Article
Polymer Science
Ramona Marina Grigorescu, Paul Ghioca, Lorena Iancu, Madalina Elena David, Rodica-Mariana Ion, Cristian-Andi Nicolae, Raluca Augusta Gabor, Elena Ruxandra Radu, Mihaela Ganciarov, Bogdan Spurcaciu, Elvira Alexandrescu, Florin Ciuprina
Summary: The study investigates the feasibility of using waste printed circuit boards to produce recycled polyvinyl chloride composites, finding that under suitable filler content, the composites exhibit good homogeneity and mechanical properties.
JOURNAL OF APPLIED POLYMER SCIENCE
(2022)
Article
Materials Science, Multidisciplinary
E. L. Schneider, H. M. Veit, W. L. Hartmann, C. M. Stolz, L. C. Robinson, C. T. Oliveira, A. S. Vargas
Summary: This study evaluated the influence of waste from printed circuit boards on the properties of cementitious matrix, finding that with partial replacement of lightweight aggregates, the consistency index of mortar decreased and compressive strength was also reduced. However, the matrix has potential to be used in the construction industry for blocks or non-structural elements.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2021)
Article
Green & Sustainable Science & Technology
Amit Kumar, Maria E. Holuszko, Travis Janke
Summary: This study explores the use of gravity separation, commonly used in the mining industry, to separate the non-metal fraction of printed circuit boards. Experimental results show that a yield of 47% with 86% organic content and 70% combustible recovery can be achieved using dense media separation. The washability behavior of the non-metal fraction is assessed and found to be difficult to clean. The float-sink products exhibit concentrations of organic stream, fiberglass, and metals within specific density ranges.
ADVANCED SUSTAINABLE SYSTEMS
(2022)
Article
Engineering, Chemical
Kai Dean Kang, I. M. S. K. Ilankoon, Meng Nan Chong, Ta Yeong Wu
Summary: This study investigates value recovery using coarse printed circuit boards (PCBs) through organic swelling pre-treatment. The experiment demonstrates the effectiveness of organic swelling in causing cracks and delamination in the multi-layered structure of the PCBs. Copper concentrate with high copper contents can be obtained by performing organic swelling for coarse PCBs. The weakened PCBs after organic swelling can be subjected to a less energy-intensive mechanical method to yield embedded copper foils.
MINERALS ENGINEERING
(2023)
Article
Engineering, Environmental
Solene Touze, Valerie Laperche, Agathe Hubau, Pauline Moreau
Summary: In this study, portable X-ray fluorescence (pXRF) and inductively coupled plasma-mass spectrometry (ICP-MS) after acid digestion were used to analyze the chemical composition of waste printed circuit boards (WPCB). The results showed that the 200 μm particle size sample had homogeneity and reliability, and pXRF measurements with loose powder showed low data dispersion. For samples with a particle size of 750 μm and 2 mm, the homogeneity needed to be compensated by increasing the number of repetitions. pXRF could provide a rapid non-intrusive approach for first-level screening of metal contents.
Article
Environmental Sciences
Pushpa Gautam, Arup Kumar De, Indrajit Sinha, Chhail Kumar Behera, Kamalesh Kumar Singh
Summary: This study focuses on producing copper oxide nanoparticles from discarded printed circuit boards (PCBs) to obtain a value-added nanoproduct. The synthesized nanoparticles were confirmed to be pure monoclinic CuO of size 19.23 nm without any impurity. These nanoparticles have a high specific surface area and mesoporous structure, making them suitable for photocatalytic degradation under visible light irradiation. Utilizing e-waste from PCBs to produce nanomaterials helps reduce environmental problems.
ENVIRONMENTAL RESEARCH
(2023)
Article
Engineering, Chemical
Lingtao Zhu, Mingming Zhang, Jingfeng He, Chengguo Liu, Yake Yao, Jiang Xu, Bin Liu, Sipeng Yin, Xuan Xu
Summary: The study successfully utilized a vibrated gas-solid fluidized bed to recover the metallic fraction of waste printed circuit boards (WPCBs), achieving high separation and recovery efficiency by adjusting operational conditions such as vibration frequency and amplitude.
ADVANCED POWDER TECHNOLOGY
(2021)
Article
Engineering, Chemical
Jong-Won Choi, John Kwame Bediako, Ji-Hye Kang, Che-Ryong Lim, Yub Raj Dangi, Hyo-Jin Kim, Chul-Woong Cho, Yeoung-Sang Yun
Summary: The study developed an in-situ microwave-assisted leaching and selective separation process using biphasic aqua regia-ionic liquid systems to efficiently recover precious metals from waste printed circuit boards, achieving high selective separation efficiencies.
SEPARATION AND PURIFICATION TECHNOLOGY
(2021)
Article
Engineering, Environmental
Huichao Chu, Can Qian, Bingyang Tian, Shiyue Qi, Jia Wang, Baoping Xin
Summary: The pyrometallurgy coupling indirect bioleaching strategy effectively extracts copper and nickel from waste printed circuit boards, with calcination pretreatment significantly improving copper release while inhibiting nickel release. Treated waste PCBs can be safely reused as non-hazardous materials, reducing environmental risks associated with them.
RESOURCES CONSERVATION AND RECYCLING
(2022)
Article
Green & Sustainable Science & Technology
Guilherme Botelho Meireles de Souza, Mariana Bisinotto Pereira, Lucas Francisco dos Santos, Christian Goncalves Alonso, Veeriah Jegatheesan, Lucio Cardozo-Filho
Summary: This study explored the application of supercritical water technology in managing waste printed circuit boards, focusing on their recycling-oriented characterization and organic degradation. The study also investigated the subsequent treatment of liquid decomposition by-products, identified major gaseous products, and proposed a strategy to enhance combustible gas production.
JOURNAL OF CLEANER PRODUCTION
(2022)
Article
Engineering, Environmental
Guofu Dai, Jun Han, Chenlong Duan, Ligang Tang, Yonghui Peng, Youmei Chen, Haishen Jiang, Zhenhua Zhu
Summary: The study focused on enhancing the flotation efficiency of waste printed circuit boards by alkaline immersion treatment. SEM-EDS analysis revealed complete liberation of metal and nonmetal in the crushed products. By adjusting alkaline immersion time and pH value, a good flotation effect was achieved. XPS analysis showed changes in nonmetal molecular structure, leading to improved dispersion in slurry and increased hydrophilicity. This study offers a new route to enhance the recycling efficiency of waste printed circuit boards.
Article
Engineering, Environmental
Shuyu Chen, Run Li, Yaqi Shen, Lu Zhan, Zhenming Xu
Summary: This study conducted thermogravimetric analysis and kinetic analysis, revealing the positive self-catalytic influence of co-existing metals in waste printed circuit boards (WPCBs) during pyrolysis. It provides a theoretical basis for understanding the catalytic influence of these metals during the pyrolysis process.
FRONTIERS OF ENVIRONMENTAL SCIENCE & ENGINEERING
(2022)
Article
Materials Science, Multidisciplinary
Kang Yan, Chongwei Liu, Liping Liu, Min Xiong, Jiongtong Chen, Zhongtang Zhang, Shuiping Zhong, Zhifeng Xu, Jindi Huang
Summary: The effective recycling of waste printed circuit boards (WPCBs) can help conserve resources and reduce environmental pollution. This study investigates the pyrolysis and combustion characteristics of WPCBs in different atmospheres through thermogravimetric and Gaussian fitting analyses. The study also analyzes the pyrolysis products and combustion processes of WPCBs using thermogravimetric and Fourier transform infrared analyses (TG-FTIR) and thermogravimetry-mass spectrometry (TG-MS). The findings suggest that the pyrolysis and combustion processes of WPCBs involve multiple overlapping reactions. This study provides a theoretical basis for pollution control, process optimization, and reactor design in the pyrolysis of WPCBs.
INTERNATIONAL JOURNAL OF MINERALS METALLURGY AND MATERIALS
(2022)
Article
Engineering, Environmental
Yunfeng Zhu, Bo Li, Yonggang Wei, Shiwei Zhou, Hua Wang
Summary: Resource shortages and metal demand increase, making resource recycling and environmental sustainability necessary for the abundant waste printed circuit boards (WPCB) generated. Pyrolysis is a promising pathway that converts WPCB into high value-added products to lessen the environmental burden. This study analyzes the characteristics of WPCB, introduces the types of pyrolysis reactors and the characteristics of pyrolysis products for WPCB, and summarizes the conventional and advanced pyrolysis technologies applied to manage and recover WPCB sustainably. The study also discusses the prospects, imperatives, and challenges of establishing a circular economy for WPCB and examines the economic feasibility and future challenges of WPCB pyrolysis.
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
(2023)
Article
Chemistry, Multidisciplinary
Leandro H. de S. Silva, Agostinho A. F. Junior, George O. A. Azevedo, Sergio C. Oliveira, Bruno J. T. Fernandes
Summary: Technological advancements have led to improvements in daily life, but also raised concerns about how to deal with electronic waste, particularly waste PCBs. Recycling waste PCBs, which contain precious materials and components, is challenging due to their diverse composition. A proposed method aims to evaluate the economic feasibility of recycling ICs from WPCBs, involving estimating IC area and weight, and determining the potential metal recovery. The use of deep learning models like YOLO has shown promising results in detecting ICs from WPCBs, with the potential to extract a significant amount of metals and silicon elements for recycling.
APPLIED SCIENCES-BASEL
(2021)
Article
Engineering, Environmental
Xiaojian Liu, Bei Wang, Yayun Ma, Xiangyang Zhou, Juan Yang, Yuehui He, Jingjing Tang, Fanyun Su, Wan Yang
Summary: This study proposes a combined process of reduction roasting of herb-medicine residue and oxalic acid leaching to improve the recovery efficiency of lithium from spent lithium-ion batteries. By utilizing the reducing gas produced from the pyrolysis of herb-medicine residue, the layered structure of the cathode powder is destroyed and converted into Li2CO3, Ni, Co, and MnO. Additionally, selective extraction of lithium is achieved using oxalic acid, and the efficiency and kinetics of lithium extraction are improved under the combined action of herb-medicine residue and oxalic acid.
Article
Engineering, Environmental
Muxina Konarova, Nuno Batalha, Gabriel Fraga, Mohamed H. M. Ahmed, Steven Pratt, Bronwyn Laycock
Summary: This study presents a proof of concept for a technology that integrates PET recovery from mixed plastic waste and plastic pyrolysis. By depolymerizing PET into TPA using a low volatility oil as medium, it achieves low-pressure operation and a selective separation and recovery of TPA from the product mix. Full PET conversion and high TPA recovery were achieved, making it an effective solution for processing mixed waste streams and improving the yield and quality of liquid product from thermal pyrolysis compared to untreated feedstock.
Article
Engineering, Environmental
Zhenhua Sun, Jing Li, Xuejiang Wang, Siqing Xia, Jianfu Zhao
Summary: This study investigated the influence of in-situ formed MgFe2O4 on the hydrothermal treatment of swine manure. The results showed that the in-situ formation of MgFe2O4 improved the dehydration and decarboxylation of organic components in swine manure, thereby improving its carbonization degree. Furthermore, it enhanced the stabilization of heavy metals and the retention of phosphorus. MgFe2O4 modified hydrochars exhibited remarkable adsorption capacity for Pb(II) and Cu(II) without any leaching of heavy metals.
Article
Engineering, Environmental
Yijing Jiang, Boyang Leng, Jingxin Xi
Summary: The increased generation of municipal solid waste has had a significant impact on the economy, environment, and public health. The current waste treatment process has limitations. By developing a comprehensive social costing model, this study assesses the impacts of municipal solid waste management throughout its life cycle and provides policymakers with best practices and feasibility information.
Article
Engineering, Environmental
Marina Hernandes de Paula e Silva, Ricardo Coser Mergulha, Jose Geraldo Vidal Vieira, Andrea Brasco Pampanelli, Rodrigo Salvador, Diogo Aparecido Lopes Silva
Summary: This study developed and implemented a self-assessment tool to assist companies in decision-making processes for establishing circular flows based on Lean Manufacturing and Circular Economy principles. The tool utilized a maturity model and was applied to nine companies of varying characteristics. The findings revealed that certain companies showed higher maturity in water-waste and chemical-emissions management, with larger enterprises focusing on these strategies. However, many companies lacked sufficient training and employee awareness prior to seeking cleaner alternatives, and comprehensive actions to manage the product lifecycle were lacking. To address these gaps, the tool provided tailored recommendations for each company to improve their processes, products, and value chain.
Article
Engineering, Environmental
Gamze Dogdu, Turgay Pekdemir, Sanaz Lakestani, Seyda Karabork, Osman Cavus
Summary: This paper presents data on food waste associated with mini size food packaging services, highlighting the difficulties in emptying the food and consumer wastefulness as the main causes. These findings have significant implications for the sustainability of food and relevant packaging.
Article
Engineering, Environmental
Qingxia Li, Xin Kong, Yuxin Chen, Jianan Niu, Jia Jing, Jin Yuan, Yifeng Zhang
Summary: This study investigates how to enhance methane production from food waste after hydrothermal pretreatment. The results demonstrate a significant increase in methane yield when zero-valent iron and magnetite are used together, and high organic loading is favorable for methane production. Microbial diversity analysis further reveals the dominant pathways and metabolic processes involved in methane generation.
Article
Engineering, Environmental
D. H. H. Sim, I. A. W. Tan, L. L. P. Lim, E. T. Lau, B. H. Hameed
Summary: The development of controlled-release fertilizer formulation is important for preventing environmental pollution caused by nutrient leaching and volatilization. This study combined biochar-based fertilizer with encapsulation technology to improve the nutrient release mechanism. Optimal conditions for synthesizing urea-impregnated biochar (UIB) were determined using central composite design, and the release of nitrogen was described by mathematical models. Results showed that encapsulated UIB (EUIB) achieved complete release of nitrogen in water and exhibited improved water retention in sandy-textural soil. Therefore, EUIB derived from peppercorn waste has the potential to be used as a sustainable controlled-release fertilizer for agriculture.
Article
Engineering, Environmental
Yuchuan Wang, Neslihan Akdeniz
Summary: Incorporating biochar into composting systems can increase compost temperatures. This study developed a heat transfer model for a biochar-amended co-composting system and found that biochar increased thermal conductive losses but also enhanced microbial activity, resulting in an overall increase in total heat unit. When biochar was applied on the surface, it mainly functioned as an insulator.
Article
Engineering, Environmental
George Tsalis, Birger Boutrup Jensen, Jessica Aschemann-Witzel
Summary: This paper empirically explores the relationship between retail price promotions and household food waste. The results show that households with a higher proportion of discount food purchases and environmental awareness tend to waste less food, while larger households and those lacking food handling skills tend to waste more food.
Article
Engineering, Environmental
Lukas Friederici, Arne Koch, Patrick Martens, Jana Pantzke, Sebastiano Di Bucchianico, Thorsten Streibel, Christopher P. Rueger, Ralf Zimmermann
Summary: The increasing demand for lightweight materials has led to a rise in fiber-reinforced plastic (FRP) production. However, the properties and compositional range of FRPs pose challenges to recycling strategies. Pyrolysis has emerged as a promising method for separating the fibers from the polymer matrix. This study investigated the pyrolysis process using thermal analysis and high-resolution mass spectrometry, and also assessed the toxicity of the recovered fibers using an in vitro model.
Review
Engineering, Environmental
Devika Kannan, Shakiba Khademolqorani, Nassibeh Janatyan, Somaieh Alavi
Summary: This paper introduces Smart Waste Management (SWM) that applies Industry 4.0 technologies in waste management. A framework called SWM4.0 is developed, which highlights the importance of smart people, smart cities, smart enterprises, and smart factories in achieving successful waste management. The paper also suggests future research directions and managerial implications.