Securing Indium Utilization for High-Tech and Renewable Energy Industries.

Indium has emerged as a strategic metal for high-tech and renewable industries, being catalogued as a critical material to foster a greener future. Nevertheless, its global sustainability is not well addressed. Here, using dynamic substance flow analysis, we study the indium industry evolution between 2010 and 2020 and estimate its future demand in the medium and long term toward 2050 to identify potential paths and mechanisms to decrease indium losses and to identify the key stages in its life cycle. As electronics and photovoltaic industries will play a crucial role in the indium demand, we assess their indium demand employing three cumulative photovoltaic capacity scenarios (8.5, 14, and 60 TW by 2050) with different dominant photovoltaic sub-technologies. Results show that liquid-crystal displays and photovoltaic panels will drive indium future demand, increasing its current demand by 2.2-4.2, 2.6-7.0, and 6.8-38.3 times for the 8.5, 14, and 60 TW scenarios, respectively, threatening with shortages that could occur as early as the next decade. Therefore, measures to reduce losses in primary production, innovations and improvements in electronics and solar panels, and indium recycling with an effective circular economy strategy could promote and secure the future sustainability of indium.

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

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.

Estimating the Evolution of Urban Mining Resources in Hong Kong, Up to the Year 2050.

Rapid urban metabolism is causing many resources to flow from consumption to waste. But many of these wastes could be secondary resources, and cities could become urban mines and an increasing supply of future resources. Hong Kong, one of the most developed and populated cities in the world, has demonstrated a completely metabolic evolution to be an urban mine, since the 1970s. Covering 14 types of e-waste and eight types of end-of-life vehicles, this study first investigates Hong Kong's evolution as an urban mine. The potential output weight of the urban mine quickly grew from 117 kt in 2000 to 368 kt in 2014, and it is estimated to remain in the range of 300-350 kt over the years 2015-2050, with 40-50 kg/cap/year. The economic potential of urban mining, for 18 metals, plastic, glass, and rubber tires, will be approximately US$2 billion annually, mainly contributed by precious and rare metals. All the obtained results contribute to Hong Kong's waste management and promise to have positive impact on urban mining and circular economy for other, less-developed cities or regions.

Examining the Temporal Demand and Sustainability of Copper in China.

A comprehensive study is carried out to determine (1) the annual historical demand and supply, (2) the annual prospective demand, and (3) the carrying capacity and future sustainability of copper resources in China. The results of the first analysis show that both the demand and the supply have substantially increased since 2000 after remaining relatively minute for the period from 1950 to 2000. By 2015, the per capita total and domestic demands had reached 7.6 and 5.4 kg, respectively. The annual demand prospects suggest that the copper demand will peak in 2030 and either stabilize or marginally drop thereafter. This was found to be the case for all population variants and demand growth rates that were considered herein, with the exception of the "stable scenario". Under the considered scenarios, the domestic demand in the year 2050 is predicted to fall by 6.7-15 million metric tons (Mt), while the total demand will likely fall by 9.4-21.2 Mt. The projected drastic increase in the cumulative primary demand suggests that China should pursue more industrially sustainable options. If the current trends continue, demand will likely surpass even the projected reserve base of 2050 sometime from 2025 to 2035 unless necessary actions to change the course are initiated as soon as possible. Chinese efforts to promote recycling in recent decades have been admirable but are not sufficient to meet the primary demand, thus leaving a large proportion of the demand to be met using imports. Thus, to reduce the primary copper imports, it is desirable to increase recycling rates to 60-70%. The shortcomings of the domestic recycling industry include poor end-of-life collection and an elastic policy framework. These issues merit attention in the short term to increase the long-term sustainability of copper resources in China.

Mineral processing simulation based-environmental life cycle assessment for rare earth project development: A case study on the Songwe Hill project.

Rare earth elements (REE), including neodymium, praseodymium, and dysprosium are used in a range of low-carbon technologies, such as electric vehicles and wind turbines, and demand for these REE is forecast to grow. This study demonstrates that a process simulation-based life cycle assessment (LCA) carried out at the early stages of a REE project, such as at the pre-feasibility stage, can inform subsequent decision making during the development of the project and help reduce its environmental impacts. As new REE supply chains are established and new mines are opened. It is important that the environmental consequences of different production options are examined in a life cycle context in order that the environment footprint of these raw materials is kept as low as possible. Here, we present a cradle-to-gate and process simulation-based life cycle assessment (LCA) for a potential new supply of REE at Songwe Hill in Malawi. We examine different project options including energy selection and a comparison of on-site acid regeneration versus virgin acid consumption which were being considered for the project. The LCA results show that the global warming potential of producing 1 kg of rare earth oxide (REO) from Songwe Hill is between 17 and 87 kg CO2-eq. A scenario that combines on-site acid regeneration with off-peak hydroelectric and photovoltaic energy gives the lowest global warming potential and performs well in other impact categories. This approach can equally well be applied to all other types of ore deposits and should be considered as a routine addition to all pre-feasibility studies.

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

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 promise to have positive impact on waste disposal and mining activities globally, as the circular economy comes to displace linear economic pathways.

Dynamic Stocks and Flows Analysis of Bisphenol A (BPA) in China: 2000-2014.

Bisphenol A (BPA), a synthetic organic chemical, is creating a new category of ecological and human health challenges due to unintended leakage. Effectively managing the use and leakage of BPA can benefit from an understanding of the anthropogenic BPA cycles (i.e., the size of BPA flows and stocks). In this work, we provide a dynamic analysis of the anthropogenic BPA cycles in China for 2000-2014. We find that China's BPA consumption has increased 10-fold since 2000, to ∼3 million tonnes/year. With the increasing consumption, China's in-use BPA stock has increased 500-fold to 14.0 million tonnes (i.e., 10.2 kg BPA/capita). It is unclear whether a saturation point has been reached, but in 2004-2014, China's in-use BPA stock has been increasing by 0.8 kg BPA/capita annually. Electronic products are the biggest contributor, responsible for roughly one-third of China's in-use BPA stock. Optical media (DVD/VCD/CDs) is the largest contributor to China's current End-of-Life (EoL) BPA flow, totaling 0.9 million tonnes/year. However, the EoL BPA flow due to e-waste will increase quickly, and will soon become the largest EoL BPA flow. The changing quantities and sources of EoL BPA flows may require a shift in the macroscopic BPA management strategies.

Chilling Prospect: Climate Change Effects of Mismanaged Refrigerants in China.

The global community has responded to the dual threats of ozone depletion and climate change from refrigerant emissions (e.g., chlorofluorocarbons, CFCs, and hydrofluorocarbons, HFCs) in refrigerators and air conditioners (RACs) by agreeing to phase out the production of the most damaging chemicals and replacing them with substitutes. Since these refrigerants are "banked" in products during their service life, they will continue to impact our environment for decades to come if they are released due to mismanagement at the end of life. Addressing such long-term impacts of refrigerants requires a dynamic understanding of the RACs' life cycle, which was largely overlooked in previous studies. Based on field surveys and a dynamic model, we reveal the lingering ozone depletion potential (ODP) and significant global warming potential (GWP) of scrap refrigerants in China, the world's largest producer (62%) and consumer (46%) of RACs in 2015, which comes almost entirely from air conditioners rather than refrigerators. If the use and waste management of RACs continue with the current trend, the total GWP of scrap refrigerants in China will peak by 2025 at a level of 135.2 ± 18.9 Mt CO2e (equal to approximately 1.2% ± 0.2% of China's total greenhouse gas emissions or the national total of either The Netherlands and Czech Republic in 2015). Our results imply an urgent need for improving the recycling and waste management of RACs in China.

Evaluating waste printed circuit boards recycling: Opportunities and challenges, a mini review.

Rapid generation of waste printed circuit boards has become a very serious issue worldwide. Numerous techniques have been developed in the last decade to resolve the pollution from waste printed circuit boards, and also recover valuable metals from the waste printed circuit boards stream on a large-scale. However, these techniques have their own certain specific drawbacks that need to be rectified properly. In this review article, these recycling technologies are evaluated based on a strength, weaknesses, opportunities and threats analysis. Furthermore, it is warranted that, the substantial research is required to improve the current technologies for waste printed circuit boards recycling in the outlook of large-scale applications.

Uncovering the Recycling Potential of "New" WEEE in China.

Newly defined categories of WEEE have increased the types of China's regulated WEEE from 5 to 14. Identification of the amounts and valuable-resource components of the "new" WEEE generated is critical to solving the e-waste problem, for both governmental policy decisions and recycling enterprise expansions. This study first estimates and predicts China's new WEEE generation for the period of 2010-2030 using material flow analysis and the lifespan model of the Weibull distribution, then determines the amounts of valuable resources (e.g., base materials, precious metals, and rare-earth minerals) encased annually in WEEE, and their dynamic transfer from in-use stock to waste. Main findings include the following: (i) China will generate 15.5 and 28.4 million tons WEEE in 2020 and 2030, respectively, and has already overtaken the U.S. to become the world's leading producer of e-waste; (ii) among all the types of WEEE, air conditioners, desktop personal computers, refrigerators, and washing machines contribute over 70% of total WEEE by weight. The two categories of EEE-electronic devices and electrical appliances-each contribute about half of total WEEE by weight; (iii) more and more valuable resources have been transferred from in-use products to WEEE, significantly enhancing the recycling potential of WEEE from an economic perspective; and (iv) WEEE recycling potential has been evolving from ∼16 (10-22) billion US$ in 2010, to an anticipated ∼42 (26-58) billion US$ in 2020 and ∼73.4 (44.5-103.4) billion US$ by 2030. All the obtained results can improve the knowledge base for closing the loop of WEEE recycling, and contribute to governmental policy making and the recycling industry's business development.

Assessing the sustainability of lead utilization in China.

Lead is not only one of heavy metals imposing environment and health risk, but also critical resource to maintain sustainable development of many industries. Recently, due to the shortage of fossil fuels, clean energy vehicles, including electric bicycle, have emerged and are widely adopted soon in the world. China became the world's largest producer of primary lead and a very significant consumer in the past decade, which has strained the supplies of China's lead deposits from lithosphere and boost the anthropogenic consumption of metallic lead and lead products. Here we summarize that China's lead demand will continually increase due to the rapid growth of electric vehicle, resulting in a short carrying duration of lead even with full lead recycling. With these applications increasing at an annual rate of 2%, the carrying duration of lead resource until 2030 will oblige that recycling rate should be not less than 90%. To sustain lead utilization in China, one approach would be to improve the utilization technology, collection system and recycling technology towards closed-loop supply chain. Other future endeavors should include optimizing lead industrial structure and development of new energy.

"Control-alt-delete": rebooting solutions for the E-waste problem.

A number of efforts have been launched to solve the global electronic waste (e-waste) problem. The efficiency of e-waste recycling is subject to variable national legislation, technical capacity, consumer participation, and even detoxification. E-waste management activities result in procedural irregularities and risk disparities across national boundaries. We review these variables to reveal opportunities for research and policy to reduce the risks from accumulating e-waste and ineffective recycling. Full regulation and consumer participation should be controlled and reinforced to improve local e-waste system. Aiming at standardizing best practice, we alter and identify modular recycling process and infrastructure in eco-industrial parks that will be expectantly effective in countries and regions to handle the similar e-waste stream. Toxicity can be deleted through material substitution and detoxification during the life cycle of electronics. Based on the idea of "Control-Alt-Delete", four patterns of the way forward for global e-waste recycling are proposed to meet a variety of local situations.

Win-Win: Anthropogenic circularity for metal criticality and carbon neutrality.

Resource depletion and environmental degradation have fueled a burgeoning discipline of anthropogenic circularity since the 2010s. It generally consists of waste reuse, remanufacturing, recycling, and recovery. Circular economy and "zero-waste" cities are sweeping the globe in their current practices to address the world's grand concerns linked to resources, the environment, and industry. Meanwhile, metal criticality and carbon neutrality, which have become increasingly popular in recent years, denote the material's feature and state, respectively. The goal of this article is to determine how circularity, criticality, and neutrality are related. Upscale anthropogenic circularity has the potential to expand the metal supply and, as a result, reduce metal criticality. China barely accomplished 15 % of its potential emission reduction by recycling iron, copper, and aluminum. Anthropogenic circularity has a lot of room to achieve a win-win objective, which is to reduce metal criticality while also achieving carbon neutrality in a near closed-loop cycle. Major barriers or challenges for conducting anthropogenic circularity are deriving from the inadequacy of life-cycle insight governance and the emergence of anthropogenic circularity discipline. Material flow analysis and life cycle assessment are the central methodologies to identify the hidden problems. Mineral processing and smelting, as well as end-of-life management, are indicated as critical priority areas for enhancing anthropogenic circularity. Electronic Supplementary Material: Supplementary material is available in the online version of this article at 10.1007/s11783-023-1623-2 and is accessible for authorized users.

Countries' vulnerability to food supply disruptions caused by the Russia-Ukraine war from a trade dependency perspective.

Disruptions of key food and fertilizer exports from Russia and Ukraine have exposed many countries to challenges accessing some commodities since these countries' war began. We evaluated the short-term, external, and direct impacts of disruptions of six food commodities and three types of fertilizer supplies from Russia and Ukraine on food access for all trading partners of the two countries by applying a set of trade and socioeconomic indicators. We found that the external food supplies of 279 countries and territories were affected to varying degrees; 24 countries-especially Georgia, Armenia, Kazakhstan, Azerbaijan, and Mongolia-are extremely vulnerable because they depend almost entirely on a variety of food imports from Russia and Ukraine. Access to fertilizers was affected in 136 countries and territories, particularly Estonia (potassic fertilizer), Mongolia (nitrogenous fertilizers), Kazakhstan (mixed fertilizers), and Brazil, the United States, China, and India (all types of fertilizers). An integrated assessment of countries' import types, purchasing power parity per capita, and populations indicated that the Democratic Republic of the Congo, Ethiopia, Egypt, and Pakistan are most vulnerable to such supply disruptions. Development of research into diversification and decentralization strategies for food access is needed to guide stable food supply policies.

Single-use plastic bag alternatives result in higher environmental impacts: Multi-regional analysis in country with uneven waste management.

Single-use plastics (SUPs) have been the focus of plastic pollution control, and limiting their use while shifting to other alternatives have been widely promoted in various countries. This study tries to verify the life cycle environmental performances of single-use plastic bag and its alternatives under different scenarios in real world. China is chosen as case study, where provincial variability is prominent in waste disposal, and strictest plastics ban has issued lately in this worldwide biggest market. The study found that HDPE plastic bags have relatively lowest environmental footprints regarding to Acidification Potential, Global Warming Potential, Chemical Oxygen Demand, Eutrophication Potential, Fossil Fuel Depletion Potential and Water Use. Sticking to current waste treatment, large-scale promotion of degradable products will increase environmental impacts by 1.4-22.6 times nationwide. Xinjiang has highest impact of using plastic bag at household level, due to its long-distance transport and high landfill ratio. Henan and Hebei will trigger the most significant changes in Global Warming Potential of 4.6 and 4.4 times if single-use plastic bags are all replaced with other alternatives. Uncertainty and sensitivity test further prove the robustness of results, and extends geographical implications of the findings. These suggest that introduction of new alternatives requires systematic deployment with full life cycle thinking, and SUPs pollution control should be a holistic transformation. Reducing bag weight while ensuring carrying capacity, purchasing local products to shorten transportation distances and shifting towards cleaner energy sources are synergetic ways to reduce the environmental impact of single-use plastic products.

Examining the Temporal and Spatial Models of China's Circular Economy Based upon Detailed Data of E-Plastic Recycling.

Examining the circular economy model is crucial to enable the scaling up of industry and anthropogenic circularity practice. Electrical and electronic waste plastic (e-plastic) has become the focus of urban mining and circular economy due to its rapid growth, valuable resource and potential risks. This article focuses on the recycling companies' experience in China from 2012 to 2017. The average recycling rate was 33.3% and the recycling amount in 2017 was 558 kt. A two-dimensional coupling model of economic development and renewable resources is firstly constructed. Eventually, four typical resource-based regional models are summarized, namely for demonstration regional model, commissioned regional model, traditional model and potential regional model. It also puts forward differentiated suggestions in terms of maintaining demonstration, strengthening policies, promoting transformation, and tapping potential. At the same time, it is recommended to explore the construction of large-region resource-based recycling centers and big data centers in resource-based demonstration areas.

Emerging anthropogenic circularity science: principles, practices, and challenges.

Material depletion over reliance of linear economies and environmental pollution may be resolved by applying the principles and practices of anthropogenic circularity science. Here we systematically review the emergence of anthropogenic circularity science in the interdisciplinary development of green chemistry, supply chain, and industrial ecology at different scales. The first, second, and third laws of circularity chemistry are proposed as forming the basic principles of circularity science. To close the loop on critical materials, these three basic principles have been exemplified in the anthropogenic circularity practices. We highlight the spatial distribution of critical metal, waste generation, and recycling rate. Future opportunities and challenges for a circular economy and urban mining will predominate in anthropogenic circularity. Therefore, anthropogenic circularity science will play an increasing role in enabling a smooth transition to a circular society.

Estimation of waste outflows for multiple product types in China from 2010-2050.

Material flow has been accelerated from underground natural minerals and is accumulating as aboveground waste stock. China is not only the largest producer and consumer of material-driven products, but also the largest generator of product waste. No official annual product waste data are released for China, which creates challenges especially in light of China's emerging waste management policies. Previous studies have presented only estimations of waste streams for single products. In this study, we considered three product types and 33 technological products and collected all the available data. A Kuznets curve and Bass diffusion model were employed to forecast their future consumption. Based on urban consumption metabolism, we created one systematic estimation model of product waste generation related to material flow and social regulation. Typical technological product waste outflows were estimated from 2010 to 2050, which can assist further material flow and environmental impact research, as well as waste management policy-making and technology development. The created model can be potentially extended to other types of product waste estimation.

Mapping anthropogenic mineral generation in China and its implications for a circular economy.

Anthropogenic mineral is absorbing wide concern in the context of circular economy, but its generation mechanism and quantity from product to waste remain unclear. Here we consider three product groups, 30 products, and use the revised Weibull lifespan model to map the generation of anthropogenic mineral and 23 types of the capsulated materials by targeting their evolution from 2010 to 2050. Total weight of anthropogenic mineral on average in China reached 39 Mt in 2010, but it will double in 2022 and quadruple in 2045. Stocks of precious metals and rare earths will increase faster than most base materials. The total economic potential in yearly-generated anthropogenic mineral is anticipated to grow markedly from 100 billion US$ in 2020 to 400 billion US$ in 2050. Furthermore, anthropogenic mineral of around 20 materials will be capable to meet projected consumption of three product groups by 2050.

Forecasting the temporal stock generation and recycling potential of metals towards a sustainable future: The case of gallium in China.

Gallium is one such co-product mineral, being used for consumer electronics and contemporary renewable energy applications. China is the top producer of gallium and supplies over 70% of global demand. However, supply uncertainty of primary gallium is increasing due to a shortage of reserves. Thus, development of recycling technologies to complement primary production should be prioritized, with more country-specific attention due to its low investment cost and short-term feasibility. In this study, possible end-of-life (EoL) gallium waste generation in China until 2050 was forecasted using linear regression and constructed a scenario analysis based on population and annual demand growth parameters. Similarly, cumulative domestic demand was estimated using 1%, 5%, 10%, 15%, 20%, and 30% recycling rates to investigate the effect of recycling on sustainability of gallium resources. Based on the used method, study results were different; however, continuous demand growth and resource use are expected in most cases. The annual total gallium stock generation in 2050 will reach to 368 t under linear regression forecasting while it will likely fall between 59 t and 148 t according to scenario analysis. Linear projections show that cumulative demand will surpass even reserve base in 2047 whilst scenario analyses demonstrate that cumulative demand will exceed reserve between 2037 and 2047, if there would be unable to implement necessary recycling routes in the short term. The linear regression cumulative demand prediction urges the need of substitution, while the scenario analysis demonstrates the importance of increasing EoL recycling rates. The latter should also be supported with improved EoL collection rates, technological transfer from high-tech countries to China and appropriate policy advancement. The output of the study also convinces the importance of moving towards a circular economic model in the anthropogenic flow of gallium utilization.