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Shenzhen, China

Zeng X.,Tsinghua University | Li J.,Tsinghua University | Ren Y.,Dongjiang Environmental Co.
IEEE International Symposium on Sustainable Systems and Technology | Year: 2012

Various lithium batteries including primary lithium batteries (PLBs) and rechargeable lithium batteries (RLBs) have been extensively used in electrical and electrics. China as a populous and rapid developing country has become an important manufacturer, consumer and supplier of lithium batteries. This paper predicates the amount of various discarded lithium batteries based on the latest statistics and models. The discarded PLBs as a typical utilization in micro-computer is forecasted and exceed 200 metric tons in 2020. However, pushing by the electric vehicle industry, the quantity and weight of discarded RLBs in 2020 can surpass 25 billion units and 500 thousand metric tons, respectively. Further, China will reveal a much rapider speed of discarding of lithium batteries than total global level. © 2012 IEEE.

Zeng X.,Tsinghua University | Li J.,Tsinghua University | Xie H.,Dongjiang Environmental Co. | Liu L.,Tsinghua University
Chemosphere | Year: 2013

Recycling processes for waste printed circuit boards (WPCBs) have been well established in terms of scientific research and field pilots. However, current dismantling procedures for WPCBs have restricted the recycling process, due to their low efficiency and negative impacts on environmental and human health. This work aimed to seek an environmental-friendly dismantling process through heating with water-soluble ionic liquid to separate electronic components and tin solder from two main types of WPCBs-cathode ray tubes and computer mainframes. The work systematically investigates the influence factors, heating mechanism, and optimal parameters for opening solder connections on WPCBs during the dismantling process, and addresses its environmental performance and economic assessment. The results obtained demonstrate that the optimal temperature, retention time, and turbulence resulting from impeller rotation during the dismantling process, were 250. °C, 12. min, and 45. rpm, respectively. Nearly 90% of the electronic components were separated from the WPCBs under the optimal experimental conditions. This novel process offers the possibility of large industrial-scale operations for separating electronic components and recovering tin solder, and for a more efficient and environmentally sound process for WPCBs recycling. © 2013 Elsevier Ltd.

Wang P.,CAS Research Center for Eco Environmental Sciences | Zhang Q.,CAS Research Center for Eco Environmental Sciences | Lan Y.,Dongjiang Environmental Co. | Gao R.,Shenzhen Dongjiang Heritage Technologies Co. | And 8 more authors.
Scientific Reports | Year: 2014

The sources of polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs) found in animal feed additive (feed grade cupric sulfate, CuSO4) were investigated and traced back to the formation of chlorinated organic compounds in the chlor-alkali industry. PCDD/Fs could be transported through the supply chain: hydrochloric acid (HCl) by-produced during formation of chlorinated organic compounds in chlor-alkali industry → spent acid etching solution (acid-SES) generated in printed circuit board production → industrial cupric salt → CuSO4 in animal feed, and finally enter the food chain. The concentration ranges in HCl and acid-SES were similar, of which the level in acid-SES was also consistent with that in various cupric salt products including CuSO4 based on Cu element content. PCDD/Fs also showed very similar congener profiles in all the sample types. This indicates a probable direct transport pathway of PCDD/Fs into the food chain, which may eventually be exposed to humans through consumption. To date this is the first study in China that systematically reports on the PCDD/Fs transport from industrial pollution sources to industrial processes and finally enters the human food chain.

Duan H.,Shenzhen University | Hu J.,Dongjiang Environmental Co. | Tan Q.,Tsinghua University | Liu L.,Tsinghua University | And 2 more authors.
Environmental Science and Pollution Research | Year: 2016

Over the last decade, there has been much effort to promote the management of e-waste in China. Policies have been affected to prohibit imports and to control pollution. Research has been conducted in laboratories and on large-scale industrial operations. A subsidy system to support sound e-waste recycling has been put in place. However, the handling of e-waste is still a concern in China and the issue remains unresolved. There has been relatively little work to follow up this issue or to interpret continuing problems from the perspective of sustainable development. This paper first provides a brief overview of conventional and emerging environmental pollution in Chinese “famous” e-waste dismantling areas, including Guiyu in Guangdong and Wenling in Zhejiang. Environmentalists have repeatedly proven that these areas are significantly polluted. Importing and backyard recycling are decreasing but are ongoing. Most importantly, no work is being done to treat or remediate the contaminated environmental media. The situation is exacerbated by the rising tide of e-waste generated by domestic update of various electronics. This study, therefore, employs a Sales Obsolescence Model approach to predict the generation of e-waste. When accounting for weight, approximately 8 million tons of e-waste will be generated domestically in 2015, of which around 50 % is ferrous metals, followed by miscellaneous plastic (30 %), copper metal and cables (8 %), aluminum (5 %), and others (7 %). Of this, 3.6 % will come from scrap PCBs and 0.2 % from lead CRT glass. While more and more end-of-life electronics have been collected and treated by formal or licensed recyclers in China in terms of our analysis, many of them only have dismantling and separation activities. Hazardous e-wastes, including those from PCBs, CRT glass, and brominated flame retardant (BFR) plastics, have become problematic and probably flow to small or backyard recyclers without environmentally sound management. Traditional technologies are still being used to recover precious metals—such as cyanide method of gold hydrometallurgy—from e-waste. While recovery rates of precious metals from e-waste are above 50 %, it has encountered some challenges from environmental considerations. Worse, many critical metals contained in e-waste are lost because the recovery rates are less than 1 %. On the other hand, this implies that there is opportunity to develop the urban mine of the critical metals from e-waste. © 2015, Springer-Verlag Berlin Heidelberg.

Li Y.,Tsinghua University | Li J.,Tsinghua University | Chen S.,Dongjiang Environmental Co. | Diao W.,Dongjiang Environmental Co.
Environmental Pollution | Year: 2012

Groundwater contamination by leachate is the most damaging environmental impact over the entire life of a hazardous waste landfill (HWL). With the number of HWL facilities in China rapidly increasing, and considering the poor status of environmental risk management, it is imperative that effective environmental risk management methods be implemented. A risk assessment indices system for HWL groundwater contamination is here proposed, which can simplify the risk assessment procedure and make it more user-friendly. The assessment framework and indices were drawn from five aspects: source term, underground media, leachate properties, risk receptors and landfill management quality, and a risk assessment indices system consisting of 38 cardinal indicators was established. Comparison with multimedia models revealed that the proposed indices system was integrated and quantitative, that input data for it could be easily collected, and that it could be widely used for environmental risk assessment (ERA) in China. © 2012 Published by Elsevier Ltd. All rights reserved.

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