Search Results (1,872)

The transition to a circular economy requires effective food waste (FW) collection and recycling systems. This study aims to evaluate general public attitudes, behaviours, and systemic challenges related to FW sorting in Latvia, in light of the recent mandate for separate biowaste collection. The study covers two important sections—assessment of the amount of FW generated in primary production sectors, and a pilot case study of biodegradable waste sorting in selected households in Latvia. A mixed-methods approach was used, combining a nationwide survey of 458 entities involved in primary food production and 115 households, followed by 99 households with backyards voluntarily participating in a pilot case study to evaluate their BW management practices. The research findings reveal that there is a need to establish a precise/specific framework for the evaluation of FW for each sector; the development of appropriate coefficients would facilitate the process of estimating waste generated by primary production in the future. Research findings revealed that inhabitants are interested in home composting; however, the implementation of home composting requires active support from project implementers, including increasing environmental awareness and providing financial incentives. These results offer practical insights for municipalities and national stakeholders aiming to increase biowaste collection rates and support country-level broader sustainability goals. The research results have practical application with the possibility to replicate the best practices and recommendations to other countries or regions within the EU and beyond. Full article

The recycling of polymer composites remains a significant challenge due to both technical and economic obstacles. This study investigates the recycling potential of acrylonitrile butadiene styrene (ABS) composites filled with carbon powder (CP), employing injection moulding and fused filament fabrication (FFF) technologies. Laboratory-based experiments were conducted using ABS reinforced with 0.5, 1.0, and 1.5 wt.% CP to explore the tensile properties of mechanically recycled ABS+CP composites. The results indicate that CP addition positively influences tensile behaviour and that the ABS+CP composite maintains both tensile strength and stiffness after repeated processing. A concentration of 1.5 wt.% CP proved to be the optimal filler amount. The results for re-injection-moulded ABS + 1.5 wt.% CP demonstrate enhancements in tensile strength of approximately 3% and elastic modulus of approximately 15%, relative to virgin ABS. Similarly, such specimens reprocessed via FFF showed an average increase of 12% in tensile strength and of 27% in elastic modulus relative to virgin ABS across all three printing orientations (X, Y, and Z). These findings suggest improved interfacial adhesion and filler dispersion upon recycling. The study confirms the practical feasibility of ABS composite recycling and highlights their potential for structural and decorative use due to their appealing granite-like appearance. Full article

This study explores how older Chinese migrants in London engage with climate change discourse using participatory co-design workshops. Although already practising sustainability behaviours such as recycling, this group faces significant barriers—particularly language difficulties and cultural differences—that limit their active participation in broader climate initiatives. The research addresses three key aspects: (1) identifying opportunities for sustainable practices within migrants’ daily routines; (2) understanding their influential roles within families and communities; and (3) examining their trusted sources and preferred channels for climate communication. Results highlight that family and community networks, combined with digital platforms (e.g., WeChat) and visually engaging materials, play essential roles in disseminating climate information. Participants expressed strong motivations rooted in intergenerational responsibility and economic benefits. The findings emphasise the necessity of inclusive and peer-led communication strategies that are attuned to older migrants’ linguistic preferences, media habits, and cultural values—underscoring their significant but often overlooked potential to meaningfully contribute to climate action. Full article

The fashion industry faces a critical sustainability crisis, contributing up to 10% of global carbon emissions and generating 92 million tons of textile waste annually. The study highlights the complex interplay of material flows, business models, power structures, and cultural mindsets, presenting a multi-scaled framework for advancing cleaner production and circularity in one of the world’s most resource-intensive sectors. This study proposes a transformative model for circular bioeconomy in fashion, integrating systems-change theory, degrowth economics, and emotional durability. Through case studies, including Patagonia, Eileen Fisher, and EU policy frameworks, the paper demonstrates how circular strategies can reduce waste, extend product lifecycles, and promote ethical labor practices. Notably, brands implementing take-back programs and recycled materials have diverted over 1.5 million garments from landfills and achieved up to 70% recycled content. The study critically addresses challenges such as technological solutionism, systemic greenwashing, and waste colonialism, concluding that incremental changes are insufficient. A paradigm shift in business models, consumer culture, and policy is essential for a regenerative and just fashion future. Full article

This study examines the determinants of capital structure in small agricultural enterprises in Serbia, with a particular emphasis on the external context shaped by circular economy (CE) indicators. Using a balanced panel of 254 firms between 2014 and 2022 (2286 firm-year observations), we estimate random-effects models with panel-corrected standard errors. The dependent variable is financial leverage, while explanatory variables include internal firm characteristics (liquidity, debt ratio, profitability, and asset tangibility) and territory-level CE indicators (municipal waste generated per capita, municipal waste recycling rate, and greenhouse-gas emissions from production activities). The model is statistically significant (χ² = 82.49; p < 0.01) and explains 33.7% of leverage variation. The results show that debt ratio positively and strongly relates to leverage, whereas profitability exhibits a negative and significant association, consistent with the pecking-order theory. Regarding the CE context, higher waste generation and higher GHG emissions are associated with lower leverage, while a higher recycling rate has a positive, marginal effect, suggesting that improved circular performance may ease access to external finance by lowering perceived risk among creditors. These findings highlight that environmental performance and local circularity conditions matter for financing decisions in agriculture. Policy implications include promoting CE practices and local recycling capacities to support sustainable financing. Future research should test dynamic specifications and enterprise-level CE metrics. Full article

The circular economy (CE) supports sustainable development through local action, with municipalities playing a central role in governance, service provision, and citizen involvement. This paper presents a systemic analysis of public attitudes, behaviours, and perceptions related to CE, aiming to identify governance gaps and recommend strategies to align implementation with societal needs. Data was collected through a survey across five consumption categories: food, textiles, plastics, electronics, and mobility. The findings indicated that the public is generally willing to adopt circular practices provided adequate services are available. The study applied the 10R framework to categorize circular strategies and mapped services to these relevant governance instruments: infrastructure, economic and planning instruments, education and information, and collaboration. A document analysis of multi-level governance frameworks further contextualized the results. A polarized engagement pattern emerged: preventive strategies like Reduce and Repair are supported by both public behaviour and municipal services, while end-of-pipe approaches such as Recycling and Landfilling continue to dominate. In contrast, mid-level strategies (Reuse, Refurbish, Remanufacture, and Repurpose) are significantly underrepresented. This gap highlights a critical shortfall in governance and service provisioning. The study concludes that advancing CE requires targeted interventions in infrastructure, improved access to circular services, and greater public awareness to enable broader participation. Full article

Research has often overlooked examination of circular consumption practices from the consumer’s perspective by primarily focusing on specific consumption activities, hindering researchers from obtaining comprehensive insights into consumers’ upstream and downstream roles. Addressing this gap would highlight their role as simultaneous product users and resource suppliers. The framework draws from the concepts of the circular economy, attitude–behavior–context theory, and practice theory to develop a model that explores circular consumption behavior based on 8R-strategies for addressing and reducing product demand and disposal. These strategies comprise refuse, rethink, reduce, reuse, repair, refurbish, repurpose, and recycle. The proposed model was empirically tested using partial least squares structural equation modeling with data collected from 528 consumers. The results show that the antecedents positively impacted circular consumption behavior, with environmental concern and consumer social responsibility acting as partial mediators. Habits moderated the relationship between these variables, though they showed insignificant moderation between circular economy knowledge and circular consumption behavior. The findings underscore the importance of consumers’ role as both product users and resource suppliers in circular consumption practices. Full article

The integration of machine learning (ML) into sustainable construction materials research, particularly focusing on construction and demolition waste (CDW), has accelerated in recent years, driven by the dual need for digital innovation and environmental responsibility. This study presents a comprehensive scientometric analysis of the global research landscape on ML applications for predicting the performance of sustainable construction materials. A total of 542 publications (2007–2025) were retrieved from Scopus and analyzed using VOSviewer (V1.6.20) and Biblioshiny (Bibliometrix R-package, V5.1.1) to map publication trends, leading sources, key authors, keyword co-occurrence, and emerging thematic clusters. The results reveal a sharp rise in publications after 2018, peaking in 2024, in parallel with the growing global emphasis on the circular economy and the UN Sustainable Development Goals. Leading journals such as Construction and Building Materials, the Journal of Building Engineering, and Materials have emerged as key publication venues. Keyword analysis identified core research areas, including compressive strength prediction, recycled aggregates, and ML algorithm development, with recent trends showing increasing use of ensemble and deep learning methods. The findings highlight three thematic pillars—Performance Characterization, Algorithmic Modeling, and Sustainability Practices—underscoring the interdisciplinary nature of the field. This study also highlights regional disparities in research output and collaboration, underscoring the need for more inclusive and diverse global partnerships. Overall, this study provides a comprehensive and insightful view of the rapidly evolving ML-CDW research landscape, offering valuable guidance for researchers, practitioners, and policymakers in advancing data-driven, sustainable solutions for the future of construction. Full article

Ensuring the long-term integrity of structural materials in extreme environments is a critical challenge in the design of equipment for nuclear fuel cycle operations. In particular, the durability of materials exposed to high temperatures and chemically aggressive environments during the processing of irradiated reactor components remains a key concern. This study investigates the high-temperature corrosion behavior of 12Cr18Ni10Ti austenitic stainless steel in the reaction chamber of a beryllium chlorination plant developed for recycling irradiated beryllium reflectors from the JMTR (Japan Materials Testing Reactor). The chlorination process was conducted at temperatures ranging from 500 °C to 1000 °C in a chlorine-rich atmosphere. Post-operation analysis of steel samples extracted from the chamber revealed that uniform wall thinning was the predominant degradation mechanism. However, in high-temperature regions near the heating element, localized forms of damage, specifically pitting and intergranular corrosion, were detected, indicating that thermal stresses exacerbated localized attack. These findings contribute to the assessment of the service life of structural components under extreme conditions and offer practical guidance for material selection and design optimization in high-temperature chlorination systems used in nuclear applications. Full article

For the successful commercialization of cocoa in the global market, ensuring product quality and compliance with regulations—such as EU regulation, which established maximum cadmium (Cd) levels for cocoa products—is essential. Moreover, cocoa cultivation in Colombian soils, an alternative to coca cultivation, is in many cases an unsustainable practice due to soil degradation, which is accompanied by a drastic decrease in soil organic carbon content. This study evaluated the use of a nature-based solution for cadmium remediation in cocoa cultivation soils by applying three organic amendments: biochar derived from cocoa pod shells (Cocoachar), spent coffee grounds (SCGs), and SCG-derived biochar (SCGchar). The effects of these organic amendments, applied at rates of 5, 10, and 15% (w/w), were evaluated in an in vitro incubation experiment (climate chamber) using soil samples collected from Zulia (mountain soils) and Tibú (alluvial soils), located in the Catatumbo region of Norte de Santander (Colombia). Soil analyses included available Cd concentrations (by atomic absorption spectroscopy), physicochemical properties (pH, organic matter, electrical conductivity), and other mineral elements. The results showed that Cocoachar significantly reduced Cd concentrations while enhancing soil quality, particularly by increasing pH and improving soil organic matter content. The application of 15% Cocoachar reduced Cd levels from 0.056 to 0.012 mg kg⁻¹ and increased soil pH from 6.3 to 7.0 in Zulia. In Tibú, the addition of 15% Cocoachar lowered Cd levels from 0.12 to 0.05 mg kg⁻¹ and raised the pH from 5.0 to 6.1. SCGchar primarily enhanced soil organic carbon, increasing its content from 1.87% to 2.35% in Zulia and from 0.66% to 1.53% in Tibú, thereby supporting ecological balance and sustainable soil fertility. Overall, the recycling of cocoa and coffee by-products into biochar offers a solution within the circular economy and a sustainable way to cultivate cocoa. This in vitro exploratory study must be confirmed with field trials and Cd analyses in cocoa beans. Full article

This study examines stakeholder perspectives regarding the feasibility, benefits, and challenges associated with the development of multipurpose shipyards that encompass shipbuilding, repair, and recycling within Indonesia’s maritime industry. A convergent mixed-methods approach was utilised to collect quantitative and qualitative data from 37 stakeholders, including managers, employees, shipowners, regulators, subcontractors, academics, and community representatives. The Stakeholder Salience Model and Diffusion of Innovations theory provided the integrated statistical and thematic analysis. Results indicated significant stakeholder support (97.3%) for multipurpose shipyards, with 81.1% expressing positive perceptions and 16.2% very positive perceptions. Results indicate that ship repair (97.3%) and shipbuilding (86.5%) are seen as critical activities, with 59.5% of respondents highlighting the importance of ship recycling. The advantages of the multipurpose yard concept for Indonesia included improved operational efficiency (70.2%), increased market competitiveness (54.1%) and job creation (91.9%). Major challenges identified include technical complexities (62.2%), regulatory ambiguities (45.9%), substantial capital investment (43.2%), and skill shortages (40.5%). The study suggests improvements in governmental regulations, financial support for businesses, and training for the workforce. Phased implementation and stakeholder collaboration can align economic, environmental, and safety objectives, potentially decreasing Indonesia’s dependence on foreign shipping services. This study integrates stakeholder theory with innovation diffusion, providing replicable insights for sustainable practices in shipyards within archipelagic economies like Indonesia, the Philippines, and Vietnam, where similar geographic and infrastructure challenges shape the maritime industries. Full article

Emerging organic contaminants (EOCs), including polychlorinated bisphenyls (PCBs), pharmaceuticals, personal care products, pesticides, polycyclic aromatic hydrocarbons (PAH), and dyes, are among the most hazardous pollutants found in water bodies and sediments. These substances pose serious threats to the environment and human health due to their high toxicity, long-range mobility, and bioaccumulation potential. Although various methods for degradation of organic pollutants exist, photocatalysis using ultraviolet (UV) and visible light (VIS) has emerged as a promising approach. However, its practical applications remain limited due to challenges such as the use of powdered photocatalysts, which complicates their removal and recycling in industrial settings, and the restricted solar availability of UV light (~4% of the solar spectrum). This review investigates the effectiveness of hybrid electrospun conductive polymer nanofibers on metal oxide photocatalysts such as TiO₂ and ZnO (including doped and co-doped forms) and fabricated via mono- or coaxial electrospinning, in the degradation of EOCs in water under visible light. Furthermore, strategies to enhance the fabrication of these hybrid electrospun conductive nanofibers as visible-light-responsive photocatalysts, such as the inclusion of dopants and/or plasmonic materials, are discussed. Finally, the current challenges and future research directions related to electrospun nanofibers combined with photocatalysts for the degradation of EOCs in water treatment applications are outlined. Full article

This article presents a systematic literature review of data envelopment analysis (DEA) models used to evaluate circular economy (CE) practices. The review is based on 151 peer-reviewed articles published between 2015 and 2024. By analyzing this collection, this review categorizes different DEA models and their levels of application, discusses the data sources utilized, and identifies the prevailing methodologies and evaluation criteria used to measure the CE performance. Despite the extensive literature on measuring the circular economy using DEA, a critical evaluation of existing DEA approaches that highlights their strengths and weaknesses is still missing. Our analysis shows that DEA models provide valuable insights when assessing circular strategies, namely, R2—Reduce, R8—Recycling, and R9—Recovering. Over 40% of the surveyed literature focuses on China, with nearly 20% on the European Union. Other regions are sparsely represented within our sample, highlighting a potential gap in the current research landscape. Full article

The transition toward sustainable infrastructure in the construction sector necessitates the practical integration of Circular Economy (CE) principles, particularly through the valorization of recycled materials in concrete applications. This review critically synthesizes recent advancements in the use of recycled polyethylene terephthalate (PET), glass powder, and crumb rubber as partial replacements for conventional aggregates in Ordinary Portland Cement (OPC)-based concrete. The incorporation of these secondary materials has demonstrated the ability to reduce the environmental footprint of concrete production—achieving up to 25% reductions in greenhouse gas emissions and diverting significant volumes of waste from landfills—while maintaining structural viability with compressive strength retention levels exceeding 90% in several optimized mix designs. Enhanced ductility, thermal resistance, and reduced density further support their application in specialized construction scenarios. Beyond material characterization, the review systematically examines implementation enablers, including regulatory alignment, life-cycle-based procurement, and design-for-deconstruction strategies. It also highlights critical gaps such as the absence of harmonized standards, variability in recycled material quality, and systemic barriers to market uptake. Addressing these challenges is essential for scaling CE integration and achieving measurable sustainability gains across the built environment. This study aims to inform policy, practice, and research trajectories by linking material innovation with operational frameworks that support regenerative construction systems. Full article

This study examines the pedagogical potential of LEGO^® SERIOUS PLAY^® (LSP) in optometric education, aiming to foster critical reflection on optics, sustainability, and professional identity. A qualitative interpretative phenomenological analysis was conducted with 48 students from Optics and Optometry and Renewable Energies programs at ISEC Lisboa. Participants took part in LSP sessions focused on optics and sustainability, using metaphorical models to express their reflections. Data were collected via observations, group discussions, and open-ended questionnaires, and analyzed with Grounded Theory. In the optics theme, models revealed both scientific and symbolic views, with visual correction (46.7%), professional roles (21.3%), and perception (14.7%) being most frequent. Statistically significant differences appeared by academic background (p < 0.001) and experience (p = 0.0018): optometry students emphasized clinical roles, while environmental students highlighted perception. For sustainability, main categories included sustainable practices (41.7%), polluting industries (15.3%), ecological footprint (13.9%), and social responsibility (12.5%). Actions proposed included recycling, reuse, and biodegradable materials. Age was linked to action-oriented responses (p = 0.038), with no differences by gender or nationality. LSP emerged as an effective tool for deep reflection, interdisciplinary learning, and ethical engagement, supporting integration of sustainability and identity in technical education. Further research should explore its long-term educational impact. Full article