Search Results (15,959)

The development of carbon-neutral construction materials has stimulated interest in alkali-activated systems for the valorization of industrial non-hazardous waste. This study proposes an original comparative approach to assess the cementing reactivity of several wastes, including black and white fly ash, bottom ash, fine glass dust, and float-glass polishing sludge, through their use as partial replacements for metakaolin (MK). Formulations containing 5–50 wt% of fine waste powders (<45 μm) were prepared and mechanically compared with a reference MK-based geopolymer. Formulations containing waste additions to the reference geopolymeric paste were also evaluated to investigate their role as aggregates/fillers. Mechanical testing identified float-glass polishing sludge as the most reactive precursor, achieving a compressive strength of 25 MPa at 10 w% addition, compared with 16 MPa for the reference material. Bottom ash and black and white fly ash reached approximately 19–21 MPa at 5–10% replacement or addition. Conversely, bottom ash at substitution levels above 5% reduced mechanical performance owing to its high crystallinity and unfavorable Si/Al molar ratio. Microstructural characterization by XRD, FT-IR, density measurements, and SEM was correlated with the observed cementing activity. These results provide a basis for performance-based design criteria aimed at the sustainable valorization of locally available industrial by-products in alkali-activated materials. Full article

Poultry feather waste, one of the major by-products of the poultry industry, represents an underutilized protein-rich biomass with significant potential for sustainable valorization within the circular bioeconomy. This narrative review examines recent advances in the use of poultry feathers as a renewable source of keratin for the development of keratin-based biomaterials. A structured literature search of original research articles published between 2015 and 2026 resulted in a final primary evidence map of 524 records, which was used to evaluate current knowledge on poultry feather management, keratin structure and properties, extraction technologies, and the development of feather-derived biomaterials. The reviewed literature indicates that keratin recovery can convert feather waste into higher-value materials, although its environmental performance depends on the extraction route, energy and chemical requirements, and comparison with established feather-management pathways. Recent advances highlight the potential of feather-derived keratin for biodegradable films, composites, hydrogels, coatings, packaging, biomedical, agricultural, and environmental applications. However, challenges remain regarding scalable extraction technologies, material performance, process standardization, and industrial implementation. This review provides a comprehensive overview of current research and identifies future directions for integrating poultry feather valorization into circular bioeconomy strategies, supporting resource efficiency and the development of sustainable bio-based materials. Full article

The European Union aims to double circular material use by 2030, yet the rate reached only 12.2% in 2024, and environmental tax revenue remains dominated by energy taxes. This article examines whether the composition and timing of environmental taxation and agricultural specialisation are associated with the circular transition. Using an unbalanced EU-27 panel for 2010–2024 (CMUR and recycling) and 2005–2023 (economic indicators), this study estimates two-way fixed-effects lagged and interaction models with Eurostat data. The aggregate environmental tax revenue share shows no systematic association with the five circular outcomes. Disaggregated results show that energy tax revenue is associated with lower private investment in circular sectors, transport tax revenue with higher municipal waste recycling, and pollution tax revenue with a weak increase in circular sector gross value added. Resource tax coefficients are statistically insignificant and imprecisely estimated. Lagged models reveal different patterns across outcomes but no common transmission horizon. The associations of the aggregate tax revenue share with recycling and circular employment weaken as agricultural specialisation increases. However, the associations lose statistical significance when country-specific linear trends are included. The findings suggest that tax composition and economic context are more informative than the aggregate tax burden, while the observational design and sensitivity of the results require cautious policy interpretation. Full article

Designing with reclaimed materials introduces uncertainty as a persistent condition rather than a temporary lack of information. While circular construction increasingly relies on digital infrastructures for traceability and documentation, existing approaches often assume stable and comparable material information. This paper presents ReShelter, a full-scale reclaimed timber demonstrator, as a framework for designing with differentiated uncertainty in circular construction. The project combines heterogeneous timber resources, staged inspection strategies, adaptive design methods, robotic fabrication, and on-site documentation workflows. Four reclaimed timber streams from industrial, demolition, and waste sources, each with distinct levels of geometric complexity and available information, were integrated through source-specific representation and assessment methods. Rather than pursuing complete material characterisation, the workflow establishes fit-for-purpose confidence across design, fabrication, and assembly. Results show how uncertainty can be transformed into actionable constraints through adaptive joint systems, scan-based fabrication, and differentiated data models while retaining architectural flexibility and design intent. During assembly, LiDAR scanning, Gaussian splatting, and semantic annotation were used to document both geometric change and the reasoning behind on-site adaptations. By formalising workflows that valorise reclaimed materials rather than virgin resources, the paper proposes architectural methods that accommodate partial and evolving knowledge, supporting resilient, expressive, and resource-conscious circular building practices. Full article

The inherent toxicity of antimony-based fillers in conventional resin-based friction materials necessitates the exploration of sustainable substitutes for wind turbine braking applications. This study therefore aims to formulate a high-performance, environmentally benign alternative using a ternary filler system comprising fly ash microspheres (industrial solid waste), molybdenum disulfide (MoS₂), and talc. To optimize the filler proportions, an L9(3⁴) orthogonal array design was implemented, systematically assessing the influence of each component on the friction coefficient, wear rate, and mechanical integrity. Dry sliding wear tests were conducted against an HT250 cast iron disc to simulate operational conditions. The experimental results identify the optimal composition (T3: 6 wt% MoS₂, 6 wt% talc, 4 wt% fly ash) as achieving a low wear rate of 0.7 × 10⁻⁷ cm³/(N·m) at 350 °C, alongside an 88% recovery rate for the friction coefficient, with these key tribological metrics proving directly comparable to those of traditional antimony-containing formulations. The underlying mechanism for this improved performance lies in the synergistic interaction of the three fillers, which facilitates the development of a stable and cohesive tribofilm on the contact surface. Furthermore, analysis confirms that abrasive wear remains the prevailing material removal mechanism, thereby validating the practical feasibility of this newly developed, non-toxic composite material. Full article

Background/Objectives: Intensive care is resource-intensive, and routine nursing hygiene contributes substantially to material consumption. This systematic review synthesised evidence comparing single-use and reusable or traditional reusable products in hygiene-related nursing care in intensive and critical care settings, considering clinical, economic, and environmental outcomes. Methods: A systematic review with structured narrative synthesis was conducted in accordance with PRISMA 2020. MEDLINE via PubMed, Scopus, Web of Science Core Collection, and CINAHL Ultimate via EBSCOhost were searched from inception to 25 August 2026. No language, date, or publication-type filters were applied at the database level. Primary empirical comparative studies and process-based life cycle assessments reporting original inventory data were eligible; English or Italian full text was required for inclusion. Two reviewers independently screened studies, extracted data, and performed design-appropriate methodological appraisal, with a third reviewer available to resolve disagreements. The review was registered in PROSPERO (CRD420261376160). Results: Eight studies were included: four quasi-experimental or before–after studies, three randomized trials, and one process-based life cycle assessment. The seven patient-based studies included 2665 participants across adult, paediatric, and neonatal intensive care settings. Environmental evidence was limited to two complementary studies from a single Australian ICU: reusable linen was associated with a 50% reduction in carbon emissions, from 7206 to 3605 kg CO₂e, and substantial reductions in landfill waste. Economic findings were product- and context-dependent; disposable bathing systems and diapers were generally less costly in the settings examined, whereas reusable linen increased overall expenditure by approximately 3%. Clinical findings showed no uniform advantage for either product category. After adjustment, linen type was not independently associated with pressure injury, bathing studies showed heterogeneous microbiological findings and no consistent physiological advantage between methods, and one neonatal before–after study reported lower probable sepsis with disposable diapers. Conclusions: Current evidence does not support a general advantage of either reusable or single-use hygiene products across intensive care. Environmental benefits were demonstrated for reusable linen, whereas economic and clinical outcomes varied by product, setting, and analytical approach. The evidence base remains small and heterogeneous, and no included study assessed clinical, economic, and environmental outcomes concurrently. Integrated comparative studies, particularly in European intensive care settings, are needed. Full article

The building and construction sector accounts for approximately 37% of global CO₂ emissions and nearly 50% of material extraction, driving urgent demand for sustainable material alternatives. Bio-based composites derived from recycled waste and biomass offer a promising pathway toward a circular built environment, yet their production remains hampered by biomass batch variability, the absence of standardized process protocols, and sensitivity to environmental conditions. Digital twin (DT) technology, with its capacity for real-time monitoring, predictive simulation, and closed-loop optimization, has been widely applied in building operation and maintenance but has received scant attention at the material production end. This paper addresses this cross-disciplinary gap by proposing a five-layer DT conceptual framework for the standardized production of bio-based composites, developed using the Design Science Research paradigm. The framework comprises a physical layer, a data acquisition layer, a virtual model layer, a decision and control layer, and a lifecycle-circularity layer, mapped onto five production stages from raw material to recovery. An observe–simulate–decide–adjust (OSDA) closed-loop mechanism runs across all stages. A synthetic-data simulation of the OSDA closed-loop mechanism across 200 virtual production batches illustrates a 48.5% reduction in performance variability (95% CI: 42.9–53.7%) and a 99.0% reduction in the reject rate (95% CI: 96.9–100.0%) in a biochar–recycled-HDPE panel scenario; sensitivity analysis confirms robustness across a range of moisture penalty assumptions. These results are derived from a simplified regression model and constitute numerical proof-of-concept rather than empirical validation. The study contributes a structured, standards-aligned architecture that bridges digital twins and circular building materials, providing a methodological reference and conceptual justification for industry stakeholders. Full article

The global economy is confronted by two parallel grand challenges: the unsustainable accumulation of plastic waste and the escalating demand for high-performance, sustainable energy storage technologies. This perspective operates at the nexus of these challenges and establishes a conceptual roadmap for upcycling post-consumer plastics into functional battery components. In particular, the potential of four widely available waste polymers, polyethylene terephthalate (PET), polyvinyl chloride (PVC), polystyrene (PS), and polymethyl methacrylate (PMMA), is examined for the fabrication of nanofibrous separator membranes through electrospinning. The distinct physicochemical characteristics of these polymers are analyzed in relation to key separator requirements, including porosity, electrolyte wettability, thermal stability, and ionic transport. Because studies employing waste-derived polymers remain limited, relevant research based on commercial polymers and alternative membrane fabrication approaches is also discussed to provide broader insight into structure-property-performance relationships. Environmental aspects related to recycling pathways, solvent systems, and life cycle considerations are also evaluated. Finally, major challenges such as feedstock variability, limited electrochemical validation, and scale-up limitations are identified, and future research directions are proposed. By integrating plastic waste upcycling with separator engineering, this perspective outlines a pathway toward circular and sustainable materials for next-generation energy storage systems. Full article

Large-scale and recurrent Sargassum beaching events along the coastlines of Brazil, Mexico, and the Caribbean pose significant environmental, social, and economic challenges due to biomass accumulation and decomposition. Meanwhile, valorization of underutilized waste streams into composite materials can advance circular economy strategies. Building upon previous findings on Sargassum-based particleboards, this study investigated increased pressing temperature and residual high-density polyethylene (HDPE) incorporation as strategies to improve dimensional stability. Medium-density particleboards were manufactured from Sargassum biomass and sugarcane bagasse, with and without residual HDPE, using bio-based castor oil polyurethane resin. The panels were characterized regarding physical, mechanical, and thermal properties to assess their suitability for non-structural applications. HDPE-containing formulations showed reduced 24 h thickness swelling from 21% to 15%, while exhibiting an overall reduction in mechanical performance, particularly in bending and internal bond strength properties. Despite this trade-off, the developed particleboards demonstrated potential for furniture and indoor building applications while simultaneously valorizing marine, agro-industrial, and plastic residues. These findings support Sargassum biomass as a sustainable feedstock for particleboard production and indicate that residual HDPE can improve 24 h thickness swelling performance, contributing to circular economy strategies and low-impact material development for applications across the built environment sector. Full article

The extensive use of plastic materials across the fisheries sector, including fishing, aquaculture and fish product manufacturing and processing, represents a significant source of environmental pollution. In particular, end-of-life fishing nets, typically made of oil-based polymers, contribute to the accumulation of persistent plastic waste in marine ecosystems. Mechanical recycling has recently emerged as a promising strategy to recover such materials and reintroduce them into production cycles, supporting circular economy practices. In this work, post-consumer polypropylene (PP) fishing nets were collected and mechanically recycled. The recovered polymer was blended with virgin PP at 10 wt% and 30 wt% and processed via extrusion. The resulting materials were characterized in terms of rheological, structural, and mechanical properties to assess their processability and performance. The results demonstrate that recycled PP derived from fishing nets can be effectively reprocessed and used as a secondary raw material, enabling the development of more sustainable polymer systems while reducing dependence on virgin plastics and mitigating environmental impact. Full article

Mining and metallurgical wastes contain potentially valuable mineral resources but pose growing environmental risks. This review proposes a mineralogy-guided framework for converting these wastes into low-carbon binders and construction materials. Rather than classifying residues by origin or bulk oxide composition, it distinguishes them according to the reaction roles of their mineral phases. The framework first distinguishes self-sufficient systems, in which activation unlocks the intrinsic mineral inventory of the waste sufficiently for matrix or product formation, from mineralogically compensated systems, in which additional functional mineral solids are required to supply deficient reactive Si, Al, Ca, sulfate, alkalinity, or other phase-forming components. Binary and multicomponent formulations are then interpreted according to the specific mineralogical functions supplied by the complementary solids and the resulting changes in reaction pathways and products. Thermal, hydrothermal, mechanochemical, alkaline, and carbonation-based processing routes are compared in relation to phase composition, co-precursor function, and the mechanical, thermal, and service properties of concretes, foams, and backfill materials. Evidence indicates that performance depends more on chemical complementarity than on maximizing waste content. Environmental benefits must also account for contaminant immobilization, carbon dioxide binding, and the energy and reagent demand of pretreatment. Mineralogy-informed machine-learning models may support inverse mixture design, but their transferability remains constrained by feedstock heterogeneity and limited standardized data. The framework links mineralogy, processing, reaction products, performance, and scale-up. Full article

This paper investigates the possibility of pressure-assisted thermomechanical consolidation and thermal treatment without applied pressure during the low-temperature consolidation of oil-saturated aluminosilicate sorbents for their subsequent application in the conditioning of liquid oil-containing radioactive waste (RAW). The Premium and Absorbent sorbents saturated with transformer oil not containing radionuclides were used as model RAW systems. It was established that pressure-assisted thermomechanical consolidation leads to the formation of a denser structure and a reduction in hydrocarbon-phase losses compared with thermal treatment without applied pressure. For Premium, mass losses decreased from 0.74 to 0.35 g (by 53%), and for Absorbent, from 0.75 to 0.47 g (by 37%), and the consolidated samples were characterized by a more homogeneous microstructure and increased resistance to exudation. It was established that the efficiency of hydrocarbon-phase retention is determined by both the treatment conditions and the mineral composition of the sorbent. The obtained results indicate the prospects of low-temperature pressure-assisted thermomechanical consolidation at a temperature of 150 °C, a pressure of 1.5 MPa, and a holding time of 20 s for the conditioning of oil-containing RAW without the use of additional binding components. Full article

As a class of low-cost and broad-spectrum antibiotics in wide aquaculture use, residues of tetracyclines (TCs) are imperiling aquatic organisms and public health worldwide, leading to a high demand for TC removal from the aquaculture environment. In addition, considerable consumption of thick-shell mussels generates massive mussel shell waste, and their treatment has been an economic and environmental issue. Herein, a low-cost and high-efficiency mussel shells-based material was successfully prepared for TC removal by thermal modification of shell waste of Mytilus coruscus. Morphological and structural characterizations revealed the phase transformation of calcium carbonate to calcium oxide. The shell-based material calcined at 1050 °C (MC1050) yielded a Langmuir-fitted maximum removal capacity (q_m) of 68.0 mg/g towards oxytetracycline (OTC). Thermodynamic calculations indicate that OTC removal by MC1050 is a spontaneous and endothermic process. OTC removal by MC1050 is likely achieved via multiple co-existing pathways, where Ca-OTC co-precipitation driven by CaO-phase hydration and resultant high-pH conditions dominates, accompanied by auxiliary surface-interaction contributions. Furthermore, MC1050 achieves removal efficiencies exceeding 96% for the ten target TCs spiked at 20 μg/L in real-world freshwater and marine aquaculture effluent matrices. Overall, the developed shell-based material shows promising performance for wastewater treatment and facilitates the resource utilization of waste mussel shells. Full article

This paper presents an experimental study on the behavior of the bond between cotton knitted textile cut-offs and a polymer–cement binder. The first part of the research examined the influence of polymer–cement coating on the maximum tensile load of this type of textile. For this purpose, the maximum tensile force of plain textiles and polymer–cement-coated textiles, with one and two layers of textiles, was tested. The results showed that polymer–cement coating increases the maximum tensile force by an average of 36%, and double polymer–cement coating by an average of 79% compared to twice the maximum force of the textile itself. The second part of the research examined the influence of the overlap length of independent textile parts on the transfer of tensile force from one part to another. Three overlap lengths were tested: 25 mm, 38 mm and 50 mm. The results indicate the conclusion that it is possible to make a continuous polymer–cement–textile surface from knitted textile parts, and suggest that for this type of textile, an overlap length greater than 25 mm is sufficient to transfer the same order of magnitude of maximum tensile forces as for continuous textiles. Additional research is needed to more precisely determine the sufficient overlap length. This research confirmed the hypothesis that cotton knitted textile waste cut-offs could be effectively bonded with a polymer–cement binder to enable the transfer of tensile forces and used as a material for the manufacture of textile formwork. Full article

The cold chain sector is responsible for approximately 4% of global GHG–greenhouse gas emissions. Its passive thermal packaging, which has historically been dominated by expanded polystyrene (EPS), is both a crucial functional component and a significant environmental liability. Regulation (EU) 2025/40 on packaging and packaging waste (PPWR), along with the Single-Use Plastics Directive, the Ecodesign for Sustainable Products Regulation, and the Digital Product Passport, creates cumulative regulatory pressure on EPS and opens the market to alternative passive solutions. This systematic literature review, conducted according to the PRISMA 2020 protocol, addresses three research questions regarding the maturity of EPS alternatives such as phase change materials, vacuum insulated panels, mycelium composites, moulded pulp, dry-moulded fibre, and reusable pooled systems. It examines the cumulative effects of the EU regulatory framework and the systemic interventions needed for a circular transition, interpreted through the ten-R hierarchy. The review introduces the Cold Chain Packaging Circular Transition Framework (CCP-CTF), which is articulated across four dimensions and implemented as a composite indicator across five transition regimes, in addition to a residual EPS scenario. This framework is visualised as a Cold Chain Sustainability Thermometer—a calibrated assessment tool for researchers, policymakers, and industry operators navigating the 2026–2040 PPWR implementation timeline. The review identifies key knowledge gaps, including limited integration of decarbonisation accounting at the packaging-logistics interface, fragmentation of Extended Producer Responsibility schemes in the pharmaceutical sector, and the lack of harmonised eco-modulation criteria for cold chain packaging at the European Union level. Full article