Waste Management & Research最新文献

This article proposes a framework for developing predictive models of end-of-life product flows, highlighting the importance of conducting thorough analyses before developing waste management and end-of-life product flow strategies. The framework emphasizes the importance of recognizing the nature and quality of the available data and finding a balance between model development time and detail requirements. It is designed to adapt to source material heterogeneity and address varying data availability scenarios, such as the presence or absence of radio frequency identification chips. A case study for the city of Gatineau is presented, showcasing the framework's application through agent-based simulation models in a geographic information systems environment. The study focuses on creating models of municipal solid waste generation based on socioeconomic and demographic factors and collection data to accurately predict the quantity and quality of waste streams, enabling municipalities to assess the environmental impact of their waste management strategies.

The development of the solar market has been fast in the past decades, and the number of photovoltaic module installations is large. The photovoltaic modules have a lifetime of about 25 years and need recovery after that. The aluminium-back surface field (Al-BSF) module is the first kind of large-scale installed module and will come to its end of life in the next few years. The recycling of silicon material in the Al-BSF module is investigated in this work. The components of the module are separated, and the silicon material in the module is collected and then purified by (aluminium-silicon) Al-Si solvent refining for reuse. It is found that Al-Si solvent refining removed key impurity elements, namely boron and phosphorus, in the collected silicon. Kinetics has a great effect on boron and phosphorus removal, and boron and phosphorus contents in purified silicon decrease with decreasing cooling rate. The boron and phosphorus contents in silicon are lowered to 0.28 and 0.03 ppmw, respectively, after two times of Al-Si solvent refining with the cooling rate of 5.55 * 10^-4 K second^-1, and it meets the requirement of solar-grade silicon.

In this systematic review, advancements in plastic recycling technologies, including mechanical, thermolysis, chemical and biological methods, are examined. Comparisons among recycling technologies have identified current research trends, including a focus on pretreatment technologies for waste materials and the development of new organic chemistry or biological techniques that enable recycling with minimal energy consumption. Existing environmental and economic studies are also compared. The findings highlight differences in the environmental characteristics of various recycling methods, including their ability to recover plastic resins, carbon footprint, electricity consumption and gas emissions. The comparisons also reveal the challenges associated with these methods: mechanical recycling often encounters economic barriers due to contamination and inefficiencies in sorting and cleaning processes; thermolysis is constrained by high energy demands and operational costs, whereas chemical and biological recycling faces limitations related to scalability and material costs. Additionally, current challenges, emerging research areas and future directions in plastic recycling are discussed. For example, the role of innovative techniques, such as artificial intelligence, in refining recycling processes is emphasized. The importance of incorporating circular economy principles in the integrated sustainable analysis of recycling processes is also highlighted. The innovative contribution of this review is to address both technological developments and their environmental and economic implications. The focus is placed on literature from the past 10 years to ensure coverage of the most recent advancements. Overall, the insights of this review article aim to guide researchers, policymakers and industry stakeholders in improving sustainable management practices for plastic waste.

Plastics are integral to modern life but present significant environmental and economic challenges due to ineffective waste management systems. This article provides a comprehensive review of global plastic waste management (PWM) strategies, focusing on advancements in processing technologies, policy frameworks and their practical applications. It highlights the role of the World Intellectual Property Organization (WIPO) and regulatory bodies across the United States, Canada, Europe, Britain, India, Japan, Australia and China in fostering sustainable PWM practices. The study evaluates key processing techniques, including pyrolysis, gasification, supercritical water conversion, plasma-assisted processes, mechanical reprocessing and landfilling, emphasizing their technological advancements, limitations and scalability. Supercritical water conversion (operating at >374°C and 22.1 MPa) and plasma-assisted processing (using ionized gas at >3000°C) are identified as advanced methods capable of converting plastics into simpler molecules or valuable by-products. However, these technologies face challenges such as high energy requirements, operational costs and limited scalability. Persistent issues, including microplastic pollution, environmental impacts and the chemical-intensive nature of certain processes, are critically analysed. Drawing on extensive reviews of patents, case studies and real-world implementations, the study also examines the reuse potential of plastic by-products in diverse industries and evaluates state-level PWM initiatives in India. This review provides actionable insights for policymakers, researchers and industry stakeholders, highlighting critical gaps and opportunities to enhance the sustainability and scalability of PWM systems. By addressing persistent challenges, it contributes to advancing a circular economy for plastics and sustainable waste management practices globally.

Construction and demolition waste (CDW) worldwide generation accounts 10 billion tonnes yearly. The major fraction is landfilled requiring innovative recycling methods to reduce the associated environmental impacts and to increase its circularity. Our study demonstrated the feasibility of using different CDW fines to develop recycled cements and optimized the content of CDW recycled cements with well-graded crushed stone (WGCS) for use as pavement base layer. We scaled up the study obtaining CDW cement and aggregates from a local recycling plant, as well as pilot pavement sections designed, constructed and field deflections measured. As results, the CDW cement pastes exhibited accumulated heat values of up to 111 J g^-1 and achieved a compressive strength of approximately 16 MPa. The unconfined compressive strength and resilient modulus (RM) achieved using CDW cement and WGCS were 2-3 and >3000 MPa, respectively. The sections constructed using CDW cement exhibited intermediate behaviour compared to those obtained using reference materials (6% Portland cement-WGCS and a conventional granular base made using WGCS). The deflection decreased over time owing to the pozzolanic reaction.

This mini-review aims at proving that waste-to-energy (WtE) is an essential cornerstone for circular economy (CE). Based on literature, the history of thermal waste treatment over the last 150 years is investigated, from open burning to WtE with resource recovery and final sink function. The results show that in the past incineration solved the issues it was designed for but often created new and sometimes even worse problems: The introduction of incineration in the 19th century improved urban sanitation, decreased waste volume and prolonged operational life of landfills. But it also polluted the environment, triggering an unprecedented scientific and engineering effort of all stakeholders. Today, WtE is one of the best investigated and optimized technologies in waste management. It enables the recovery of energy as heat and electric power and facilitates the 'cleaning' of cycles by the destruction of hazardous organic substances. Recent developments in resource recovery from WtE residues allow to recycle metals and, in the case of sewage sludge, even phosphorus by thermal recycling. Combined with carbon capture and storage technology, WtE stands for a quantifiable contribution to greenhouse gas reduction. Today, WtE is indispensable to reach the goals of CE, namely recycling of energy and materials, supplying safe final sinks for persistent organic substances and minimizing the need for sinks for hazardous inorganic substances.

The environmental problems caused by plastic pollution have increased at an astonishing speed. However, attempts to study the dynamics of plastic-reducing behaviours are few and far between. In this regard, based on the attitudinal-contextual-behavioural (ABC) theory of pro-environmental behaviours, this study conducts an online survey to analyse the functioning of media exposure on Chinese consumers' three types of plastic bag reducing behaviours during shopping, including saving inner plastic packaging bags by putting many goods into one bag, hand-carrying and bringing reusable bags. Employing the snowball sampling method, this study successfully collected 361 valid questionnaires for analysis. The findings of this study indicate that environmental concern and locus of control play mediating roles between media exposure and plastic-reducing behaviours. However, the study finds no supporting evidence for the mediating function of plastic pollution knowledge. These results have implications for plastic crisis managers and governmental officials. In designing media content for environmental education campaigns, it is advisable to prioritize strategies that evoke emotions over a sole focus on disseminating knowledge about plastic pollution.

Managing solid waste continues to be an environmental, technical and economic challenge, especially for developing countries. Though these countries' urban local bodies (ULBs) are moving up the waste management hierarchy, most waste is still openly dumped. One key reason for this choice is the non-accounting of (a) social costs associated with open dumping (OD) and (b) direct/indirect benefits of other options. The current study conducts a complete social cost-benefit analysis (SCBA) comparing OD to sanitary landfilling, composting, bio-methanation, incineration and gasification alternatives. The study finds that when only private costs/benefits are considered, a mix of OD and sanitary landfills is preferred; however, when external costs/benefits are factored in, the mix shifts towards alternatives like incineration and gasification. These learnings from the SCBA are then applied to Mumbai, which generates 9000 tonnes of waste daily. To determine the optimal mix for Mumbai ULB, a constrained optimization exercise is carried out considering the technical feasibility of the alternatives and the ULB's capital budget. The study finds that with the current practice of OD, the net present value (NPV) of the social costs over a 30-year horizon will be over US$ 6-9 billion. However, even if one-fifth of the ULB's capital budget is allocated towards other waste management alternatives, the mix would shift towards sophisticated technologies and the NPV of social costs would reduce to around half that amount.

Over the past decades, medical waste management (MWM) has evolved into a paramount global challenge, intertwining environmental sustainability and public health dimensions. This manuscript traces the paradigm shift from the foundational Basel Convention of 1989 to the significant sway of World Health Organization publications on contemporary debates. Utilizing a mixed approach strategy that blended qualitative and quantitative techniques, the research employed extensive literature review, co-citation and co-word analysis methodologies to ascertain the direction of contemporary trends in MWM. Within the scope of the research findings, current strategies reveal noticeable gaps, especially those that lack sound policy structures, comprehensive insights and effective operational frameworks. Co-citation evaluations spotlight predominant themes in academic references. Foremost among them are the socioeconomic factor, environmental significance, medical waste (MW) stabilization and sustainable society, sequenced by cluster magnitude. Co-word analysis unveils that, despite the long-standing presence of incineration plants, pyrolysis has, since 2016, prioritized environmental considerations. The recycling ethos peaked in 2014, but the sustainability paradigm burgeoned in 2020, with the 'circular economy' gaining momentum in 2021. Emerging trend analysis underscores the mounting significance of circular waste technologies and sustainability as indispensable solutions. Results demonstrate MW advancements and highlight emerging trends shaping the future of the field. The research concludes by accentuating the necessity of global collaborative efforts, integrating cutting-edge technologies and infusing sustainability and circularity tenets into societal frameworks to navigate MWM's intricate landscape. Future research trajectories, including wastewater governance, novel mobile waste disposal strategies and a cyclic waste classification paradigm, are proposed.

Cadmium (Cd)-enriched adsorbents wastes possess great environmental risk due to their large-scale accumulation and toxicity in the natural environment. Recycling spent Cd-enriched adsorbents into efficient catalysts for advanced applications could address the environmental issues and attain the carbon neutral goal. Herein, a facile strategy is developed for the first time to reutilize the alkali lignin (AL)-derived biochar (ALB) absorbed with Cd into cadmium sulphide (CdS)/C composite for the efficient methylene blue (MB) removal. The ALB is initially treated with Cd-containing solution, then the recycling ALB samples with adsorbed Cd are converted to the final CdS/C composite using NaS₂ as the sulphurizing reagent for vulcanization reaction. The optimal ALB400 demonstrates a high adsorption capacity of 576.0 mg g^-1 for Cd removal. Then the converted CdS/C composite shows an efficient MB removal efficiency of 94%. The photodegradation mechanism is mainly attributed to carbon components in the CdS/C composite as electron acceptor promoting the separation of photoelectrons/holes and slowing down the abrasion of CdS particles. The enhanced charge transfer and contact between the carrier and the active site thus improves the removal performance and reusability. This work not only develops a method for removing Cd from wastewater effectively and achieving the waste resource utilization but also further offers a significant guidance to use other kinds of spent heavy metal removal adsorbents for the construction of low-cost and high value-added functional materials.