Distribution of polychlorinated biphenyls and polybrominated diphenyl ethers in soils of a previous E-waste processing center

Surface soil samples were taken from a previous electronic waste (E-waste) recycling centerin Taizhou area, Zhejiang province, China. Concentrations, profiles, and possible sources of 19 polychlorinated biphenyls and 7 poly-brominated diphenyl ethers were analyzed to assess their current state in the soil after phase out of massive dismantling of E-wastes. The concentrations of the 7 polybrominated diphenyl ethers ranged from 11 to 128 µg kg^?1 with an average of 41 ± 10 µg kg^?1 (dw), with 2,2′,4,4′-tetrabromdiphenyl ether being the most abundant. These values were substantially lower than the levels in 2006. The concentrations of the 19 polychlorinated biphenyls ranged from 36 to 760 µg kg^?1, with an average of 181 ± 68 µgkg^?1 (dw) which was also lower than the levels in 1995 or 2006. However, the concentrations of some tetra-, penta- and hexa-chlorobiphenyls were comparable or even higher than before. Furthermore, the average concentration of 7 indicator polychlorinated biphenyls was 108 ± 41 µg kg^?1(dw) which exceeded the New Dutch List target value of 20 µgkg^?1. Principal component analysis indicated that polychlorinated biphenyls were mainly distributed into three groups in accordance with the number of chlorine atoms and anthropogenic source. Therefore, the impact of the historical dismantling of E-wastes is still significant.     

Zero E-waste: Regulatory impediments and blockchain imperatives

• Copyrights on electronic products are impediments in promoting circular economy. • Manufacturers antagonize refurbishment and remanufacturing to maximize profit. • International harmonization of copyright laws will aid repair and remanufacture. • Blockchain–digital immutable ledgers–can promote trust among stakeholders. The concept of zero waste is an ideal situation that will require different solutions for different categories of waste. Electronic waste (E-waste), the fastest growing category of solid hazardous waste presents various unique challenges. Electronic product repair, reuse and remanufacture (3re) are crucial for effective source reduction of E-waste and the integration of the electronics industry into a circular or zero-waste economy framework. Increasingly, 3re implementation is restricted by regulatory difficulties, particularly the invocation of copyright laws. Here, we use the examples of electronic printer cartridges and restored compact discs (CDs) to identify the challenges and to explore solutions for managing the risks associated with E-waste through circular economy and the opportunities presented by innovative Blockchain solutions. A set of international consensuses on judicial definitions, such as 3re, refurbish fake/counterfeit product and copyright exhaustion, are proposed to accelerate source reduction in E-waste management toward the goal of zero waste.     

电子废物不当处置的重金属污染及其环境风险评价 Ⅱ．分布于人居环境（村镇）内的电子废物拆解作坊及其附近农田的土壤重金属污染

电子废物拆解活动一般集中于村镇内靠近人居环境的区域,其污染对当地居民身体健康的影响最为直接.为了了解电子废物拆解活动所造成的重金属污染,对广东省清远市龙塘镇、石角镇内电子废物拆解作坊共29个表土样本以及附近农田33个土壤样本进行了取样,并分析了重金属Zn、Cu、Pb和Cd含量.结果表明,龙塘镇电子废物拆解作坊表土中4种重金属的总含量平均值高达11086mg·kg-1,远高于电子废物焚烧迹地,其中Zn、Cu、Pb和Cd平均含量分别为3039.6、6371.5、1635.4和39.3mg·kg-1.从事电子废物拆解业历史较短的石角镇的拆解作坊表土中,4种重金属总含量和各金属平均含量均低于龙塘镇,显示出拆解历史越长,污染越严重的倾向.与焚烧工序相比,拆解工序中的Zn、Cd污染更为严重,Cu污染相近,Pb污染相对较低.在拆解作坊附近33个农田土壤样本中,Zn含量不超标,Cd含量超标最严重,超标率为78.8%,最大超标倍数达25.7倍,其次是Cu,超标率为63.7%,最大超标倍数达6.3倍,再次为Pb,超标率为48.5%,最大超标倍数为2.1倍.4种重金属的综合超标率达到81.8%.农田土壤中4种重金属与拆解作坊表土中重金属具有一定的同源性,并表现出共迁移特征.由此可见,研究地区大规模的电子废物拆解活动已对当地居民造成了严重的健康风险。     

电子废物不当处置的重金属污染及其环境风险评价 Ⅴ. 电子废物焚烧迹地土壤金属污染对土壤微生物生物量和土壤呼吸的影响

在广东省清远市龙塘镇电子废物焚烧区附近分别设置了主要受电子废物焚烧造成的重金属近距离沉降影响的污染区(U)和距离焚烧活动核心区约1km的水平迁移污染区(L),并在焚烧活动核心区非主风向一侧山丘的反向坡地设置了对照区(CK),探讨了不同程度的重金属污染对土壤微生物生物量碳(MBC)和土壤呼吸(SR)的影响.结果表明,土壤Cu、Pb、Cd的含量平均值均呈U区>L区>CK区,在污染严重的U区,Cu、Pb、Cd、Ni、Cr和Zn的含量平均值分别是对照区的52.2倍、5.1倍、3.2倍、2.1倍、1.9倍和1.5倍.相应地,U区土壤MBC、土壤基础呼吸(BR)和基质诱导呼吸(SIR)的平均值分别只有对照区的48.0%、28.4%和15.3%,而在污染程度相对较轻的L区则分别为对照区的97.0%、70.1%和60.7%.土壤MBC和SIR均与土壤中Zn、Cu、Pb含量呈极显著负相关(p<0.01).以上结果表明,土壤微生物的生长和土壤生物活性受到了电子废物焚烧排放物(特别是重金属)生物毒性的严重影响,土壤SIR是响应最为敏感的指标.     

国外电子废弃物资源化概述

随着信息工业的飞速发展,以及人们对电子废弃物认识的深入和环保意识的加强,电子废弃物的回收利用已逐渐成为一项新兴产业。通过分析国外发达国家对电子废弃物的环境管理、工艺技术以及回收体系状况,总结了发达国家的成功经验,对我国建立和完善电子废弃物管理体系,发展研究电子废弃物资源化技术提出对策和建议。     

国外电子废弃物回收处理系统及相关法律法规建设对中国的启示

电子废弃物再生资源化过程的环境保护已成为一个突出的和亟待解决的问题。系统地研究发达国家的电子废弃物回收处理系统及相关法律法规的实施和发展情况,将为建立适合中国国情的电子废弃物管理系统及法律法规建设提供宝贵的经验,一方面,它可以促进中国电子废弃物资源再生化领域的良性循环,另一方面也为环保部门有效地实施污染控制提供参考依据。     

电子废物回收处理项目的BOT建设方式初探

在综合概述目前我国电子废物环境管理困境及其障碍性因素的基础上,提出了按BOT（建设-运营-转让）建设方式规划电子废物回收处理项目的建议,简述了BOT目方式的基本特征和项目实施过程中值得商榷的几个问题。     

Decision factors for e-waste in Northern Mexico: To waste or trade

Currently, around the globe, environmental and social problems derive from the inappropriate recycling of electronic products. Moreover, improper recycling is not the only issue to address in electronic products. Others include: energy intensity in their manufacture, employment generation related to the international trade in used electronics, and access to technology by low-income communities. Nevertheless, policies and controls created to provide socially and environmentally sound management of used electronics do not match the complexity of the system. In order to understand the e-waste system, particularly used computers, as a whole, a field study was done between 2010 and 2011 in ten Mexican cities. Ninety-five diverse stakeholders were interviewed to uncover factors regarding the decision to waste or trade still-usable computers. Structured analysis was used to create Data Flow Diagrams (DFDs) to describe the critical parts of the system. The results show that perceived value and geographical location determine the rate in which computers are disposed and the opportunities to waste or trade them, including the trade of their materials. Among businesses and other organizations, legislation has a stronger effect. Technological change is another important factor, largely driving the change in materials and new products. Designing policies responding to this diversity may prevent unforeseen problems and stimulate solutions.     

Legacies and health risks of heavy metals,polybrominated diphenyl ethers,and polychlorinated dibenzo-dioxins/furans at e-waste recycling sites in South China

● Heavy metals and organic toxins may persist in legacy sites for a long time. ● Contaminants pose potential harms to the nearby community (HI > 1). ● PCDD/Fs had the risk of endocrine disruption and reproductive risk. ● Further intervention is needed to reduce pollution and related risks. Informal electronic-waste (e-waste) recycling sites pose substantial health risks to surrounding environments and populations, yet they are not properly regulated. In this study, the soil levels of copper, lead, cadmium, eight polybrominated diphenyl ethers (PBDEs), and 18 polychlorinated dibenzo-dioxins/furans (PCDD/Fs) were measured at two e-waste recycling sites in South China between 2014 and 2019. Both sites have been abandoned for natural restoration. Our results indicate that the mean Cd and PCDD/F levels at Site A in 2019 were higher than those recommended by current safety guidelines. Meanwhile, the highest exposure among children was 1.36 × 10⁻² mg/(kg·d) for Cu, followed by 5.05 × 10⁻³ mg/(kg·d) for Pb, 9.71 ng/(kg·d) for PBDEs, and 6.82 ng TEQ/(kg·d) for PCDD/Fs. Children were at elevated risk for health problem posed by Pb and Cu exposure at both sites (hazard quotient > 1) and by PCDD/Fs at Site A. Further risk assessment was conducted on the target organs and endpoints of heavy metals and PCDD/Fs. The hazard index (HI) for the target organ mixed-risk of heavy metals was high (HI = 1.27), as was that of PCDD/Fs (HI = 1.66), which can disrupt endocrine function and pose a risk of reproductive toxicity in children. Owing to incomplete cleaning, contaminants persist in soils over long periods and may harm nearby environments and communities. Our study demonstrates that heavy metal, PBDE, and PCDD/F contamination have not yet been remediated, and intervention is needed to reduce pollution and associated risks in areas affected by e-waste.