E-waste Research Articles

Recyclability and recovery of carbon from waste printed circuit boards within a circular economy perspective: A review.

Waste printed circuit boards (WPCBs) are a significant component of electronic waste (e-waste) and are among the fastest-generating waste flows. The potentially negative impacts caused by e-waste on the environment and human health pose an increasingly apparent threat to people's everyday lives and well-being. The nonmetallic fraction (predominantly carbon) of WPCBs is characterized by heavy weight, low resource value, and complex composition, and these characteristics significantly restrict the recycling of the WPCBs to achieve a circular economy. To bring more attention and better guidance to carbon recycling in printed circuit boards, this study utilizes a recyclability model to analyze the potential carbon recycling in WPCBs. It also utilizes existing life cycle assessment results to evaluate the carbon emissions of WPCBs in waste management systems and to identify potential opportunities for carbon recovery within the entire system. In addition, this study reviews the latest technological advances in recovering carbon from WPCBs, including separation, oxidation, and activation. The properties of recycled carbon, such as porosity, adsorption, and electrochemical characteristics, are also a key focus of this review. The application of recycled carbon plays a crucial role in shaping the future direction of e-waste carbon recycling and its potential contribution to achieving a circular economy. The research results are expected to guide future carbon recycling processes and provide a reference for industrial development.

Selective gold extraction from e-waste leachate via sulfur-redox mechanisms using sulfhydryl-functionalized MOFs.

Urban mining of precious metals from electronic waste (e-waste) offers a dual advantage by addressing solid waste management challenges and supplying high-value metals for diverse applications. However, traditional extraction methods generally suffer from poor selectivity and limited capacity in complex acidic leachate. Herein, we present a sulfhydryl-functionalized zirconium-based metal-organic framework (Zr-MSA-AA) as a recyclable and highly selective adsorbent for efficient gold recovery. Specifically, the Zr-MSA-AA exhibits high recovery capacity (1021 mg g-1), remarkable pH-universal, and superb selectivity (Kd of 2.2 × 107 mL g-1) for gold ions across wide pH range and competitive conditions. Comprehensive mechanistic investigations highlight the pivotal role of sulfhydryl groups in selectively capturing gold ions. The redox-transformation of sulfhydryl and sulfonic acid groups mediated the reduction of Au(III) to Au(0) through the nucleation of chlorine-stabilized gold clusters. This unique mechanism, driven by the redox activity of designed sulfhydryl sites, not only mitigates interference from competing cations but also facilitates rapid adsorption kinetics (kf of 1.17 × 10-7 m s-1) for gold ions, surpassing the performance of previous adsorbents. Consequently, Zr-MSA-AA demonstrates exceptional practical applicability, achieving high-purity gold recovery (23.8 Karat) from real e-waste leachate through straightforward physical separation methods. This study introduces an alternative practical strategy for utilizing sulfur's redox activity in adsorbent design, advancing the sustainable recycling of non-renewable metal resources while contributing to environmental conservation.

Biodegradable, ionic thermoelectric composites via self-assembly of dipeptides and deep eutectic solvents

The growing demand for biodegradable conductive composites is driven by the need to mitigate electronic waste and advance bioelectronics for healthcare applications. Self-assembled peptide composites, particularly diphenylalanine (FF) derivatives, represent a promising class of materials for such electronics due to their inherent biodegradability and ease of hybridization with functional materials. However, the integration of ionic species with these peptides is often limited by the disruption of non-covalent interactions between FF derivatives. In this study, we developed biodegradable, ionic thermoelectric composites by co-assembling Fmoc-FF with deep eutectic solvents (DESs) composed of choline chloride (ChCl) and ethylene glycol (EG). Spectroscopic analyses revealed that Fmoc-FF formed eutectogels through π-π interactions between Fmoc groups, resulting in a highly porous colloidal network. The Fmoc-FF eutectogels exhibited an ionic conductivity of up to 47.5 mS·cm−1 and a Seebeck coefficient of 7.39 mV·K−1, making them suitable for heat harvesting. Additionally, they were entirely degraded within 48 h under proteolytic conditions, confirming their biodegradability. The eutectogels also displayed self-healing and shear-thinning behaviors, highlighting compatibility with additive manufacturing techniques for device integration.Graphical

Advances in the Recovery of Critical Rare Dispersed Metals (Gallium, Germanium, Indium) from Urban Mineral Resources.

Urban mineral resources, with their significant recycling potential, have increasingly accumulated worldwide and become an important source for extracting valuable metals, particularly critical rare dispersed metals (CRDMs) such as gallium, germanium, and indium. As the electronics industry continues to grow rapidly, the demand for CRDMs is rising. However, CRDMs in primary mineral resources are often found in small, dispersed concentrations, making extraction challenging. In contrast, urban mineral resources contain relatively higher concentrations of CRDMs, making their comprehensive exploitation more advantageous than that of primary minerals. This paper underscores the importance of metal recycling by examining the current state of e-waste recycling from urban mineral resources in China. It outlines the general process of e-waste recycling, briefly compares the advantages and disadvantages of common metal recycling methods, and summarizes the current status of CRDMs recycling from various electronic wastes. Finally, this paper discusses the development trends and future prospects of metal recycling technology in urban minerals.

Application of AI in the whole process of WEEE recycling and reuse

Application of AI in the whole process of WEEE recycling and reuse

Gold leaching performance of amino acids under alkaline conditions

ABSTRACT This study investigates the gold leaching potential of amino acids, focusing on glycine, alanine, and histidine, under various conditions. Results reveal that under alkaline environments, amino acids exhibit gold solubility, with glycine demonstrating superior efficacy compared to alanine and histidine. Strong oxidants like potassium permanganate enhance glycine-induced gold leaching, albeit with partial glycine decomposition. Notably, increasing glycine concentration beyond 0.05 M proves counterproductive. Electrochemical tests affirm that strong alkalinity fosters gold dissolution, with glycine’s dissolution capability peaking at 0.05 M concentration. Conversely, at 0.1 M, glycine’s dissolution efficacy diminishes. At a pH of 13, glycine achieved a gold leaching rate of 84.36% from gold-containing electronic waste. These findings underscore the importance of controlling amino acid concentrations in optimizing gold leaching processes, particularly favoring heap leaching over agitated methods.

Occupational Exposure to Mercury at an Electronics Waste and Lamp Recycling Facility - Ohio, 2023.

Workers in electronics waste and lamp recycling facilities are at risk of exposure to elemental mercury through inhalation of mercury vapor and mercury-containing dust. Employers at an electronics waste and lamp recycling facility in Ohio that crushes mercury-containing lamps expressed concerns about mercury exposure from work processes and requested a health hazard evaluation by CDC's National Institute for Occupational Safety and Health (NIOSH). In April 2023, NIOSH conducted a multidisciplinary investigation to assess elemental and inorganic mercury exposures, including epidemiologic, environmental, and ventilation assessments. Results indicated that mercury vapor was detected throughout the facility, with six of 14 workers having elevated urine mercury levels. These workers had a median job tenure of 8 months; four did not speak English, and five reported symptoms consistent with mercury toxicity, such as metallic or bitter taste, difficulty thinking, and changes in personality. Recommendations included improving the ventilation system, changing work practices to reduce mercury exposure, and providing training and communication tailored to the worker. As the electronic waste recycling industry continues to grow, it is important for employers to evaluate mercury exposure and safeguard employees using a hierarchy of controls. Health departments should consider monitoring occupational mercury exposure in recycling facilities, and clinicians should be aware of the potential for mercury toxicity among workers in these settings.

Chemical substances in plastics of electrical and electronic equipment and waste recycling problems

Chemical substances in plastics of electrical and electronic equipment and waste recycling problems

Cytocompatible, disintegrable, low-voltage operation n-type organic thin film transistors

The constant demands for the better performance of consumer electronics have led to shorter usage lifespans, resulting in a significant increase in electronic waste (e-waste).

E-waste recycling in an optimized way for copper recovery by leaching and a case study on E-waste generation and management in Dhaka city.

The widespread adoption of electronic devices has enhanced living standards but has also led to a surge in electronic waste (e-waste), creating serious environmental and health challenges. Although various methods exist to recover valuable metals from e-waste, each has notable drawbacks. Among these, chemical leaching with aqua regia is widely used but is both highly corrosive and hazardous. This study introduces a safer, more environmentally friendly approach to copper recovery from e-waste using an iron-based leaching solution. A combination of experimental procedures and computational modeling was employed to optimize copper extraction from printed circuit boards (PCBs). The experiments involved treating PCBs with iron-based solutions of different concentrations and testing the effectiveness over two distinct time periods. The most effective recovery rate, 72.69% over five days, was achieved using a 50:50 mixture of ferrous and ferric sulfate. Computational analysis with Python's SciPy library further identified 5.92g of PCB as the ideal input quantity for the process. In addition to the lab-based work, a survey of Dhaka's primary e-waste recycling hubs, Nimtoli and Elephant Road, revealed that approximately 1173 tons of e-waste are processed in these areas each year. Based on experimental findings, the survey findings have a projection to generate over 35 million BDT annually through copper recovery. However, despite government initiatives to regulate e-waste management, unsafe handling practices remain widespread. These practices not only endanger workers and the environment but also hinder regulatory efforts. The study emphasizes the urgent need for stricter regulations, greater public awareness, and the adoption of eco-friendly methods, like the proposed iron-based solution, to ensure safer and more effective copper recovery.

Engineering Interference-Removal and Target-Response Cascade Zones on Wood Channels for Straightforward Detection of Uric Acid in Saliva

The detection of biomarkers is crucial for assessing disease status and progression. Uric acid (UA), a common biomarker in body fluids, plays an important role in the diagnosis and monitoring of conditions such as hyperuricemia, chronic kidney disease, and cardiovascular disease. However, the low concentration of UA in non-invasive body fluids, combined with numerous interfering substances, makes its detection challenging. Therefore, there is a pressing need to develop advanced sensor platforms that exhibit both high sensitivity and excellent specificity for accurate monitoring of UA levels in various body fluids. In this study, an electrochemical sensing system is developed by integrating a cascade interference-removal zone and a target-response zone on a wooden channel membrane (CM) for the pretreatment-free detection of UA in body fluids. In this design, cysteine-doped ZIF-67(Co) nanocrystals, a mimic with multi-enzyme activity, are modified in the interference-removal zone. The target-response zone on the other side of the CM is contacted with a solution containing Fe3+ and [Fe(CN)6]3- ions. Using saliva as a proof-of-concept, the interference species, including ascorbic acid (AA), dopamine (DA), and glutathione (GSH), are oxidized and removed when passing through the interference-removal zone, while UA reaches the target-response zone and triggers the growth of Prussian blue (PB) on site. Utilizing the peroxidase-like activity of PB, UA concentration is directly determined based on changes in transmembrane ion currents. The resulting sensing system exhibits higher sensitivity than commercial UA meters and demonstrates straightforward, continuous, and non-invasive monitoring of UA in saliva after consuming purine-rich foods. The technology provides a simple, reliable and low-cost device for sensing UA in complex biological matrices. Moreover, the CM based sensing device also provides the benefit of being incineratable and biodegradable, reducing medical and electronic waste, making it eco-friendly for daily diagnostics.

Economical 550 V energy harvesting from plastic and electronic wastes using human bodily motions

Economical 550 V energy harvesting from plastic and electronic wastes using human bodily motions

Sponging for Gold: A self-assembling sponge pulls gold from electronic waste.

Sponging for Gold: A self-assembling sponge pulls gold from electronic waste.

High-performance biodegradable dielectric composite: Towards minimizing electronic waste

Polymer-based dielectric capacitors are crucial in modern electronics due to their wide capacitance range, high operating voltage, lightweight nature, and graceful failure reliability. However, the predominant use of nondegradable dielectric polymers raises environmental concerns. This study addresses this issue by preparing flexible biodegradable dielectric composite films of poly(butylene adipate-co-terephthalate) (PBAT) incorporating varying amounts of nitrogen-doped and non-doped biochar derived from banana peel waste. It was found that the incorporation of biochar in the nanocomposite improved various properties such as dielectric properties, biodegradability, mechanical strength, and thermal stability. The PBAT nanocomposite with 10 wt% N-doped biochar exhibited an 83 % rise in dielectric constant compared to pure PBAT while maintaining a low dielectric loss of 0.071 at 1000 Hz. This approach offers a cost-effective and environmentally sustainable method, showing potential for advancing next-generation disposable electronic materials with enhanced performance attributes.

A Conceptual Framework of Predictors of Electronic Wastes Disposal Behaviour Among Youths in South-South, Nigeria: The Moderating Effect of Education

A Conceptual Framework of Predictors of Electronic Wastes Disposal Behaviour Among Youths in South-South, Nigeria: The Moderating Effect of Education

Applying cross-scale regulations to Sedum plumbizincicola for strengthening the bioremediation of the agricultural soil that contaminated by electronic waste dismantling and revealing the underlying mechanisms by multi-omics.

Electronic waste dismantling has induced the surrounding agricultural soils suffered from combined contamination of heavy metals and organic pollutants. Lower efficiency and complex mechanisms of bioremediation remain to be resolved. Here, we adopted regulations to Sedum plumbizincicola cross aboveground and belowground scales to strengthen the bioremediation efficiency. Results showed that the S. plumbizincicola intercropping with the Astragalus sinicus L. that inoculated with Rhizobium had the highest performance in reduction of Cd, PBDEs and PCBs from soils by 0.11 mg/kg, 67.93 μg/kg and 38.91 μg/kg, respectively. Rhizosphere soil metabolomics analysis demonstrated that reductions in Cd and PBDEs significantly associated with 2-Methylhippuric acid and L-Saccharopine, which were involved in phenylalanine metabolism, biosynthesis of amino acids and lysine. Metagenomic analysis revealed that these functional pathways were mediated by Frankia, Mycobacterium, Blastococcus, etc. microbial taxa, which were also significantly altered by regulations. Moreover, regulation regimes significantly affected transcription genes of S. plumbizincicola. Functional annotation revealed that cross-scale regulations significantly improve bioremediation efficiency through microorganisms and metabolites in the rhizosphere and transcription genes of S. plumbizincicola, which were illustrated to promote plant growth and tolerance to environmental stress. Our integration of multi-omics provides comprehensive and deep insights into molecular mechanisms in the cross-scale regulations of S. plumbizincicola, which would favor remediation techniques advances for the soil contaminated by electronic waste dismantling.

The evolution of green computing: Current practices and societal implications

This paper examines the evolution of green computing from its early conceptualization to current practices, and explores the implications of this paradigm shift for society. Through a comprehensive review of recent literature, case studies, and industry reports published between 2019 and 2024, the study analyzes the key drivers, technologies, and best practices shaping the landscape of sustainable computing. The findings highlight significant progress in energy-efficient hardware, software optimization techniques, data center innovations, and electronic waste management strategies. However, challenges persist in terms of standardization, policy frameworks, and the digital divide. A holistic framework for advancing green computing practices, emphasizing multi-stakeholder collaboration, user awareness, and alignment with the United Nations Sustainable Development Goals, is proposed. The paper concludes by discussing the profound societal implications of green computing, from mitigating climate change and resource depletion to fostering digital inclusion and responsible innovation.

E-Waste Disposal Behavior: A Mediator for Sustainable Consumption

This review focuses on sustainable consumption behaviors which play a crucial role in reducing electronic waste. E-waste has become a global environmental concern due to the massive generation of discarded electronic products, with improper disposal contributing to pollution, health risks, and resource depletion. Through a systematic analysis of secondary data, this review identifies key factors that can inform strategies for improving e-waste management. The collective findings demonstrate that factors such as attitude towards a safe environment, eco-literacy, subjective norms, perceived behavioral control, volume accumulation, monetary return expectation, and others; play a crucial role in influencing the behavior of urban consumers towards e-waste disposal behavior and sustainable consumption. By reviewing the existing research, this review highlights the need for targeted interventions to promote responsible e-waste disposal, contributing to broader efforts toward a circular economy and sustainable urban living.

Analysis of E-Waste Recycling Intention in Ho Chi Minh City, Vietnam

Due to the increased demand for electrical and electronic devices, Vietnam has emerged as one of the major importers of electronic goods in Southeast Asia. This corresponds to Vietnam facing an escalating issue of electronic waste. In light of this concern, the purpose of this study was to investigate the individual intention regarding the recycling of electronic waste. To achieve this objective, a survey was conducted among 1020 respondents with varying genders, and educational levels in Ho Chi Minh City. The collected data was analyzed sing SPSS and AMOS software, enabling the development of a structural model. The findings of the study found that social pressure was the most influential factor affecting the intention to recycle electronic waste. Following closely behind were inconveniences, economic factors, attitudes, and awareness. Based on the outcome, it is recommended that policymakers should focus on creating effective advocacy programs, enhancing convenience, and improving public understanding and awareness in order to help reduce electronic waste.

Identifying the effect of sodium dodecylbenzene sulfonate surfactant and dispersed pcb-based particles as a novel heat treatment quenchant on the hardness of S45C medium carbon steel

In this study, the effect of Sodium Dodecylbenzene Sulfonate (SDBS) addition as a surfactant on the performance of the Printed Circuit Board (PCB) particle-dispersed quenchant in terms of thermal conductivity, particle stability, the microstructure and hardness of S45C medium carbon steel has been investigated. Conventional quenchants have fixed, uncontrollable cooling rates. Adding solid particles creates a thermal bridge, enabling adjustable cooling rates to address this limitation. The solid particles in the quenchant were synthesized from PCB. The surfactant helps to improve particle dispersion and avoid agglomeration by modifying the surface tension between the particles and the fluid. PCB particle-dispersed media have been prepared and used as quenchants to study the effect of PCB dispersion, and its concentrations on the heat transfer rate during quenching. Based on this research results, particle stability measurement by zeta potential shows the stability improvement up to –21.53 mV after 7wt % of surfactant addition, compared to distilled water. Due to the better particle dispersion, the thermal conductivity of the quenchant is also improved by 39 %, maximized at 0.82 W/mK when compared with the quenchant without surfactant at only 0.61 W/mK. Furthermore, the quenched steel hardness also increases by 29 %, maximized at 58 HRC at 7wt % surfactant and 0.3wt % PCB particles composition. The Dispersed PCB particles in the quenchant allow the heat flow from high to lower temperature efficiently. The experimental results show that a water-based quench medium with PCB particle dispersion is an alternative quench medium to obtain a more controlled cooling rate in steel heat treatment and is one solution for utilizing PCB electronic waste