Qifei Huang

Bio: Qifei Huang is an academic researcher. The author has contributed to research in topics: Material flow analysis & Household hazardous waste. The author has an hindex of 3, co-authored 4 publications receiving 184 citations.

Hazardous waste generation and management in China: A review

Abstract: Associated with the rapid economic growth and tremendous industrial prosperity, continues to be the accelerated increase of hazardous waste generation in China. The reported generation of industrial hazardous waste (IHW) was 11.62 million tons in 2005, which accounted for 1.1% of industrial solid waste (ISW) volume. An average of 43.4% of IHW was recycled, 33.0% was stored, 23.0% was securely disposed, and 0.6% was discharged without pollution controlling. By the end of 2004, there were 177 formal treatment and disposal centers for IHW management. The reported quantity of IHW disposed in these centers was only 416,000 tons, 65% of which was landfilled, 35% was incinerated. The quantity of waste alkali and acid ranked the first among IHW categories, which accounted for 30.9%. And 39.0% of IHW was generated from the raw chemical materials and chemical products industry sectors. South west China had the maximum generation of IHW, accounted for 40.0%. In addition, it was extrapolated that 740,000 tons of medical wastes were generated per year, of which only 10% was soundly managed. The generation of discarded household hazardous waste (HHW) is another important source of hazardous waste. A great proportion of HHW was managed as municipal solid waste (MSW). Hazardous waste pollution controlling has come into being a huge challenge faced to Chinese environmental management.

Rethinking China's strategic mineral policy on indium: implication for the flat screens and photovoltaic industries

Abstract: Indium is an indispensable component of many products, especially the liquid crystal displays (LCD) flat screens (FS) and thin film photovoltaic (PV) cells. China is the world's largest producer of primary indium and products containing indium. Despite this, there has been relatively little examination of the scarcity and strategic mineral policy for indium. Using a material flow analysis approach, a dynamic model has been built to quantify the indium flows, availability, and scarcity in China. The results show that China has transitioned from primarily exporting indium to primarily consuming indium. Forecasting until the year 2020, the domestic demand is led by LCD televisions and monitors (74%), followed by laptops (8%), and PV cells (5%). Accumulated use of indium in production from 2011 to 2020 could reach 7800 t, that is close to China's estimated 2008 reserves and represents three-fourths of the world's current total reserves. Despite this, end of life (EoL) recycling is forecasted to be too insignificant to influence the indium market supply in the short term. Therefore, by the year around 2020, China could face a serious shortage of both primary production and EoL-recovered indium to meet the production demand. From a long-term perspective, the world's development and installation of thin-film PV modules could be significantly threatened because indium demand within PV modules could grow rapidly over the coming decades. A promising solution to prevent an indium shortage in China is to promote the urban mining of indium from the EoL FS and PV industries. Copyright © 2015 John Wiley & Sons, Ltd.

Converting spent lithium cobalt oxide battery cathode materials into high-value products via a mechanochemical extraction and thermal reduction route.

Abstract: This study innovatively combines mechanochemistry and high-temperature thermal reduction to achieve the recovery of valuable metals from spent LIBs. First, under the action of mechanical force, the crystal structure of lithium cobalt oxide (LiCoO2) found in the cathode materials of spent LIBs was destroyed and converted into lithium carbonate (Li2CO3) and Li-free residue (C/Co3O4) using dry ice as a co-grinding reagent. The optimum Li2CO3 recovery conditions were determined to be as follows: a ratio of dry ice: LiCoO2 powder mass of 20:1; a rotation speed of 700 rpm, and a reaction time of 1.5 h. With these conditions the maximum percentage of Li2CO3 recovered was 95.04 wt%. The Co3O4 in Li-free residue was reduced to a high-value Co0 product via a high-temperature (800 °C) heat treatment. Gibbs free energy analysis confirmed that the carbon in the Li-free residue could be used as a self-reducing reagent for the thermal reduction of Co3O4. The reactants and products of each step were characterized by XRD, FT-IR, XPS and SEM techniques. The green route for recycling spent LIBs that this study proposes realizes the green and cost-effective conversion of LiCoO2 to high-value products, which may become an outstanding example of recycling spent LIBs.

Quantifying material flow of oily sludge in China and its implications.

Abstract: Oily sludge is classified as hazardous waste. If not treated properly, it can cause negative impacts on human health and the ecological environment. However, the current lack of macro and micro scientific understanding of the treatment of oily sludge hinders its sound management. In this study, at the microlevel, we selected two of the most common treatment processes of oily sludge and establish a database through data collection and estimation. Material flow analysis was adopted to reveal the generation, pretreatment, recycling, and disposal processes of mechanical separation and incineration. At the macrolevel, this article predicted the material flow of China's whole process management of oily sludge and analyzed the typical flow characteristics of valuable resources in the whole process to guide the formulation of relevant policies in the future. The annual generation of oily sludge in China was between 4.45 and 6.22 Tg, and the average comprehensive utilization rate was approximately 36%. We are still far away from a sound management system despite new legislative revisions. Close supervision and technical processes should be further enhanced shortly.

An inventory of trace element inputs to agricultural soils in China.

Abstract: It is important to understand the status and extent of soil contamination with trace elements to make sustainable management strategies for agricultural soils. The inputs of trace elements to agricultural soils via atmospheric deposition, livestock manures, fertilizers and agrochemicals, sewage irrigation and sewage sludge in China were analyzed and an annual inventory of trace element inputs was developed. The results showed that atmospheric deposition was responsible for 43-85% of the total As, Cr, Hg, Ni and Pb inputs, while livestock manures accounted for approximately 55%, 69% and 51% of the total Cd, Cu and Zn inputs, respectively. Among the elements concerned, Cd was a top priority in agricultural soils in China, with an average input rate of 0.004 mg/kg/yr in the plough layer (0-20 cm). Due to the spatial and temporal heterogeneity of the sources, the inventory as well as the environmental risks of trace elements in soils varies on a regional scale. For example, sewage sludge and fertilizers (mainly organic and phosphate-based inorganic fertilizers) can also be the predominant sources of trace elements where these materials were excessively applied. This work provides baseline information to develop policies to control and reduce toxic element inputs to and accumulation in agricultural soils.

A review on the growing concern and potential management strategies of waste lithium-ion batteries

Abstract: This review paper discusses the available literature on end-of-life lithium-ion batteries (LIBs) from a waste management standpoint. The amount of LIBs entering the waste stream has increased in recent years because of their growing prevalence in electronic devices and vehicles. The electric vehicle (EV) industry, in particular, is expected to create a high demand for LIBs and this paper has identified them as a major contributor to the LIB waste stream in the near future. Waste LIBs exhibit many hazardous characteristics, such as the ability to spontaneously ignite and/or release hazardous chemicals under landfill conditions. The authors review the current findings with regards to their hazardous properties and present potential solutions to help mitigate these problems. One major solution is to manage LIBs as a hazardous or universal waste, which would entail special regulations for this waste stream. While lead-acid and nickel-cadmium batteries are often regulated as a hazardous or universal waste, most countries, such as the U.S., currently manage LIBs as a general solid waste. However, it may be plausible to consider these types of batteries as a hazardous or universal waste because they have frequently exceeded federal and state regulatory thresholds for certain metals, such as lead. This paper also identifies recycling as another major solution for end-of-life LIB management. Based on life cycle impact assessment studies, recycling certain types of LIBs results in a lower resource depletion potential and less air emissions than a cradle-to-grave management scenario.

Global status of recycling waste solar panels: A review

Abstract: With the enormous growth in the development and utilization of solar-energy resources, the proliferation of waste solar panels has become problematic. While current research into solar panels has focused on how to improve the efficiency of the production capacity, the dismantling and recycling of end-of-life (EOL) panels are seldom considered, as can be seen, for instance, in the lack of dedicated solar-panel recycling plants. EOL solar-panel recycling can effectively save natural resources and reduce the cost of production. To address the environmental conservation and resource recycling issues posed by the huge amount of waste solar panels regarding environmental conservation and resource recycling, the status of the management and recycling technologies for waste solar panels are systemically reviewed and discussed in this article. This review can provide a quantitative basis to support the recycling of PV panels, and suggests future directions for public policy makers. At present, from the technical aspect, the research on solar panel recovery is facing many problems, and we need to further develop an economically feasible and non-toxic technology. The research on solar photovoltaic panels' management at the end of life is just beginning in many countries, and there is a need for further improvement and expansion of producer responsibility.

Solving spent lithium-ion battery problems in China: Opportunities and challenges

Abstract: Consumer electronics (CE) and electric vehicles (EVs) associated with renewable and sustainable energy have been rapidly changing human lifestyles and transportation habits since 1990s. These active innovations have resulted in a large amount of spent lithium-ion batteries (LiBs) in China. At least two problems are declining the sustainability of production and final disposal of LiBs: one is potential environmental and health risk, and the other is that more and more valuable resources are being stored in spent LiBs without appropriate recycling. We found that a lack of effective regulation, collection systems and recycling technologies are major barriers and challenges to solve the problems. And in order to develop a comprehensive management scheme for this waste stream in China, we proposed a three-pronged approach: (1) new regulation or policy is quite a necessity to deal with the challenges unique to spent LiBs recycling; (2) collection systems for CE and EV batteries can be substantially established based upon past experience of general e-waste management and extended producer responsibility, respectively; and (3) more emphasis needs to be placed on new technology for spent LiBs recycling, to tackle the large quantities of stored spent LiBs.

Urban Mining of E-Waste is Becoming More Cost-Effective Than Virgin Mining

Abstract: Stocks of virgin-mined materials utilized in linear economic flows continue to present enormous challenges. E-waste is one of the fastest growing waste streams, and threatens to grow into a global problem of unmanageable proportions. An effective form of management of resource recycling and environmental improvement is available, in the form of extraction and purification of precious metals taken from waste streams, in a process known as urban mining. In this work, we demonstrate utilizing real cost data from e-waste processors in China that ingots of pure copper and gold could be recovered from e-waste streams at costs that are comparable to those encountered in virgin mining of ores. Our results are confined to the cases of copper and gold extracted and processed from e-waste streams made up of recycled TV sets, but these results indicate a trend and potential if applied across a broader range of e-waste sources and metals extracted. If these results can be extended to other metals and countries, they p...