Chemical hazards associated with treatment of waste electrical and electronic equipment

This review paper summarizes the existing knowledge on the chemical hazards associated with recycling and other end-of-life treatment options of waste electrical and electronic equipment (e-waste). The hazards arise from the presence of heavy metals (e.g., mercury, cadmium, lead, etc.), flame retardants (e.g., pentabromophenol, polybrominated diphenyl ethers (PBDEs), tetrabromobisphenol-A (TBBPA), etc.) and other potentially harmful substances in e-waste. If improperly managed, the substances may pose significant human and environmental health risks. The review describes the potentially hazardous content of e-waste, examines the existing e-waste management practices and presents scientific data on human exposure to chemicals, workplace and environmental pollution associated with the three major e-waste management options, i.e., recycling, incineration and landfilling. The existing e-waste management practices and associated hazards are reviewed separately for developed and developing countries. Finally, based on this review, the paper identifies gaps in the existing knowledge and makes some recommendations for future research.     

Electrical and electronic waste management in China: progress and the barriers to overcome.

Serious adverse impacts on the environment and human health from e-waste recycling have occurred in the past and continue to occur in China today, due to a lack of national management strategies. China has made great efforts to face the challenges of the approaching peak increase in the domestic generation of e-waste and the illegal shipment of e-waste from other countries. This study examined recent progress and analysed the main problems associated with this issue in China. It was found that the material and the financial flows of e-waste in China had their own specific characteristics. Nearly 60% of the generated e-wastes were sold to private individual collectors and passed into informal recycling processes. More than 90% of Chinese citizens are reluctant to pay for the recycling of their e-waste. This is due to their traditional understanding that there remained value in these end-of-life products. Regulations concerning e-waste in China have been drafted but their deficiencies are obvious. The extended producer responsibilities (EPR) have been introduced but are not well defined. Eight formal facilities have been planned and are under construction or are in operation along the eastern coast of China but it will be difficult for them to compete with the informal processes for the reasons identified during the study.     

Informal electronic waste recycling: a sector review with special focus on China

Informal recycling is a new and expanding low cost recycling practice in managing Waste Electrical and Electronic Equipment (WEEE or e-waste). It occurs in many developing countries, including China, where current gaps in environmental management, high demand for second-hand electronic appliances and the norm of selling e-waste to individual collectors encourage the growth of a strong informal recycling sector. This paper gathers information on informal e-waste management, takes a look at its particular manifestations in China and identifies some of the main difficulties of the current Chinese approach. Informal e-waste recycling is not only associated with serious environmental and health impacts, but also the supply deficiency of formal recyclers and the safety problems of remanufactured electronic products. Experiences already show that simply prohibiting or competing with the informal collectors and informal recyclers is not an effective solution. New formal e-waste recycling systems should take existing informal sectors into account, and more policies need to be made to improve recycling rates, working conditions and the efficiency of involved informal players. A key issue for China’s e-waste management is how to set up incentives for informal recyclers so as to reduce improper recycling activities and to divert more e-waste flow into the formal recycling sector.     

A material flow analysis on current electrical and electronic waste disposal from Hong Kong households

A material flow study on five types of household electrical and electronic equipment, namely television, washing machine, air conditioner, refrigerator and personal computer (TWARC) was conducted to assist the Government of Hong Kong to establish an e-waste take-back system. This study is the first systematic attempt on identifying key TWARC waste disposal outlets and trade practices of key parties involved in Hong Kong. Results from two questionnaire surveys, on local households and private e-waste traders, were used to establish the material flow of household TWARC waste. The study revealed that the majority of obsolete TWARC were sold by households to private e-waste collectors and that the current e-waste collection network is efficient and popular with local households. However, about 65,000 tonnes/yr or 80% of household generated TWARC waste are being exported overseas by private e-waste traders, with some believed to be imported into developing countries where crude recycling methods are practiced. Should Hong Kong establish a formal recycling network with tight regulatory control on imports and exports, the potential risks of current e-waste recycling practices on e-waste recycling workers, local residents and the environment can be greatly reduced.     

Difficulties in applying extended producer responsibility policies in developing countries: case studies in e-waste recycling in China and Thailand

Developing Asian countries have started to apply the principle of extended producer responsibility (EPR) to electronics and electrical equipment waste (e-waste). This policy approach aims to give electronic appliance manufacturers and importers responsibility for the collection and recycling of discarded electronic equipment. China and Thailand have drafted regulations on the recycling of e-waste with common characteristics such as the financial responsibility of producers and subsidies for collection. Although the proposed system is sensible, taking into account the fact that e-waste is a market-traded commodity, there are two major difficulties in implementing EPR in developing countries. First, it may be difficult for governments to collect funds from producers or importers if smuggled, imitation, or small shop-assembled products have a large share in the market. Second, the system creates incentives for collectors and recyclers to over-report the amount of collected e-waste in order to gain extra subsidies from the fund. Other policy measures such as the enforcement of pollution control regulations on informal recyclers, the prevention of smuggling, and the protection of intellectual property rights should accompany EPR policies.     

复合重金属污染高岭土的电动修复

根据电子废弃物拆解场地的污染特征,以复合重金属(Cu,Cd,Pb)污染高岭土为研究对象,考察了电动技术对污染土壤的修复效果。实验结果表明:在电压梯度为1 V/cm、阳极液为自来水、阴极液为柠檬酸-柠檬酸钠缓冲液(pH=5)、靠近阴极设置活性炭渗透反应墙(PRB)的条件下电动修复96 h后,Cu,Cd,Pb的平均去除率分别可达79.93%,99.43%,39.36%;土壤的酸碱性对电动修复效果影响显著,通过在阴极添加缓冲液维持土壤偏酸性条件,有利于重金属污染物的电动去除;在靠近阴极设置活性炭PRB可富集重金属,减少阴极液的污染;迁移率大的酸可提取态重金属较易去除,残渣态重金属稳定性强,去除率较低。     

Processes in informal end-processing of e-waste generated from personal computers in Vietnam

Informal treatment of e-waste plays an important role in many countries which have no or weak formal waste management structures. One of the challenges for assessing informal e-waste recycling technologies is to identify their disadvantages and potential technology improvement. The analysis of informal recycling processes starts with a balance of input and output materials for each of the processes. Main obstacles are the fact that in most cases, mixed or variety materials serve as input and, secondly by nature, the informal sector does not systematically measure and monitor the process. This study presents the processes and available data for informal e-waste recycling of desktop personal computer as it consists of components made of plastic and many metals within the Vietnamese context. To identify the most relevant processes, critical flows and technology gap, two scenarios are compared: (1) current situation in which recycling activities are taken in recycling craft villages and (2) appropriately selected BAT. The selected materials from e-waste cover a wide range of recycling processes and technologies: Printed Circuit Board treatment, metal (ferrous metal, aluminum and copper) and plastic recycling.

     

Polybrominated diphenyl ethers in e-waste: Level and transfer in a typical e-waste recycling site in Shanghai,Eastern China

Very few data for polybrominated diphenyl ethers (PBDEs) were available in the electronic waste (e-waste) as one of the most PBDEs emission source. This study reported concentrations of PBDEs in e-waste including printer, rice cooker, computer monitor, TV, electric iron and water dispenser, as well as dust from e-waste, e-waste dismantling workshop and surface soil from inside and outside of an e-waste recycling plant in Shanghai, Eastern China. The results showed that PBDEs were detected in the majority of e-waste, and the concentrations of ΣPBDEs ranged from not detected to 175 g/kg, with a mean value of 10.8 g/kg. PBDEs were found in TVs made in China after 1990. The mean concentrations of ΣPBDEs in e-waste made in Korea, Japan, Singapore and China were 1.84 g/kg, 20.5 g/kg, 0.91 g/kg, 4.48 g/kg, respectively. The levels of ΣPBDEs in e-waste made in Japan far exceed the threshold limit of RoHS (1.00 g/kg). BDE-209 dominated in e-waste, accounting for over 93%. The compositional patterns of PBDEs congeners resembled the profile of Saytex 102E, indicating the source of deca-BDE. Among the samples of dust and surface soil from a typical e-waste recycling site, the highest concentrations of Σ₁₈PBDEs and BDE-209 were found in dust in e-waste, ranging from 1960 to 340,710 ng/g and from 910 to 320,400 ng/g, which were 1–2 orders of magnitude higher than other samples. It suggested that PBDEs released from e-waste via dust, and then transferred to surrounding environment.     

Potential e-waste generated from households in Indonesia using material flow analysis

Waste of electronic and electrical equipment (e-waste) generated in Indonesia is expected to increase due to high growth of the Indonesian economy and fast development in technology. As Indonesia has not yet had specified criteria on e-waste, in this study, e-waste is defined as any obsolete or unwanted electronic and electrical equipment that is introduced into the recycling and disposal process. The objective of this study is to estimate the e-waste generated in Indonesian households using the method of material flow analysis. The amount of generated e-waste could be used for constructing an e-waste recycling management system in Indonesia. E-waste materials that need to be treated could be known. In this study, some types of equipment, such as television, washing machine, refrigerator, personal computer, and mobile phone, were chosen to be tracers. Using the modified material flow analysis model proposed by Steubing et al. (Waste Manage 30:473–482, 38), the potential e-waste that was generated from households was estimated. The total estimated accumulation of generated e-waste from households in 2015 and 2025 is about 285,000 and 622,000 tonnes, respectively. If a proper recycling system was in place, a new source for valuable materials recovery would be created, as well as protecting the environment and health.     

Waste electrical and electronic equipment (WEEE) management in Korea: generation, collection, and recycling systems

In Korea, generation of waste electrical and electronic equipment (WEEE), or electronic waste (e-waste), has rapidly increased in recent years. The management of WEEE has become a major issue of concern for solid waste communities due to the volumes of waste being generated and the potential environmental impacts associated with the toxic chemicals found in most electronic devices. Special attention must be paid when dealing with WEEE because of toxic materials that it contains (e.g., heavy metals, polybrominated diphenyl ethers, phthalates, and polyvinyl chloride). If managed improperly, the disposal of WEEE can adversely affect the environment and human health. Environmental regulatory agencies; electronic equipment manufacturers, retailers, and recyclers; environmental nongovernmental organizations; and many others are much interested in updated statistics with regard to how much WEEE is generated, stored, recycled, and disposed of. In Korea, an extended producer responsibility policy was introduced in 2003 not only to reduce the amount of electronic products requiring disposal, but also to promote resource recovery from WEEE; the policy currently applies to a total of ten electrical and electronic product categories. This article presents an overview of the current recycling practices and management of electrical and electronic waste in Korea. Specifically, the generation rates, recycling systems and processes, and recent regulations of WEEE are discussed. We estimated that 1 263 000 refrigerators, 701 000 washing machines, 1 181 000 televisions, and 109 000 airconditioning units were retired and handled by the WEEE management system in 2006. More than 40% of the products were collected and recycled by producers. Four major producers’ recycling centers and other WEEE recycling facilities are currently in operation, and these process a large faction of WEEE for the recovery of valuable materials. Much attention should still be paid to pollution prevention and resource conservation with respect to WEEE. Several suggestions are made in order to deal with electronic waste management problems effectively and to prevent potential impacts.     

Status quo of e-waste management in mainland China

In China, the use and obsolescence of both electronic and electrical equipment have increased rapidly in recent years. China has also begun to take measures to cope with this problem since it began experiencing a rapid process of industrialization and urbanization in the 1990s. In this paper, the profile of the electrical and electronic waste (e-waste) problem in China is depicted from such aspects as domestic e-waste and imported e-waste, along with their recycling systems, policies, and regulations. Based on statistics of the consumption of major household appliances and personal computers, a forecast is made of the numbers of obsolete major household appliances and personal computers. The results show that currently the number of electrical and electronic products in use in China is tremendous. An investigation on household appliances and personal computers in Beijing was made to assess the use and obsolescence of these products. Also, the legal issues relating to e-waste in China are summarized, and these will be the juristic foundation for the solution of e-waste problems.     

养猪业清洁生产途径与循环经济发展模式探讨

近年来,我国养猪业发展迅速,农村经济增长较快,农民收入和生活水平明显提高。同时,养猪业产生的猪粪便污染日趋严重,已严重影响当地居民生产生活和身体健康。为了彻底消除农村养猪场猪粪便污水和臭味污染,改善农村环境质量,促进农业经济发展,总结了长期从事清洁生产和循环经济发展研究的实践经验,提出了养猪业清洁生产途径和循环经济发展模式,意在从源头预防控制污染,大力推进养猪业清洁生产与农村经济可循环持续发展,并供关心我国养猪清洁生产与循环经济发展的同行借鉴参考。     

Recycling of non-metallic fractions from waste electrical and electronic equipment (WEEE): A review

The world’s waste electrical and electronic equipment (WEEE) consumption has increased incredibly in recent decades, which have drawn much attention from the public. However, the major economic driving force for recycling of WEEE is the value of the metallic fractions (MFs). The non-metallic fractions (NMFs), which take up a large proportion of E-wastes, were treated by incineration or landfill in the past. NMFs from WEEE contain heavy metals, brominated flame retardant (BFRs) and other toxic and hazardous substances. Combustion as well as landfill may cause serious environmental problems. Therefore, research on resource reutilization and safe disposal of the NMFs from WEEE has a great significance from the viewpoint of environmental protection. Among the enormous variety of NMFs from WEEE, some of them are quite easy to recycle while others are difficult, such as plastics, glass and NMFs from waste printed circuit boards (WPCBs). In this paper, we mainly focus on the intractable NMFs from WEEE. Methods and technologies of recycling the two types of NMFs from WEEE, plastics, glass are reviewed in this paper. For WEEE plastics, the pyrolysis technology has the lowest energy consumption and the pyrolysis oil could be obtained, but the containing of BFRs makes the pyrolysis recycling process problematic. Supercritical fluids (SCF) and gasification technology have a potentially smaller environmental impact than pyrolysis process, but the energy consumption is higher. With regard to WEEE glass, lead removing is requisite before the reutilization of the cathode ray tube (CRT) funnel glass, and the recycling of liquid crystal display (LCD) glass is economically viable for the containing of precious metals (indium and tin). However, the environmental assessment of the recycling process is essential and important before the industrialized production stage. For example, noise and dust should be evaluated during the glass cutting process. This study could contribute significantly to understanding the recycling methods of NMFs from WEEE and serve as guidance for the future technology research and development.     

Generation amount prediction and material flow analysis of electronic waste: a case study in Beijing, China.

The draft legislation on e-waste prepared by the Chinese national government assigns management responsibility to local governments. It is an urgent task for the municipal government to plan an effective system as soon as possible to divert the e-waste flow from the existing informal e-waste recycling processes. This paper presents a case study implemented in Beijing, the capital city of China, with the purpose of predicting the amount of obsolete equipment for five main kinds of electronic appliances from urban households and to analyse the flow after the end of their useful phase. The amount to be handled was 885,354 units in 2005 and is predicted to double by 2010. Due to consumption growth and the expansion of urbanization it is estimated that the amount will increase to approximate 2,820,000 units by 2020: 70% of the obsolete appliances will be awaiting collection for possible recycling, 7% will be stored at the owner's home for 1 year on average and 4% will be discarded directly and enter the municipal solid waste collecting system. The remaining items will be reused for about 3 years on average after the change of ownership. The results of this study will assist the waste management authorities of Beijing to plan the collecting system and facilities needed for management of e-waste generated in the near future.     

TSP,PM<Subscript>10</Subscript> and health risk assessment for heavy metals (Cr,Ni, Cu,Zn, Cd,Pb) in the ambience of the production line for waste cathode ray tube recycling

Recently, a typical semi-automatic recycling line is proved to be a feasible method for resource recovery of raw material of waste CRTs. However, there are no relevant studies about health risk assessment of the particles and heavy metals diffused from this physical recycling process for CRTs. In this study, TSP, PM₁₀ and heavy metals (Cr, Ni, Cu, Zn, Cd and Pb) in the ambience of the workshop have been evaluated. The mean concentrations of TSP and PM₁₀ in the workshop were 481.5 and 316.9 μg/m³, respectively. Meanwhile, it can be seen that Zn (8.1 and 7.9 μg/m³, respectively) was the most enriched metal in TSP and PM₁₀, followed by Pb (3.2 and 3.0 μg/m³, respectively). Health risk assessment showed that the total hazard index was 3.29, exceeding the danger threshold. The health risk of different metals was Cr > Cd > Ni. In short, the research results show that mechanical–physical process for e-waste recycling do exist the pollutant mission. So the effective measures should be taken to reduce the harm of pollutants on the workers’ health.     

关于遏制废旧铅酸蓄电池环境污染现象的建议

近几年,我国废旧铅酸蓄电池的回收处理工作取得了很大进展,但由于各种原因引起的环境污染现象仍触目惊心.回收处理废旧铅酸蓄电池提取再生铅,与原生铅相比更节能环保,符合资源回收和循环利用法则.但目前回收和处理市场很不规范,存在严重的环境污染问题,着重讨论用政策引导的方式规范废旧铅酸蓄电池回收处理市场,实现资源节约和环境保护的双重目的.     

Collection and recycling of electronic scrap: a worldwide overview and comparison with the Brazilian situation

Recycling and the related issue of sustainable development are increasing in importance around the world. In Brazil, the new National Policy on Solid Wastes has prompted discussion on the future of electronic waste (e-waste). Over the last 10 years, different e-waste collection systems and recycling processes have been applied globally. This paper presents the systems used in different countries and compares the world situation to the current Brazilian reality. To establish a recycling process, it is necessary to organize efficient collection management. The main difficulty associated with the implementation of e-waste recycling processes in Brazil is the collection system, as its efficiency depends not only on the education and cooperation of the people but also on cooperation among industrial waste generators, distributors and the government. Over half a million waste pickers have been reported in Brazil and they are responsible for the success of metal scrap collection in the country. The country also has close to 2400 companies and cooperatives involved in recycling and scrap trading. On the other hand, the collection and recycling of e-waste is still incipient because e-wastes are not seen as valuable in the informal sector. The Brazilian challenge is therefore to organize a system of e-waste management including the informal sector without neglecting environmentally sound management principles.     

Generation of copper rich metallic phases from waste printed circuit boards

The rapid consumption and obsolescence of electronics have resulted in e-waste being one of the fastest growing waste streams worldwide. Printed circuit boards (PCBs) are among the most complex e-waste, containing significant quantities of hazardous and toxic materials leading to high levels of pollution if landfilled or processed inappropriately. However, PCBs are also an important resource of metals including copper, tin, lead and precious metals; their recycling is appealing especially as the concentration of these metals in PCBs is considerably higher than in their ores. This article is focused on a novel approach to recover copper rich phases from waste PCBs. Crushed PCBs were heat treated at 1150 °C under argon gas flowing at 1 L/min into a horizontal tube furnace. Samples were placed into an alumina crucible and positioned in the cold zone of the furnace for 5 min to avoid thermal shock, and then pushed into the hot zone, with specimens exposed to high temperatures for 10 and 20 min. After treatment, residues were pulled back to the cold zone and kept there for 5 min to avoid thermal cracking and re-oxidation. This process resulted in the generation of a metallic phase in the form of droplets and a carbonaceous residue. The metallic phase was formed of copper-rich red droplets and tin-rich white droplets along with the presence of several precious metals. The carbonaceous residue was found to consist of slag and ～30% carbon. The process conditions led to the segregation of hazardous lead and tin clusters in the metallic phase. The heat treatment temperature was chosen to be above the melting point of copper; molten copper helped to concentrate metallic constituents and their separation from the carbonaceous residue and the slag. Inert atmosphere prevented the re-oxidation of metals and the loss of carbon in the gaseous fraction. Recycling e-waste is expected to lead to enhanced metal recovery, conserving natural resources and providing an environmentally sustainable solution to the management of waste products.     

Analysis of recycling structures for e-waste in Vietnam

E-waste management in Vietnam poses real challenges such as the lack of specific e-waste legislation, the strong involvement of “craft villages” and the missing of monitoring data. Many issues (e.g., pollution level, generated waste, health of workers and resident living at recycling sites) lead to the limited access to these craft villages. Thus, there is no comprehensive picture on e-waste management in Vietnam available today. This research focuses on the current situation of e-waste management. Sources of e-waste, collection and treatment in Vietnam are investigated by utilizing most available sources of information (published journals, unpublished works from projects and reports from institutes, ministry) together with the interviewed data from experts, collectors, workers and especially, biggest traders in the field. Based on this information, the processes applied in Vietnam, both in the formal and informal sector, have been analyzed systematically in terms of inputs, outputs, potential emissions and related risks for workers. From these aspects, a comparison in terms of legal frameworks, collection and treatment at both formal and informal sector between Vietnam and other countries in Asian region was undertaken. Thus, major challenges of e-waste management and relatively comprehensive image of e-waste management and treatment in Vietnam have been identified.     

我国电子废物回收处理产业政策及机遇与挑战分析

针对近年我国频繁出台的电子废物回收处理产业政策,系统论述了其发展脉络,并从循环经济角度出发,分析了我国电子废物产业发展的主体思路,同时还对我国电子废物回收处理产业发展机遇与存在的问题进行剖析,对如何稳定企业的电子废物来源、提升产业技术水平及降低企业运营成本进行建议性分析。