Measuring treatment costs of typical waste electrical and electronic equipment: A pre-research for Chinese policy making

Incorporating self-employed maintainers into WEEE formal recycling system: A system dynamic approach

The establishment and operation of a formal recycling system for waste electrical and electronic equipment is an important measure to reduce environmental hazards and improve the recycling of resources, but how to incorporate self-employed maintainers into the system has formed an important research gap. Based on the perspective of extended producer responsibility, we argue that self-employed maintainers are required to assume the corresponding environmental responsibility for the environmental externality caused by informal maintenance activities. Using qualitative structural analysis techniques of system dynamics approach with quantitative simulation analysis techniques, we construct an incentive model for self-employed maintainers' participation in formal recycling system, based on which we propose four incentive strategies. A simulation analysis is further conducted by using the case of waste mobile phones recycling in Qingdao to verify the effectiveness of our incentive model and strategies.

Do government intervention measures promote e-waste recycling in China?

To improve the low e-waste recycling rate, the Chinese government has introduced a series of intervention measures. However, the effectiveness of government intervention measures is controversial. This paper constructs a system dynamics model to study the impact of Chinese government intervention measures on e-waste recycling from a holistic perspective. Our results demonstrate that the current Chinese government intervention measures do not promote e-waste recycling. By studying the adjustment strategies of government intervention measures, it can be found that the most effective adjustment strategy is to increase government policy support while increasing the punishments for recyclers. If the government only adjusts a kind of intervention measures, it is better to increase punishments than to increase incentives. And increasing the punishment for recyclers is more effective than increasing the punishment for collectors. If the government chooses to increase incentives, then the government should only increase policy support. This is because increasing the subsidy support is ineffective.

Analysis of Critical Success Factors to Design E-waste Collection Policy in India: A Fuzzy DEMATEL Approach

The design of an e-waste collection policy is challenging, especially for a country like India, where the economy is a developing state, and there is a large diversity in socio-economic factors. The e-waste collection policy impacts the various stakeholders such as the manufacturer, the raw material producers, the assemblers, the retailers, the generator (households and bulk consumers), the scrap dealers, the smelters, the recyclers, and the regulators. The design of an e-waste collection policy needs to consider the appropriate set of Critical Success Factors (CSFs), which will maximise the e-waste collection providing business sustainability to the stakeholders while satisfying the environmental regulations in the operating locations. Twenty-three CSFs identified and categorised in six implication dimensions for the e-waste collection policy framework based on a literature survey and experts committee view. The fuzzy DEMATEL approach is employed to analyse the CSFs to design an e-waste collection policy in India from a comprehensive perspective. Cause and effect interrelationship is established among the CSFs, and also their impacts are evaluated to segregate the CSFs into cause group (prominent influencing and independent) and effect group (influenced and dependent). The CSFs such as technology involvement, green practices, environmental program, certification and licensing, public ethics and stakeholder's awareness for circular economy are prominent influencing CSFs for e-waste collection policy in India. The current study is expected to provide a platform for policymakers to design the e-waste collection policy.

Cost-benefit analysis of waste photovoltaic module recycling in China

With the rapid development of renewable energy, the impact on environment and resource caused by waste photovoltaic modules has been realized gradually. To solve the problem, recycling becomes an effectual way. Therefore, the aim of this paper was to assess the economic feasibility of the photovoltaic modules recycling project in China by using cost-benefit analysis. It was found that, under the estimated treatment quantity will generate in China in 2020-2034, the recovery cost per kilowatt (kW) of photovoltaic modules will be 25.11 USD, the unit benefit is 25.68 USD/kW, and the unit net benefit is 0.57 USD/kW. The net present value (NPV) and benefit-cost ratio (BCR) are 21.14 million USD and 1.023. The sensitivity analysis indicated that the sale benefits of recycled materials and tax were the most sensitive factors affecting the project's economy. Finally, we proposed ways to improve the economy for the government and related enterprises.

High-value utilization of waste tires: A review with focus on modified carbon black from pyrolysis

Recently, the recycling of waste tires has caused widespread concern for its environmental issues. The experience of the producer responsibility and tax system is of great beneficial to developing countries. The article also elaborates on the efforts of Chinese government to focus on establishing and perfecting waste tire treatment system by strengthen legislation. The main reasons such as immature market, non-uniform policy and repeated taxation for the survival difficulties of waste tire recycling enterprises in China are summarized. Among numerous resource methods, pyrolysis has been considered as a promising thermochemical process to deal with the waste tires. Unlike other similar reviews that mainly focus on its liquid phase, special attention has been given to solid char, pyrolysis carbon black, due to its wide application and high-value utilization in the future. We summarize the available research on application of pyrolysis carbon black as an alternative to commercial carbon black in rubber manufacture, as activated carbon in pollution control and as biochar for soil improvement. Analysis of the available data revealed that 1) the influence of temperature and time has been basically established; 2) catalyst type, dosage and reactor selection should be adjusted according to product demand; 3) pickling has become the primary means of improving pyrolysis carbon black; 4) the type of modifier and modification method must be adjusted according to the specific characteristics of the raw materials and needs to be combined with the experimental results to realize resource utilization and give full play to its economic value.

Economic and environmental feasibility of hydrometallurgical process for recycling waste mobile phones

Waste mobile phones contain significant amounts of valuable metals and non-metallic materials. Consequently, the extraction of valuable materials from discarded phones, which is a more cost-effective method compared with primary mining, is an essential step for maximizing the recovery of secondary resources and minimizing e-waste pollution. We designed a green and efficient path for recovering valuable metals from waste mobile phones and explored its technical feasibility from both environmental and economic perspectives through life cycle assessment and revenue expenditure model. The results showed that the hydrometallurgical process had three characteristics of high recovery efficiency, significant environmental friendliness and economic feasibility. The recovery efficiencies of valuable metals were higher than 90%. Simultaneously, the return on investment was 29%, indicating that the recycling enterprises can achieve self-sufficiency. Thirdly, the environmental benefits were more significant compared to environmental damage released by hydrometallurgical process, representing a significant environmental friendliness. Within the overall recycling process, the core process made the greatest contribution to the environmental burden (45.38-65.68%), followed by manual disassembly process. A comparison of sub-processes in core process revealed that the mechanical crushing and sorting phase had the greatest environmental impacts that were primarily attributed to power consumption. Consequently, future research should focus on the development of energy-efficient pretreatment techniques and energy-saving equipment. The industrial practice of recycling waste mobile phones is still in its infancy in China. Future studies should also focus on the comparing different treatment processes, with the aim of providing technical support for the advancement of industry.

A review on management of spent lithium ion batteries and strategy for resource recycling of all components from them

The wide use of lithium ion batteries (LIBs) has brought great numbers of discarded LIBs, which has become a common problem facing the world. In view of the deleterious effects of spent LIBs on the environment and the contained valuable materials that can be reused, much effort in many countries has been made to manage waste LIBs, and many technologies have been developed to recycle waste LIBs and eliminate environmental risks. As a review article, this paper introduces the situation of waste LIB management in some developed countries and in China, and reviews separation technologies of electrode components and refining technologies of LiCoO₂ and graphite. Based on the analysis of these recycling technologies and the structure and components characteristics of the whole LIB, this paper presents a recycling strategy for all components from obsolete LIBs, including discharge, dismantling, and classification, separation of electrode components and refining of LiCoO₂/graphite. This paper is intended to provide a valuable reference for the management, scientific research, and industrial implementation on spent LIBs recycling, to recycle all valuable components and reduce the environmental pollution, so as to realize the win-win situation of economic and environmental benefits.

Shredding and liberation characteristics of refrigerators and small appliances

Mechanical disaggregation, or shredding, is an important part of the recycling process. Occurring at the beginning of the processing sequence, it significantly affects the efficiency of downstream processing stages. This study examines the size reduction and liberation characteristics of the single-stage shredding of household appliances to improve the efficiency and quality of the recycling process. Several disposed appliances, including 75L refrigerators and five major categories of small appliances (vacuum cleaners, videocassette recorders (VCRs), electric rice cookers, fans, and electric heaters), were shredded using a high-speed vertical shredder under varying discharge clearance conditions. The fragments were analyzed according to size, composition, and degree of liberation. It was found that single-stage crushing with the high-speed vertical shredder was sufficient to produce fragments at an appropriate size and with a high degree of liberation. Based on the experimental results, an optimal shredding and separation scheme for the process is proposed.