Henan Province International Collaboration Lab of Forest Resources Utilization, School of Forestry, Henan Agricultural University, Zhengzhou, 450002, China.
Division of Engineering, Saint Mary's University, Halifax, NS, B3H 3C3, Canada.
Environ Pollut. 2024 Feb 1;342:123081. doi: 10.1016/j.envpol.2023.123081. Epub 2023 Dec 8.
E-waste, encompassing discarded materials from outdated electronic equipment, often ends up intermixed with municipal solid waste, leading to improper disposal through burial and incineration. This improper handling releases hazardous substances into water, soil, and air, posing significant risks to ecosystems and human health, ultimately entering the food chain and water supply. Formal e-waste recycling, guided by circular economy models and zero-discharge principles, offers potential solutions to this critical challenge. However, implementing a circular economy for e-waste management due to chemical and energy consumption may cause environmental impacts. Consequently, advanced sustainability assessment tools, such as Life Cycle Assessment (LCA), have been applied to investigate e-waste management strategies. While LCA is a standardized methodology, researchers have employed various routes for environmental assessment of different e-waste management methods. However, to the authors' knowledge, there lacks a comprehensive study focusing on LCA studies to discern the opportunities and limitations of this method in formal e-waste management strategies. Hence, this review aims to survey the existing literature on the LCA of e-waste management under a circular economy, shedding light on the current state of research, identifying research gaps, and proposing future research directions. It first explains various methods of managing e-waste in the circular economy. This review then evaluates and scrutinizes the LCA approach in implementing the circular bioeconomy for e-waste management. Finally, it proposes frameworks and procedures to enhance the applicability of the LCA method to future e-waste management research. The literature on the LCA of e-waste management reveals a wide variation in implementing LCA in formal e-waste management, resulting in diverse results and findings in this field. This paper underscores that LCA can pinpoint the environmental hotspots for various pathways of formal e-waste recycling, particularly focusing on metals. It can help address these concerns and achieve greater sustainability in e-waste recycling, especially in pyrometallurgical and hydrometallurgical pathways. The recovery of high-value metals is more environmentally justified compared to other metals. However, biometallurgical pathways remain limited in terms of environmental studies. Despite the potential for recycling e-waste into plastic or glass, there is a dearth of robust background in LCA studies within this sector. This review concludes that LCA can offer valuable insights for decision-making and policy processes on e-waste management, promoting environmentally sound e-waste recycling practices. However, the accuracy of LCA results in e-waste recycling, owing to data requirements, subjectivity, impact category weighting, and other factors, remains debatable, emphasizing the need for more uncertainty analysis in this field.
电子废物是指过时电子设备产生的废弃材料，通常与城市固体废物混合在一起，通过掩埋和焚烧等不当处理方式释放出有害物质，对生态系统和人类健康构成重大威胁，并最终进入食物链和供水系统。在循环经济模式和零排放原则的指导下，对电子废物进行正规的回收利用，为这一关键挑战提供了潜在的解决方案。然而，由于化学和能源消耗，实施电子废物管理的循环经济可能会对环境造成影响。因此，生命周期评估 (LCA) 等先进的可持续性评估工具已被应用于研究电子废物管理策略。虽然 LCA 是一种标准化方法，但研究人员已经采用了不同的途径来对不同的电子废物管理方法进行环境评估。然而，据作者所知，目前缺乏一项全面的研究来关注 LCA 方法在正规电子废物管理策略中的机会和局限性。因此，本综述旨在调查循环经济下电子废物管理的 LCA 现有文献，阐明研究现状，识别研究差距，并提出未来的研究方向。本文首先解释了在循环经济中管理电子废物的各种方法。然后，本综述评估和审查了在实施电子废物循环生物经济的 LCA 方法。最后，提出了增强 LCA 方法在未来电子废物管理研究中的适用性的框架和程序。电子废物管理的 LCA 文献表明，在正规电子废物管理中实施 LCA 的方法存在很大差异，导致该领域的结果和发现也存在很大差异。本文强调，LCA 可以确定正规电子废物回收的各种途径的环境热点，特别是金属方面。它可以帮助解决这些问题，并在电子废物回收方面实现更大的可持续性，特别是在火法冶金和湿法冶金途径。与其他金属相比，回收高价值金属在环境方面更合理。然而，生物冶金途径在环境研究方面仍然有限。尽管将电子废物回收成塑料或玻璃具有潜力，但在这个领域，LCA 研究的背景资料还很缺乏。本综述得出的结论是，LCA 可以为电子废物管理的决策和政策过程提供有价值的见解，促进环境友好的电子废物回收实践。然而，由于数据要求、主观性、影响类别权重和其他因素，电子废物回收中 LCA 结果的准确性仍存在争议，这强调了在该领域进行更多不确定性分析的必要性。
