Search Results (3,450)

Chinese home-cooked dishes (CHCDs) link agricultural production and daily consumption, but their resource dependence and sustainability remain poorly quantified. We standardized 341 recipes from China’s 34 provincial-level administrative regions, conducted a production-to-consumption analysis using emergy (solar-equivalent available energy directly and indirectly required for a product or service), and evaluated six optimization scenarios. Mean emergy input was 5.93 × 10¹² sej·dish⁻¹, with nonrenewable purchased inputs accounting for 77.99%. Ingredients, oil and sauces, and cooking contributed 69.17%, 21.69%, and 9.14%, respectively. Plant-based production relied on labor and chemical inputs; animal-based production relied on feed. Ruminant meats had relatively high nonrenewable inputs and environmental loads; vegetables had lower values. Across CHCDs, the emergy sustainability index (ESI), transformity, emergy consumption intensity, and food processing intensity averaged 0.26, 1.02 × 10⁶ sej·J⁻¹, 1.45 × 10¹² sej·serving⁻¹, and 4.64 × 10¹¹ sej·serving⁻¹, respectively. Sustainability declined from plant-based through mixed to animal-based dishes. Shandong cuisine ranked highest and Zhejiang cuisine lowest in combined sustainability and efficiency. Combining crop–livestock recycling, mechanization and energy-efficiency improvements, technological advancement and scaling up, moderate oil and sauce reduction, and cooking-efficiency improvements was projected to increase ESI by 19.34% relative to baseline. These results support dish-level emergy accounting for improving agri-food sustainability. Full article

Amid global economic uncertainty caused by the COVID-19 pandemic and geopolitical conflict, countries worldwide have prioritized urban economic resilience (UER). Using panel data for 283 Chinese cities from 2012 to 2023, this paper applies a difference-in-differences model to estimate the effect of the Pilot Battery Recycling Policy (PBRP) on UER. The results show that: (1) The estimated PBRP coefficient is positive at 0.004 units, equivalent to approximately 4.5% of the sample mean, and the result remains stable across a series of robustness and identification tests. (2) The mechanism and bootstrap mediation analyses provide evidence consistent with three potential city-level transmission channels associated with pilot designation: higher government technology spending, improved energy utilization, and greater total factor productivity. (3) The policy effect is positive and significant in upstream and downstream cities of the Yangtze River Basin, declining resource-based cities, and medium- and small-sized cities; it is negative in regenerative resource-based cities and megacities, while the remaining subgroup estimates are statistically insignificant. The subgroup patterns indicate that industrial foundations, adjustment costs, market capacity, and city scale may help shape policy effectiveness. (4) The Spatial Durbin Model identifies a positive direct effect on pilot cities and a negative indirect effect on neighboring cities under both selected spatial weight matrices. The matrix-specific admissibility and numerical checks confirm the validity of the spatial decomposition. Taken together, the findings point to a positive contribution of pilot designation to local economic resilience. The city-level results point to technological investment, energy-use efficiency, and productivity growth as potential transmission channels, while regional coordination can help manage cross-city competition for recycling resources and capacity. Full article

This paper presents a comprehensive review of bituminous binder modification using Styrene–Butadiene–Styrene (SBS) copolymer. Bitumen is one of the most widely used binder types in road engineering, and its modification has been extensively studied to enhance performance characteristics. The review outlines the historical development of bitumen modification, discusses binder structural models, and examines the influence of SBS on binder properties. The review focuses on ageing process of Polymer-Modified Bitumen (PMB) and Highly Modified Bitumen (HiMA). The complexity of binder’s origin, polymer structure, ageing factors and the presence of cross-linking agents or other compounds creates significant challenges in predicting binder performance after technological and exploitation ageing. This uncertainty directly affects the assessment of long-term durability and recycling potential. Therefore, it is relevant to incorporate a broader range of ageing factors into standardized laboratory testing procedures to develop effective rejuvenation strategies for SBS-modified PMBs. Full article

The textile industry plays a significant role in global economic growth, employment, and trade, yet it is among the most resource-intensive and environmentally damaging sectors. Growing concerns about waste, resource scarcity, and pollution highlight the need to shift from linear production towards circular economy systems. In this transition, eco-design has become a key strategy, because it supports circular practices such as durability, repairability, reuse, and recyclability. Although research is growing, work on eco-design in circular textile systems remains scattered, and there is limited understanding of how eco-design principles are integrated into circular economy practices and which factors influence their success. To address this gap, a systematic literature review of 49 peer-reviewed articles was conducted using the SPAR-4-SLR method, and the mechanisms linking eco-design to circular textile systems were identified through thematic synthesis. The organizational, technological, and regulatory factors shaping implementation were also analyzed. The results show that eco-design integration occurs at the product, process, and system levels and requires a combination of technological innovation, organizational capability, and supportive regulation. This review consolidates fragmented knowledge of eco-design within circular economy frameworks and offers insights into the conditions needed to enable circular transformation in the textile sector. Full article

The growing demand for sustainable and affordable housing requires construction systems that reduce material consumption, embodied environmental impacts, construction waste, and life-cycle costs while retaining the value of building components across multiple use cycles. This study presents a systematic scoping review and evidence map of circular economy strategies and reuse readiness in modular sustainable and affordable housing. A structured literature search covering publications from 2016 to 2026 identified 283 records, of which 49 studies were included following screening and eligibility assessment. The included studies were coded according to circular economy strategies within the 0R–10R framework, building life-cycle stages, modular technology typologies, sustainability and affordability indicators, and reuse-readiness attributes. The evidence map shows that the literature remains predominantly focused on life-cycle assessment, carbon emissions, waste reduction, reuse, and recycling. In contrast, early-stage circular strategies, including refuse, rethink, reduce, and redesign, as well as repair, refurbishment, remanufacturing, social value, life-cycle affordability, and operational reuse readiness, remain insufficiently examined. The findings further demonstrate that prefabrication or modularity alone does not ensure circularity. High reuse readiness depends on demountable connections, non-destructive disassembly, component standardization, durability, repairability, material traceability, reverse logistics, and credible second-life scenarios. Based on the mapped evidence, this study develops an evidence-informed Integrated Digital Circular Modular Ecosystem pathway that connects circular design, material passports, reuse-readiness assessment, BIM and digital twins, component grading, reverse logistics, circular marketplaces, and life-cycle performance evaluation. By integrating reuse readiness, life-cycle affordability, and digital traceability within a single evidence-informed pathway, the study provides a structured basis for researchers, policymakers, and industry stakeholders to evaluate and advance modular housing beyond construction efficiency toward long-term circularity and component value retention. As a conceptual synthesis, the pathway requires further validation through expert assessment and application to actual modular housing projects. Full article

The Australian construction industry generated approximately 29.2 million metric tonnes (Mt) of construction and demolition waste (C&DW) in 2022–2023, of which about 23.7 Mt (81.2%) was recovered, primarily through recycling (80.6%). Recovery concentrated on concrete, bricks, and rubble from large constructions, while C&DW from smaller projects was often directed to landfills. Most recovered materials are downcycled, have low market demand and contribute to unstable markets and continued reliance on virgin materials. To investigate these gaps, nine semi-structured expert interviews, two case studies, and a SWOT (Strengths, Weaknesses, Opportunities and Threats) analysis were conducted. The findings were organised into four clusters: (1) regulatory and governance, (2) operational and technological, (3) procurement, cost and market, and (4) stakeholder management barriers significantly impact C&D waste management practices. The study recommends four drivers and six enablers to enhance circular economy 3R (reduce, reuse, recycle) practices, including standardisation and harmonisation of reused and recycled products’ quality and cost, mandating circular procurement, increasing incentives and penalties, on-site sorting, awareness and capacity building, and digital technology application for data management. This integrated approach can guide policymakers and practitioners in strengthening C&DW reduction practices and developing an economically viable market for reused and recycled products. Full article

Circular economy implementation is feasible through digital tracking of raw materials. The aim of this article is to analyze the possibilities for deploying blockchain or Ethereum as Distributed Ledger Technology (DLT) platforms. Various decision-selection algorithms were examined for choosing a suitable platform and network type (public, private). The article analyses the drawbacks and barriers to achieving a circular economy in accordance with sustainable development criteria. Based on the regulatory framework and operational projects, it is shown that digital technologies improve the efficiency of raw material processing and life cycle tracking. To build an effective network, a separator is proposed as a separate participant in addition to producers, processors, and consumers. Their functions are waste classification and sorting, and receiving and transmitting heterogeneous data streams while preserving the privacy of sensitive ones. Drawing on the specifics of circular economy implementation, selection criteria are proposed, including deployment cost, data immutability, energy consumption, need for new technology, and others. A superior decision support tree tailored to material recycling is proposed. Its advantage is fast decision-making and selection of an appropriate platform within the DLT landscape. The proposed conceptual framework is not a universal solution as it can be adapted to different recycling schemes, especially when the regulatory framework, technologies, materials, flows, scheme participants, stakeholders, or other factors change. Full article

The rapid growth of computer e-waste poses significant environmental and resource-management challenges, particularly within university communities, where the use and replacement of electronic equipment are increasingly frequent. Although previous studies have examined general recycling awareness, participation, and e-waste management practices, there remains a lack of comprehensive and psychometrically validated instruments specifically designed to assess the multidimensional determinants of computer e-waste recycling behavior among university students. Therefore, this study aimed to develop and psychometrically validate a multidimensional Likert-type scale for assessing perceived individual and contextual determinants associated with computer e-waste recycling among university students. The novelty of the study lies in integrating five complementary dimensions—education, awareness and policy compliance; community participation; business and technological practices; innovation and technological adoption; and cultural and media influence—within a circular economy framework. An ex post facto instrumental design was employed. Data were collected through Google Forms from 385 university students selected by convenience sampling. Instrument development was informed by a Scopus-based literature review, from which an initial pool of 77 items was generated. Content validity was evaluated through expert judgment using Aiken’s V, and construct validity was examined through exploratory and confirmatory factor analyses using SPSS 25 and AMOS 24. The final instrument comprised 28 items distributed across five dimensions. Confirmatory factor analysis demonstrated a satisfactory model fit (RMSEA = 0.046, CFI = 0.951, TLI = 0.946), while reliability coefficients indicated adequate to excellent internal consistency, with Cronbach’s alpha values ranging from 0.763 to 0.899 across dimensions and an overall alpha of 0.985. These findings support the scale as a valid and reliable tool for assessing perceived individual, institutional, technological, social, and cultural determinants associated with computer e-waste recycling among university students. The instrument may assist higher education institutions in identifying dimensions in which students report comparatively less favorable perceptions, evaluating sustainability interventions, and supporting circular economy strategies aligned with Sustainable Development Goal 12. Full article

Rare-earth-based permanent magnets are key elements for today’s technologies. Their recycling is crucial for securing the supply of critical raw materials and ensuring a sustainable circular economy in magnet production. In this study, hydrogen decrepitated NdFeB powders recovered from end-of-life magnets were processed using planetary ball milling to obtain powders suitable for recycled magnet production. The magnets were sourced from a wind turbine, scooter motor, and ring magnet, and exhibit different compositions and properties. The structural, morphological, and magnetic properties of the hydrogenated and ball-milled powders were investigated considering the effects of the milling time and ball diameters. Submicron-sized powders were achieved within 10 min with 5 mm balls, while longer milling times were required to obtain similar particle size reduction with 10 mm balls. Milling resulted in structural damage to the hydrogenated powders. Furthermore, although milling decreased the magnetization of the powders, an increase in the coercive field was observed for certain milling times. Micrometric powders sourced from the wind turbine, milled for 10 min using 5 mm balls, exhibited the highest coercive field of 0.27 T. This behavior is discussed considering the effect of the particle size reduction, the structural damage, the particle agglomeration, and the local compositional changes. We conclude that the powders produced from different source magnets exhibit similar patterns of morphological, structural, and magnetic changes under milling, and only the Tc and the Hc of the powders depend on their original magnet. Ball milling represents a promising technique for particle size refining in the hydrogen processing of magnetic scraps, a crucial step in the magnet-to-magnet recycling process. Full article

Carbon sequestration and emission reduction via biochar represent a promising approach for carbon storage. Continuously collected roadway fallen leaves serve as an attractive precursor for biochar-based carbon sequestration. However, the realistic carbon sequestration potential (derived from biochar production) of these urban waste resources remains poorly quantified and deserves further investigation. Against the backdrop of global sustainability goals, this study estimated the potential of using roadway fallen leaves for carbon sequestration at the urban scale of Hangzhou, based on government reports and pyrolysis experiments. Results indicated that there were a total of 691,472 roadway trees in Hangzhou. If the fallen leaves of the roadway trees in Hangzhou were subjected to oxygen-limited pyrolysis at a temperature of 300 °C for carbon sequestration purposes, the potential total carbon sequestration capacity was estimated to be 2273 ± 55 tons of carbon, equivalent to 8334 ± 200 tons of carbon dioxide. Leaf-derived biochar carbon sequestration index (LBCS) was established for potential use in the future Certified Emission Reduction (CCER). Different leaf types and pyrolysis conditions correspond to different LBCS values. LBCS for Camphor tree (300 °C) was 3.64 $\mathrm{kg} \mathrm{C}·{\mathrm{tree}}^{-1}{·\mathrm{year}}^{-1}$. Thermal maps of carbon sequestration potential of roadside leaf resources in 13 counties and districts of Hangzhou made by this study provided a reference for potential future practices. It was further estimated that with one-third of the tree leaves used for leaf-derived biochar (300 °C) carbon sequestration between 2027 and 2060, the cumulative carbon sequestration potential could reach up to 18.96 billion tons CO₂-eq by 2060, contributing 29–68% of the global GHGs emission reduction goal for bioenergy with carbon capture and storage (BECCS). We noted that this long-term cumulative estimate relied on linear extrapolation assumptions and contained uncertainties. This research offered new insights and quantitative baseline data for advancing negative-carbon technology using urban leaf waste, supporting local waste recycling practices and the urban implementation of the United Nations 2030 Agenda toward carbon-neutrality objectives. Full article

In recycling of plastic packaging, the deinking of post-consumer waste (PCW) is a key technology to achieve high-quality recyclates that can be used in demanding applications. Removing printing inks minimises the contamination in the mechanical recycling process, enabling the production of (semi)-transparent recycled films with low odour and fewer defects. While the deinking of uniformly printed model films is thoroughly researched and the general mechanism well understood, these findings are not readily transferable to industrial implementation on household PCW. This study systematically investigates the deinking of household PCW flakes using industrially available surfactants. Deinking parameters (water temperature, washing time, lye concentration) are varied with no surfactant added as well as for four industrially available surfactant formulations. The deinking efficiency is determined via an image-based statistical analysis. Via a multiple linear regression, median grey values of the experiments allow insights into the deinking mechanism of PCW flakes. Depending on the surfactant and deinking parameters, either the hydrolysis of the binding agent by sodium hydroxide (NaOH) or the surfactant-based decrease of interfacial energy on the printed surface proved dominant for the overall deinking mechanism. Full article

Polymer Additive Manufacturing (AM) offers substantial opportunities for material-efficient and distributed production, yet its transition towards genuine circularity remains constrained by cumulative material degradation, fragmented recovery strategies, and the limited integration of lifecycle, environmental, economic, and industrial considerations. This critical systematic review examines circularity in polymer AM beyond conventional end-of-life recycling by integrating material behaviour, manufacturing-induced evolution, degradation mechanisms, lifecycle performance and value retention, recovery pathways, and sustainability assessment within a unified systems perspective. Following a PRISMA-based selection process, 3214 records were progressively screened to a final corpus of 175 peer-reviewed studies published between 2015 and 2025. The evidence demonstrates that polymer circularity is not an intrinsic material property, but an emergent lifecycle outcome governed by polymer chemistry, manufacturing history, cumulative degradation, functional-value retention, waste-stream quality, recovery technology, infrastructure, and environmental and economic conditions. Based on this synthesis, the review introduces Intelligent Circular Polymer Additive Manufacturing (ICPAM), a lifecycle-wide framework integrating Design for Circularity, degradation-aware manufacturing, adaptive recovery, digital intelligence, industrial implementation, and continuous feedback. ICPAM further incorporates multi-criteria decision support for selecting context-dependent circular strategies and a qualitative/semi-quantitative maturity assessment for identifying lifecycle bottlenecks and implementation priorities. The resulting framework shifts polymer AM circularity from reactive waste management towards proactive lifecycle engineering, while recognizing that emerging regenerative materials and digital technologies still require substantial industrial validation before their full circular potential can be realized. Full article

The city of Skopje faces persistent inefficiencies in waste management, characterised by rising waste generation and limited progress in sustainable treatment solutions. This paper addresses the need for a structured approach to identify barriers to implementing Waste-to-Energy (WtE) technology, focusing on incineration-based energy recovery as a potential option for improving waste management while generating energy. Interpretive Structural Modelling (ISM) and Cross-Impact Matrix Multiplication Applied to Classification (MICMAC) were applied to six categories of implementation challenges: operational, technical, financial, regulatory, social, and environmental. ISM identified hierarchical relationships within each category, while MICMAC classified challenges according to their driving and dependence powers. The results revealed distinct structural patterns across categories, with underlying barriers including inadequate waste separation and collection, lack of integrated waste information, competitive renewable energy prices, regulatory preferences for waste reuse, recycling and reduction over WtE, institutional distrust, and combustion residue management. The findings reveal interconnected barriers with distinct structural roles, while conceptual mitigation measures and relevant SDG linkages are proposed based on the identified barriers and literature. The proposed ISM-MICMAC framework provides a structured approach for analysing WtE implementation barriers and can be adapted to other contexts following appropriate contextual and quantitative assessment. Full article

Laser powder bed fusion (LPBF) is a disruptive additive manufacturing process for producing high-performance Inconel superalloy parts with complex shapes for the aerospace, energy, and other demanding industries. However, uniform part quality remains a persistent challenge, as process parameters, melt-pool dynamics, microstructural evolution, defect formation, and mechanical performance are closely coupled across a wide range of spatial and temporal scales. In previous reviews, these dimensions have been considered in isolation with limited insight into their interactions and implications for predictive process control. The present review aims to address this lacuna by proposing a unified Process–Structure–Property–Control (PSPC) framework for LPBF-produced Inconel 625, 718, and 738. The discussion begins with material attributes governing alloy processability, and then synthesises the melt-pool physics governing thermal behaviour, solidification, and energy transfer. Attention then turns to a critical assessment of grain evolution, defect formation, and process stability, showing how the thermal history governs microstructural development and, in turn, mechanical performance via linked process–structure–property relationships. Progress in multiscale numerical modelling, such as finite-element analysis, computational fluid dynamics, phase-field modelling, cellular automata, and phase-diagram calculation (CALPHAD), is reviewed to establish a comprehensive modelling ecosystem for predictive LPBF. The review also discusses the potential of emerging technologies, such as beam shaping, multi-laser processing, in situ monitoring, artificial intelligence, and powder recyclability, to increase the robustness and productivity of the process. Building on these advances, a digital-twin-enabled predictive-manufacturing framework that integrates physics-based models, data-driven algorithms, and real-time monitoring is introduced to enable closed-loop process optimisation. The review ends with a scientific synthesis and future research roadmap for intelligent, reliable, and autonomous LPBF of next-generation Inconel superalloys. Full article

The environmental sustainability of passenger-car electrification depends not only on powertrain technology but also on vehicle size, material intensity, energy-system decarbonisation, and end-of-life management. This study applies prospective life cycle assessment to compare battery electric vehicles (BEVs) with gasoline-powered internal combustion engine vehicles (ICEVs) across A/B, C, and SUV segments for 2025 and 2050, including a Paris Agreement-aligned 2050 pathway. ReCiPe 2016, IPCC 2021, Cumulative Energy Demand, CML-IA, and Ecological Scarcity 2021 were applied to evaluate climate, energy, resource, ecosystem, and policy-weighted environmental pressures, while well-to-tank and tank-to-wheel modelling quantified operational emissions. Environmental burdens generally increased with vehicle segment, and BEVs showed higher production-stage impacts because of traction batteries and electric-powertrain components. Recycling reduced most indicators but increased eutrophication in some variants, demonstrating the risk of burden shifting. In the integrated manufacturing-to-wheel assessment, BEVs achieved approximately 49% lower greenhouse gas emissions than gasoline ICEVs in the A/B segments and 54–55% lower emissions in the C and SUV segments under 2025 conditions. The results show that electrification alone is insufficient to ensure sustainable mobility. Its environmental benefits are maximised when combined with vehicle right-sizing, appropriately sized batteries, low-carbon electricity, energy-efficient manufacturing, and high-quality closed-loop recycling. Full article