Large-scale lithium-ion batteries (LIBs) are overtaking as power sources for electric vehicles and grid-scale energy-storage systems for renewable sources. Accordingly, large amounts of LIBs are expected to be discarded in the near future. Recycling technologies for waste LIBs, particularly for valuable rare metals (Li, Co, and Ni) used in cathode active materials, need to be developed to construct continuous LIB supply chains. Various recovery methodologies, such as pyrometallurgy, hydrometallurgy, and direct recycling, as well as their advantages, disadvantages, and technical features, are briefly introduced. We review the electrochemical performances of these cathode active materials based on recycled rare metals from LIB waste. Moreover, the physicochemical properties and electrochemical performance of the cathode active materials with impurities incorporated during recycling, which have high academic significance, are outlined. In hydrometallurgy-based LIB recycling, the complete removal of impurities in cathode active materials is not realistic for the mass and sustainable production of LIBs; thus, optimal control of the impurity levels is of significance. Meanwhile, the studies on the direct recycling of LIB showed the necessity of almost complete impurity removal and restoration of physicochemical properties in cathode active materials. This review provides a survey of the technological outlook of reusing cathode active materials from waste LIBs.

Improving waste and resource management (WaRM) around the world can halve the weight of plastics entering the oceans, significantly mitigate global heating and contribute directly to 12 of 17 sustainable development goals (SDGs). Achieving such results demands understanding and learning from historical evolution of WaRM. The baseline is 1970, prior to environmental legislation. Early steps in the Global North focused on the \'technical fix\' within strictly enforced legal frameworks, first bringing hazardous wastes and municipal solid wastes (MSW) under control, then gradually ramping up environmental standards. Using modern technologies to the Global South often failed due to institutional and financial constraints. From 1990, focus switched to integrating technical and governance aspects: local institutional coherence, financial sustainability, provider inclusivity, user inclusivity, national legislative and policy framework. The Global North rediscovered recycling, using policy measures to promote segregation at source; this relied on new markets in emerging economies, which had largely disappeared by 2020. The Global South is making progress on bringing wastes under control, but around 2.7 billion people lack access to waste collection, while ~40% of collected MSW is open dumped or burned - a continuing global waste emergency. So, much remains to be done to move further towards a circular economy. Three policy priorities are critical for all countries: access to sustainable financing, rethinking sustainable recycling and worldwide extended producer responsibility with teeth. Extending services to unserved communities (SDG11.6.1) requires a people-centred approach, working with communities to provide both quality services and decent livelihoods for collection and recycling workers.

Cigarettes are the globally consumed product that contributes to public health problems and is the source of the most prevalent form of litter in the world, Cigarette butts. Cigarette butts are a major source 4000 toxic chemicals, affecting the health of wildlife, humans, and the environment and their decomposition can take years due to the resistance of cellulose acetate to bacterial and fungal degradation. In 2016, the world production of cigarettes exceeded 5.7 trillion, with the majority of them consisting of cellulose acetate filters. Consequently, a massive amount of hazardous waste leaches out in the environment. Incineration and landfilling are methods of disposal, but they can result in the emission of harmful fumes and be costly. To combat this environmental issue, researchers have explored the recycling of cigarette butts in various materials, including asphalt concrete, fired clay bricks, and as a carbon source, among others. Various approaches can be used to reduce cigarette butts pollution, but efficient collection logistics by consumers remains a crucial factor for successful recycling. This paper provides innovative solutions to mitigate the cigarette butts litter problem and the feasibility of recycling methods. Despite recent progress in cigarette butts recycling solutions, there is still much room for research in this area.

Electric vehicles (EVs) are one of the most promising decarbonization solutions to develop a carbon-negative economy. The increasing global storage of EVs brings out a large number of power batteries requiring recycling. Lithium iron phosphate (LFP) is one of the first commercialized cathodes used in early EVs, and now gravimetric energy density improvement makes LFP with low cost and robustness popular again in the market. Developments in LFP recycling techniques are in demand to manage a large portion of the EV batteries retired both today and around ten years later. In this review, first the operation and degradation mechanisms of LFP are revisited aiming to identify entry points for LFP recycling. Then, the current LFP recycling methods, from the pretreatment of the retired batteries to the regeneration and recovery of the LFP cathode are summarized. The emerging direct recovery technology is highlighted, through which both raw material and the production cost of LFP can be recovered. In addition, the current issues limiting the development of the LIBs recycling industry are presented and some ideas for future research are proposed. This review provides the theoretical basis and insightful perspectives on developing new recycling strategies by outlining the whole-life process of LFP.

Electrifying transportation through the large-scale implementation of electric vehicles (EVs) is an effective route for mitigating urban atmospheric pollution and greenhouse gas emissions and alleviating petroleum-derived fossil fuel reliance. However, huge dumps of spent lithium-ion batteries (LIBs) have emerged worldwide as a consequence of their extensive use in EVs. With the increasing shortage in LIB raw materials, the recycling of spent LIBs has become a fundamental part of a sustainable approach for energy storage applications, considering the potential economic and environmental benefits. In this mini-review, we will provide a state-of-the-art overview of LIB recycling processes (e.g., echelon utilization, pretreatment, valuable metal leaching and separation). We then discuss the sustainability of current LIB recycling processes from the perspectives of life cycle assessment (LCA) and economic feasibility. Finally, we highlight the existing challenges and possibilities of LIB recycling processes and provide future directions that can bridge the gap between proof-of-concept bench demonstrations and facility-scale field deployments through mutual efforts from academia, industry, and government. It is expected that this review could provide a guideline for enhancing spent LIB recycling and facilitating the sustainable development of the field.

Huge quantities of unwanted pharmaceuticals are left in households, notably as a consequence of the rising drug demand caused by improved healthcare and the aging population. Unwanted pharmaceuticals may thus easily end up polluting ecosystems upon disposal. This pharmaceutical waste issue has been aggravated during the coronavirus disease pandemic (COVID-19) by excess prescription and panic buying. Unwanted household pharmaceuticals are normally collected by owners and volunteers, then incinerated in centralized facilities, yet with low efficiency during the COVID-19 lockdowns. Most pharmaceuticals could be recycled because they are rather stable, however there is actually no sustainable strategy to manage unwanted pharmaceuticals in a pandemic. Here I review the management of unwanted pharmaceuticals in households during the pandemic, with emphasis on drug take-back programs, waste minimization and recycling efforts. Reducing pharamaceutical waste could be done by informing people on what to do with unwanted pharmaceutical products; using machine-readable codes for automatic sorting; and applying existing techniques for recovery of active pharmaceutical ingredients for reuse. I propose a new strategy where owners sort their unwanted pharmaceuticals and submit information online. This will generate coded mailing labels that allow the owner to separate pharmaceuticals into categories such as opened, unused, expired, and non-expired. Once collected by recycling facilities and manufacturers, active ingredients will be extracted to create new pharmaceuticals which will be recycled to other patients.

We face an urgent and complex challenge to produce large amounts of healthful animal and plant foods for an estimated 10 billion people by 2050 while maintaining essential ecosystem services. To compound this challenge, we must do so while not further degrading our environment and conserving essential nutrients such as copper, magnesium, phosphorus, selenium, and zinc that are in short supply for fertilization. Much good research has been done, but to meet this challenge, we need to greatly increase on-farm and watershed-scale research including on-farm evaluations and demonstrations of the putative best combinations of stewardship techniques over multiple years in real-world settings, which are backed by data on nutrient inputs, soil, air, and water chemistry (fluxes) and water discharge. We also need to work with farmers, specialists, and generalists in highly creative interdisciplinary teams that resist forming silos and that use combinations of techniques linked to agroecology and industrial ecology in combination with state-of-the-art engineering. Some of these research and demonstration farms need to be in catchments prone to pollution of aquatic and terrestrial ecosystems with nitrogen, phosphorus, and other nutrients. Some promising approaches include mixed crop-livestock systems, although these alone may not be productive enough without updating to meet the dietary needs of an estimated 10 billion people by 2050. Other approaches could be state-of-the-art multi-trophic production systems, which include several species of plants integrated into production with vertebrates (e.g., ruminants, pigs, poultry), invertebrates (e.g., insects, earthworms) and fish, shrimp, or crayfish to utilize wasted feed and excreta, and recycle nutrients back to the animals (via plants or invertebrates) in the systems. To cut costs and increase desirable outputs, we must recycle nutrients much better within our food production systems and produce both animal and plant foods more efficiently as nutrients cycle through systems.

Recovery and recycle of wastewater are essential because of the need of huge quantities of water everywhere in this world. Presence of heavy metals in wastewater such as iron (Fe), molybdenum (Mo), manganese (Mn), zinc (Zn), nickel (Ni), copper (Cu), vanadium (V), cobalt (Co), tungsten (W), chromium (Cr), arsenic (As), silver (Ag), antimony (Sb), cadmium (Cd), mercury (Hg), lead (Pd), uranium (U), etc is the serious environmental issues and risk for human and animal health. Adsorbents are simple and low-cost methods to treat the pollutants and heavy metals of wastewater. The adsorbents are capable to treat the wastewater prepared from different wastes such as domestic, agricultural, industrial, animal and marine waste etc. In recent years, novel nanomaterials are also used as adsorbents which enhance the treatment efficiency of wastewater. Adsorption is a mass transfer phenomenon revolving shift of elements from a fluid to a solid phase based on the concentration gradient. The mechanism which helps in separation of contaminants from the effluent and the factors governing the efficiency of adsorption are discussed elaborately.

Municipal solid waste management is one of the major issues throughout the world. Inappropriate management of municipal solid waste (MSW) can pose a major hazard. Anaerobic processing of MSW followed by methane and biogas generation is one of the numerous sustainable energy source options. Compared with other technologies applicable for the treatment of MSW, factors like economic aspects, energy savings, and ecological advantages make anaerobic processing an attractive choice. This review discusses the framework for evaluating conversion of municipal solid waste to energy and waste derived bioeconomy in order to address the sustainable development goals. Further, this review will provide an innovative work foundation to improve the accuracy of structuring, quality control, and pre-treatment for the ideal treatment of different segments of MSW to achieve a sustainable circular bioeconomy. The increasing advancements in three essential conversion pathways, in particular the thermochemical, biochemical, and physiochemical conversion methods, are assessed. Generation of wastes should be limited and resource utilization must be minimised to make total progress in a circular bioeconomy.

As a critical and strategic metal, tungsten is widely used in the fields of machinery, mining and military industry. With most of the tungsten resources reserves in the world, China is the largest producer and exporter of tungsten. This has resulted in the generation of a huge amount of tungsten slag (slag) stored in China. This slag always contains not only valuable elements, such as tungsten (W), scandium (Sc), tin (Sn), niobium (Nb) and tantalum (Ta), but also toxic elements, such as arsenic (As), lead (Pb), chromium (Cr) and mercury (Hg). Due to a lack of developed technologies, most of these slags cannot be treated safely, which results in a waste of resources and serious environmental and ecological risks. In this review we briefly describe the distribution and proportion of tungsten deposits in China, the tungsten extraction process and the properties of tungsten slag. We also mainly discuss the comprehensive treatments for the valuable and toxic slag, including the amounts of valuable metal elements that can be recovered and the stabilization of toxic elements. These aspects are summarized in a comparison of their advantages and disadvantages. In particular, we focus on the efforts to analyze the relationship between the existing processes and attempts to establish a comprehensive technology to treat tungsten slag and also suggest areas for future research.