Response to Waste Electrical and Electronic Equipments in China

Critical Review pubs.acs.org/est

Response to Waste Electrical and Electronic Equipments in China: Legislation, recycling system, and advanced integrated process Lei Zhou and Zhenming Xu* School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, P. R. China S Supporting Information *

ABSTRACT: Over the past 30 years, China has been suffering from negative environmental impacts from distempered waste electrical and electronic equipments (WEEE) recycling activities. For the purpose of environmental protection and resource reusing, China made a great effort to improve WEEE recycling. This article reviews progresses of three major fields in the development of China’s WEEE recycling industry: legal system, formal recycling system, and advanced integrated process. Related laws concerning electronic waste (e-waste) management and renewable resource recycling are analyzed from aspects of improvements and loopholes. The outcomes and challenges for existing formal recycling systems are also discussed. The advantage and deficiency related to advanced integrated recycling processes for typical e-wastes are evaluated respectively. Finally, in order to achieve high disposal rates of WEEE, high-quantify separation of different materials in WEEE and high added value final products produced by separated materials from WEEE, an idea of integrated WEEE recycling system is proposed to point future development of WEEE recycling industry.

1. INTRODUCTION The electronics industry has become one of major growth points in economy in China recently, especially in coastal areas.1,2 The revenue of information and communication equipment reached to 3901.4 billion Yuan Renminbi (RMB), making up to 9.8% of the country’s industrial output value at the end of 2007.3 The total sale of electronic product market in China has exceeded 10,000 billion Yuan in 2010 and electronic industry has been to the forth place around the world.4 Along with the accelerating update of technology and continuous expansion of electronic industrial market, waste electrical and electronic equipment (WEEE) becomes a serious problem in environmental protection and human health. It is not only a crisis of quantity5 but also a crisis of toxic parts,6 such as the beryllium, lead, cadmium, mercury, etc.7 In addition, China is now facing dual pressure of electronic wastes (e-wastes) from both domestic generation and illegal imports.8 Although the Basel Convention is attempted to prohibit the trans-boundary movements of toxic e-waste,9 it fails as a result of political and economic pressures.10 E-waste is treated in China since the 1990s and a large number of e-wastes came from overseas. As shown in Figure 1, the percentage of e-waste amount from overseas was increased to 70% in 201011 and it is estimated that 1.5−3.3 million tons of WEEE are imported to China via illegal ways each year.12 Nevertheless, e-waste is not only a kind of dangerous toxic and harmful material, but also a potential precious resources.14,15 In response of perceived problem of WEEE management in China, Chinese government actively issued a series of laws and regulations to promote environmentally friendly collection and © 2012 American Chemical Society

Figure 1. Whole picture of the WEEE recycling of China in 201013.

recycling.16 These built upon and strengthened earlier regulations on the prevention of pollution from solid waste. Some national pilot programs in Qingdao, Beijing, Tianjin, and Hangzhou etc have been initiated by the National Development and Reform Commission (NDRC) to determine the more suitable recycling systems.17 Meanwhile, lots of national voluntary initiatives were created by industry alone to collect and reuse Received: Revised: Accepted: Published: 4713

October 24, 2011 March 30, 2012 April 1, 2012 April 2, 2012 dx.doi.org/10.1021/es203771m | Environ. Sci. Technol. 2012, 46, 4713−4724

Environmental Science & Technology

Critical Review

“extended producer responsibility (EPR)”, catalog management system and licensed scheme for WEEE recycling enterprises. Regulation on Management of Waste Electrical and Electronic Equipments Recycling and Disposal (NDRC, MIIT) is a counterpart of the EU WEEE directive. This regulation aims to reduce the volume of e-waste, and establish modern recycling system.34 It stipulates that the WEEE can be collected separately but must be recycled together in licensed enterprises.16 Besides, it requires that the stakeholders (i.e., producers, importers of e-products) must pay for e-waste recycling. According to this law, China sets up a special fund to assist WEEE recycling system.35 These laws have attracted intensive attentions in domestic WEEE domain and got positive responses from stakeholders. Producers of e-products begin to adopt cleaner production process and cooperate with distributors to collect their own end-of-life e-products. As a bridge between producers and consumers, distributors are responsible for “old-for-new service”, which is a policy launched by the State Council in May, 2009. This policy encourages customers to send their waste home appliances to the appointed distributors and provides subsidies to customers who are involved in this activity when they buy new e-products. Besides, distributors and local government disseminate knowledge of e-waste recycling to consumers. Specialized enterprises take the advantage of the special fund to improve their recycling technology and develop the reuse of recycled materials. In designing WEEE recycling regulations in China, it is important to follow the experiences of developed countries,4,42 such as EU, America and Japan which have their owned referential legal system (Table 2). At this stage, three problems arise: First, there are no current appropriate national specific guidelines to execute published laws. Specific monitoring standards and examination approach are important to realize the goal of regulations, however, they are absent in Chinese laws. Second, confusion about the stakeholders’ responsibilities limits the feasibility of these laws. According to Table 1, Chinese policy set forth the “polluter pays principle” in 2006 but not explicitly brought up the responsibility of Chinese government. The main contents of regulations prefer to use equivocal words like “encourage” and “should”, which is extremely adverse to the enforcement of these laws. Third, more than a dozen of regulations have been published in a short time that distracted stakeholders. There is no sufficient time for them to improve their current processes to get licensed. Down of some small specialized enterprises and increase in e-waste volume bring great pressure to the transformation of China’s WEEE recycling industry.

end-of-life electronic products (e-products). Moreover, to ensure “good practice” at the recycling and reusing stage, advanced technology is always studied by research institutes and specialized companies, such as integrated recycling processes for crushed printed circuit boards (PCBs) and waste nickel−cadmium batteries. In order to provide global view of the development of WEEE recycling in China, this article reviews the status of related policies, existing formal recycling systems and advanced integrated recycling processes for several typical e-wastes. Finally, we will propose a promising method to update WEEE recycling system in future.

2. RELATED REGULATIONS AND LAWS OF WEEE IN CHINA The Chinese government has drafted a comprehensive body of law on environmental protection.18−21 At the initial stage, the government has enacted several general environmental laws (Supporting Information (SI) Table S1) for e-waste recycling management, including General Environmental Law, The Solid Waste Pollution Control Law, etc. However, these laws gave an overall strategy of environmental protection but were not feasible in practice.22−24 Besides, China’s current e-waste recycling has its own characteristics due to the national economic level and the public environmental protection awareness. Therefore, China has issued specific and pertinent legislation in the past decade to direct and normalize WEEE recycling. The most important ones are summarized as followed in Table 1. As the regulations and laws listed above, it is clear that the purpose of laws is to standardize e-waste recycling and renewable resources reuse.28 The promulgation of The Technical Policy on Pollution Prevention of Discarded Appliances and Electronic Product (MIIT, MOST, MEP) and The Ordinance on Management of Pollution Control from Electronic Information Products (MIIT) reflects the evolving trend of Chinese environmental policy, from “End-to-end management” to “Source management”, which means that Chinese government changes the focus on e-wastes management from “waste disposal” to “pollution source control and resource recycling”. The essential objectives of Chinese policy are to reduce, minimize, recycle, and reuse e-wastes. More current laws not only encourage environmentally friendly processing for e-waste recycling, but also provide a special fund to support e-waste recycling system, and employ a licensed scheme for e-waste recycling industry.29 The Ordinance on Management of Pollution Control from Electronic Information Products (EIPSs)30 is recognized as a counterpart to the EU’s Restriction of the use of certain Hazardous Substances directive (RoHS Directive 2002/95/EC)31 which restricts six substances in electrical information products (EIPs) including Pb, Hg, Cd, Cr6+, PBB, and PBDE,32 but excludes a fixed deadline for the prohibition. Compared with RoHS, this Ordinance requires that manufacturers provide the information from hazardous substances present both in components and in whole product, as well as the lifespan and related environmental protection information (i.e., name, content, whether the product can be recycled at its end of life). Administrative Measure on Pollution Prevention of Waste Electrical and Electronic Equipments (MEP)33 is the first Administrative Measure subjecting to WEEE management. It regulates the activities of production, disassembly, recycling, disposal, and storage of e-waste and puts forth the principle of

3. FORMAL RECYCLING SYSTEMS OF WEEE IN CHINA Along with the development of legislation, national and local governments, manufacturers and distributors of e-products, and specialized companies begin to establish their own recycling systems which can gain the experiences of WEEE recycling and suppress the informal recycling. 3.1. National Pilot Programs for WEEE Recycling. Since December 2003 when national pilot programs for waste resources were promoted in China, NDRC has designed 34 national pilot programs43,44 mainly in developed cities and coastal cities among which 14 are for WEEE recycling system, 9 for metal recycling, 3 for discarded household appliances recycling, and the rest for other type of recycling, such as waste 4714

dx.doi.org/10.1021/es203771m | Environ. Sci. Technol. 2012, 46, 4713−4724

issued by

Administrative Measure on Pollution Prevention of Waste Electrical and Electronic Equipments (February 1, 2008) Circular Economy Promotion Law (January 1, 2009) Regulation on Management of Waste Electrical and Electronic Equipments Recycling and Disposal (January 1, 2011)

The Ordinance on the management of waste household electrical and electronic products recycling and disposal (Draft, 2005) Technical Policy on Pollution Prevention of Discarded Appliances and Electronic Product (April 27, 2006) The Ordinance on Management of Pollution Control from Electronic Information Products (March 1, 2007) The Ordinance on Renewable resources recycling management (May 1, 2007)

detail guiding principles on Reduce, Reuse and Recycle (3R) of e-products during the production, consumption and other processes mandatory disassembly and centralized recycling of e-waste. Certification for recycling enterprises. Establish special fund to finance e-waste recycling and disposal

National People’s Congress (NPC) NDRC, MIIT

MEP

encourage environmentally friendly processing of renewable resources recycling and the relevant technological innovation. Qualified certification for recycling enterprises. Establish modern renewable resources recycling system regulate the activities of production, disassembly, recycling, disposal and storage of e-waste. Specify the responsibility of stakeholders

business engaged in disassembly, recycling, disposal and storage of e-waste (including individual business) business engaged in production, transport and consumption of commodity manufacturer, distributors, recycling operators and specialized enterprise of e-products

renewable resources recovery enterprises and individual business

producers and importers of the listed e-products

manufacturers, distributors, consumers, collectors of discarded appliances and e-products manufacturer, collectors and consumers of discarded appliances and e-products

manufacturers, distributors, consumers, collectors of batteries

stipulate guidance of production, collection, transport, storage, recycling and disposal of battery. Prohibit produce and sale oxidation mercury batteries. encourage environmentally friendly technology for battery production establish special fund to finance e-waste recycling and disposal. encourage the relevant technological innovation. oblige the producer to be responsible for e-waste collection and recycling. encourage the establishment of multivariate recycling system of e-waste. Set forth the “3R” principle and “polluter pays principle”. Stipulate general rules of eco-design and information disclosure of toxic substances which contained in e-products restrict the usage of six hazardous substances in e-product (corresponding with the RoHS Directive). Require eco-design and information disclosure of e-product.

main concerns manufacturer of e-products and provincial environmental department

major related contents encourage eco-design and cleaner production of e-product. Ban on the environmental harmful technology for e-waste disposal

The Ministry of Commerce (MOFCOM)

Ministry Of Industry And Information Technology (MIIT), Ministry of Science and Technology (MOST), MEP MIIT

National Development and Reform Commission (NDRC)

The Circular on Strengthening Environmental Ministry of Environmental Protection Management of Waste Electrical and Electronic (MEP) Equipment (August 26, 2003) The Technical Policy on Pollution Prevention of MEP Waste Batteries (October 3, 2003)

laws/regulations

Table 1. Summary of China’s Specific National Legislation on WEEE12,17,18,25−27

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properties

related legislation/laws

• No federal legislation

taken effect in early time • States have their own laws

• Related laws have been

Chapter 661 (2006)

• Public Laws of Maine,

of 2003 (2006)

Recycling Act (EWRA)

• Electronic Waste

America

• Related laws have been taken effect in early time • Related laws have been recognized as the templates • These three laws correspond to production stage, end-life stage and life cycle of EEE

• Directive 2002/96/EC on WEEE (2003) • Directive 2002/95/EC on the restriction of the use of certain hazardous substances in electrical and electronic equipment (2003) • Directive 2005/32/EC on EcoDesign of Energy-using Products (2007)

EU

Table 2. Comparison of Legislations of Different Countries and Regions31,36−41

for part of recycling cost

• Customers must be responsible

home appliances recycling

• The earliest law about waste

Recycling Law (2001)

• Home Appliance

Japan

4716

China’s actual situation

international rules and

effect a short time ago • Related laws meet both

• Related laws have been taken

Disposal (2011)

Equipments Recycling and

of Waste Electrical and Electronic

Products (2007) • Regulation on Management

Electronic Information

of Pollution Control from

• The Ordinance on Management

China

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In October 2010, the town of Guiyu was selected by NDRC and MEP to implement a pilot program of integrated WEEE recycling system.49 As designed, the 2500 acres industrial park of WEEE recycling in Guiyu will be divided into six district and run for recycling waste appliances.50 3.3. National Voluntary Collective Initiatives. The top original equipment manufacturers (OEMs) launched some voluntary initiatives for establishing WEEE collection system in China since the early of this century.51 One of most prominent voluntary collective partnerships was initiated since October 2005 by Nokia, Motorola and China Mobile, which named “Green Box Program” (SI Figure S3). This program aims to establish a collective take-back scheme for used phone accessories and mobile phones. In 2007, more than 500 maintenance service centers of Nokia in more than 200 cities participated in this program. This scheme has now been expanded to 12 Xingwang industrial parks and some famous universities too. SUNING Appliance Co., Ltd. cooperated with China Huaxing Environmental Protection Group Company to launch an “old-for-new service” for waste appliances since 2009. In this system, Huaxing group is responsible for “door-to-door collection” and recycling process. SUNING provides subsidies to customers who are involved in this activity when they buy new e-products in SUNING market. By 2011, the Chinese “old-for-new service” has collected more than 40 million units of waste appliances.52 A new online trading platform for this service will open on July 2012 in order to simplify and standardize this collective activity. 3.4. Specialized Companies of WEEE Recycling. With the development of national and local pilot programs, some specialized companies are created and energetically participate in WEEE recycling industry in China, such as Huaxing Environmental Protection Group Company, Hangzhou Dadi Environmental Protection Company, Hunan Vary Tech Co., Ltd., Shanghai Xin Jinqiao Environmental Co., Ltd., Yangzhou Ningda Precious Metal Co., Ltd., Shenzhen GEM High-tech Co., Ltd. etc. These specialized companies are located all around China. The main recycle materials include metals (Cu, Fe, Al, Co, Ni, Sn, Au, Ag, Ge, and In), plastics (acrylonitrile butadiene styrene, PP polystyrene, low-density Polyethylene and polyurethane foam) and glass. Shenzhen GEM High-tech Co., Ltd. is one of state-class high technology enterprises specialized in resource recovering and recycling. As founded in 2001, GEM began to devote all exertion to exploit “urban mines”, which are committed to recycle annually 500 000 tons of e-wastes, used batteries, and wasted Co and Ni scraps. By recovering from the waste materials, the annual output of GEM is over RMB 50 million (approximately US$ 8 million). GEM launched more than 100 collection activities for used batteries since 2008, and recycled more than 1 million tons of e-wastes. So far, the WEEE collection net of GEM covers nearly 100 cities in Hubei province, Jiangxi province and Hunan province. According to the report of Hunan environmental protection department,53 the recovery rate of used batteries in China was raised from 1% to 5% due to the contribution of GEM. 3.5. Challenges for WEEE Recycling System. In summing up experiences of these existing systems, there are four important points that should be stressed: first, the “old-fornew service” is an excellent way to collect discarded home appliances and improve the public environmental awareness

batteries. The NDRC claims that the pilot programs must take an analysis of recycling costs for improving related technologies and processes.27 The Beijing Municipal Commission of Development and Reform (MCDR) directed the pilot in Beijing was undertaken by Huaxing Environmental Protection Group Company since 2005. According to the report of Beijing Environmental Protection Bureau, the Huaxing Group invested a total of RMB 80 million (US$ 12 million) in establishing its WEEE recycling plant (SI Figure S2) with the annual capacity of 1.2 million discarded appliances. Like Beijing city, Zhejiang Province built the WEEE pilot program by a local specialized company, Hangzhou Dadi Environmental Protection Company. Under the leadership of Zhejiang Provincial Economic and Trade Commission (ZETC), Dadi undertook this project of waste electrical household appliances recycling in 2004. Based on the principle of “multi channel collection, together recycling”, Dadi set up three collection stations at the beginning: one is in shopping mall providing “old-for-new service”, the other two are community collection centers. The company aims to recycle 10 000 units of waste appliances per year and 1.6 t of waste printed circuit boards (PCBs) per day. In addition, Dadi develops advanced waste recycling techniques and equipments with independent intellectual property in joint efforts with colleges and institutes such as Tsinghua University, Zhejiang University and Chinese Research Academy of Environmental Sciences. At present, China pilot projects have been scaled up. The amount of recycled discarded appliances of Huaxing Group grew from 106 000 units in 2007 to 360 000 units in 2009, and the number of collection net increased to more than 200 per district of Beijing city in 2008. In other pilot cities, the online monitoring platform of WEEE recycling information is open to public from 2007, aiming to regulate the activities of WEEE recycling and to improve public environmental awareness and performance. 3.2. Local Recycling System of WEEE: The Town of Guiyu. The town of Guiyu, in Guangdong Province, is wellknown around the world after a report by Nongovernmental organizations (NGOs), the Basel Action Network and Silicon Valley Toxics Coalition in 2002,45 on WEEE trading and processing. The informal WEEE recycling activities were lucrative in Guiyu since the late 1980s due to its low cost of imported e-waste and labor.46However, unprotected manual disassembly, open incineration and acid washing were the main techniques employed.47 These unconfined techniques released large amount of hazardous waste, for example, the elevated heavy metal contaminants such as Cd, Cu, Ni, Pb, and Zn were found in some river sediments nearby the WEEE recycling site in Guiyu.48 These contaminants cause serious environmental and health consequences,45 including respiratory disease and kidney stones. Before those related laws took effect, most of e-wastes in China were disposed in Guiyu through nonenvironmentally friendly processes. Compared with other regions of China, the natives of Guiyu were nearly the earliest ones to gain experience of WEEE recycling from those unconfined techniques. Along with the development of techniques and related legislation, formal recycling has been scaled up in Guiyu. At present, Guiyu is at the leading position in the world in waste electronic components collection and recycling, which lets Guiyu be qualified to construct an industrial park of WEEE recycling. 4717



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Figure 2. Locations of 55 pilot cities for WEEE recycling.

Table 3. Table of Subsidies for Formal WEEE Recycling System (Including Traffic Subsidy)58 type of WEEE

television

refrigerator

washing machine

PC

air conditioner

others

subsidy

US$ 3.8/unit

US$ 4.6/unit

US$ 2.5/unit

US$ 3.8/unit

US$ 1.5/unit

VAT exempted

and performance; second, the special fund and subsidies for formal recycling system make enterprises actively be involved in these activities and increase their profits well; third, the advanced technologies applied in these recycling systems significantly reduce the risk to the environment and to humans, and enhance the resources recovery; lastly, the reasonable legislation system protects the rights and the market competitiveness of formal system. Although the achievements are remarkable, it is important to recognize the challenges in existing formal WEEE recycling systems. First, efforts continue to improve the formal collection channels. The economic and industrial level of China led to a flourishing immature WEEE recycling activity since the early 1990s.54 This phenomenon resulted in only 10% of e-waste in 2007 going to formal systems.55 China’s government made efforts to limit immature WEEE recycling activities via implementing licensed scheme, Regulation on Management of Waste Electrical and Electronic Equipments Recycling and Disposal, and “old-for-new service”. Till 2011, more than 70% of e-wastes in 55 pilot cities (Figure 2) are collected and recycled by formal system.56 However, informal recycling of e-waste is still a dominant practice in the rest cities. Second, efforts continue to help formal system get out of the red. The cost of WEEE recycling averages 110RMB (US$ 16) per unit by environmentally sound processing, not including transport charge and labor cost.57 This situation made some small specialized company was at a money-loss before 2008. Chinese government recognized this problem and explicitly stipulated subsidies for formal systems in 2009 (Table 3). Meanwhile, the government encourages specialized companies to

make more profit by increasing the added value of recycled e-waste. For example, the recovered copper can be processed into copper products and the recovered plastic can be processed into wood plastic composite products. Third, the implementation of more pilot programs needs to be speeded up. By the end of 2010, more than 100 specialized companies are carrying out WEEE recycling programs and “old-for-new service” in 24 provinces and 4 municipalities.59 Although this recycling map has not yet covered the whole China, an estimated 30 million units of waste appliances are recycled by formal systems in 2010. Nevertheless, the government should implement pilot programs in more cities to avoid region−to-region e-wastes transfer. Fourth, public environmental awareness and performance needs to be reinforced. Wang et al.60 did a survey and found that 63.21% of domestic e-wastes in Beijing in 2009 were flow to immature recycling because of residents’ behavior. The public performance in recycling can determine the competitive relationship between immature and formal systems. Cooperating with environmental protection organization and communities, Chinese government must improve people’s awareness of environmental protection.

4. ADVANCED INTEGRATED PROCESS FOR WEEE RECYCLING IN CHINA With the support of Chinese government, lots of recycling technology researches have been conducted.61−63 Integrated mechanical/physical process draws more attention in recycling field,64−68 due to its environmentally friendly property and feasibility.69,70 Generally, the integrated mechanical/physical 4718



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recycling processes have three major steps: the first stage is to disassemble or to dismantle, which picks out hazardous and valuable components from WEEE and classify these materials extensively. The second step namely crushing is to use one or several types of crusher to strip metals from the base components of WEEE. The last stage is to separate and recover different valuable materials from crushed mixture by one or several separation equipments and these recovered materials are collected separately for further purification and reuse. The core of mechanical/physical recycling system is separation process. Monorecycling process, referring to mechanical/ physical recycling process which adopts one single separation method, is widely used in WEEE recycling field. However, monorecycling process always has some drawbacks and cannot satisfy the high standards of WEEE recycling (SI). Therefore, the combination of different recycling process is potentially an effective way. These integrated processes have the following advantages: • Environmentally friendly • High disposal rate • High quantify separation (including recovery rate and purity) • High added value final products • High degree of automation In China, all the pilot programs and large specialized companies own complete WEEE recycling system, which includes collection channel, integrated recycling process and reuse production line. The abundant materials recovered in recycling process are separately reused as products, such as secondary aluminum, copper products and wood plastic composite products etc. As a result, recovery ratio of waste metals is high in China. In 2010, recycled nonferrous metals made up 40% of total production in China. The quantity of recycled aluminum reached 7 million tons, which accounted for more than 50% of yearly production. On January 1, 2011, Chinese government for the first time explicitly put forward “Waste electrical and electronic products recycling directory”,71 which proclaimed the government’s determination to recycle five typical waste appliances: television, refrigerator, washing machine, air conditioner, and computer. Besides, printed circuit boards, toner cartridges, and batteries are three main e-wastes recycled in China. And the

volume of other e-wastes, such as radios and mobile phones, is smaller compared to waste home appliances. In this case, the most advanced regular integrated processes adopted in WEEE recycling industry are employed for above typical e-wastes. These integrated processes are designed to maximize valuable materials (aluminum, copper and plastic etc) recovery, and minimize the final disposal. 4.1. Waste Household Electric Appliances Recycling. An environmentally friendly recycling process (Figure 3) which integrated magnetic separation (MS) with eddy current separation (ECS) was proposed to recover waste refrigerantcontained home appliances.72,73 Table 4 showed its specialties include high automation, high disposal rate and high-quantify separation. The entire flow line was located in an enclosed workshop. Exhausted gas and dust were discharged after being treated by activated carbon adsorption and hop-pocket dust collector. This process can prevent secondary pollution to the environment. Comparing with other recovery process, this process was not only economical (cost $ 1.28 per refrigerator) but also provided with simple operation.71 Nevertheless, the cost of this highly automated process was still higher than that of manual recovery, which led to a meager profit to specialized companies. Discarded computers and televisions need another type of process due to their occupation of cathode ray tube (CRT) and printed circuit boards (PCBs). The waste CRT is hazardous and the key of its reutilization lies in lead-contained CRT glass separation technology.74−76 China Household Electric Appliances Research Institute (CHEARI) developed second generation CRT glass separation equipment77 in using heated metal wire technology. This new equipment can achieve proper separation between panel glass and funnel glass. Funnel glass which contains lead has not been left on panel glass. Comparing with the first generation separation equipment, the second one was more efficient and safe: the size of recycled CRT is 23−74 cm; the whole time of process is 30−100 s.78 Since 2008, this new equipment was in service in Sichuan Changhong Electric Co., Ltd. with an annual capacity of 40 000 televisions. In addition, the similar recycling process has been industrialized in Beijing and Zhejiang province.79 However, Chinese government prohibited the production of television with CRT since Nov 1, 2005. This interdict limits the

Figure 3. Integrated process of waste refrigerant-contained home appliances recycling.

Figure 4. Integrated process of WPCBs recycling.

Table 4. Main Characteristics of Waste Refrigerant-Contained Home Appliances Recycling Process capacity

power

operators

polyurethane foam recovery rate

ferrous recovery rate

nonferrous metal recovery rate

plastic recovery rate

20−30 units/h

260 kW

6 persons

>90 vol%

>98 wt %

>95 wt %

>95 wt %

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Figure 5. Schematic illustration of reuse of recycled nonmetals from WPCBs.

development of technology for CRT recycling since no more CRT could be recycled in several decades. 4.2. Waste Printed Circuit Boards Recycling. In order to recycle valuable materials existing in waste printed circuit boards (WPCBs), an integrated Cyclone air separation−corona electrostatic separation (CAS-CES) process80,81 is highlighted. As shown in Figure 4, the process included three main stages: two-step crushing breaks the large particle into small ones with size less than 1.0 mm;82 cyclone air separation (CAS) collected fine nonmetal particles and increased metal proportion of feed materials for Corona Electrostatic Separation (CES); and CES recovered metallic materials.83,84 The effect of this combination process was remarkable: first, fine nonmetal particles were largely removed by CAS, which increase metal recovery rate to 95% and 98%; second, metal content in nonmetal residue was less than 1%; third, the process was still in effect when the range of particle size varied.85 Now, this CAS-CES process is applied in Shanghai Xin Jinqiao Environmental Co., Ltd. and Yangzhou Ningda Precious Metal Co., Ltd. with the productivity of 500 kg/h-1000 kg/h and capacity of 5000 tons of WPCBs per year. However, due to the problems of fine nonmetal particles, this novel process needs to be further improved to increase its reliability86 as CAS cannot remove all fine nonmetal particles before processed by CES. In addition, quantified separation and purification can be enhanced by repeating separation process as many times as desired. Besides, to prevent secondary pollution and increase addedvalue of WPCBs, the nonmetals recovered are reused for producing varied products.87,88 Guo et al.89−93 developed diverse methods (Figure 5) to reuse nonmetals from WPCBs in this CAS-CES process. 4.3. Waste Toner Cartridges Recycling. As waste toner cartridges contain valuable materials as well as toxic residual toner, Ruan et al.94 developed a combination process to recover useful materials. This integrated process (Figure 6) involved crushing, magnetic separation (MS) and eddy current separation (ECS). During the step of crushing, remained toners were collected by bag-type dust collector to prevent secondary air

Figure 6. Integrated process of waste toner cartridges recycling.

pollution. The whole process was sealed and high effective as shown in Figure 6. Compared with traditional manual dismantling, this integrated process can recycle 500 kg waste toner cartridges in one hour by one worker which is used to be accomplished by 100 workers in 2.5 h.94 Besides, the high recovery rate could avoid air pollution as little toners were leaked into the environment. This process is applied in Shanghai Xin Jinqiao Environmental Co., Ltd. However, due to the small collection quantity of waste toner cartridges, Shanghai Xin Jinqiao failed to run in designed capacity at present. 4.4. Waste Batteries Recycling. Waste batteries are hazardous as they contain high concentration of toxic element,95,96 such as mercury (Hg) and cadmium (Cd).97,98 Therefore, waste batteries recycling industry is not well developed as waste household appliances recycling.99 Huang et al.100−102 developed a novel process (Figure 7) for recovering metals from waste nickel−cadmium batteries through vacuum metallurgy separation (VMS) and magnetic separation (MS). This bench scale process achieved a promising performance as showed in Figure 7. The profits of 1 ton waste Ni−Cd batteries recycling through this integrated process was at least US$1308. Although the proposed integrated process is energy consuming, high market value of recovered material makes it rewarding. Besides, heavy metals and harmful metals have been 4720



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government will propose more specific laws to crack down on immature WEEE recycling and definitely allocate a special fund to support e-waste recycling systems. In addition, “old-for-new service” should be standardized and encouraged in a related Administrative Measure to form a virtuous cycle of WEEE recycling. On the other hand, the advanced processes still face limitation, such as higher cost than manual recovery technologies, low utilization rate of equipment, and less reliability. Therefore, it is necessary to develop a novel system to improve the utilization ratio of equipments, save energy and protect the environment. To this end, an ideal integrated WEEE recycling system (Figure 8) is put forward. The integrated WEEE recycling system follows “comprehensive utilization” principle, which intends to recycle all the components of WEEE and reuse all the recovered materials in an environmentally friendly way. The principle of “comprehensive utilization” is not only for WEEE, but also for processing equipment. The key point for this system is that it recycles various e-wastes in one recycling process. In this case, we would like to use one device to replace several pieces of equipment of same function applied in different processes. For instance, this system will use one multifunctional crusher to crush all e-wastes and use one magnetic separator to separate all ferromagnetic materials. In addition, reutilization of recovered materials is an important part in this integrated system to realize the fine separation of WEEE and increase the added-value of final products. If this integrated WEEE recycling system is put into service as expected, it can not only recover different valuable materials from mixed e-waste, but also produce various products by reusing these recovered materials. As shown in Figure 8, plastics and nonmetals can be processed to wood plastic composite products, and copper can

Figure 7. Integrated process of waste Ni−Cd batteries recycling.

well separated and recovered to avoid second pollution. It is clear that this process was high-quantify separation, environmentally friendly, and profitable.100 Besides, some of waste lead-acid batteries and waste lithiumion batteries are recycled by specialized companies in China. However, there are no published reports about related research progress recently.

5. FUTURE OF WEEE RECYCLING IN CHINA After a decade of effort, China has a relatively developed legislative system, formal recycling systems, and advanced recycling technologies.103 However, the WEEE recycling is now still small scale in parts of China rather than at the industrial level around the country. There are two reasons for this phenomena: limitations of legislative system and applied recycling technologies. As discussed in Section 2, regulations and related laws of WEEE in China are imperfect. In the following years, China’s

Figure 8. Schematic of integrated WEEE recycling system. 4721



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be further purified to copper products. Such a system will also shows promise in energy savings, emission reducductions, and be economically effective.

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ASSOCIATED CONTENT

S Supporting Information *

The related definitions, table of China’s general environmental policies, schemas of existing recycling system, and descriptions of single separation method for WEEE recycling. This material is available free of charge via the Internet at http://pubs.acs.org.

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AUTHOR INFORMATION

Corresponding Author

*Phone: +86 21 54747495; fax: +86 21 54747495; e-mail: [email protected]. Notes

The authors declare no competing financial interest.

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ACKNOWLEDGMENTS This work was supported by the National High Technology Research and Development Program of China (863 program 2009AA06Z318) and the National Natural Science Foundation of China (Grant No.21077071 and No.51178262).

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