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Marimuthu V, Ramasamy A. Mechanical characteristics of waste-printed circuit board-reinforced concrete with silica fume and prediction modelling using ANN. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024; 31:28474-28493. [PMID: 38558342 DOI: 10.1007/s11356-024-33099-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Accepted: 03/22/2024] [Indexed: 04/04/2024]
Abstract
The use of electronic waste in cement concrete as a fibre additive has proven to be very promising for improving mechanical characteristics and developing sustainable construction materials to reduce the waste dumped in landfills. The following study investigated the effect of electronic waste (printed circuit boards (PCBs)) on the mechanical properties of concrete and predicted the same properties with an appropriate machine learning technique. PCB fibres 45 mm in length and 1.5 mm in width were manufactured and added as fibre additions to two sets of concrete mixes with and without silica fume. A 10% volume replacement of cement was substituted with silica fume (SF) to enhance the characteristics of PCB fibre-reinforced concrete and minimize cement consumption. The study included an evaluation of the fresh properties and mechanical characteristics after a 28-day curing period; thereafter, the results were compared and studied using the Levenberg-Marquardt backpropagation algorithm for predictions. The results show that the mechanical properties improved up to a 5% addition of PCB fibres, resulting in strengths of 63.55 MPa and 69.92 MPa for mixtures of PCB5% and SFPCB5%, respectively. A similar trend was achieved for other properties, such as the tensile and flexural strengths. The results of the ANN model predicted values with R2 values ranging from 0.94 to 0.99, indicating the efficacy of the model.
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Affiliation(s)
- VishnuPriyan Marimuthu
- Department of Civil Engineering, SRM Institute of Science and Technology, Tamil Nadu, Kattankulathur, Chengalpattu, India, 603203.
| | - Annadurai Ramasamy
- Department of Civil Engineering, SRM Institute of Science and Technology, Tamil Nadu, Kattankulathur, Chengalpattu, India, 603203
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Li X, Chen L, Yu G, Song L, Weng D, Ma Y, Wang J. Rapid Fabrication of High-Resolution Flexible Electronics via Nanoparticle Self-Assembly and Transfer Printing. NANO LETTERS 2024; 24:1332-1340. [PMID: 38232321 DOI: 10.1021/acs.nanolett.3c04316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2024]
Abstract
Printed electronic technology serves as a key component in flexible electronics and wearable devices, yet achieving compatibility with both high resolution and high efficiency remains a significant challenge. Here, we propose a rapid fabrication method of high-resolution nanoparticle microelectronics via self-assembly and transfer printing. The tension gradient-electrostatic attraction composite-induced nanoparticle self-assembly strategy is constructed, which can significantly enhance the self-assembly efficiency, stability, and coverage by leveraging the meniscus Marangoni effect and the electric double-layer effect. The close-packed nanoparticle self-assembly layer can be rapidly formed on microstructure surfaces over a large area. Inspired by ink printing, a transfer printing strategy is further proposed to transform the self-assembly layer into conformal micropatterns. Large-area, high-resolution (2 μm), and ultrathin (1 μm) nanoparticle microelectronics can be stably fabricated, yielding a significant improvement over fluid printing methods. The unique deformability, recoverability, and scalability of nanoparticle microelectronics are revealed, providing promising opportunities for various academic and real applications.
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Affiliation(s)
- Xuan Li
- Department of Mechanical Engineering, Tsinghua University, Beijing 100084, P. R. China
| | - Lei Chen
- Department of Mechanical Engineering, Tsinghua University, Beijing 100084, P. R. China
| | - Guoxu Yu
- Department of Mechanical Engineering, Tsinghua University, Beijing 100084, P. R. China
| | - Lele Song
- Department of Mechanical Engineering, Tsinghua University, Beijing 100084, P. R. China
| | - Ding Weng
- Department of Mechanical Engineering, Tsinghua University, Beijing 100084, P. R. China
| | - Yuan Ma
- Department of Mechanical Engineering, Tsinghua University, Beijing 100084, P. R. China
| | - Jiadao Wang
- Department of Mechanical Engineering, Tsinghua University, Beijing 100084, P. R. China
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Priyan MV, Annadurai R, Alaneme GU, Ravella DP, Pradeepkumar S, Olaiya BC. A study on waste PCB fibres reinforced concrete with and without silica fume made from electronic waste. Sci Rep 2023; 13:22755. [PMID: 38123638 PMCID: PMC10733379 DOI: 10.1038/s41598-023-50312-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2023] [Accepted: 12/18/2023] [Indexed: 12/23/2023] Open
Abstract
This research goal is to appraise the effect of electronic waste on concrete properties by examining the mechanical properties of concrete reinforced with waste printed circuit boards (PCBs). PCB fibres, each 50 mm long, were mixed in varying proportions (1-5% by weight of cement). Silica fume (SF) was used as a 12% weight replacement for cement to conserve the properties of PCB fibre-reinforced concrete while tumbling cement consumption. Following a 28-day curing period, the fresh and hardened characteristics of PCB fibre-reinforced concrete were juxtaposed with those of conventional concrete. The experimental results led to the conclusion that 5% by weight of cement is the most effective proportion of PCB fibres to include in both PCB fibre-reinforced concrete and silica fume-modified PCB fibre-reinforced concrete. The addition of PCB fibres and silica fume significantly increased the mechanical strength of the concrete, making it suitable for high-strength concrete applications. Based on a similar investigational research design, an artificial neural network model was created, and it played a critical role in predicting the mechanical properties of the concrete. The model produced accurate results, with an R-squared (R2) value greater than 0.99.
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Affiliation(s)
- M Vishnu Priyan
- Department of Civil Engineering, SRM Institute of Science and Technology, Kattankulathur, Chengalpattu, 603203, Tamil Nadu, India.
| | - R Annadurai
- Department of Civil Engineering, SRM Institute of Science and Technology, Kattankulathur, Chengalpattu, 603203, Tamil Nadu, India
| | - George Uwadiegwu Alaneme
- Department of Civil, School of Engineering and Applied Sciences, Kampala International University, Kampala, Uganda.
- Department of Civil Engineering, Michael Okpara University of Agriculture, Umudike, Umudike, Nigeria.
| | - Durga Prasad Ravella
- Department of Civil Engineering, Chaitanya Bharathi Institute of Technology, Hyderabad, India
| | - S Pradeepkumar
- Ministry of Environment, Forest and Climate Change, Government of India, New Delhi, India
| | - Bamidele Charles Olaiya
- Department of Civil, School of Engineering and Applied Sciences, Kampala International University, Kampala, Uganda
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Priyan MV, Annadurai R, Onyelowe KC, Alaneme GU, Giri NC. Recycling and sustainable applications of waste printed circuit board in concrete application and validation using response surface methodology. Sci Rep 2023; 13:16509. [PMID: 37783749 PMCID: PMC10545695 DOI: 10.1038/s41598-023-43919-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Accepted: 09/29/2023] [Indexed: 10/04/2023] Open
Abstract
The present investigation aims to examine the mechanical and durability properties of concrete that has been reinforced with a waste printed circuit board (WPCB) towards a low-carbon built environment. It assessed the fresh and hardened characteristics of the low-carbon concrete reinforced with WPCB fibres, after a curing period of 7 and 28 days. The evaluation was done by quantifying slump, compressive strength, split tensile strength, flexural strength, sorptivity, rapid, and acid tests. It further analysed eleven discrete concrete mixes with WPCB fibres at a weight percentage ranging from 1 to 5% in the cement mixture. The results indicate that incorporating WPCB fibre into concrete improves its mechanical strength. The results revealed that incorporating 5% WPCB fibre yielded the most favourable outcomes. The properties of WPCB fibre-reinforced concrete have been theoretically validated through Response Surface Methodology (RSM), which employs various statistical and mathematical tools to analyse the experimental data. The results derived from RSM were compared with the experimental results. It was found that the RSM model demonstrated a high level of accuracy (R2 ≥ 0.98) in validating the mechanical properties of WPCB fibre concrete. The statistical model exhibited no indication of prediction bias and demonstrated a statistically significant outcome, with a p-value below 0.5.
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Affiliation(s)
- M Vishnu Priyan
- Department of Civil Engineering, SRM Institute of Science and Technology, Kattankulathur, Chengalpattu, 603203, Tamil Nadu, India.
| | - R Annadurai
- Department of Civil Engineering, SRM Institute of Science and Technology, Kattankulathur, Chengalpattu, 603203, Tamil Nadu, India
| | - Kennedy C Onyelowe
- Department of Civil Engineering, Michael Okpara University of Agriculture, Umudike, Nigeria
- Department of Civil, School of Engineering and Applied Sciences, Kampala International University, Kampala, Uganda
| | - George Uwadiegwu Alaneme
- Department of Civil Engineering, Michael Okpara University of Agriculture, Umudike, Nigeria.
- Department of Civil, School of Engineering and Applied Sciences, Kampala International University, Kampala, Uganda.
| | - Nimay Chandra Giri
- Department of Electronics and Communication Engineering, Centurion University of Technology and Management, R. Sitapur, 752050, Odisha, India
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Lin CC, Lo SL, Liou SYH. Application of synthetic data to establish the working framework for multivariate statistical analysis of river pollution traceability - the heavy metals in Nankan River, Taiwan. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:70479-70492. [PMID: 35589891 DOI: 10.1007/s11356-022-20603-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 04/29/2022] [Indexed: 06/15/2023]
Abstract
This study applied multivariate statistical analysis (MSA) to synthetic data simulated by a river water quality model to verify whether the MSA can correctly infer the pollution scenario assigned in the river water quality model. The results showed that when assessing the number and possible locations of pollution sources based on the results of cluster analysis (CA), two instead of three pollution point source were identified when considering the hydraulic variations of surface water. When discussing the principal component analysis (PCA) result, the second principal component (PC2) and the Pearson correlation coefficients among the pollutants should also be considered, which can infer that Cu, Pb, Cr, and Ni are contributed by the same pollutant point source, and Cu is also influenced by another pollutant point source. This result also implies that the solid and liquid partition coefficients (Kd) of pollutants can affect the interpretation of the PCA results, so the Kd values should be determined before tracing the pollution sources to facilitate the evaluation of the source characteristics and potential targets. This study established a working framework for surface water pollution traceability to enhance the effectiveness of pollution traceability.
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Affiliation(s)
- Chun-Chun Lin
- Graduate Institute of Environmental Engineering, National Taiwan University, 71, Chou-Shan Rd, Taipei, 10617, Taiwan, Republic of China
| | - Shang-Lien Lo
- Graduate Institute of Environmental Engineering, National Taiwan University, 71, Chou-Shan Rd, Taipei, 10617, Taiwan, Republic of China.
| | - Sofia Ya-Hsuan Liou
- Department of Geosciences, National Taiwan University, 71, Chou-Shan Rd, Taipei, 10617, Taiwan, Republic of China
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Liu M, Lv J, Qin C, Zhang H, Wu L, Guo W, Guo C, Xu J. Chemical fingerprinting of organic micropollutants in different industrial treated wastewater effluents and their effluent-receiving river. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 838:156399. [PMID: 35660429 DOI: 10.1016/j.scitotenv.2022.156399] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 05/26/2022] [Accepted: 05/28/2022] [Indexed: 06/15/2023]
Abstract
Industry wastewater is considered one of the worst polluters of our precious water ecologies. However, the types of pollutants present in wastewater from industrial wastewater treatment plants (IWTPs) are still unclear. In this study, a simple and effective chemical fingerprinting method for checking the source-sink relationships among different industrial wastewaters and their effluent-receiving river was established. 107, 228, 155, and 337 chemicals were screened out in wastewater from electronics, steel, textile, and printing and dyeing plants, respectively. Chemical fingerprinting of the detected chemicals was performed, and results showed that aromatic compounds were the most prevalent among the pollutant categories (i.e., 56, 189, and 168 in electronics, iron and steel, and printing and dyeing plants, respectively). The traceability analysis of the chemicals selected in the effluent determined the characteristic pollutants of different industrial enterprises. Sixty-eight compounds were identified as the characteristic pollutants in the different process stages of wastewater of the four IWTPs. Of the 84 effluent-receiving river water signature pollutants, 47.6% (n = 40) were also detected in the effluent from the four IWTPs. Effective screening of organic pollutants in industrial wastewater and determining their sources will help accelerate the improvement of industrial wastewater treatment technology.
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Affiliation(s)
- Mingyuan Liu
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; Center for Environmental Health Risk Assessment and Research, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Jiapei Lv
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; Center for Environmental Health Risk Assessment and Research, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Chenghua Qin
- China National Environmental Monitoring Centre, Beijing 100012, China
| | - Heng Zhang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; Center for Environmental Health Risk Assessment and Research, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Linlin Wu
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; Center for Environmental Health Risk Assessment and Research, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Wei Guo
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; Center for Environmental Health Risk Assessment and Research, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Changsheng Guo
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; Center for Environmental Health Risk Assessment and Research, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
| | - Jian Xu
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; Center for Environmental Health Risk Assessment and Research, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
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Morphology, Phase and Chemical Analysis of Leachate after Bioleaching Metals from Printed Circuit Boards. MATERIALS 2022; 15:ma15134373. [PMID: 35806498 PMCID: PMC9267160 DOI: 10.3390/ma15134373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 06/06/2022] [Accepted: 06/08/2022] [Indexed: 11/17/2022]
Abstract
The article presents the assessment of solutions and dried residues precipitated from solutions after the bioleaching process of Printed Circuit Boards (PCB) utilizing the Acidithiobacillus ferrooxidans. The obtained dried residues precipitated from bioleaching solution (leachate) and control solution were tested using morphology, phase, and chemical composition analysis, with particular emphasis on the assessment of crystalline and amorphous components. The analysis of the dried residues from leachate after bioleaching as well as those from the sterile control solution demonstrated a difference in the component oxidation—the leachate consisted of mainly amorphous spherical particles in diameter up to 200 nm, forming lacy aggregates. In the specimenform control solution larger particles (up to 500 nm) were observed with a hollow in the middle and crystalline outer part (probably Fe2O3, CuFeS2, and Cu2O). The X-ray diffraction phase analysis revealed that specimen obtained from leachate after bioleaching consisted mainly of an amorphous component and some content of Fe2O3 crystalline phase, while the dried residue from control solution showed more crystalline components. The share of the crystalline and amorphous components can be related to efficiency in dissolving metals during bioleaching. Obtained results of the investigation confirm the activity and participation of the A. ferrooxidans bacteria in the solubilization process of electro-waste components, with their visible degradation–acceleration of the reaction owing to a continuous regeneration of the leaching medium. The performed investigations allowed to characterize the specimen from leachate and showed that the application of complementary cross-check of the micro (SEM and S/TEM) and macro (ICP-OES and XRD) methods are of immense use for complete guidance assessment and obtained valuable data for the next stages of PCBs recycling.
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Salinas-Rodríguez E, Hernández-Ávila J, Cerecedo-Sáenz E, Arenas-Flores A, Veloz-Rodríguez MA, Toro N, Gutiérrez-Amador MDP, Acevedo-Sandoval OA. Leaching of Copper Contained in Waste Printed Circuit Boards, Using the Thiosulfate-Oxygen System: A Kinetic Approach. MATERIALS 2022; 15:ma15072354. [PMID: 35407686 PMCID: PMC8999890 DOI: 10.3390/ma15072354] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 03/11/2022] [Accepted: 03/16/2022] [Indexed: 11/16/2022]
Abstract
The present work is related to the treatment of crushed waste of printed circuit boards (WPCBs) from electrical and electronic devices (WEEE), carrying out the recovery of copper in solution. In the first stage, the studied material was characterized by AAS, SEM-EDS, and XRD. The results revealed significantly high amounts of copper (744.42 mg/g), compared with the rest of the metals present in the sample, mainly iron and zinc. In the second stage of the work, alkali dynamic leaching experiments were carried out in the S2O3−2− O2 medium, evaluating important kinetic variables in order to verify the controlling step of the system and adjust the data to a kinetic model. According to the results obtained from the various experimental tests executed, it was found that in the studied system of S2O3−2− O2, the leaching of copper was preferably adjusted to the model of spherical particles with a shrinking core finding a mixed chemical−diffusive control, with values of Ea = 25.78 kJ/mol and n = 0.22 (for the leaching reagent), indicating that the reaction was controlled by the oxygen transport to the solid−liquid interface and also by the chemical reaction in the surface of particles, obtaining up to 99.82% copper in solution.
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Affiliation(s)
- Eleazar Salinas-Rodríguez
- Academic Area of Earth Science and Materials, Institute of Basis Sciences and Engineering, Autonomous University of the State of Hidalgo, Highway Pachuca-Tulancingo km. 4.5, Mineral de la Reforma 42184, Hidalgo, Mexico; (J.H.-Á.); (E.C.-S.); (A.A.-F.); (M.A.V.-R.)
- Correspondence: (E.S.-R.); (O.A.A.-S.); Tel.: +52-771-207-4171 (E.S.-R.); +52-771-151-7643 (O.A.A.-S.)
| | - Juan Hernández-Ávila
- Academic Area of Earth Science and Materials, Institute of Basis Sciences and Engineering, Autonomous University of the State of Hidalgo, Highway Pachuca-Tulancingo km. 4.5, Mineral de la Reforma 42184, Hidalgo, Mexico; (J.H.-Á.); (E.C.-S.); (A.A.-F.); (M.A.V.-R.)
| | - Eduardo Cerecedo-Sáenz
- Academic Area of Earth Science and Materials, Institute of Basis Sciences and Engineering, Autonomous University of the State of Hidalgo, Highway Pachuca-Tulancingo km. 4.5, Mineral de la Reforma 42184, Hidalgo, Mexico; (J.H.-Á.); (E.C.-S.); (A.A.-F.); (M.A.V.-R.)
| | - Alberto Arenas-Flores
- Academic Area of Earth Science and Materials, Institute of Basis Sciences and Engineering, Autonomous University of the State of Hidalgo, Highway Pachuca-Tulancingo km. 4.5, Mineral de la Reforma 42184, Hidalgo, Mexico; (J.H.-Á.); (E.C.-S.); (A.A.-F.); (M.A.V.-R.)
| | - Maria A. Veloz-Rodríguez
- Academic Area of Earth Science and Materials, Institute of Basis Sciences and Engineering, Autonomous University of the State of Hidalgo, Highway Pachuca-Tulancingo km. 4.5, Mineral de la Reforma 42184, Hidalgo, Mexico; (J.H.-Á.); (E.C.-S.); (A.A.-F.); (M.A.V.-R.)
| | - Norman Toro
- Faculty of Engineering and Architecture, Universidad Antonio Prat, Iquique 1100000, Chile;
| | - Maria del P. Gutiérrez-Amador
- Apan High School, Autonomous University of the State of Hidalgo, Highway Apan-Calpulalpan km. 8, Apan 43920, Hidalgo, Mexico;
| | - Otilio A. Acevedo-Sandoval
- Academic Area of Chemistry, Institute of Basis Sciences and Engineering, Autonomous University of the State of Hidalgo, Highway Pachuca-Tulancingo km. 4.5, Mineral de la Reforma 42184, Hidalgo, Mexico
- Correspondence: (E.S.-R.); (O.A.A.-S.); Tel.: +52-771-207-4171 (E.S.-R.); +52-771-151-7643 (O.A.A.-S.)
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Shamkhalichenar H, Tiersch TR, Choi JW. An Impedimetric Sensing Probe Based on Printed Circuit Board Technology for Monitoring in Cryobiology Applications. JOURNAL OF THE ELECTROCHEMICAL SOCIETY 2021; 168:067505. [PMID: 36777921 PMCID: PMC9910178 DOI: 10.1149/1945-7111/ac045a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Cryopreservation of living cells is an effective tool for protection, maintenance, and distribution of genetic resources, which involves exposure to cryogenic temperatures and requires precise control over various parameters to avoid potential cell damages. Hundreds of protocols have been reported for cryopreservation of aquatic species, but replicating them is challenging without a reliable monitoring technique during a cryopreservation process. In this work, we aim to use electrical impedance as a monitoring parameter to assist standardization of cryopreservation processes and reporting. Specifically, this paper reports an impedance sensing probe compatible with cryogenic temperatures and conventional containers in cryopreservation of aquatic species based on printed circuit board technology its characterization in cryopreservation conditions including different sperm extenders (buffer) compositions and concentrations, presence of cryoprotectant, and multiple cooling rates. The developed probe based on printed circuit board (PCB) technology shows a capability of measuring conditions during cryopreservation differentiating among samples with different buffer contents and cryoprotectants. The probe also demonstrates the capability to distinguish different cooling regimes and detect phase change phenomena. This PCB-based sensing platform provides quantitative impedance measurement data during the cryopreservation process at sample preparation, cooling, and while frozen. Technology such as this offers opportunities for improving the reproducibility of protocols generated by the aquatic species community and can be made widely available as open hardware.
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Affiliation(s)
- Hamed Shamkhalichenar
- School of Electrical Engineering and Computer Science, Louisiana State University, Baton Rouge, Louisiana 70803, United States of America
| | - Terrence R. Tiersch
- Aquatic Germplasm and Genetic Resources Center, School of Renewable Natural Resources, Louisiana State University Agricultural Center, Baton Rouge, Louisiana 70820, United States of America
| | - Jin-Woo Choi
- School of Electrical Engineering and Computer Science, Louisiana State University, Baton Rouge, Louisiana 70803, United States of America
- Center for Advanced Microstructures and Devices, Louisiana State University, Baton Rouge, Louisiana 70803, United States of America
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Impact of Grinding of Printed Circuit Boards on the Efficiency of Metal Recovery by Means of Electrostatic Separation. MINERALS 2021. [DOI: 10.3390/min11030281] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
This paper analyses the impact of the method of grinding printed circuit boards (PCBs) in a knife mill on the efficiency and purity of products obtained during electrostatic separation. The separated metals and plastics and ceramics can be used as secondary raw materials. This is in line with the principle of circular economy. Three different screen perforations were used in the mill to obtain different sizes of ground grains. Moreover, the effect of cooling the feed to cryogenic temperature on the final products of separation was investigated. The level of contamination of the concentrate, intermediate, and waste obtained as a result of the application of fixed, determined electrostatic separation parameters was assessed using ICP-AES, SEM–EDS, XRD, and microscopic analysis as well as specific density. The yields of grain classes obtained from grinding in a knife mill were tested through sieve analysis and by using a particle size analyser. The test results indicate that using a knife mill with a 1 mm screen perforation along with cooling the feed to cryogenic temperature significantly improves the efficiency of the process. The grinding products were characterised by the highest release level of the useful substance—metals in the free state. The purity of the concentrate and waste obtained from electrostatic separation was satisfactory, and the content of the intermediate, in which conglomerates of solid metal–plastic connections were present, was very low. The yield of concentrate and waste amounted to 26.2% and 71.0%, respectively. Their purity, reflected in the content of the identified metals (valuable metals), was at the level of 93.3% and 0.5%, respectively. In order to achieve effective recovery of metals from PCBs by means of electrostatic separation, one should strive to obtain a feed composed of grains <1000 μm and, optimally, <800 μm.
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Printed Circuit Board (PCB) Technology for Electrochemical Sensors and Sensing Platforms. BIOSENSORS-BASEL 2020; 10:bios10110159. [PMID: 33143106 PMCID: PMC7693744 DOI: 10.3390/bios10110159] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 10/26/2020] [Accepted: 10/27/2020] [Indexed: 12/15/2022]
Abstract
The development of various biosensors has revolutionized the healthcare industry by providing rapid and reliable detection capability. Printed circuit board (PCB) technology has a well-established industry widely available around the world. In addition to electronics, this technology has been utilized to fabricate electrical parts, including electrodes for different biological and chemical sensors. High reproducibility achieved through long-lasting standard processes and low-cost resulting from an abundance of competitive manufacturing services makes this fabrication method a prime candidate for patterning electrodes and electrical parts of biosensors. The adoption of this approach in the fabrication of sensing platforms facilitates the integration of electronics and microfluidics with biosensors. In this review paper, the underlying principles and advances of printed board circuit technology are discussed. In addition, an overview of recent advancements in the development of PCB-based biosensors is provided. Finally, the challenges and outlook of PCB-based sensors are elaborated.
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Efficient Bond of PDMS and Printed Circuit Board with An Application on Continuous-flow Polymerase Chain Reaction. BIOCHIP JOURNAL 2020. [DOI: 10.1007/s13206-020-4403-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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Effect of Chloride Ions on Electro-Coagulation to Treat Industrial Wastewater Containing Cu and Ni. SUSTAINABILITY 2020. [DOI: 10.3390/su12187693] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A series of experiments with different NaCl concentrations added to the PCB (printed circuit board) wastewater were prepared to investigate the chloride effect on the formation of aluminum floc and removal efficiency of Cu and Ni. The effects of pH, current density, and different concentration of NaCl were studied and the results are discussed. Results imply that chloride ions are favored to avoid the passivation of the aluminum anode in the EC (electro-coagulation) system. Chloride ions used as the electrolyte can facilitate the release of Al3+, which results in the current efficiency of over 100% in the EC system. For the PCB factory’s wastewater, the EC system could remove Cu2+ and Ni2+ effectively (both Cu and Ni concentration of treated wastewater was less than 1.0 mg/L within three minutes). PCB wastewater’s pH value could maintain stably about 9.0 in the EC system when the initial pH value was around 2.5. The estimated electricity consumption for treating PCB wastewater by the EC process was about 0.894 kWh for each meter of cubic wastewater.
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MPPE/SEBS Composites with Low Dielectric Loss for High-Frequency Copper Clad Laminates Applications. Polymers (Basel) 2020; 12:polym12091875. [PMID: 32825522 PMCID: PMC7564947 DOI: 10.3390/polym12091875] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Revised: 08/16/2020] [Accepted: 08/18/2020] [Indexed: 11/16/2022] Open
Abstract
Copper clad laminates (CCLs) with low dissipation factor (Df) are urgently needed in the fields of high-frequency communications devices. A novel resin matrix of modified poly (2,6-dimethyl-1,4-phenylene ether) (MPPE) and styrene-ethylene/butylene-styrene (SEBS) was employed in the fabrication of high-frequency copper clad laminates (CCLs). The composites were reinforced by E-glass fabrics, which were modified with phenyltriethoxysilane (PhTES). The composite laminates obtained exhibited impressive dielectric loss of 0.0027 at 10 GHz when the weight ratio of MPPE to SEBS was 5:1. In order to modify the dielectric constant (Dk), coefficient of thermal expansion (CTE) and other performances of laminates, Li2TiO3 (LT) ceramic powders were introduced into the resin matrix. The composite laminates showed low dielectric loss of 0.0026 at 10 GHz and relatively high flexural strength of 125 MPa when the mass ratio of LT fillers to resin is 0.4. Moreover, the composite laminates all maintain low water uptake (<0.5%). The microstructure and thermal properties of composite laminates filled with LT ceramic powders were also tested. These results show that copper clad laminates prepared with modified polyphenylene ether (MPPE)/SEBS and LT ceramic fillers have strong competitiveness to fabricate printed circuit boards (PCBs) for high-frequency and high-speed applications.
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Wang ZH, Fang GQ, He JJ, Yang HX, Yang SY. Semi-aromatic thermosetting polyimide resins containing alicyclic units for achieving low melt viscosity and low dielectric constant. REACT FUNCT POLYM 2020. [DOI: 10.1016/j.reactfunctpolym.2019.104411] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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16
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Zhao D, Chen W, Qu C, Liu C, Cui B, Li G, Song J, Li L, Zheng S, Chang J, Tang Y, Shang L, Zhang H. Factors influencing thermal, mechanical, optical, and adhesive properties of segmented poly(imide siloxane) copolymers films. J Appl Polym Sci 2019. [DOI: 10.1002/app.48148] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Daoxiang Zhao
- Institute of Petro chemistryHeilongjiang Academy of Science Harbin China
| | - Weijun Chen
- Institute of Petro chemistryHeilongjiang Academy of Science Harbin China
| | - Chunyan Qu
- Institute of Petro chemistryHeilongjiang Academy of Science Harbin China
| | - Changwei Liu
- Institute of Petro chemistryHeilongjiang Academy of Science Harbin China
| | - Baojun Cui
- Institute of Petro chemistryHeilongjiang Academy of Science Harbin China
| | - Gang Li
- Institute of Petro chemistryHeilongjiang Academy of Science Harbin China
| | - Junjun Song
- Institute of Petro chemistryHeilongjiang Academy of Science Harbin China
| | - Liaoliao Li
- Institute of Petro chemistryHeilongjiang Academy of Science Harbin China
| | - Shuai Zheng
- School of Materials Science and EngineeringHarbin University of Science and Technology Harbin China
| | - Jiaying Chang
- Institute of Petro chemistryHeilongjiang Academy of Science Harbin China
| | - Yao Tang
- Institute of Petro chemistryHeilongjiang Academy of Science Harbin China
| | - Liming Shang
- Institute of Petro chemistryHeilongjiang Academy of Science Harbin China
| | - Haitao Zhang
- Institute of Petro chemistryHeilongjiang Academy of Science Harbin China
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Hopmann C, Höfs C, Schomburg WK, Kosloh J, Sackmann J. Development of thermoplastic films for ultrasonic manufacturing of printed circuit boards. ADVANCES IN POLYMER TECHNOLOGY 2018. [DOI: 10.1002/adv.22130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Christian Hopmann
- Institute of Plastics Processing (IKV) in Industry and the Skilled Crafts at RWTH Aachen University; Aachen Germany
| | - Christopher Höfs
- Institute of Plastics Processing (IKV) in Industry and the Skilled Crafts at RWTH Aachen University; Aachen Germany
| | | | - Julia Kosloh
- Design and Development of Microsystems (KEmikro); Aachen Germany
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Ozkan E, Elginoz N, Germirli Babuna F. Life cycle assessment of a printed circuit board manufacturing plant in Turkey. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:26801-26808. [PMID: 28963629 DOI: 10.1007/s11356-017-0280-z] [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: 02/24/2017] [Accepted: 09/19/2017] [Indexed: 06/07/2023]
Abstract
The objective of this study is to investigate the environmental impacts of a printed circuit board (PCB) manufacturing plant through streamlined life cycle assessment approach. As a result, the most effective recommendations on minimizing the environmental impacts for the mentioned sector are revealed and first steps towards establishing a country specific database are taken. The whole PCB production consists of two consecutive stages: namely board fabrication followed by the manufacturing of PCB. Manufacturing of PCB contributes the highest shares to freshwater aquatic ecotoxicity potential (FAETP) and ozone layer depletion potential (ODP). Eighty-nine percent of FAETP is found to be generated from the manufacturing of PCB. Almost all of this contribution can be attributed to the disposal of copper containing wastewater treatment sludge from etching operations to incineration. On the other hand, PCB manufacturing has 73% share in total ODP. Within the manufacturing of PCB, as etching operations are found to be of importance for all the impact categories except eutrophication potential (EP), it is recommended to focus further studies on in-plant control of etching.
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Affiliation(s)
- Elif Ozkan
- Department of Environmental Engineering, Istanbul Technical University, 34469, Istanbul, Turkey
| | - Nilay Elginoz
- Department of Civil Engineering, Istanbul Technical University, Maslak, 34469, Istanbul, Turkey
| | - Fatos Germirli Babuna
- Department of Environmental Engineering, Istanbul Technical University, 34469, Istanbul, Turkey.
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Correa MMJ, Silvas FPC, Aliprandini P, Moraes VTD, Dreisinger D, Espinosa DCR. SEPARATION OF COPPER FROM A LEACHING SOLUTION OF PRINTED CIRCUIT BOARDS BY USING SOLVENT EXTRACTION WITH D2EHPA. BRAZILIAN JOURNAL OF CHEMICAL ENGINEERING 2018. [DOI: 10.1590/0104-6632.20180353s20170144] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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20
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Bunekar N, Tsai TY, Huang HP. Effect of Functionalized Graphene with Modified Clay on Flammability of Copper Clad Laminated Novolac Cured Epoxy Composites. POLYM-PLAST TECH MAT 2018. [DOI: 10.1080/03602559.2018.1493120] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Naveen Bunekar
- Department of Chemistry, Chung-Yuan Christian University, Taoyuan, Republic of China
- Center for Nanotechnology, Chung-Yuan Christian University, Taoyuan, Republic of China
| | - Tsung-Yen Tsai
- Department of Chemistry, Chung-Yuan Christian University, Taoyuan, Republic of China
- Master Program in Nanotechnology, Chung-Yuan Christian University, Taoyuan, Republic of China
- Center for Nanotechnology, Chung-Yuan Christian University, Taoyuan, Republic of China
| | - Hsien-Ping Huang
- Master Program in Nanotechnology, Chung-Yuan Christian University, Taoyuan, Republic of China
- Center for Nanotechnology, Chung-Yuan Christian University, Taoyuan, Republic of China
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21
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Chen Y, Sun Y, Zhu Q, Wang B, Yan X, Qiu S, Li Q, Hou P, Liu C, Sun D, Cheng H. High-Throughput Fabrication of Flexible and Transparent All-Carbon Nanotube Electronics. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2018; 5:1700965. [PMID: 29876218 PMCID: PMC5979759 DOI: 10.1002/advs.201700965] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 01/15/2018] [Indexed: 05/22/2023]
Abstract
This study reports a simple and effective technique for the high-throughput fabrication of flexible all-carbon nanotube (CNT) electronics using a photosensitive dry film instead of traditional liquid photoresists. A 10 in. sized photosensitive dry film is laminated onto a flexible substrate by a roll-to-roll technology, and a 5 µm pattern resolution of the resulting CNT films is achieved for the construction of flexible and transparent all-CNT thin-film transistors (TFTs) and integrated circuits. The fabricated TFTs exhibit a desirable electrical performance including an on-off current ratio of more than 105, a carrier mobility of 33 cm2 V-1 s-1, and a small hysteresis. The standard deviations of on-current and mobility are, respectively, 5% and 2% of the average value, demonstrating the excellent reproducibility and uniformity of the devices, which allows constructing a large noise margin inverter circuit with a voltage gain of 30. This study indicates that a photosensitive dry film is very promising for the low-cost, fast, reliable, and scalable fabrication of flexible and transparent CNT-based integrated circuits, and opens up opportunities for future high-throughput CNT-based printed electronics.
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Affiliation(s)
- Yong‐Yang Chen
- College of Information Science and EngineeringNortheastern University3‐11 Wenhua RoadShenyang110819China
| | - Yun Sun
- Shenyang National Laboratory for Materials ScienceInstitute of Metal ResearchChinese Academy of Sciences72 Wenhua RoadShenyang110016China
| | - Qian‐Bing Zhu
- Shenyang National Laboratory for Materials ScienceInstitute of Metal ResearchChinese Academy of Sciences72 Wenhua RoadShenyang110016China
- School of Material Science and EngineeringUniversity of Science and Technology of China96 Jinzhai RoadHefei230026China
| | - Bing‐Wei Wang
- Shenyang National Laboratory for Materials ScienceInstitute of Metal ResearchChinese Academy of Sciences72 Wenhua RoadShenyang110016China
- School of Material Science and EngineeringUniversity of Science and Technology of China96 Jinzhai RoadHefei230026China
- University of Chinese Academy of Sciences19 A Yuquan RoadBeijing100049China
| | - Xin Yan
- College of Information Science and EngineeringNortheastern University3‐11 Wenhua RoadShenyang110819China
| | - Song Qiu
- Suzhou Institute of Nano‐Tech and Nano‐BionicsChinese Academy of Sciences398 Ruoshui RoadSuzhou215123China
| | - Qing‐Wen Li
- Suzhou Institute of Nano‐Tech and Nano‐BionicsChinese Academy of Sciences398 Ruoshui RoadSuzhou215123China
| | - Peng‐Xiang Hou
- Shenyang National Laboratory for Materials ScienceInstitute of Metal ResearchChinese Academy of Sciences72 Wenhua RoadShenyang110016China
| | - Chang Liu
- Shenyang National Laboratory for Materials ScienceInstitute of Metal ResearchChinese Academy of Sciences72 Wenhua RoadShenyang110016China
- School of Material Science and EngineeringUniversity of Science and Technology of China96 Jinzhai RoadHefei230026China
| | - Dong‐Ming Sun
- Shenyang National Laboratory for Materials ScienceInstitute of Metal ResearchChinese Academy of Sciences72 Wenhua RoadShenyang110016China
- School of Material Science and EngineeringUniversity of Science and Technology of China96 Jinzhai RoadHefei230026China
| | - Hui‐Ming Cheng
- Shenyang National Laboratory for Materials ScienceInstitute of Metal ResearchChinese Academy of Sciences72 Wenhua RoadShenyang110016China
- School of Material Science and EngineeringUniversity of Science and Technology of China96 Jinzhai RoadHefei230026China
- Tsinghua‐Berkeley Shenzhen InstituteTsinghua University1001 Xueyuan RoadShenzhen518055China
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Hait S. Comprehensive characterization of printed circuit boards of various end-of-life electrical and electronic equipment for beneficiation investigation. WASTE MANAGEMENT (NEW YORK, N.Y.) 2018; 75:103-123. [PMID: 29454818 DOI: 10.1016/j.wasman.2018.02.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Revised: 02/05/2018] [Accepted: 02/07/2018] [Indexed: 06/08/2023]
Abstract
Comprehensive characterization of printed circuit board (PCB) of end-of-life electrical and electronic equipment (EEE) is obligatory for prospective profitable beneficiation. In this study, beneficiation oriented comprehensive characterization of two brands of PCBs each of 16 end-of-life EEE was conducted in terms of their physicochemical characteristics with special emphasis on the content of 16 general elements, 2 precious metals and 15 rare earth elements (REEs). General elements and their highest weight percent composition found in different PCBs of the EEEs were Cu (23% in laptop), Al (6% in computer), Pb (15% in DVD player) and Ba (7% in TV). The high abundant of precious metals such as Au (316 g/ton) and Ag (636 g/ton) in mobile phone and laptop, respectively coupled with rapid obsolescence age makes waste PCBs of information technology and telecommunication equipment the most potent resource reservoir. Additionally, most of the waste PCBs were observed to contain REEs in considerable quantity with Sc up to 31 g/ton and Ce up to 13 g/ton being the major constituents. Comprehensive characterization of waste PCBs therefore will systematically help towards better understanding of e-waste recycling processes for beneficiation purpose and sustainable resource circulation and conservation.
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Affiliation(s)
- Subrata Hait
- Department of Civil and Environmental Engineering, Indian Institute of Technology Patna, Bihta, Bihar, India.
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23
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Gwak G, Kim DI, Hong S. New industrial application of forward osmosis (FO): Precious metal recovery from printed circuit board (PCB) plant wastewater. J Memb Sci 2018. [DOI: 10.1016/j.memsci.2018.02.022] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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24
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Error Separation Method for Precision Measurement of the Run-Out of a Microdrill Bit by Using a Laser Scan Micrometer Measurement System. JOURNAL OF MANUFACTURING AND MATERIALS PROCESSING 2018. [DOI: 10.3390/jmmp2010004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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25
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Priya A, Hait S. Qualitative and quantitative metals liberation assessment for characterization of various waste printed circuit boards for recycling. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2017; 24:27445-27456. [PMID: 28980132 DOI: 10.1007/s11356-017-0351-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Accepted: 09/26/2017] [Indexed: 06/07/2023]
Abstract
Metals liberation and composition are decisive attributes in characterization of e-waste for metal recycling. Though end-of-life printed circuit board (PCB) is an integral part of e-waste as secondary resource reservoir, yet no standardized procedure exists for metals liberation and dissolution for its characterization. Thus, the paper aims at assessment of metals liberation upon comminution employing scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS) followed by comparative assessment of the existing United States Environmental Protection Agency (USEPA) digestion procedures, viz., USEPA 3050B, USEPA 3051A, and USEPA 3052, in effective dissolution of metals from comminuted particles of waste PCBs of computer, laptop, mobile phone, and television. Effect of comminution and digestion conditions was assessed to have significant role in metal liberation and dissolution from PCBs. The SEM-EDS analysis demonstrated partial release of metals from the silica matrix of PCBs. The USEPA digestion methods showed statistically significant (P < 0.05) difference with greater dissolution of metals complexed to PCB matrix by the USEPA 3052 method owing to use of strong acid like hydrofluoric acid. Base metals like Cu and Zn and toxic metals such as Pb and Cd were present in abundance in PCBs and in general exceeded the total threshold limit concentration (TTLC). The maximum contents of Cu (20.13 ± 0.04 wt.%) and Zn (1.89 ± 0.05 wt.%) in laptop PCBs, Pb (2.26 ± 0.08 wt.%) in TV PCBs, and Cd (0.0812 ± 0.0008 wt.%) in computer PCBs were observed.
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Affiliation(s)
- Anshu Priya
- Department of Civil and Environmental Engineering, Indian Institute of Technology Patna, Bihta, Patna, Bihar, 801 103, India
| | - Subrata Hait
- Department of Civil and Environmental Engineering, Indian Institute of Technology Patna, Bihta, Patna, Bihar, 801 103, India.
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26
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Ma L, Zhu G, Liu C, Qu C, Jia H, Li L, Cao Z, Zhang H. Synthesis, characterization, and properties of thermoplastic polyimides derived from 4,4’-(hexafluoroisopropylidene)diphthalic anhydride in diethylene glycol dimethyl ether. HIGH PERFORM POLYM 2017. [DOI: 10.1177/0954008317737823] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
By regulating the order of monomer addition, four kinds of copolymer polyimides (PIs) were prepared using diethylene glycol dimethyl ether (DEGDE) and N, N-dimethylacetamide (DMAc) as the solvents. The molecular weights of polyamide acids (PAAs) ranged from 3.8 × 105 to 9.2 × 105. All of the films displayed high glass transition temperatures ( Tgs) ranging from 313°C to 346°C. The polymer films show excellent thermal stabilities with 5% weight loss at temperatures of 505–524°C and char yields at 800°C were as high as 55% under nitrogen. The peel strengths of flexible copper (Cu) clads were in the range from 0.337 N cm−1 to 0.598 N cm−1. Compared to the molecular weight and peel strength of fresh PAA, those of PAAs prepared using DMAc significantly decreased after storage for 3 months at 0°C. However, when DEGDE was used as the solvent, the molecular weights of the PAAs and the thermal properties of the PIs were maintained after long storage time.
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Affiliation(s)
- Liqun Ma
- College of Materials Science and Engineering, Qiqihar University, Qiqihar, China
| | - Guangyu Zhu
- College of Materials Science and Engineering, Qiqihar University, Qiqihar, China
| | - Changwei Liu
- Institute of Petro chemistry, Heilongjiang Academy of Science, Harbin, China
| | - Chunyan Qu
- Institute of Petro chemistry, Heilongjiang Academy of Science, Harbin, China
| | - Hongge Jia
- College of Materials Science and Engineering, Qiqihar University, Qiqihar, China
| | - Liaoliao Li
- Institute of Petro chemistry, Heilongjiang Academy of Science, Harbin, China
| | - Zhibo Cao
- Alan G. MacDiarmid Institute, Jilin University, Changchun, China
| | - Hui Zhang
- College of Materials Science and Engineering, Qiqihar University, Qiqihar, China
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Ong LK, Tran Nguyen PL, Soetaredjo FE, Ismadji S, Ju YH. Kinetic evaluation of simultaneous waste cooking oil hydrolysis and reactive liquid-liquid Cu extraction from synthetic Cu-containing wastewater: Effect of various co-contaminants. Sep Purif Technol 2017. [DOI: 10.1016/j.seppur.2017.06.049] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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28
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Lambert A, Asokan M, Issac G, Love C, Chyan O. Thin-film UV–vis spectroscopy as a chemically-sensitive monitoring tool for copper etching bath. J IND ENG CHEM 2017. [DOI: 10.1016/j.jiec.2017.03.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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29
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Moschou D, Tserepi A. The lab-on-PCB approach: tackling the μTAS commercial upscaling bottleneck. LAB ON A CHIP 2017; 17:1388-1405. [PMID: 28294256 DOI: 10.1039/c7lc00121e] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Commercialization of lab-on-a-chip devices is currently the "holy grail" within the μTAS research community. While a wide variety of highly sophisticated chips which could potentially revolutionize healthcare, biology, chemistry and all related disciplines are increasingly being demonstrated, very few chips are or can be adopted by the market and reach the end-users. The major inhibition factor lies in the lack of an established commercial manufacturing technology. The lab-on-printed circuit board (lab-on-PCB) approach, while suggested many years ago, only recently has re-emerged as a very strong candidate, owing to its inherent upscaling potential: the PCB industry is well established all around the world, with standardized fabrication facilities and processes, but commercially exploited currently only for electronics. Owing to these characteristics, complex μTASs integrating microfluidics, sensors, and electronics on the same PCB platform can easily be upscaled, provided more processes and prototypes adapted to the PCB industry are proposed. In this article, we will be reviewing for the first time the PCB-based prototypes presented in the literature to date, highlighting the upscaling potential of this technology. The authors believe that further evolution of this technology has the potential to become a much sought-after standardized industrial fabrication technology for low-cost μTASs, which could in turn trigger the projected exponential market growth of μTASs, in a fashion analogous to the revolution of Si microchips via the CMOS industry establishment.
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Affiliation(s)
- Despina Moschou
- Centre for Advanced Sensor Technologies, Department of Electronic and Electrical Engineering, University of Bath, BA2 7AY, Bath, UK.
| | - Angeliki Tserepi
- Institute of Nanoscience and Nanotechnology, National Center for Scientific Research "Demokritos", Patriarchou Gregoriou and 27 Neapoleos Str., 153 41 Aghia Paraskevi, Attiki, Greece.
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Zhang G, Wang H, He Y, Yang X, Peng Z, Zhang T, Wang S. Triboelectric separation technology for removing inorganics from non-metallic fraction of waste printed circuit boards: Influence of size fraction and process optimization. WASTE MANAGEMENT (NEW YORK, N.Y.) 2017; 60:42-49. [PMID: 27530083 DOI: 10.1016/j.wasman.2016.08.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Revised: 07/27/2016] [Accepted: 08/09/2016] [Indexed: 06/06/2023]
Abstract
Removing inorganics from non-metallic fraction (NMF) of waste printed circuit boards (WPCBs) is an effective mean to improve its usability. The effect of size fraction on the triboelectric separation of NMF of WPCBs was investigated in a lab triboelectric separation system and the separation process was optimized in this paper. The elements distribution in raw NMF collected from typical WPCBs recycling plant and each size fraction obtained by sieving were analyzed by X-ray fluorescence (XRF). The results show that the main inorganic elements in NMF are P, Ba, Mn, Sb, Ti, Pb, Zn, Sn, Mg, Fe, Ca, Cu, Al and Si. The inorganic content of each size fraction increased with the size decreasing. The metal elements are mainly distributed in -0.2mm size fraction, and concentrated in middle product of triboelectric separation. The loss on ignition (LOI) of positive product and negative product is higher than that of the middle product for the -0.355mm size fraction, while the LOI presents gradually increasing trend from negative to positive plate for the +0.355mm size fraction. Based on the separation results and mineralogical characterizations of each size fraction of NMF, the pretreatment process including several mineral processing operations was added before triboelectric separation and better separation result was obtained.
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Affiliation(s)
- Guangwen Zhang
- School of Chemical Engineering and Technology, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China; Key Laboratory of Coal Processing and Efficient Utilization, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China
| | - Haifeng Wang
- School of Chemical Engineering and Technology, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China; Key Laboratory of Coal Processing and Efficient Utilization, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China.
| | - Yaqun He
- School of Chemical Engineering and Technology, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China; Key Laboratory of Coal Processing and Efficient Utilization, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China; Advanced Analysis & Computation Center, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China
| | - Xing Yang
- School of Chemical Engineering and Technology, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China; Key Laboratory of Coal Processing and Efficient Utilization, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China
| | - Zhen Peng
- School of Chemical Engineering and Technology, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China; Key Laboratory of Coal Processing and Efficient Utilization, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China
| | - Tao Zhang
- Advanced Analysis & Computation Center, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China
| | - Shuai Wang
- Advanced Analysis & Computation Center, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China
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Kaya M. Recovery of metals and nonmetals from electronic waste by physical and chemical recycling processes. WASTE MANAGEMENT (NEW YORK, N.Y.) 2016; 57:64-90. [PMID: 27543174 DOI: 10.1016/j.wasman.2016.08.004] [Citation(s) in RCA: 215] [Impact Index Per Article: 26.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2016] [Revised: 08/02/2016] [Accepted: 08/04/2016] [Indexed: 05/11/2023]
Abstract
This paper reviews the existing and state of art knowledge for electronic waste (e-waste) recycling. Electrical and/or electronic devices which are unwanted, broken or discarded by their original users are known as e-waste. The main purpose of this article is to provide a comprehensive review of e-waste problem, strategies of e-waste management and various physical, chemical and metallurgical e-waste recycling processes, their advantages and disadvantages towards achieving a cleaner process of waste utilization, with special attention towards extraction of both metallic values and nonmetallic substances. The hazards arise from the presence of heavy metals Hg, Cd, Pb, etc., brominated flame retardants (BFRs) and other potentially harmful substances in e-waste. Due to the presence of these substances, e-waste is generally considered as hazardous waste and, if improperly managed, may pose significant human and environmental health risks. This review describes the potential hazards and economic opportunities of e-waste. Firstly, an overview of e-waste/printed circuit board (PCB) components is given. Current status and future perspectives of e-waste/PCB recycling are described. E-waste characterization, dismantling methods, liberation and classification processes are also covered. Manual selective dismantling after desoldering and metal-nonmetal liberation at -150μm with two step crushing are seen to be the best techniques. After size reduction, mainly physical separation processes employing gravity, electrostatic, magnetic separators, froth floatation, etc. have been critically reviewed here for separation of metals and nonmetals, along with useful utilizations of the nonmetallic materials. The recovery of metals from e-waste material after physical separation through pyrometallurgical, hydrometallurgical or biohydrometallurgical routes is also discussed along with purification and refining. Suitable PCB recycling flowsheets for industrial applications are also given. It seems that hydrometallurgical route will be a key player in the base and precious metals recoveries from e-waste. E-waste recycling will be a very important sector in the near future from economic and environmental perspectives. Recycling technology aims to take today's waste and turn it into conflict-free, sustainable polymetallic secondary resources (i.e. Urban Mining) for tomorrow. Recycling technology must ensure that e-waste is processed in an environmentally friendly manner, with high efficiency and lowered carbon footprint, at a fraction of the costs involved with setting multibillion dollar smelting facilities. Taking into consideration our depleting natural resources, this Urban Mining approach offers quite a few benefits. This results in increased energy efficiency and lowers demand for mining of new raw materials.
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Affiliation(s)
- Muammer Kaya
- Mining Engineering Department, Eskişehir Osmangazi University, Eskişehir, Turkey.
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Kim YH, Lim YW, Kim YH, Bae BS. Thermally Stable Siloxane Hybrid Matrix with Low Dielectric Loss for Copper-Clad Laminates for High-Frequency Applications. ACS APPLIED MATERIALS & INTERFACES 2016; 8:8335-8340. [PMID: 26982015 DOI: 10.1021/acsami.6b01497] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We report vinyl-phenyl siloxane hybrid material (VPH) that can be used as a matrix for copper-clad laminates (CCLs) for high-frequency applications. The CCLs, with a VPH matrix fabricated via radical polymerization of resin blend consisting of sol-gel-derived linear vinyl oligosiloxane and bulky siloxane monomer, phenyltris(trimethylsiloxy)silane, achieve low dielectric constant (Dk) and dissipation factor (Df). The CCLs with the VPH matrix exhibit excellent dielectric performance (Dk = 2.75, Df = 0.0015 at 1 GHz) with stability in wide frequency range (1 MHz to 10 GHz) and at high temperature (up to 275 °C). Also, the VPH shows good flame resistance without any additives. These results suggest the potential of the VPH for use in high-speed IC boards.
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Affiliation(s)
- Yong Ho Kim
- Laboratory of Optical Materials and Coating (LOMC) Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST) , Daejeon, Republic of Korea
| | - Young-Woo Lim
- Laboratory of Optical Materials and Coating (LOMC) Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST) , Daejeon, Republic of Korea
| | - Yun Hyeok Kim
- Laboratory of Optical Materials and Coating (LOMC) Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST) , Daejeon, Republic of Korea
| | - Byeong-Soo Bae
- Laboratory of Optical Materials and Coating (LOMC) Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST) , Daejeon, Republic of Korea
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Zhang G, Wang H, Zhang T, Yang X, Xie W, He Y. Removing inorganics from nonmetal fraction of waste printed circuit boards by triboelectric separation. WASTE MANAGEMENT (NEW YORK, N.Y.) 2016; 49:230-237. [PMID: 26777553 DOI: 10.1016/j.wasman.2015.12.022] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Revised: 12/23/2015] [Accepted: 12/23/2015] [Indexed: 05/28/2023]
Abstract
Metals recycling from WPCBs has been studied for a long time, which results in the appearance of many proven techniques. However, the nonmetal fraction in WPCBs has not been fully recycled due to hybridpropertiesof inorganic and organic composition. In order to improve the usability of the nonmetal fraction from WPCBs, nonmetal materials separation by using a laboratory triboelectric separation system was carried out to improve the reuse efficiency of WPCBs nonmetal fraction. The optimum tribocharger material was investigated by using the charge-mass ratio measurement system, and PMMA is the optimum tribocharger material compared with PVC, PPFT, PPR, SS. The effects of airflow, voltage and feed rate on triboelectric separation were investigated. The product LOI of positive plate is up to 77.26% with recovery rate of 25.49%, while the product LOI of negative plate is down to 47.35% with recovery rate of 35.37%, and the remove rate of inorganics is up to 43.02% by triboelectric separation. The analysis results of X-ray diffraction indicate that the main inorganic materials mixed in nonmetal fraction are SiO2, Al2O3, CaO, Cu, Fe, Sn. The X-ray fluorescence analysis shows that the triboelectric separation can effectively remove the content of SiO2 and Al2O3. The scanning electron microscope images show that inorganics tribocharge positively and distribute in product collection grooves that close to negative plate.
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Affiliation(s)
- Guangwen Zhang
- School of Chemical Engineering and Technology, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China; Key Laboratory of Coal Processing and Efficient Utilization, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China
| | - Haifeng Wang
- School of Chemical Engineering and Technology, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China; Key Laboratory of Coal Processing and Efficient Utilization, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China.
| | - Tao Zhang
- School of Chemical Engineering and Technology, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China; Advanced Analysis & Computation Center, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China
| | - Xing Yang
- School of Chemical Engineering and Technology, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China; Key Laboratory of Coal Processing and Efficient Utilization, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China
| | - Weining Xie
- School of Chemical Engineering and Technology, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China; Key Laboratory of Coal Processing and Efficient Utilization, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China
| | - Yaqun He
- School of Chemical Engineering and Technology, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China; Key Laboratory of Coal Processing and Efficient Utilization, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China; Advanced Analysis & Computation Center, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China
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Silvas FPC, Correa MMJ, Caldas MPK, de Moraes VT, Espinosa DCR, Tenório JAS. Printed circuit board recycling: Physical processing and copper extraction by selective leaching. WASTE MANAGEMENT (NEW YORK, N.Y.) 2015; 46:503-10. [PMID: 26323203 DOI: 10.1016/j.wasman.2015.08.030] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Revised: 08/20/2015] [Accepted: 08/20/2015] [Indexed: 05/22/2023]
Abstract
Global generation of waste electrical and electronic equipment (WEEE) is about 40 million tons per year. Constant increase in WEEE generation added to international legislations has improved the development of processes for materials recovery and sustainability of electrical and electronic industry. This paper describes a new hydrometallurgical route (leaching process) to recycle printed circuit boards (PCBs) from printers to recover copper. Methodology included PCBs characterization and a combined route of physical and hydrometallurgical processing. Magnetic separation, acid digestion and chemical analysis by ICP-OES were performed. On leaching process were used two stages: the first one in a sulfuric media and the second in an oxidant media. The results showed that the PCBs composition was 74.6 wt.% of non-magnetic material and 25.4 wt.% of magnetic one. The metallic fraction corresponded to 44.0 wt.%, the polymeric to 28.5 wt.% and the ceramic to 27.5 wt.%. The main metal was copper and its initial content was 32.5 wt.%. On sulfuric leaching 90 wt.% of Al, 40 wt.% of Zn and 8.6 wt.% of Sn were extracted, whereas on oxidant leaching tests the extraction percentage of Cu was 100 wt.%, of Zn 60 wt.% and of Al 10 wt.%. At the end of the hydrometallurgical processing was obtained 100% of copper extraction and the recovery factor was 98.46%, which corresponds to a 32 kg of Cu in 100 kg of PCB.
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Affiliation(s)
- Flávia P C Silvas
- Department of Chemical Engineering, Polytechnic School of the University of São Paulo, R. do Lago, 250, 05424-970, PO 61548, São Paulo, Brazil.
| | - Mónica M Jiménez Correa
- Department of Chemical Engineering, Polytechnic School of the University of São Paulo, R. do Lago, 250, 05424-970, PO 61548, São Paulo, Brazil.
| | - Marcos P K Caldas
- Department of Chemical Engineering, Polytechnic School of the University of São Paulo, R. do Lago, 250, 05424-970, PO 61548, São Paulo, Brazil; Federal Institute of Technology, Science and Education of Espírito Santo, Rd ES-010, Km 6,5 - Manguinhos, CEP 29173-087 Serra, ES, Brazil.
| | - Viviane T de Moraes
- Department of Chemical Engineering, Polytechnic School of the University of São Paulo, R. do Lago, 250, 05424-970, PO 61548, São Paulo, Brazil.
| | - Denise C R Espinosa
- Department of Chemical Engineering, Polytechnic School of the University of São Paulo, R. do Lago, 250, 05424-970, PO 61548, São Paulo, Brazil.
| | - Jorge A S Tenório
- Department of Chemical Engineering, Polytechnic School of the University of São Paulo, R. do Lago, 250, 05424-970, PO 61548, São Paulo, Brazil.
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Yang S, Bai S, Wang Q. Preparation of fine fiberglass-resin powders from waste printed circuit boards by different milling methods for reinforcing polypropylene composites. J Appl Polym Sci 2015. [DOI: 10.1002/app.42494] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Shuangqiao Yang
- State Key Laboratory of Polymer Materials Engineering; Polymer Research Institute of Sichuan University; Chengdu 610065 China
| | - Shibing Bai
- State Key Laboratory of Polymer Materials Engineering; Polymer Research Institute of Sichuan University; Chengdu 610065 China
| | - Qi Wang
- State Key Laboratory of Polymer Materials Engineering; Polymer Research Institute of Sichuan University; Chengdu 610065 China
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Wongkaew K, Sunsandee N, Pancharoen U, Nootong K, Ramakul P. Purification of Sn(IV) and recovery of Pd(II) from flexible printed circuit board industry wastewater via HFSLM: Temperature effect investigation. J IND ENG CHEM 2015. [DOI: 10.1016/j.jiec.2014.07.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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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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Abstract
Recycling of metallic fractions from waste printed circuit boards (PCBs) using gravity separation and hydrometallurgy was investigated. The obtained research fruits were listed as follows: (1) When being pulverized to finer than 0.4mm, waste PCBs could be generally dissociated from plastics. (2) Shaking table was shown to be suitable for processing pulverized PCBs. Pulverized PCBs containing 6.97% copper was enriched to 33.55% in a single operation and the copper recovery was 90.3% in the best size range of separation. (3) Pressure oxidation leaching was shown to be effective for separating copper from aluminum and tin. The leaching extraction of aluminum and tin were 86.6% and 96.3%, copper extraction was 1% or less under the optimal conditions.
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Zhou P, Guo J, Zhou X, Zhang W, Liu L, Liu Y, Lin K. PM2.5, PM10 and health risk assessment of heavy metals in a typical printed circuit noards manufacturing workshop. J Environ Sci (China) 2014; 26:2018-2026. [PMID: 25288545 DOI: 10.1016/j.jes.2014.08.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Revised: 02/02/2014] [Accepted: 02/28/2014] [Indexed: 06/03/2023]
Abstract
A typical Printed Circuit Board (PCB) manufacturer was chosen as the object of this study. During PCB processing, fine particulate matter and heavy metals (Cu, Zn, Pb, Cr, Cd and Ni) will be released into the air and dust, which then impact workers' health and the environment. The concentrations of total suspended particle (TSP), PM10 and PM2.5 in the off-site were 106.3, 90.0 and 50.2μg/m(3), respectively, while the concentrations of TSP, PM10 and PM2.5 in the workshops ranged from 36.1 to 365.3, from 27.1 to 289.8 and from 22.1 to 212.3μg/m(3), respectively. Almost all six of the heavy metals were detected in all of the particle samples except Cd. For each workshop, it was obvious that Zn was the most enriched metal in TSP, followed by Cu>Pb (Cr)>Ni>Cd, and the same trend was found for PM10 and PM2.5. In the dust samples, Cu (which ranged from 4.02 to 56.31mg/g) was the most enriched metal, followed by Zn, Cr, Pb, Ni and Cd, and the corresponding concentrations ranged from 0.77 to 4.47, 0.37 to 1.59, 0.26 to 0.84, 0.13 to 0.44 and nd to 0.078mg/g, respectively. The health risk assessment showed that noncancerous effects are unlikely for Zn, Pb, Cr, Cu, Cd and Ni. The carcinogenic risks for Cd and Ni were all lower than 10(-6), except for Cr. This result indicates that carcinogenic risks for workers are relatively possible in the workshops. These findings suggest that this technology is advanced from the perspective of environmental protection in the waste PCB's recycling industry.
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Affiliation(s)
- Peng Zhou
- School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Jie Guo
- School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Xiaoyu Zhou
- School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Wei Zhang
- School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Lili Liu
- School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Yangcheng Liu
- School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Kuangfei Lin
- School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai 200237, China.
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Zhou X, Guo J, Zhang W, Zhou P, Deng J, Lin K. Occurrences and inventories of heavy metals and brominated flame retardants in wastes from printed circuit board production. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2014; 21:10294-10306. [PMID: 24777328 DOI: 10.1007/s11356-014-2927-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2014] [Accepted: 04/15/2014] [Indexed: 06/03/2023]
Abstract
Pollutants including heavy metals and brominated flame retardant were detected in 10 types of production wastes from a typical printed circuit board manufacturing plant, and their inventories were estimated. Rinsing water from etching process had the highest concentrations of copper (665.51 mg/L), lead (1.02 mg/L), nickel (3.60 mg/L), chromium (0.97 mg/L), and tin (1.79 mg/L). Powdered solid waste (SW) from the cut lamination process contained the highest tetrabromobisphenol-A (TBBPA) levels (49.86 mg/kg). Polybrominated diphenyl ethers (PBDEs) were absent in this plant, in agreement with the international regulations of PBDE phase out. The pollutant inventories in the wastes exhibited in the order of copper > > zinc > tin ≈ nickel > lead > chromium > > TBBPA. The potential environmental impact of pollutants in SW during production and disposal were further investigated. A high partitioning of pollutant concentration between the total suspended particle and SW (-0.10 < log K TS < 2.12) was observed for most pollutants, indicating the emission pathway from SW to the airborne atmosphere in the workshop. Although SW met the toxicity characteristic leaching procedure, drilling powder with the smallest particle diameter still showed high leachabilities of lead and tin which may lead to a negative environmental impact during disposal.
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Affiliation(s)
- Xiaoyu Zhou
- State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, East China University of Science and Technology, Shanghai, 200237, People's Republic of China
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41
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Zhao GH, Luo XZ, Chen G, Zhao YJ. A long-term static immersion experiment on the leaching behavior of heavy metals from waste printed circuit boards. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2014; 16:1967-1974. [PMID: 24934650 DOI: 10.1039/c4em00099d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Printed circuit boards (PCBs) are the main components of electrical and electronic equipment (EEE). Waste PCBs contain several kinds of heavy metals, including Cu, Pb and Zn. We characterize the leaching of heavy metals (Cu, Pb, Zn and Ni) from waste PCBs in a pH range of 3.0 to 5.6 using a novel approach based on batch pH-static leaching experiments in this work. The results indicate that the leaching behavior of Cu, Pb, Zn and Ni is strongly dependent on pH. Leaching behavior also varies with different pH values and leaching times. The maximum concentrations of Cu, Pb, Zn and Ni in leachate from waste PCBs were 335.00, 17.57, 2.40 and 2.33 mg L(-1), respectively. The highest Pb, Ni, and Cu concentrations leached significantly exceeded the European Union waste-acceptance limit values with respect to inert waste landfills. The leaching of metals follows the shrinking core model with surface reaction control.
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Affiliation(s)
- Guo-Hua Zhao
- College of Biological and Chemical Engineering, Jiaxing University, Jiaxing 314001, People's Republic of China.
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42
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Lin KH, Chiang HL. Liquid oil and residual characteristics of printed circuit board recycle by pyrolysis. JOURNAL OF HAZARDOUS MATERIALS 2014; 271:258-265. [PMID: 24637450 DOI: 10.1016/j.jhazmat.2014.02.031] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Revised: 02/20/2014] [Accepted: 02/21/2014] [Indexed: 06/03/2023]
Abstract
Non-metal fractions of waste printed circuit boards (PCBs) were thermally treated (200-500°C) under nitrogen atmosphere. Carbon, hydrogen, and nitrogen were determined by elemental analyzer, bromine by instrumental neutron activation analysis (INAA), phosphorus by energy dispersive X-ray spectrometer (EDX), and 29 trace elements by inductively coupled plasma atomic emission spectrometer (ICP-AES) and mass spectrometry (ICP-MS) for raw material and pyrolysis residues. Organic compositions of liquid oil were identified by GC (gas chromatography)-MS, trace element composition by ICP system, and 12 water-soluble ions by IC (ionic chromatography). Elemental content of carbon was >450 mg/g, oxygen 300 mg/g, bromine and hydrogen 60 mg/g, nitrogen 30 mg/g, and phosphorus 28 mg/g. Sulfur was trace in PCBs. Copper content was 25-28 mg/g, iron 1.3-1.7 mg/g, tin 0.8-1.0mg/g and magnesium 0.4-1.0mg/g; those were the main metals in the raw materials and pyrolytic residues. In the liquid products, carbon content was 68-73%, hydrogen was 10-14%, nitrogen was 4-5%, and sulfur was less than 0.05% at pyrolysis temperatures from 300 to 500°C. Phenol, 3-bromophenol, 2-methylphenol and 4-propan-2-ylphenol were major species in liquid products, accounting for >50% of analyzed organic species. Bromides, ammonium and phosphate were the main species in water sorption samples for PCB pyrolysis exhaust.
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Affiliation(s)
- Kuo-Hsiung Lin
- Department of Environmental Engineering and Science, Fooyin University, Kaohsiung, Taiwan
| | - Hung-Lung Chiang
- Department of Health Risk Management, China Medical University, Taichung, Taiwan.
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Lin CC, Wang JD, Hsieh GY, Chang YY, Chen PC. Increased Risk of Death with Congenital Anomalies in the Offspring of Male Semiconductor Workers. INTERNATIONAL JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HEALTH 2013; 14:112-6. [DOI: 10.1179/oeh.2008.14.2.112] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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Vidyadhar A, Chalavadi G, Das A. Stratification and segregation features of pulverized electronic waste in flowing film concentration. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2013; 118:49-54. [PMID: 23399878 DOI: 10.1016/j.jenvman.2013.01.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2012] [Revised: 01/05/2013] [Accepted: 01/11/2013] [Indexed: 06/01/2023]
Abstract
Gravity separation of metals from plastics in pulverized e-waste using flowing film concentration in a shaking table was investigated. Over 51% rejection of plastics in a single stage operation was achieved under optimum conditions. The shaking table was shown to be suitable for processing ground PCBs. Pulverized e-waste containing 22% metals was enriched to around 40% metals in a single pass. Statistical models for the mass yield of metal-rich stream and its grade were developed by design of experiments. Optimization was carried out to maximize the mass yield at a target product grade and preferred operating regimes were established. Experiments were designed to prevent metal loss and over 95% recovery values were obtained under all conditions. Settling distances of metals and plastics were computed and shown to be good indicators of separation performance. Particle morphology and stratification in the troughs in between the riffles were shown to influence the separation significantly. Water flow-assisted motion of the plastics was captured and its role in determining the effectiveness of separation was described. The efficacy of tabling was well established for treating ground PCBs. The wet process was shown to be environment friendly and sustainable. It is also relatively cheap and has good potential for industrial application. However, rigorous cost estimates will be required before commercial application.
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Affiliation(s)
- A Vidyadhar
- MNP Division, CSIR-National Metallurgical Laboratory, Jamshedpur 831 007, India
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45
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Yu W, Lao XQ, Pang S, Zhou J, Zhou A, Zou J, Mei L, Yu ITS. A survey of occupational health hazards among 7,610 female workers in China's electronics industry. ARCHIVES OF ENVIRONMENTAL & OCCUPATIONAL HEALTH 2013; 68:190-195. [PMID: 23697691 DOI: 10.1080/19338244.2012.701244] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
To investigate the occupational hazards among Chinese female workers in the electronics industry, the authors systematically sampled a total of 8,300 female workers at random across 4 provinces in a variety of electronics factories. A detailed questionnaire was used to collect information on occupational hazards and the occurrence of occupation-related diseases. The results show that 4,283 female workers (51.9%) were exposed to 1 or more occupational hazards. The most common chemical hazard was organic solvent, and the second most common was heavy metals. The ergonomic hazards included repetitive movements, poor standing posture, and the lifting of heavy goods. More than 60% of the female workers self-reported occupation-related diseases. These results showed that occupational health hazards were common in the electronics industry in China and that they caused serious occupation-related health problems for the female workers therein.
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Affiliation(s)
- Wenlan Yu
- National Institute of Occupational Health and Poison Control, Chinese Center for Disease Control and Prevention, Beijing, China
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46
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Zhou L, Xu Z. Response to waste electrical and electronic equipments in China: legislation, recycling system, and advanced integrated process. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2012; 46:4713-4724. [PMID: 22463615 DOI: 10.1021/es203771m] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Over the past 30 years, China has been suffering from negative environmental impacts from distempered waste electrical and electronic equipments (WEEE) recycling activities. For the purpose of environmental protection and resource reusing, China made a great effort to improve WEEE recycling. This article reviews progresses of three major fields in the development of China's WEEE recycling industry: legal system, formal recycling system, and advanced integrated process. Related laws concerning electronic waste (e-waste) management and renewable resource recycling are analyzed from aspects of improvements and loopholes. The outcomes and challenges for existing formal recycling systems are also discussed. The advantage and deficiency related to advanced integrated recycling processes for typical e-wastes are evaluated respectively. Finally, in order to achieve high disposal rates of WEEE, high-quantify separation of different materials in WEEE and high added value final products produced by separated materials from WEEE, an idea of integrated WEEE recycling system is proposed to point future development of WEEE recycling industry.
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Affiliation(s)
- Lei Zhou
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, PR China
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Flandinet L, Tedjar F, Ghetta V, Fouletier J. Metals recovering from waste printed circuit boards (WPCBs) using molten salts. JOURNAL OF HAZARDOUS MATERIALS 2012; 213-214:485-490. [PMID: 22398030 DOI: 10.1016/j.jhazmat.2012.02.037] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2011] [Revised: 02/13/2012] [Accepted: 02/13/2012] [Indexed: 05/31/2023]
Abstract
Recycling of waste electrical and electronic equipments (WEEE) has been taken into consideration in the literature due to the large quantity of concerned wastes and their hazardous contents. The situation is so critical that EU published European Directives imposing collection and recycling with a minimum of material recovery [1]. Moreover, WEEEs contain precious metals, making the recycling of these wastes economically interesting, but also some critical metals and their recycling leads to resource conservation. This paper reports on a new approach for recycling waste printed circuit boards (WPCBs). Molten salts and specifically molten KOH-NaOH eutectic is used to dissolve glasses, oxides and to destruct plastics present in wastes without oxidizing the most valuable metals. This method is efficient for recovering a copper-rich metallic fraction, which is, moreover, cleared of plastics and glasses. In addition, analyses of gaseous emission show that this method is environmentally friendly since most of the process gases, such as carbon monoxide and dioxide and halogens, are trapped in the highly basic molten salt. In other respects, under operation without oxygen, a large quantity of hydrogen is produced and might be used as fuel gas or as synthesis gas, leading to a favourable energy balance for this new process.
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Affiliation(s)
- L Flandinet
- LEPMI, UMR 5279, CNRS - Grenoble INP-Université de Savoie, Université Joseph Fourier, BP75, 38402 Saint Martin d'Hères, France
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Szoboszlai Z, Kertész Z, Szikszai Z, Angyal A, Furu E, Török Z, Daróczi L, Kiss AZ. Identification and chemical characterization of particulate matter from wave soldering processes at a printed circuit board manufacturing company. JOURNAL OF HAZARDOUS MATERIALS 2012; 203-204:308-16. [PMID: 22226723 DOI: 10.1016/j.jhazmat.2011.12.030] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2011] [Revised: 11/25/2011] [Accepted: 12/10/2011] [Indexed: 05/22/2023]
Abstract
In this case study, the elemental composition and mass size distribution of indoor aerosol particles were determined in a working environment where soldering of printed circuit boards (PCB) took place. Single particle analysis using ion and electron microscopy was carried out to obtain more detailed and reliable data about the origin of these particles. As a result, outdoor and indoor aerosol sources such as wave soldering, fluxing processes, workers' activity, mineral dust, biomass burning, fertilizing and other anthropogenic sources could be separated. With the help of scanning electron microscopy, characteristic particle types were identified. On the basis of the mass size distribution data, a stochastic lung deposition model was used to calculate the total and regional deposition efficiencies of the different types of particles within the human respiratory system. The information presented in this study aims to give insights into the detailed characteristics and the health impact of aerosol particles in a working environment where different kinds of soldering activity take place.
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Affiliation(s)
- Z Szoboszlai
- Institute of Nuclear Research of Hungarian Academy of Sciences (ATOMKI), H-4001 Debrecen, P.O. Box 51, Hungary.
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Kong S, Liu H, Zeng H, Liu Y. The Status and Progress of Resource Utilization Technology of e-waste Pollution in China. ACTA ACUST UNITED AC 2012. [DOI: 10.1016/j.proenv.2012.10.071] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
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Yamane LH, de Moraes VT, Espinosa DCR, Tenório JAS. Recycling of WEEE: characterization of spent printed circuit boards from mobile phones and computers. WASTE MANAGEMENT (NEW YORK, N.Y.) 2011; 31:2553-8. [PMID: 21820883 DOI: 10.1016/j.wasman.2011.07.006] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2011] [Revised: 06/22/2011] [Accepted: 07/06/2011] [Indexed: 05/25/2023]
Abstract
This paper presents a comparison between printed circuit boards from computers and mobile phones. Since printed circuits boards are becoming more complex and smaller, the amount of materials is constantly changing. The main objective of this work was to characterize spent printed circuit boards from computers and mobile phones applying mineral processing technique to separate the metal, ceramic, and polymer fractions. The processing was performed by comminution in a hammer mill, followed by particle size analysis, and by magnetic and electrostatic separation. Aqua regia leaching, loss-on-ignition and chemical analysis (inductively coupled plasma atomic emission spectroscopy - ICP-OES) were carried out to determine the composition of printed circuit boards and the metal rich fraction. The composition of the studied mobile phones printed circuit boards (PCB-MP) was 63 wt.% metals; 24 wt.% ceramics and 13 wt.% polymers; and of the printed circuit boards from studied personal computers (PCB-PC) was 45 wt.% metals; 27 wt.% polymers and ceramics 28 wt.% ceramics. The chemical analysis showed that copper concentration in printed circuit boards from personal computers was 20 wt.% and in printed circuit boards from mobile phones was 34.5 wt.%. According to the characteristics of each type of printed circuit board, the recovery of precious metals may be the main goal of the recycling process of printed circuit boards from personal computers and the recovery of copper should be the main goal of the recycling process of printed circuit boards from mobile phones. Hence, these printed circuit boards would not be mixed prior treatment. The results of this paper show that copper concentration is increasing in mobile phones and remaining constant in personal computers.
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Affiliation(s)
- Luciana Harue Yamane
- Department of Metallurgical and Materials Engineering, University of São Paulo, Av. Prof. Mello Moraes, 2463 São Paulo, SP 05508-030, Brazil.
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