Search Results (702)

Mine waste remains a persistent challenge for the minerals industry, posing significant environmental concerns if not properly managed. The 1996 Marcopper Mining Disaster in Marinduque, Philippines, left a legacy of mine tailings that continue to threaten local ecosystems and communities. This study investigates the valorization and stabilization of Marcopper river sediments laden with mine tailings using a combined geopolymerization and cement hydration approach. Hybrid mortar samples were prepared with 7.5%, 15%, 22.5%, and 30% mine tailings by weight, utilizing potassium hydroxide (KOH) as an alkaline activator at concentrations of 1 M and 3 M, combined with Ordinary Portland Cement (OPC). The mechanical properties of the hybrid geopolymer cement mortars were assessed via unconfined compression tests, and their crystalline structure, phase composition, surface morphology, and chemical bonding were also analyzed. Static leaching tests were performed to evaluate heavy metal mobility in the geopolymer matrix. The compression tests yielded strength values ranging from 24.22 MPa to 53.99 MPa, meeting ASTM C150 strength requirements. In addition, leaching tests confirmed the effective encapsulation and immobilization of heavy metals, demonstrating the potential of this method for mitigating the environmental risks associated with mine tailings. Full article

The growing generation of organic solid waste from small-scale agriculture poses major environmental challenges in developing countries like Ecuador, where rural areas often lack waste management infrastructure. Residues from livestock rearing and traditional brewing such as poultry manure (PM), bovine manure (BM), and barley by-product (BB) are often discarded untreated. This study evaluated the bioconversion potential of Hermetia illucens (black soldier fly larvae (BSFL), using a local Ecuadorian strain reared on these substrates under natural conditions and three feeding rates (50, 100, and 150 mg·larva⁻¹·day⁻¹). Larval growth and process efficiency were analyzed on a dry-matter basis. Both substrate and feeding rate significantly influenced performance (p < 0.05). PM and BB produced the highest larval dry weights (37.4 and 35.9 mg, respectively) at 100 mg·larva⁻¹·day⁻¹, with development completed in 35 days. BM-fed larvae reached only 17.6 mg and required up to 91 days. Bioconversion peaked at 4.6% (PM100) and 4.2% (BB50), while all BM treatments showed very low efficiency (<0.8%). Waste reduction was highest in BB100 (52.9%) and PM100 (43.5%). These results demonstrate the potential of BSFL as a biological treatment option for rural organic waste streams; however, performance strongly depended on substrate quality and feeding rate, indicating that not all locally available residues are equally suitable for larval bioconversion. Full article

Post-disaster reconstruction remains largely excluded from circular-economy approaches. This gap is particularly evident in earthquake-affected inner territories, where reconstruction is constrained by severe logistical challenges—especially in relation to rubble management—and where debris is often composed of materials closely tied to local building cultures and community identities. In these contexts, rebuilding still predominantly follows linear, emergency-driven models that treat rubble primarily as waste. This study introduces Rubble as a Material Bank (RMB), a digital–material framework that reconceptualises earthquake rubble as a traceable and programmable resource for circular reconstruction. RMB defines a rubble-to-component chain that integrates material characterisation, data-driven management, robotic fabrication, and reversible architectural design. Selected downstream segments of this chain are experimentally validated through the TRAP project, developed within the European TARGET-X programme. The experimentation focuses on extrusion-based fabrication of dry-assembled wall components using rubble-derived aggregates. The results indicate that digitally governed workflows can enable material reuse, while also revealing technical and regulatory constraints that currently limit large-scale implementation. Full article

Orchard crops generate substantial quantities of diverse biomass each year, with grapevines being among the most economically significant species worldwide. Considering the scale of this biomass, there is a growing need to explore rational strategies for its utilisation, for example, for energy production or other value-added applications. Such approaches may contribute to improving resource efficiency and reducing the environmental burden associated with agricultural waste. The aim of this study was to examine the energy potential of woody post-production waste from wine processing, with particular emphasis on grape stems of four cultivars—Chardonnay, Riesling, Merlot, and Zweigelt—grown in two contrasting climatic regions: south-eastern Poland and Moravia (Czech Republic). The results demonstrated that both the grape variety and cultivation site significantly influenced the majority of bunch biometric traits, including bunch and berry weight, berry number, and stem dimensions. A moderately warm climate promoted the development of larger and heavier bunches as well as more robust stems across all examined cultivars. Energy analyses indicated that Zweigelt stems produced under moderately warm conditions and Chardonnay stems from a temperate climate exhibited the most favourable combustion properties. Nonetheless, certain constraints were identified, such as increased ash (12.20%) and moisture content (11.51%) in Chardonnay grown in warmer conditions, and elevated CO and CO₂ emissions observed for Zweigelt (1333.26 kg·mg⁻¹). Overall, the findings confirm that grape stems constitute a promising local source of bioenergy, with their energy performance determined predominantly by varietal characteristics and climatic factors. Their utilisation aligns with circular-economy principles and may help reduce the environmental impacts associated with traditional viticultural waste management. Full article

Urban tree-management operations generate substantial amounts of woody biomass that often remain underutilized despite their potential value as a local renewable fuel. This study investigates the possibility of using woodchips and sawdust delivered from municipal tree-cutting activities as boiler fuel, with a specific focus on how fuel moisture, particle size, and natural-fiber packaging influence combustion performance and emission characteristics. In collaboration with a municipal greenery-cutting company, representative batches of biomass were collected, characterized through proximate and ultimate analyses, and combusted in a small-scale boiler. Unlike conventional densification routes (pelletization/briquetting), the proposed approach uses combustible natural-fiber packaging to create modular ‘macro-pellets’ from minimally processed urban residues. The study quantifies how this low-energy packaging concept affects emissions and boiler efficiency relative to loose chips/sawdust at two moisture levels. The results demonstrate that packaging the fuel in jute bags markedly improved performance for both woodchips and sawdust by stabilizing the fuel bed, enhancing air distribution, and reducing emissions of incomplete combustion products. Boiler efficiency increased from approximately 60% for raw unpackaged fuels to 71–75% for the dried and jute-packaged variants. The findings highlight that simple preprocessing steps—drying and packaging in natural-fiber bags—can substantially enhance the energy recovery potential of urban green waste, offering a practical pathway for integrating municipal biomass residues into a sustainable fuel. Full article

With the rapid advancement of integrated thermal management systems (ITMS) for new energy vehicles (NEVs), flow losses and hydrodynamic characteristics within multi-way valves have become critical determinants of system performance. In this study, a three-dimensional computational fluid dynamics model is established for a multi-way valve used in a representative NEV ITMS, where PAG46 coolant is employed as the working fluid. The steady-state pressure-loss characteristics under three typical operating modes—cooling, heating, and waste heat recovery—are investigated, together with the transient hydrodynamic response during mode switching. The steady-state results indicate that pressure losses are primarily concentrated in regions with abrupt changes in flow direction and sudden variations in cross-sectional area, and that the cooling mode generally exhibits the highest overall pressure loss due to the involvement of all flow channels and stronger flow curvature. Furthermore, a parametric analysis of the valve body corner chamfers and valve spool fillets reveals a non-monotonic dependence of pressure drop on chamfer radius, highlighting a trade-off between streamline smoothness and the effective flow cross-sectional area. Transient analysis, exemplified by the transition from heating to waste heat recovery mode, demonstrates that dynamic changes in channel opening induce a significant reconstruction of the internal velocity and pressure fields. Local high-velocity zones, transient pressure peaks, and pronounced fluctuations of hydraulic torque on the valve spool emerge during the switching process, imposing higher requirements on the torque output and motion stability of the actuator mechanism. Consequently, this study provides a theoretical basis and engineering guidance for the structural optimization and actuator matching of multi-way valves in NEV thermal management systems. Full article

Microplastics (MPs)—synthetic polymer particles less than 5 mm in size—have emerged as ubiquitous contaminants in terrestrial and aquatic environments worldwide, raising concerns about their ecological and human health impacts. While research has predominantly focused on urban and marine settings, evidence shows that rural ecosystems are also affected, challenging assumptions of pristine conditions outside cities and coasts. This review synthesizes current knowledge on the presence, pathways, and impacts of MPs in rural environments, highlighting complex contamination dynamics driven by both local sources (agricultural plastics, domestic waste, rural wastewater, and road runoff) and regional processes (atmospheric deposition, hydrological transport, and sediment transfer). Key findings highlight that rural lakes, streams, soils, and groundwater systems are active sinks and secondary sources of diverse MPs, predominantly polyethylene (PE), polypropylene (PP), and polyethylene terephthalate (PET) in fibrous and fragmented forms. These particles vary in size, density, and color, influencing their transport, persistence, and bioavailability. Ecological effects include bioaccumulation in freshwater species, soil degradation, and potential food chain transfer, while human exposure risks stem from contaminated groundwater, air, and locally produced food. Despite these growing threats, rural systems remain underrepresented in monitoring and policy frameworks. The article calls for context-specific mitigation strategies, enhanced wastewater treatment, rural waste management reforms, and integrated microplastics surveillance across environmental compartments. Full article

This study presents a comprehensive decomposition analysis of waste-to-energy (WtE) in India through a systematic literature review (SLR) employing the PRISMA guidelines. The findings underscore the immense potential of WtE technologies in addressing India’s escalating municipal solid waste (MSW) generation amid rapid urbanization while simultaneously contributing to sustainable energy production and circular economy goals. The thematic analysis reveals four key themes: global trends in MSW generation, MSW as an alternative energy source, WtE approaches within a circular economy framework, and the impact of India’s urban expansion on MSW generation. Despite significant potential, India’s current WtE initiatives face substantial challenges, including inadequate waste segregation, policy gaps, public resistance, technological limitations, and insufficient financial investment. To effectively harness WtE technologies, strategic efforts must focus on robust policy implementation, indigenous technology advancement tailored to India’s waste characteristics, fostering public–private partnerships, and enhancing community engagement to mitigate public concerns. Future research should aim to quantify the economic, environmental, and social impacts of localized WtE interventions to guide scalable solutions. This study contributes valuable insights to policymakers, urban planners, and stakeholders aiming to transition India toward sustainable waste management and energy systems. Full article

Food supply chains play a critical role in advancing sustainability within today’s food systems. In this work, we construct a differential equation-based model with a four-layer supply chain framework that captures the intricate relationships among producers, manufacturers, distributors, and retailers while considering resource optimization, waste minimization, and supply–demand equilibrium. To better understand and predict supply chain behavior, we perform a series of model analyses. By applying chaos theory, we analyze the system’s equilibrium states and evaluate their local stability. Our findings reveal that manufacturers and retailers encounter significant difficulties when the system shifts into chaotic behavior. This can be made worse by future uncertainties. This entails formulating tailored strategies to mitigate risks. Hence, we design a set of nonlinear feedback control strategies to synchronize two chaotic supply chain networks. Theoretical validity is established using Lyapunov theory. Our simulation results confirm that the proposed strategy can eliminate synchronization errors. Furthermore, it allows for swift alignment and coordination between the networks. Overall, this synchronization method is both effective and easy to implement for managing risks and enhancing sustainability in food supply chains affected by chaotic dynamics. Full article

Effective municipal waste management is fundamental to environmental sustainability and the circular economy. This case study assesses the operational effectiveness of the Recycling/Civic Amenity Site (CAS) network in Białostocki county, Poland, during the 2014–2018 national waste management transition. A multi-criteria assessment was employed, integrating compliance audits, infrastructure checks, and spatial analysis of waste type distributions to evaluate CAS operations. The findings reveal a socio-economic divergence between more urbanised (town-and-village) and purely rural (village) municipalities, which is directly reflected in their distinct waste composition patterns. The town-and-village areas produced homogeneous, high-quality packaging waste streams that support recycling goals. Conversely, the village municipalities generated more commingled, heterogeneous streams that challenge recycling efforts. An optimised CAS model was proposed for the county to enhance sustainability by adaptively differentiating CAS services to local needs. However, a direct stock-take of all 16 CASs revealed significant infrastructural disparities, limiting the model’s potential. The study concludes that overcoming both the qualitative waste stream divergence and quantitative infrastructure disparities through tailored strategies is essential for meeting national recycling targets and achieving long-term sustainability. The methodology provides a replicable framework for pinpointing the root causes of inefficient operations, offering local authorities evidence-based tools to optimise CAS design and ensure infrastructure investments directly support overarching sustainability goals. Full article

Italian inner areas face population decline, limited access to services and fragile infrastructure; however, the micro-mechanisms through which community practices generate tangible improvements often remain unclear. Still, local communitarian initiatives, such as those represented by ecovillages, can be an effective response to the ongoing process of marginalisation, becoming true living labs for place-based transitions. Through the analysis of the Torri Superiore Ecovillage (Imperia, Italy), a recognised and well-known good practice in the national and international ecovillage circuit, we want to find answers to three research questions: (RQ1) To what extent can an ecovillage act as a living lab for social innovation and ecological transition in inner areas? (RQ2) Which demographic and governance conditions enable territorial resilience and which ones block it? (RQ3) Which environmental practices generate locally significant improvements and with what limitations? Based on qualitative and interpretative evidence (2016–2025)—field observations, internal documents and testimonies—and on essential demographic indicators (ISTAT/SNAI), this study examines the Torri Superiore Ecovillage as a small-scale living lab. Torri Superiore and the surrounding municipalities are ageing and have reduced demographic bases; however selective immigration and heterogeneity of skills act as partial buffers. The governance of the Torri Superiore Ecovillage combines clear rules, participatory routines and coordination mechanisms, promoting problem solving while remaining sensitive to leadership burdens. The “bridging” between multiple actors enables terrace maintenance, local water resource management, agroecological practices, renewable energy adoption, waste prevention/composting and light mobility to achieve tangible environmental improvements on a small scale. We frame transferability as analytical (not statistical), specify the enabling conditions (sufficient active participants, stable routines, territorial management) and outline the relevant policy implications for SNAI classes and a lightweight longitudinal observatory. Full article

Background: Municipal solid waste management is a relevant component of climate and air quality policy, yet published life cycle assessments report inconsistent conclusions on whether sanitary landfilling, waste-to-energy incineration, composting, or anaerobic digestion yields the lowest greenhouse gas and co-pollutant impacts because results depend strongly on methodological choices and local context. Objective: To synthesize and critically evaluate how key life cycle assessment assumptions and boundary decisions influence reported emissions across major waste management pathways, with primary emphasis on the United States and selected comparison to European Union policy frameworks. Methods: Peer-reviewed life cycle assessment studies and supporting technical and regulatory sources were reviewed and compared, focusing on functional unit definition, system boundaries, time horizon, energy substitution and crediting methods, and treatment of methane, nitrous oxide, and air pollutant controls; drivers of variability were identified through structured cross study comparison and sensitivity-focused interpretation. Results: Reported pathway rankings vary primarily with landfill gas collection and utilization assumptions, the carbon intensity of displaced electricity or heat for waste-to-energy systems, and the representation of biological process emissions across active and curing stages; harmonized comparisons reduce variability but do not yield a single consistently superior pathway across all plausible settings. Conclusions: Comparative conclusions are context-dependent and policy-relevant interpretation requires transparent reporting and sensitivity analysis for capturing efficiency, substitution factors, and biological emission controls, along with clear alignment between modeled scenarios and real-world operating conditions. Full article

Europe is dealing with environmental problems that require cooperation beyond national and regional borders. Air pollution, water pollution, biodiversity loss, and waste management are the major issues that are not only complex but also cross borders. Therefore, it is necessary to provide collaborative responses that go beyond the capacity of individual countries. This inquiry centers on the question of what the best way is to set up and govern the transnational cooperation in Europe to confront these major environmental challenges. A systematic bibliographic review of the research conducted between 2010 and 2025 forms the basis of this work. The research combines semantic analysis and Latent Dirichlet Allocation (LDA) modeling to study 80 selected publications to find the tenets of the themes discussed. The identified topics are urban climate change adaptation and mitigation, climate policy and management, adaptation and vulnerability frameworks, land use and biodiversity impacts, and future climate projections and assessment. The findings show that there are strong synergies between biodiversity and climate adaptation, resilience, and environmental governance, as well as the great influence of climate change on the water management sector. The study has unveiled the significance of institutional policy frameworks in bringing about environmental cooperation across borders. In addition, it depicts the relationship between local urban projects and supra-regional policy strategies, in which the two can merge and function efficiently as long as they are working towards the common goal of environmental sustainability. This study is meant to shed more light on the area of environmental governance research, discovering areas that need more exploration, and providing some signposts on how to improve environmental involvement in Europe. Full article

Waste classification is a critical aspect of sustainable waste management systems. Traditional methods for waste classification are often inadequate to handle the complexity and diversity of materials encountered in real-world scenarios. This paper proposes novel deep ensemble learning models that combine pre-trained models with ensemble methods to improve waste classification performance. The proposed model leverages transfer and ensemble learning techniques, employing both averaging and weighted averaging methods to enhance waste classification accuracy. The proposed model is evaluated comprehensively on four publicly available waste image datasets containing various waste categories: TrashNet, TrashBox, Waste Pictures and Garbage Classification. The obtained results show that the averaging and weighted averaging ensemble methods improved classification accuracy by 1% to 3% over the strongest individual models. The weighted ensemble method achieves 96% accuracy, 94% precision, 97% recall and 95% F1 score on the TrashNet dataset. Statistical significance is verified using 5-fold cross-validation and paired t-tests (p < 0.05). To ensure model explainability, the localization of important object regions is demonstrated with Grad-CAM visualizations. Overall, this study validates the potential of integrating deep image classification models with ensemble methodologies to improve the accuracy and efficiency of waste classification. The main contributions of this study can be summarized as follows: we design an efficient deep ensemble method that leverages multiple pre-trained models and ensemble techniques; we employ averaging and weighted averaging techniques to improve classification accuracy and model robustness; and lastly, we evaluate the model using multiple datasets to demonstrate generalizability, scalability and robustness. Full article

Phosphate is a crucial non-renewable mineral resource, mainly utilized in producing fertilizers that support global agriculture. As phosphorus is an indispensable nutrient for plant growth, phosphate holds a key position in ensuring food security. While deposits are distributed worldwide, the largest reserves are concentrated in Morocco. The Benguerir phosphate mining in Morocco generates heterogeneous waste (i.e., including overburden, tailings, and phosphogypsum) that complicates management and valorization, which is the beneficial reuse or value recovery from waste materials (e.g., use in cover systems, buffering, or other engineered applications). Therefore, it is essential to characterize their mineralogical properties to evaluate their environmental impact and possibilities for reuse or site revegetation. To do so, we integrate VNIR–SWIR reflectance spectroscopy with HandHeld X-ray fluorescence (HHXRF) to characterize phosphate waste rock and assess its reuse potential. For this purpose, field samples (n = 104) were collected, and their spectral reflectance was measured using an ASD FieldSpec 4 spectroradiometer (350–2500 nm) under standardized laboratory conditions. Spectra were processed (Savitzky–Golay smoothing, convex-hull continuum removal) and matched to ECOSTRESS library references; across the dataset, library matching achieved mean RMSE = 0.15 ± 0.053 (median 0.145; 0.085–0.350), median SAM = 0.134 rad, median SID = 0.029, and mean R² = 0.748 ± 0.170, with 84% of spectra yielding R² > 0.70. In parallel, HHXRF major and trace elements were measured on all samples to corroborate spectral interpretations. Together, these analyses resolve carbonate–clay–phosphate assemblages (dolomite commonly dominant, with illite/smectite–kaolinite, quartz, and residual carbonate-fluorapatite varying across samples). Elemental ratios (e.g., Mg/Ca distinguishing dolomite from calcite; K/Al indicating illite) reinforce spectral trends, and phosphate indicators delineate localized enrichment (P₂O₅ up to 23.86 wt % in apatite-rich samples). Overall, the combined workflow is rapid, low-impact, and reproducible, yielding coherent mineralogical patterns that align across spectroscopic and geochemical lines of evidence and providing actionable inputs for selective screening, targeted material reuse, and more sustainable mine reclamation planning. Full article