range. Complete reduction was achieved for both Fe2O3 and SiO2 in all cases leading to the formation of Fe and Fe-Si alloys. The reduction of alumina at moderate temperatures was the key challenge. No alumina reduction was observed during reductions at 1450 °C. A partial reduction of alumina and the formation of Fe-Al alloys was detected in the Al2O3/Fe2O3/C system at 1550 °C. The formation of Fe-Si-Al alloys was also observed in the Fe2O3/SiO2/Al2O3/C system at 1550 °C. Complete reduction of alumina was observed at 1600-1700 °C, even for up to 50 wt% alumina in the system. Optimal operating conditions and reference standards were established for the simultaneous recovery of multiple metals from waste oxides. While conserving natural resources, this novel route will lower the burden on waste storage facilities with significant contributions to the economic and environmental sustainability of industrial waste management.
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Affiliation(s)
- R Khanna
- School of Materials Science and Engineering, The University of New South Wales, NSW, 2052, Sydney, Australia.
| | - Y V Konyukhov
- Department of Functional Nanosystems and High-Temperature Materials, National University of Science and Technology "MISiS", Moscow, 119049, Russia
| | - M Ikram-Ul-Haq
- School of Materials Science and Engineering, The University of New South Wales, NSW, 2052, Sydney, Australia
| | - I Burmistrov
- Engineering Centre, Plekhanov Russian University of Economics, Moscow, 117997, Russia
| | - R Cayumil
- Facultad de Ingenieria, Universidad Andres Bello, Antonio Varas 880, Providencia, Santiago, Chile
| | - V A Belov
- Department of Physical Metallurgy and Physics of Strength, National University of Science and Technology "MISiS", Moscow, 119049, Russia
| | - S O Rogachev
- Department of Physical Metallurgy and Physics of Strength, National University of Science and Technology "MISiS", Moscow, 119049, Russia
| | - D V Leybo
- Laboratory of Inorganic Nanomaterials, National University of Science and Technology "MISiS", Moscow, 119049, Russia
| | - P S Mukherjee
- Institute of Minerals and Materials Technology (Ret.), Council of Scientific and Industrial Research, Bhubaneshwar, Orissa, 751013, India
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Liu J, Jiang Q, Wang H, Li J, Zhang W. Catalytic effect and mechanism of in-situ metals on pyrolysis of FR4 printed circuit boards: Insights from kinetics and products. CHEMOSPHERE 2021; 280:130804. [PMID: 33965868 DOI: 10.1016/j.chemosphere.2021.130804] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 04/02/2021] [Accepted: 04/30/2021] [Indexed: 06/12/2023]
Abstract
Pyrolysis is a promising method for the recovery of waste printed circuit boards (WPCBs), but few researches have noticed the influence of in-situ metals. This study conducted a series of comparisons between metal-free leftover pieces (LP) and intact boards (IB), including pyrolysis characteristics, volatile emission, kinetics, and thermodynamic parameters. The thermo-gravimetry (TG) analyses indicated that both the samples presented predominant mass loss in narrow temperature intervals, and characteristic pyrolysis temperatures of IB were approximately 15 °C lower than those of LP. Dominant constituents in evolved gases were detected by Fourier-transform infrared spectrometry as CO2, phenol, bromophenol, ethers, ketones, and aldehydes, and metals accelerated the generation of light hydrocarbons and aromatic compounds. The activation energy and thermodynamic parameters were calculated and compared, and the results verified the presence of in-situ metals led to a lower energy barrier and higher reaction extent. Moreover, conversion behaviors of Cu, Fe, Sn, and Pb manifested the formation of metal bromides and implied the reduction of brominated volatiles. The obtained results confirmed the catalytic effect of in-situ metals on PCBs pyrolysis and their bromine fixation abilities. This study contributes to fundamental knowledge that can be used to guide the pyrolysis of WPCBs.
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Affiliation(s)
- Jingxin Liu
- School of Environmental Engineering, Wuhan Textile University, Wuhan, 430073, China; Engineering Research Centre for Clean Production of Textile Dyeing and Printing, Ministry of Education, Wuhan Textile University, Wuhan, 430073, China
| | - Qihao Jiang
- School of Environmental Engineering, Wuhan Textile University, Wuhan, 430073, China
| | - Hanlin Wang
- School of Environmental Engineering, Wuhan Textile University, Wuhan, 430073, China
| | - Jinping Li
- School of Environmental Engineering, Wuhan Textile University, Wuhan, 430073, China; Engineering Research Centre for Clean Production of Textile Dyeing and Printing, Ministry of Education, Wuhan Textile University, Wuhan, 430073, China
| | - Wenjuan Zhang
- School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing, 100083, China.
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9
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Dismantling of Printed Circuit Boards Enabling Electronic Components Sorting and Their Subsequent Treatment Open Improved Elemental Sustainability Opportunities. SUSTAINABILITY 2021. [DOI: 10.3390/su131810357] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
This critical review focuses on advanced recycling strategies to enable or increase recovery of chemical elements present in waste printed circuit boards (WPCBs). Conventional recycling involves manual removal of high value electronic components (ECs), followed by raw crushing of WPCBs, to recover main elements (by weight or value). All other elements remain unrecovered and end up highly diluted in post-processing wastes or ashes. To retrieve these elements, it is necessary to enrich the waste streams, which requires a change of paradigm in WPCB treatment: the disassembly of WPCBs combined with the sorting of ECs. This allows ECs to be separated by composition and to drastically increase chemical element concentration, thus making their recovery economically viable. In this report, we critically review state-of-the-art processes that dismantle and sort ECs, including some unpublished foresight from our laboratory work, which could be implemented in a recycling plant. We then identify research, business opportunities and associated advanced retrieval methods for those elements that can therefore be recovered, such as refractory metals (Ta, Nb, W, Mo), gallium, or lanthanides, or those, such as the platinum group elements, that can be recovered in a more environmentally friendly way than pyrometallurgy. The recovery methods can be directly tuned and adapted to the corresponding stream.
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Das SK, Ellamparuthy G, Kundu T, Ghosh MK, Angadi SI. Critical analysis of metallic and non-metallic fractions in the flotation of waste printed circuit boards. POWDER TECHNOL 2021. [DOI: 10.1016/j.powtec.2021.05.061] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Zhang T, Mao X, Qu J, Liu Y, Siyal AA, Ao W, Fu J, Dai J, Jiang Z, Deng Z, Song Y, Wang D, Polina C. Microwave-assisted catalytic pyrolysis of waste printed circuit boards, and migration and distribution of bromine. JOURNAL OF HAZARDOUS MATERIALS 2021; 402:123749. [PMID: 33254771 DOI: 10.1016/j.jhazmat.2020.123749] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 08/18/2020] [Accepted: 08/19/2020] [Indexed: 06/12/2023]
Abstract
Microwave-assisted pyrolysis (MAP) of waste printed circuit boards (WPCB) was performed to investigate the characteristics of pyrolysis product and Br fixation. Pyrolysis conversion increased with increasing temperature, reaching 93.3 % at 650 °C. However, increasing heating time did not exhibit remarkable influence on pyrolysis conversion. At 350 °C, phenols were main compounds in the oil accounting for 91.15 %. As the temperature increased to 650 °C, polycyclic aromatic hydrocarbons and monocyclic aromatic hydrocarbons (except phenols) increased to 20.55 % and 19.03 %, respectively. Meanwhile, the total content of CO2, CO, CH4 and H2 in the non-condensable gases increased significantly. Addition of ZSM-5 and kaolin promoted the recombination reaction of pyrolysis products, increased the relative percentage of monocyclic aromatic hydrocarbons (except phenols) and C11-C20 compounds in the oil, and reduced non-condensable gases. The oxygen bomb-ion chromatography was used to evaluate the Br content of pyrolysis residues. Higher pyrolysis temperature enhanced transfer of Br to pyrolysis gas. K2CO3, Na2CO3 and NaOH reacted with hydrogen bromide to generate KBr and NaBr, which significantly improved the Br fixation efficiency of pyrolysis residues (i.e. from 29.11%-99.80%, 96.39 % and 86.69 %, respectively) and reduced Br content in pyrolysis gas.
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Affiliation(s)
- Tianhao Zhang
- State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, 15 Beisanhua East Road, Chaoyang District, Beijing, 100029, China; College of Chemical Engineering, Beijing University of Chemical Technology, 15 Beisanhua East Road, Chaoyang District, Beijing, 100029, China
| | - Xiao Mao
- State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, 15 Beisanhua East Road, Chaoyang District, Beijing, 100029, China; College of Chemical Engineering, Beijing University of Chemical Technology, 15 Beisanhua East Road, Chaoyang District, Beijing, 100029, China
| | - Juanshen Qu
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, 15 Beisanhua East Road, Chaoyang District, Beijing, 100029, China
| | - Yang Liu
- State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, 15 Beisanhua East Road, Chaoyang District, Beijing, 100029, China; College of Chemical Engineering, Beijing University of Chemical Technology, 15 Beisanhua East Road, Chaoyang District, Beijing, 100029, China; Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, 15 Beisanhua East Road, Chaoyang District, Beijing, 100029, China
| | - Asif Ali Siyal
- State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, 15 Beisanhua East Road, Chaoyang District, Beijing, 100029, China; College of Chemical Engineering, Beijing University of Chemical Technology, 15 Beisanhua East Road, Chaoyang District, Beijing, 100029, China
| | - Wenya Ao
- State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, 15 Beisanhua East Road, Chaoyang District, Beijing, 100029, China; College of Chemical Engineering, Beijing University of Chemical Technology, 15 Beisanhua East Road, Chaoyang District, Beijing, 100029, China; Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, 15 Beisanhua East Road, Chaoyang District, Beijing, 100029, China
| | - Jie Fu
- State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, 15 Beisanhua East Road, Chaoyang District, Beijing, 100029, China; College of Chemical Engineering, Beijing University of Chemical Technology, 15 Beisanhua East Road, Chaoyang District, Beijing, 100029, China
| | - Jianjun Dai
- State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, 15 Beisanhua East Road, Chaoyang District, Beijing, 100029, China; College of Chemical Engineering, Beijing University of Chemical Technology, 15 Beisanhua East Road, Chaoyang District, Beijing, 100029, China.
| | - Zhihui Jiang
- State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, 15 Beisanhua East Road, Chaoyang District, Beijing, 100029, China; College of Chemical Engineering, Beijing University of Chemical Technology, 15 Beisanhua East Road, Chaoyang District, Beijing, 100029, China
| | - Zeyu Deng
- State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, 15 Beisanhua East Road, Chaoyang District, Beijing, 100029, China; College of Chemical Engineering, Beijing University of Chemical Technology, 15 Beisanhua East Road, Chaoyang District, Beijing, 100029, China
| | - Yongmeng Song
- State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, 15 Beisanhua East Road, Chaoyang District, Beijing, 100029, China; College of Chemical Engineering, Beijing University of Chemical Technology, 15 Beisanhua East Road, Chaoyang District, Beijing, 100029, China
| | - Daiying Wang
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, 15 Beisanhua East Road, Chaoyang District, Beijing, 100029, China
| | - Chtaeva Polina
- State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, 15 Beisanhua East Road, Chaoyang District, Beijing, 100029, China; College of Chemical Engineering, Beijing University of Chemical Technology, 15 Beisanhua East Road, Chaoyang District, Beijing, 100029, China
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12
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Dang DH, Zhang Z. Hazardous motherboards: Changes in metal contamination related to the evolution of electronictechnologies. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 268:115731. [PMID: 33059269 DOI: 10.1016/j.envpol.2020.115731] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 09/19/2020] [Accepted: 09/22/2020] [Indexed: 06/11/2023]
Abstract
Proper management of electronic waste (e-waste) represents significant economic and environmental challenges because of the tremendous quantity of e-waste, the potential of extracting precious metals from recyclable electronics, and the risks of environmental contamination with a variety of toxic compounds. This study focused on the leaching potential of 57 elements from central processing unit mainboards manufactured over time (1980s-2010s) using river water at different pHs as an environmentally-relevant extractant. The exposure time was set to one week. The calculated contamination factors allowed classification of the elements released from mainboards into five groups with increasing leachability and thus environmental concerns. Also, the results demonstrated a changing nature of e-waste related to the technologies employed and the transition of metal contamination signatures from these electronics; newer computer mainboards have a lower risk of Pb and Sn leaching but a greater release of Li, Sb, and a few rare earth elements (Sm, Eu, Dy). These specific patterns of elemental release could become powerful geochemical forensic tracers of improper recycling activities of e-waste in the environment. Most studies until now have investigated just a few key contaminants, despite the cocktail of pollutants contained in electronics. Therefore, a full assessment of the leaching potential of pollutants from non-properly recycled e-waste and further ecotoxicological studies are timely needed.
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Affiliation(s)
- Duc Huy Dang
- School of the Environment and Chemistry Department, Trent University, Peterborough, ON, Canada.
| | - Zhirou Zhang
- School of the Environment, Trent University, Peterborough, ON, Canada
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13
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Khanna R, Saini R, Park M, Ellamparuthy G, Biswal SK, Mukherjee PS. Factors influencing the release of potentially toxic elements (PTEs) during thermal processing of electronic waste. WASTE MANAGEMENT (NEW YORK, N.Y.) 2020; 105:414-424. [PMID: 32126369 DOI: 10.1016/j.wasman.2020.02.026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2019] [Revised: 01/21/2020] [Accepted: 02/21/2020] [Indexed: 06/10/2023]
Abstract
The release of potentially toxic elements as airborne fine particulates is a significant environmental risk associated with recycling e-waste. Some of these may redeposit near emission sites or be transported over long distances causing wide-spread pollution. With an aim to identify key factors affecting particulate emissions, we report novel investigations on the adsorptive capture of particulate matter (PM) released during low temperature pyrolysis (600 °C; 15 min) of waste printed circuit boards (PCBs). A significant proportion of the released particulates (5.3 to 37%) were captured by adsorbents located downstream and in close proximity to the emitting source. Data was collected for four different PCBs and three adsorbents: alumina, silica-gel and activated carbon. With sizes ranging from nanoparticles to over 10 µm, adsorbed particulates were present as fines, spheres, oblongs, clusters and larger particles with no specific shape. Of the 24 elements identified initially in waste PCBs, only 14 were detected in released particulates: major PTEs- Zn, Sn, Pb and Cu (up to 400 ppm); minor PTEs- Ni, Mn, Cd, Cr and Ba (up to 10 ppm); trace PTEs- Co, In, Bi, Be and Sb (up to 1 ppm). Key factors influencing the release of PTEs during thermal processing were identified as basic elemental characteristics, densities, melting points, vapor pressures, initial concentrations, local bonding and mechanical strength. These results show that the presence of low melting point/high vapour pressure elements (Zn, Pb, Sn) should be minimised for a significant reduction in PTE emissions during e-waste processing.
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Affiliation(s)
- R Khanna
- School of Materials Science and Engineering (Ret.), The University of New South Wales, Kensington, Sydney, NSW 2052, Australia.
| | - R Saini
- Department of Mechanical Engineering, ABES Engineering College, Ghaziabad, 201009, India
| | - M Park
- Industrial Design, Australian School of Architecture and Design, The University of New South Wales, Kensington, Sydney, NSW 2052, Australia
| | - G Ellamparuthy
- Institute of Minerals and Materials Technology, Council of Scientific and Industrial Research, Sachivalaya Marg, Acharya Vihar, Bhubaneswar, Orissa 751013, India
| | - S K Biswal
- Institute of Minerals and Materials Technology, Council of Scientific and Industrial Research, Sachivalaya Marg, Acharya Vihar, Bhubaneswar, Orissa 751013, India
| | - P S Mukherjee
- Institute of Minerals and Materials Technology, Council of Scientific and Industrial Research, Sachivalaya Marg, Acharya Vihar, Bhubaneswar, Orissa 751013, India
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14
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Heiho A, Kanematsu Y, Nagase M, Murakami S, Tokoro C, Kikuchi Y. Life Cycle Assessment of Resource Recovery from Waste Electrical and Electronic Equipment: A Case Study of Tantalum Recovery by Chain-Using Drum-Typed Impact Mill. KAGAKU KOGAKU RONBUN 2019. [DOI: 10.1252/kakoronbunshu.45.244] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Aya Heiho
- Presidential Endowed Chair for “Platinum Society,” Organization for Interdisciplinary Research Project, The University of Tokyo
| | - Yuichiro Kanematsu
- Presidential Endowed Chair for “Platinum Society,” Organization for Interdisciplinary Research Project, The University of Tokyo
| | - Mei Nagase
- Department of Systems Innovation, The University of Tokyo
| | | | | | - Yasunori Kikuchi
- Presidential Endowed Chair for “Platinum Society,” Organization for Interdisciplinary Research Project, The University of Tokyo
- Institute for Future Initiatives, The University of Tokyo
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15
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Gu W, Bai J, Lu L, Zhuang X, Zhao J, Yuan W, Zhang C, Wang J. Improved bioleaching efficiency of metals from waste printed circuit boards by mechanical activation. WASTE MANAGEMENT (NEW YORK, N.Y.) 2019; 98:21-28. [PMID: 31421486 DOI: 10.1016/j.wasman.2019.08.013] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 07/17/2019] [Accepted: 08/09/2019] [Indexed: 05/15/2023]
Abstract
The low bioleaching efficiency of Acidithiobacillus ferrooxidans results in its sparse industrial application for metal extraction from waste printed circuit boards (WPCBs). To improve the bioleaching efficiency of Acidithiobacillus ferrooxidans, we propose the use of mechanical activation to dispose WPCBs prior to performing bioleaching. Response surface methodology (RSM), scanning electron microscope- energy dispersive spectrometer (SEM-EDS), and laser particle size analyzer (LPSA) were used to optimize and analyze the mechanical activation process, respectively. The optimal conditions for mechanical activation was a milling time of 2 h, milling speed of 340 r min-1, and ball material ratio (w/w) of 10/1; the bioleaching rates of Cu, Ni, and Zn were 94.33%, 90.69%, and 90.78%, respectively. The bioleaching rates of Cu, Ni, and Zn were 74.75%, 70.46%, and 71.05%, respectively, without mechanical activation pretreatment. SEM-EDS and LPSA analyses indicated that mechanical activation could lead to a smaller particle size and expose wrapped metals, thus improving the bioleaching efficiency oyf tyhe metals inside the WPCBs. The electrode potential of the metals was likely changed by the mechanical activation, resulting in an improvement of their bioleaching efficiency. Additionally, the bioleaching rates of Pb, Cr, and Cd after mechanical activation pretreatment were 10.29%, 74.89%, and 54.12%, respectively. Contrastingly, the bioleaching rates of Pb, Cr, and Cd without mechanical activation pretreatment were 5.18%, 59.97%, and 37.12%, respectively. Thereinto, the precipitation of PbSO4 may result in a decrease of leached Pb. We propose a mechanical activation process for improving the bioleaching efficiency of metals from WPCBs.
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Affiliation(s)
- Weihua Gu
- WEEE Research Centre of Shanghai Polytechnic University, Shanghai 201209, China; Shanghai Collaborative Innovation Centre for WEEE Recycling, Shanghai 201209, China; Research Center of Resource Recycling Science and Engineering, Shanghai Polytechnic University, Shanghai 201209, China
| | - Jianfeng Bai
- WEEE Research Centre of Shanghai Polytechnic University, Shanghai 201209, China; Shanghai Collaborative Innovation Centre for WEEE Recycling, Shanghai 201209, China; Research Center of Resource Recycling Science and Engineering, Shanghai Polytechnic University, Shanghai 201209, China.
| | - Liang Lu
- WEEE Research Centre of Shanghai Polytechnic University, Shanghai 201209, China; Shanghai Collaborative Innovation Centre for WEEE Recycling, Shanghai 201209, China; Research Center of Resource Recycling Science and Engineering, Shanghai Polytechnic University, Shanghai 201209, China
| | - Xuning Zhuang
- WEEE Research Centre of Shanghai Polytechnic University, Shanghai 201209, China; Shanghai Collaborative Innovation Centre for WEEE Recycling, Shanghai 201209, China; Research Center of Resource Recycling Science and Engineering, Shanghai Polytechnic University, Shanghai 201209, China
| | - Jing Zhao
- WEEE Research Centre of Shanghai Polytechnic University, Shanghai 201209, China; Shanghai Collaborative Innovation Centre for WEEE Recycling, Shanghai 201209, China; Research Center of Resource Recycling Science and Engineering, Shanghai Polytechnic University, Shanghai 201209, China
| | - Wenyi Yuan
- WEEE Research Centre of Shanghai Polytechnic University, Shanghai 201209, China; Shanghai Collaborative Innovation Centre for WEEE Recycling, Shanghai 201209, China; Research Center of Resource Recycling Science and Engineering, Shanghai Polytechnic University, Shanghai 201209, China
| | - Chenglong Zhang
- WEEE Research Centre of Shanghai Polytechnic University, Shanghai 201209, China; Shanghai Collaborative Innovation Centre for WEEE Recycling, Shanghai 201209, China; Research Center of Resource Recycling Science and Engineering, Shanghai Polytechnic University, Shanghai 201209, China
| | - Jingwei Wang
- WEEE Research Centre of Shanghai Polytechnic University, Shanghai 201209, China; Shanghai Collaborative Innovation Centre for WEEE Recycling, Shanghai 201209, China; Research Center of Resource Recycling Science and Engineering, Shanghai Polytechnic University, Shanghai 201209, China
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