Circular Economy最新文献

Hazardous waste from industrial production has become a global concern because of its impact on the environment and human health. However, studies on heavy metals in regional hazardous waste are rare. Thus, this study examined 93 hazardous waste samples in Beijing in 2019, to assess the distribution, occurrence, and potential eco-environmental risks of heavy metals in such waste. The results indicated high concentrations of Zn, Cu, and Ni in hazardous waste, and the leaching toxicity of Ni (270.60 mg/L), Cu (524.1 mg/L), and Pb (136.23 mg/L) exceeded Chinese identification standards for hazardous waste. Heavy metals in hazardous waste have been primarily found in remote counties around the locations of industrial enterprises. The total amount of the heavy metals followed the order: Zn > Cu > Ni > Ba > Mn > Pb. Based on the migration abilities of their detected forms, heavy metals were classified into three categories (high, middle, and low migration abilities) to characterize their potential to enter the environment. The detected amounts of heavy metals with high and middle migration ability followed the order: Zn > Cu > Ni > Mn > Pb > Ba. The potential environmental risk of heavy metals was evaluated using the potential environmental risk index, resulting in the following ranking: Ni > Pb > Mn > Zn > Cu > Ba. Daxing District exhibited the highest total environmental risk and environmental risk per unit area, whereas Miyun District showed the highest environmental risk per secondary sector of the economy and unit of GDP. This was attributed to Beijing's industrial structure. The results of this study provide fundamental data for the management and control of hazardous waste in Beijing and are expected to aid in preventing and managing environmental risks caused by such waste.

The wastewater circular economy promises improved environmental impacts within the food-water-energy nexus. This requires verification as the global sanitation sectors seek to improve environmental impacts and achieve integrated water management. Life cycle assessment (LCA) has been used to compare novel technologies for wastewater treatment and recovery, but research addressing plant-wide improvements of co-product resource recovery using real data from full-scale plants is still needed, particularly in a Latin American context. In Chile, two wastewater treatment plants (WWTPs) have embraced the circular economy configuration, recovering treated effluent, biosolids, and biogas, in addition to implementing advanced nitrogen removal using different technologies. The LCA of these two WWTPs demonstrated that Plant A improved 8 out of 10 impact categories compared to the baseline conventional scenario, while Plant B improved 5 categories out of 10. The analysis of the two plants showed the influence of influent quality on environmental impacts and the trade-off that occurs between the different technologies implemented. Plant B generated larger environmental credits through increased biogas and biosolids recovery due to thermal hydrolysis pre-treatment and anaerobic digestion, combined with cogeneration of heat and power. Plant A implemented water recovery, which provided benefits on a smaller magnitude but to more impact categories. Therefore, both plants improved environmental impacts through the wastewater circular economy, but further improvements in system configurations are recommended in each.

In recent years, the chemical production and waste generation have been rapidly increasing, presenting substantial hazards to the ecosystem and human well-being. To address this issue, a series of multilateral environmental agreements (MEAs) have been developed internationally, that provide essential decision-making support for the appropriate governance of chemicals and wastes in the participating countries. MEAs have established subsidiary bodies known as science-policy interface (SPI) institutions to provide evidence-based support and scientific assessments for environmental policies. However, the existing SPIs face limitations that hinder their ability to tackle the obstacles presented by the vast quantities of chemicals and wastes currently found in the environment. Therefore, the fifth session of the United Nations Environment Assembly made the decision to establish a science-policy panel to promote the effective management of chemicals and waste and to prevent pollution (SPP-CWP). This panel is intended to be an independent intergovernmental body, similar to the Intergovernmental Panel on Climate Change and Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services. The United Nations Environment Programme convened an ad hoc open-ended working group (OEWG) to design strategies for the SPP-CWP. Since 2022, three OEWG meetings have been conducted, and draft documents outlining the panel's scope, functions, operational principles, conflict of interest policy, institutional setup, work processes, and procedures have been formulated. In this article, we analyzed the background and development of the SPP-CWP and provided updates regarding the progress of the panel's establishment. We also suggested future trends for the SPP-CWP. We concluded that SPP-CWP will be a comprehensive and authoritative international body, providing policymakers with exhaustive reports, consequently strengthening the capacity of life cycle management of chemicals. Thus, the panel will effectively reduce or prevent waste production and pollution, promote material circulation, and minimize resource consumption, making significant contributions to the establishment of a circular economy and an environmentally friendly society.

Biological treatment technologies (such as anaerobic digestion, composting, and insect farming) have been extensively employed to handle various degradable organic wastes. However, the inherent complexity and instability of biological treatment processes adversely affect the production of renewable energy and nutrient-rich products. To ensure stable processes and consistent product quality, researchers have invested heavily in control strategies for biological treatment, with machine learning (ML) recently proving effective in optimizing treatment, predicting parameters, detecting disturbances, and enabling real-time monitoring. This review critically assesses the application of ML in biological treatment, providing an in-depth evaluation of key algorithms. This study reveals that artificial neural networks, tree-based models, support vector machines, and genetic algorithms are the leading algorithms in biological treatment. A thorough investigation of the applications of ML in anaerobic digestion, composting, and insect farming underscores its remarkable capacity to predict products, optimize processes, perform real-time monitoring, and mitigate pollution emissions. Furthermore, this review outlines the challenges and prospects encountered in applying ML to biological treatment, highlighting crucial directions for future research in this area.

This review focuses on standard Li recycling approaches for LiFePO₄ (LFP) and nickel−cobalt−manganese (NCM) cathodes. The study discusses about advances in leaching agents, including organic acid, alkaline solutions, natural organic acid, and electrochemical treatments. Emphasis is placed on the significance of selective Li leaching strategies to optimize the recycling of waste batteries. The review also outlines potential future research directions for enhancing selective recycling, providing valuable insights into the recycling of LFP and NCM batteries. Simultaneously, the article addresses the challenges associated with the transition from conventional lithium-ion batteries to all-solid-state batteries (ASSBs) in the pursuit of sustainable energy storage technologies. It highlights key points, including the challenges in developing ASSBs, the role of employing various material combinations and its preparation techniques, adopting scalable solution-based processes for commercialization, and strategies for sustainable ASSB recycling. The proposition of a fully recyclable ASSB model underscores the commitment to lower recycling costs using safer and simpler methods, positioning nanotechnology as an enabling tool for achieving advancements in materials and cell-level performance.

The production of plastic materials in the mid-20th century brought about transformative changes in consumer goods manufacturing and societal norms. However, this advancement paralleled an alarming surge in plastic pollution, driven by unrestrained consumption. This study focuses on the non-homogeneous and non-recyclable plastic waste (also known as plasmix in the Italian waste management), a residual blend resulting from plastic recycling processes. The main goals are to conduct an in-depth study of the plasmix landscape, to identify integration challenges, and to create a sustainable business model for broader adoption. Additionally, we aim to use life cycle assessment to examine the environmental effects of semi-finished plasmix-based materials that can be used to produce different products. This integrated approach ensures a holistic understanding of plasmix recycling, promoting both economic and environmental sustainability. The study contributes to sustainable waste management practices by offering a strategic approach to transform a challenging waste stream into economic opportunities. By addressing the market viability of plasmix-based products through an empirically supported business model, the research underscores the significance of recycling in mitigating plastic pollution and advancing a circular economy.

Electronic waste (e-waste) has increased because of the rapid replacement of electrical and electronic equipment. Owing to the increased emphasis on the dual properties of environmental contamination and metal resources, accurate identification of the e-waste recycling process is crucial. In this study, a product-level material flow analysis (MFA) is performed from a macroscopic social flow of waste TV sets in order to demonstrate the material metabolism of regional e-waste recycling. Previous studies have focused on the estimation of the quantity of e-waste generated or analyzing the overall amount of recycled resource output, the results derived from the estimation may have some unreliability, and our bottom-up research investigates the material flows that occur between the generation, collection and recycling of e-waste. MFA based on questionnaires and field research present accurate quantities and proportions of the recycling process. The results reveal that accelerating the construction of regional e-waste recycling systems and data networks and accurately identifying e-waste source, flow, and destination are required in order to improve resource efficiency toward carbon neutrality.