Search Results (362)

Post-consumer clothing waste is a growing problem that contributes to environmental and resource management issues. The second-hand market redirects these garments away from landfills, but a large portion still ends up as waste. These waste clothes mainly originate from developed countries and are then exported to developing countries, but almost half of the garments imported are not sold due to poor quality. This leads to the generation of more textile waste and environmental pollution. These challenges highlight need for sustainable solutions that enhance social, environmental, and economic benefits in the developing countries to which clothing waste is exported to. Encouraging methods that extend garment lifespan, promote reuse and support the principles of the circular economy creates a cleaner environment and enables more efficient use of resources. This study aimed to investigate how design can be used to catalyse change, using a co-design approach with senior female citizens from a non-governmental organization (NGO) in Cape Town, South Africa. The participants transformed second-hand clothes from the second-hand market into valuable products for reuse. The fieldwork was conducted between 23 May and 24 October 2024 to explore the role of design in enhancing sustainability, prolonging garment lifespan, and supporting local entrepreneurship. The data collection methods for this qualitative study included observational fieldwork, interactive co-design workshops, and semi-structured interviews. Analysis of the empirical data underscores the transformative potential of the intervention. Initially, the results showed that participants used intuitive sewing and unsystematic garment modification and were creative yet unaware of a structured design process and sustainability principles. Following the expert-led co-design workshops, participants’ intuitive redesign practices developed into a hybrid process combining garment assessment, design planning, reconstruction, and finishing. The project produced 37 documented outputs across clothing, footwear-related samples, and accessories, showing how selected post-consumer garments acquired renewed utility through redesign. Participants reported increased confidence, a stronger sense of purpose, and a willingness to share their upcycling skills within their communities. These findings informed a Community-Based Upcycling Framework linking garment recovery and redesign with community learning, environmental stewardship, and potential livelihood pathways. Full article

Rapid urbanization in developing countries intensifies solid waste management (SWM) challenges and demands integrated sustainability approaches. This study examines institutional actors’ perceptions of SWM governance and waste-to-construction-material conversion in Greater Amman Municipality (GAM), Jordan. We conducted semi-structured interviews with 20 experts from municipal, governmental, international, private, research, and professional organizations. Using hybrid deductive–inductive thematic analysis, the findings reveal that while participants described GAM as maintaining engineered sanitary landfill infrastructure and near-universal service coverage, participants identified systemic barriers to circular transitions: fragmented decision-making with unclear mandates and weak coordination; persistent cost-recovery gaps (participant-reported estimates of revenues covering only 30–35% of operational costs); absent building codes and quality standards for recycled materials; limited community engagement via top-down mechanisms; and weak regulatory enforcement. Contrasting perspectives emerged—operational actors emphasized technical/logistical constraints, policy actors cited regulatory/coordination failures, international actors diagnosed structural limitations, and private actors highlighted incentive/market deficits. This study uses public administration and political economy scholarship as its primary explanatory framework, using Balance Theory only as a sensitizing concept to diagnose perceived institutional imbalances, not as a formal theory to test empirically. Its elite-sample, single-case design constrains it and thus offers hypotheses that require validation through further research. Recommendations generated from participant accounts include establishing centralized coordination, developing regulatory frameworks with quality assurance measures, implementing integrated incentive-enforcement systems, and formalizing participation in the informal sector. These recommendations are presented as hypotheses for future testing rather than validated policy prescriptions. This research provides exploratory insights and hypothesis-generating guidance for sustainable urban development, emphasizing that technical solutions alone are insufficient without addressing the political economy of institutional reform, a dimension only partially explored here and requiring dedicated future research. Full article

Wood waste and residues are increasingly viewed as feedstocks for the circular bioecon-omy, yet their market development remains uneven. This rapid review synthesized 125 studies published between 1967 and 2025 to examine research trends, feedstock characteristics, market constraints, and emerging opportunities through Marketing Mix and Innovation perspectives. Research was concentrated in North America and Europe (68.0%), and quantitative approaches accounted for 75.2% of the studies. Logistics and infrastructure were the most frequently reported constraints (61.6%), followed by competition (38.4%), supply–demand conditions (32.0%), and lack of standardization (14.4%). Energy-related applications remained prominent (87.2%), while 45.6% of studies also addressed material or bioproduct applications, indicating diversification rather than replacement of established uses. The synthesis shows that technological advances alone do not create viable markets. Residue characteristics, transportation, processing capacity, competing uses, pricing and distribution arrangements, institutional coordination, policy, and financing jointly shape utilization pathways. Marketing Mix and Innovation perspectives provide complementary explanations of how these markets are configured and how they change. Wood residues can become valuable feedstocks, but their value is context dependent and relies on alignment between specific residue streams and viable markets. 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

In this work we present an integrated market, experimental, technical and economic approach to citrus waste valorization based on the extraction of essential oils from orange, lemon, lime and tangerine peels using supercritical CO₂, comprising nine varieties of citrus fruits with high production in Brazil and varying harvesting seasons. This approach has been applied to such a variety of citrus waste as a novelty, allowing the observation of specific results for each kind of citrus fruit and a robust evaluation of the proposed process solution, which includes pre-treatment and extraction and may feature energy recovery. The varieties of fruits and volumes of production were selected based on a market assessment for a proposed capacity of approximately 500 kg/d of citrus waste in the extraction facility. Samples of citrus fruit waste were pre-processed by drying at 60 °C for 24 h and submitted to extraction using CO₂ at 150 bar and 35 °C for 30 min. The provisional results of the extractions (0.33% to 4.00% wt. oil yield) were used to perform the simulation of the extraction facility and estimate the cost of manufacture of essential oil, which ranged from US$26.70 to US$323.86/kg of extract, depending on the variety of citrus fruit. As an illustrative result of the application of the present screening approach, the cost of the production of essential oils from terra, bahia, seleta and lima oranges, as well as lemons, limes and tangerines, was compatible with the market price, while the costs of manufacturing pera and valencia orange essential oils were higher than the average price for cosmetic-grade and food-grade orange oil. The use of energy recovery in the CO₂ cycle would further increase the environmental sustainability of this strategy, with 55% lower energy consumption. Full article

Municipal solid waste (MSW) incineration with energy recovery is embedded in national decarbonization strategies but emits fossil CO₂ from plastic-derived combustion, challenging the long-term sustainability of waste-to-energy systems. Carbon capture and utilization (CCU) offers a potential mitigation route, yet assessments rarely link technology economics, environmental performance, and the carbon-pricing instruments that would finance deployment. This study develops a break-even carbon-pricing framework integrating life-cycle CO₂ emissions (LCCO₂) and discounted annualized life-cycle cost (LCC; capital-recovery-factor annualization at a 4% real discount rate) for two CCU routes—methanation and methanol synthesis—applied to a 300 t/day Japanese incineration facility (84,000 t/y) under 2024 and 2050 energy-system conditions, thereby quantifying the environmental and the economic dimensions of sustainable CCU deployment in the waste sector. Two complementary indicators are distinguished: an incremental break-even carbon price, the price at which adding CCU to the existing waste-to-energy facility becomes economically neutral, and a plant-level cash balance price. Under the product-system boundary and photovoltaic-electrolysis hydrogen, both routes show lower life-cycle emissions than the baseline in both years; the magnitude—and, for methanation in 2024, the sign—of the net climate benefit depends on the downstream-use accounting boundary. The incremental break-even price for methanol falls from 20.3 × 10⁴ JPY/t-CO₂ (≈1293 USD/t-CO₂) in 2024 to 1.90 × 10⁴ JPY/t-CO₂ (≈122 USD/t-CO₂) in 2050, while that for methanation falls from 32.2 × 10⁴ JPY/t-CO₂ to 0.75 × 10⁴ JPY/t-CO₂ (≈48 USD/t-CO₂)—about half the 2023 EU ETS average price—and approaches zero at approximately a one-third capital subsidy. This collapse is driven largely by the assumed hydrogen-price decline (100 → 20 JPY/Nm³); hydrogen-supply policy, rather than carbon pricing alone, therefore appears to be the dominant lever for making CCU at MSW incineration a viable contribution to sustainable, carbon-neutral waste management. Sensitivity analyses covering the discount rate (2–8%), plant scale (300–900 t/day), methane leakage, product-market absorption, and hydrogen delivered price premiums support the robustness of this sequencing conclusion. Full article

European circular construction policies, including the EU Construction and Demolition Waste Protocol and the Level(s) framework, provide strategic guidance for improving material recovery from buildings. However, limited research documents how these frameworks operate under real project conditions, characterised by incomplete information, evolving inventories and market-dependent recovery pathways. This paper documents a pre-demolition audit carried out in the Czech context and maps the observed process onto the EU CDW Protocol and Level(s) Indicator 2.2 framework. A structured implementation approach is applied to an in-depth case study of the selective deconstruction and deep refurbishment of an office building in the Czech Republic. The results show both the circular recovery potential and operational feasibility of the audit process, illustrating how audit recommendations evolved through documentation review, field verification and engagement with potential material outlets. The findings demonstrate that feasible recovery routes depended not only on material identification and technical recyclability but also on market verification, stakeholder coordination and legal or organisational enablement. The case further highlights the importance of auditor expertise and brokerage in enabling reuse and recycling routes under real project constraints. Insights from the case study are discussed in relation to experiences reported in other European countries. This study contributes empirical evidence documented in relation to European circular-construction frameworks and suggests that PDA reporting should combine mass-based indicators with the transparent documentation of recommendation maturity, implementation constraints and reporting-boundary assumptions. Full article

Polyhydroxybutyrate (PHB), a microbial polyester belonging to the polyhydroxyalkanoate (PHA) family, has emerged as one of the most promising biodegradable alternatives to conventional petroleum-derived plastics. Its inherent marine biodegradability (typically mineralizing within months depending on material geometry and ambient temperature), biocompatibility, and ability to be synthesised from renewable and waste-derived feedstocks position PHB as a key candidate for supporting the transition towards a circular bioeconomy. Despite these advantages, widespread commercial adoption remains limited by high production costs, processing challenges, and performance constraints relative to established commodity plastics and competing biopolymers. This review critically evaluates the current state of PHB development from the perspective of sustainable commercialisation. Key aspects discussed include microbial biosynthesis pathways, feedstock selection, upstream fermentation strategies, downstream recovery technologies, and technoeconomic considerations influencing industrial feasibility. The intrinsic thermal, mechanical, and degradation characteristics of PHB are examined alongside modification approaches such as copolymerisation, polymer blending, plasticisation, and composite reinforcement that have been developed to overcome certain inherent physical–mechanical properties, narrow processing windows, and limited functional performance. Furthermore, characterisation methodologies, environmental degradation behaviour, and emerging industrial applications are assessed within the context of market requirements and sustainability objectives. Particular emphasis is placed on identifying the interconnected technical and economic bottlenecks that continue to hinder large-scale deployment, including feedstock costs, fermentation scalability, downstream processing expenses, and material performance trade-offs. By integrating advances across the entire PHB value chain, this review highlights current opportunities, remaining challenges, and future priorities required to enable the sustainable and economically viable commercialisation of PHB-based materials. Full article

The fashion and textile industry is undergoing profound transformation driven by regulatory, environmental and societal pressures to reduce its significant contributions to global waste, emissions and resource depletion. In the European Union (EU), this transition is being formalised through the Ecodesign for Sustainable Products Regulation (ESPR), which introduces mandatory sustainability and circularity requirements for textile products, including the Digital Product Passport (DPP). The emerging DPP framework is expected to include product-specific, life-cycle-based environmental information requirements, creating new compliance obligations for garment manufacturers supplying the EU market, particularly those based outside the EU. This study examines the readiness of global garment manufacturers to meet these requirements, with a focus on data availability, supply chain traceability, and alignment with the methodological expectations of the Product Environmental Footprint (PEF) framework. A mixed-methods approach is employed, combining a survey of garment manufacturers in Pakistan, Bangladesh and Turkey with a case study of upcycled garments produced for the Estonian national team for the Paris 2024 Olympic Games. The findings identify key barriers to generating DPP-compliant environmental data, including limited life cycle assessment (LCA) expertise, fragmented and inconsistent upstream datasets, insufficient digital data systems and the practical complexity of applying PEF Category Rules across diverse production contexts. The case study further demonstrates how data gaps constrain the assessment of innovative circular materials, revealing a mismatch between regulatory expectations and current industry capabilities. Overall, this study highlights the need for phased DPP implementation, simplified cradle-to-gate assessment approaches and clearer, more harmonised methodological guidance to support an achievable and equitable transition towards sustainable textile supply chains. Full article

The construction industry in Jordan faces significant economic and environmental challenges due to high material costs, fluctuating market prices, and the continued reliance on a linear economy model that prioritizes material extraction, consumption, and disposal over reuse and recycling. These challenges contribute to substantial construction waste generation and hinder the transition toward a Circular Economy (CE). Therefore, this study aimed to develop a framework for managing construction waste during the construction phase of residential building projects in Jordan and to facilitate the adoption of circular practices within the construction sector. A questionnaire survey was administered to 31 experts, and the collected data were analyzed using the Relative Importance Index (RII) and the Analytic Hierarchy Process (AHP). Subsequently, the proposed framework was evaluated through a three-round Delphi study involving an independent panel of experts. The results identified the principal barriers to implementation as the low demand for reused or recycled materials, limited stakeholder awareness, and difficulties in material disassembly. The findings further revealed that applying visual management and 5S techniques to improve site efficiency, implementing Building Information Modeling (BIM) for material and component mapping throughout the building life cycle, and providing tax incentives and grants for recycled materials were among the highest-ranked sub-strategies for supporting circular practices and minimizing construction waste. The Delphi evaluation demonstrated strong expert consensus regarding the framework’s applicability and practicality, indicating that it provides a structured, expert-informed approach that may assist policymakers and construction practitioners in promoting circular practices and reducing construction waste in Jordan. In addition, the framework has the potential to support Jordan’s Vision 2025 and contribute to the achievement of the Sustainable Development Goals (SDGs). Full article

Yttrium is one of the lesser-known critical elements, but it has recently gained significant market attention due to a dramatic price increase of up to 1400% in Europe. Although its primary application is in phosphors (e.g., in LEDs), modern society heavily depends on these technologies, making yttrium indispensable. However, the limited availability of yttrium raises concerns about its long-term supply. Therefore, there is a need for efficient techniques to recover yttrium from secondary materials to ensure a stable supply. While the wastes contain only trace amounts of yttrium and often have complex elemental compositions, they are more readily available than primary sources. The yttrium content ranges from a few percent in spent phosphors to several hundred ppm in red mud, around a few dozen ppm in phosphogypsum, and up to several ppm in coal and coal fly ashes. Although conventional hydrometallurgical methods are commonly used, they lack selectivity for yttrium recovery. In contrast, unconventional solvometallurgical and bioleaching approaches currently play a relatively minor role in recovery applications. This review discusses a range of methods investigated for yttrium recovery from different types of secondary resources, including pretreatment (where applicable), leaching, and subsequent yttrium recovery from the resulting leachates. Although the chemical and phase compositions of yttrium-bearing waste materials differ substantially, necessitating tailored treatment strategies, acid leaching remains the predominant extraction route and is most commonly followed by solvent extraction and/or oxalate precipitation. Most studies reported to date have been conducted at the laboratory scale. Despite progress and the development of promising recovery concepts, the efficient separation of high-purity yttrium from other rare earth elements and co-existing impurities continues to represent the key obstacle to commercial-scale application. Full article

Implementing technological change in rural or culturally distinct settings requires moving beyond the modernization bias that treats Western technical solutions as universally applicable. This article develops a process-based reflection on culturally grounded co-design for sustainable technology, drawing on social design, just transition principles, and appropriate technology. Rather than evaluating final project outcomes, the article examines how technology and social organization can be approached as context-specific practices that must be negotiated, adapted, and maintained with local actors. The discussion is informed by the O-Waste Project in The Gambia, which is used as an illustrative case to examine the role of local councils, women’s organizations, market committees, and implementing partners in shaping technological adoption. By emphasizing vernacular knowledge, locally maintainable systems, and participatory decision-making, the article argues that sustainable innovation depends on technical performance as well as cultural legitimacy, institutional trust, and procedural justice. The analysis suggests that development in diverse cultural contexts requires a careful balance between external technical expertise and community appropriation. The O-Waste case therefore offers process-based insights into how sustainable technologies can be introduced without reducing local communities to passive recipients of modernization. Full article

Thorium (Th) is increasingly considered a promising fertile material for sustainable nuclear energy—which is not fissile itself, but convertible to fissile ²³³U—particularly as a by-product of rare earth element (REE) processing. This study develops a parametric techno-economic assessment (TEA) framework synthesizing published data from China, Russia, the USA, India, and Europe to establish the methodological foundation for evaluating thorium recovery economics from monazite ores and REE tailings under Central Asian conditions. Monazite typically contains 4–12% ThO₂, while tailings contain 0.1–3%, making secondary resources attractive for future recovery strategies. Particular attention is given to integration with uranium tailings and the application of advanced materials such as nanocomposite sorbents and carbon-based electrodes. Reported production costs of ThO₂ range from 50 to 500 USD/kg depending on process scale, feedstock quality, and co-production of REEs. The reviewed studies consistently show that coupling thorium recovery with REE processing improves economic feasibility. Modern approaches, including hybrid technologies and electrosorption systems, may reduce operational costs and improve process efficiency. Despite challenges related to capital investment, market uncertainty, and radioactive waste management, thorium continues to attract growing interest as a potential component of future nuclear fuel cycles and advanced reactor systems, including small modular reactors. To the best of the authors’ knowledge, this is the first parametric TEA framework structured around Central Asian conditions, combining literature-derived regional data, scenario-based process economics, and Monte Carlo sensitivity analysis within a single discounted cash flow structure. Full article

Centered on lean production, this study integrates operational technologies (OT), communication technologies (CT), and information technologies (IT) within an open-system software architecture. Under stochastic customer demand, reliance on static data and experience-based decision-making constrains firms’ responsiveness to market. The integration of lean management with a data-driven database enhances operational flexibility and decision quality, enabling small and medium-sized enterprises (SMEs) in the bicycle industry to develop responsive digital factory environments with real-time monitoring and improved operational transparency. The proposed platform is applicable to both manufacturing processes and operational management, improving overall equipment effectiveness (OEE), production efficiency, process optimization, and reducing quality losses, inventory levels, and workforce misallocation. This study investigates the application of the Analytic Hierarchy Process (AHP) and multi-criteria decision-making (MCDM) within a performance framework integrating ESG indicators and a balanced scorecard to identify key success factors for digital lean improvement in the bicycle industry. A case study of a bicycle manufacturer was conducted using questionnaire surveys and expert interviews with exporters. The results indicate that the five most critical success factors are: enhancing return on invested capital, strengthening digital capabilities, improving product quality, minimizing inventory waste, and reducing lead time. These findings provide practical guidance for decision-makers in designing more effective lean management strategies in highly competitive digital markets. Furthermore, by facilitating the adoption of appropriate digital technologies under a reasonable return on investment, this approach supports the systematic implementation of Industry 4.0 initiatives and transforms traditional lean practices into more efficient and sustainable digital lean operations. Full article

Plastic waste presents a significant environmental and public health concern in Malawi, where rapid urban growth, limited waste collection services, and informal disposal practices contribute to persistent plastic waste hotspots. In Lilongwe City, the waste collection rate has been reported ranges from 10% to 30%. This means that out of the 500 to 600 tons of municipal solid waste produced each day, only about 50 to 150 tons are collected daily. These hotspots occur in settings such as drains, markets, settlement edges, riverbanks, and lakeshore environments. They intensify health-relevant exposure pathways by encouraging stagnant water, increasing flood risk, facilitating open burning, and supporting the formation of plastisphere biofilms that can contain pathogenic and antimicrobial resistant organisms. This research synthesises evidence on the main sources of plastic waste in Malawi, the mechanisms of leakage across different environments, and the associated health implications. It uses a scoping approach aligned with PRISMA-ScR guidance and is informed by the UK Research and Innovation (UKRI) funded Sustainable Plastic Attitudes to benefit Communities and their Environments (SPACES project), which highlights the influence of behavioural, governance, and environmental factors on plastic pollution. A two phase, risk-based decision framework to support targeted management of plastic waste hotspots is described. Phase 1 focuses on rapid harm reduction through the identification and ranking of hotspots according to risk severity, spatial extent, and feasibility, guiding timely interventions such as drain clearance, waste capture, and temporary stabilisation. Phase 2 addresses longer term prevention by tackling upstream drivers through policy measures, improved services, reuse and reduction schemes, and community engagement. The framework has been developed using evidence from Malawi; however, its methodology could be applied to other low- and middle-income countries that experience similar constraints and exposure pathways. The framework offers a transparent and practical tool for decision makers seeking to allocate limited resources effectively while reducing environmental and health risks associated with plastic waste. Full article