Waste elastomer streams are difficult to convert into high-value products because crosslinked rubber phases, service-induced chain degradation, heterogeneous interfaces, and mixed additives reduce melt reprocessability and make secondary processing unstable. In this study, a waste-derived elastomer composite was developed as a flexible, sealable, and energy-absorbing airbag layer for work-at-height fall-protection clothing. Waste thermoplastic polyurethane/polyurethane elastomer scraps were used as the main recycled matrix, while ground waste rubber was introduced as a secondary modifier to improve cushioning performance and increase waste utilization. The recycled elastomers were sorted, cleaned, regenerated, compounded with compatibilizing and modifying agents, and processed into composite airbag-layer films. A virgin TPU film was used as the control, and formulations containing different recycled elastomer contents were evaluated in terms of morphology, thermal stability, processability, mechanical integrity, airtightness, burst resistance, impact cushioning, elastic recovery, cyclic compression stability, and ageing resistance. The results showed that moderate recycled elastomer incorporation improved energy dissipation while maintaining acceptable film continuity and sealing performance. Among the tested formulations, R30, containing approximately 30% recycled elastomer, provided the best balance between functional performance and resource recovery. Compared with virgin TPU, R30 retained suitable tensile strength, elongation, seam stability, and pressure retention, while reducing peak impact force and increasing absorbed energy. Higher recycled contents increased waste diversion but caused larger dispersed domains, higher void content, weaker heat-sealed interfaces, and reduced airtightness and durability. These findings demonstrate that waste elastomers can be upcycled into functional inflatable cushioning layers when recycled content and interfacial compatibility are properly controlled. The proposed strategy provides a potential high-value recycling pathway for flexible polymer waste in wearable protective equipment.
Biodegradable waste constitutes over 50.8% of solid waste streams in Tarlac Agricultural University. This study evaluated the performance and biochar yields of a closed-fired, low-cost drum type carbonizer for mahogany and bamboo residues. The whole system includes a central vertical heat conduit pipe. The furnace has a based enclosure for firing, a firing bed and an ash tray. The carbonizer was fabricated from locally available materials for only 47.13 USD and operated for 3-hour batches using seasoned firewood (25-30 kg Batch −1 ; 15.5 MJ kg −1 energy input) also available in the university. The performance of the system was evaluated by operating on 3-hour batch cycles using seasoned firewood. Performance evaluation using a single-factor completely randomized design revealed a biochar recovery yield of 39.33% from bamboo, 36.00% from mahogany shells, and 26.00% from mahogany leaves. The carbonizer operated with highly consistent thermal dynamics across all treatments, showing no significant differences in its specific energy requirement of 0.545 MJ/kg, fuel consumption rate of 8.56 kg/hr, total energy consumed of 502 MJ, and operating time of 3.3 hours. Proximate analysis revealed volatile combustible matter ranging from 66.60% to 93.07%, ash content from 3.40% to 19.80%, and fixed carbon from 3.53% to 13.60%. Higher heating values of 17.09 to 18.43 MJ/kg combined with atomic H/C ratios of 1.49-1.60 indicating a low-temperature slow pyrolysis process of 350-450°C. Bamboo biochar is recommended for soil conditioning, mahogany shell biochar for composting additives, and mahogany leaf biochar as supplemental fuel. This simple design provides a technically feasible, decentralized baseline for green-campus waste management.
FRP formwork containing recycled construction waste may reduce material consumption, but recycled particles can introduce interfacial defects, weaken interlaminar load transfer, and accelerate stiffness loss under humid-heat exposure, eccentric loading, and variable boundary constraints. This study clarifies the degradation mechanism and develops an optimization design method for recycled-particle-modified FRP formwork. A coupled framework was established by linking recycled aggregate replacement ratio, particle size, water absorption, fiber volume fraction, number of plies, formwork thickness, adhesive-layer thickness, humid-heat cycles, eccentricity, distributed pressure, and boundary stiffness. Orthogonal experiments with 162 valid specimens were used to identify degradation states, calibrate damage evolution parameters, and validate a constraint-driven multi-objective optimization algorithm. The results show that increasing the recycled aggregate replacement ratio and humid-heat cycles jointly reduced elastic modulus retention, interlaminar shear resistance, and bending stiffness. When the replacement ratio exceeded 20% and humid-heat cycles exceeded 200, elastic modulus retention dropped below 0.65, indicating a critical transition in interfacial damage accumulation. After optimization, the replacement ratio was adjusted from 20% to 15.2%, the fiber volume fraction increased from 50% to 56.8%, and the ply number increased from 6 to 8. The optimized formwork achieved a 19.6% increase in bending stiffness, a 13.6% reduction in structural mass, a 16.7% reduction in interfacial shear stress, and a 20.5% reduction in maximum deflection. The main innovation lies in connecting recycled-particle-induced interface degradation with constrained structural optimization, thereby shifting recycled FRP formwork design from material feasibility assessment to service-reliability-oriented parameter control.
Waste-to-fuel (WtF) technologies are increasingly positioned as enablers of a low-carbon circular economy because they simultaneously address two structural challenges: rising residual-waste volumes and the demand for dispatchable low-carbon energy carriers. Their contribution, however, hinges not on nominal energy recovery but on feedstock quality, conversion stability, lifecycle emissions, policy alignment and exposure to price-, supply- and infrastructure-related risks. This article presents a mixed-methods comparative evaluation of six pathways—anaerobic digestion, pyrolysis, gasification, waste-oil biodiesel, refuse-derived fuel (RDF) and hydrothermal liquefaction (HTL). The six were retained after an explicit four-family taxonomy screen (thermochemical, biochemical, chemical, electrochemical), with electrochemical routes (e.g., microbial fuel cells) excluded due to sub-pilot commercial maturity and orders-of-magnitude lower volumetric energy yields. Drawing on 78 peer-reviewed sources (2021–2026) plus UN, IEA, IRENA, OECD and World Bank reports, the study triangulates techno-economic reasoning, lifecycle synthesis and a six-factor energy-risk index (technical, economic, supply, environmental, policy, infrastructure). The novelty lies in jointly ranking pathways by efficiency, carbon intensity and risk while integrating social-acceptance evidence often missing from review work. Findings indicate that no single pathway is universally optimal: anaerobic digestion and waste-oil biodiesel are the most mature and lowest-risk; gasification and pyrolysis are most flexible and high-value but carry elevated technical and market risk; HTL is promising for wet residuals but capital-intensive; and RDF is best confined to non-recyclable combustibles in cement kilns. A defensible transition therefore demands technology–feedstock matching, risk-weighted deployment, improved source segregation and transparent carbon accounting, rather than blanket technology promotion.
The discharge of dye-containing wastewater poses a serious environmental challenge due to its toxicity, persistence, and resistance to conventional treatment methods. Photocatalysis has emerged as a sustainable and effective approach for the degradation of such organic pollutants, with ZnO- and Ag 3 PO 4 -based semiconductors widely studied for their favorable optical properties. However, their practical application is limited by poor visible-light utilization and rapid electron–hole recombination. In addition, while binary composites have been extensively investigated, ternary systems such as AgBr/Ag 3 PO 4 /ZnO and their synergistic effects remain insufficiently explored. Therefore, the objective this study or this study aims to develop efficient visiblelight-driven ZnO-based photocatalysts and to evaluate the influence of composite formation on their structural, optical, and photocatalytic performance such as in environmental remediation through dye purifications. ZnO and Ag 3 PO 4 nanoparticles, along with Ag 3 PO 4 /ZnO and AgBr/Ag 3 PO 4 /ZnO nanocomposites, were synthesized via a direct precipitation method and characterized using XRD, SEM, AAS, and UV–Vis spectroscopy. Photocatalytic activity was assessed through the degradation of crystal violet under visible-light irradiation. The AgBr/Ag 3 PO 4 /ZnO nanocomposite exhibited the highest photocatalytic efficiency, attributed to reduced band gap energy and improved charge separation resulting from synergistic interactions. These findings highlight the potential of ternary composite design for enhanced visible-light-driven photocatalysis in wastewater treatment applications.
Poultry feather waste generated in poultry industries is one of the major concerns for our environment, owing to its slow degradation due to the presence of recalcitrant keratin protein. This research addresses the question: How we can accelerate the process of biodegradation of Poultry Feather Waste (PFW), which helps to curb the accumulation of PFW in nature? The main objectives of the study are: (1) Isolation of keratinophilic microbes from soil (2) to assess the biodegradation capability of isolated microbes. The present research has not been geographically reported in Northern region of India, which shows gap in literature as well as in experimental work.1 gm of sterilized PFW degradation was observed in three different culture media containing TPFW and keratinophilic microbes which were obtained after two months of natural decomposition. Maximum feather degradation was seen in FMM-II in which > 90% of the feather was degraded in just 14 days. ANOVA performed on the 7- and 14-day samples statistically validates the significance of these findings. The novelty of this research lies in its localized approach to standardizing a model for accelerated poultry farm waste (PFW) degradation. Furthermore, it addresses environmental pollutant reduction while simultaneously repurposing this organic waste into a high-value biofertilizer.
The challenge of municipal solid waste (MSW) management is one of the central issues in the transition of both circular and sustainable economies, particularly in countries where the regional disparity and financial constraints influence the implementation of policies. The growing volumes of waste, the high costs of treatment, and disproportional distribution of landfills in comparison to the upkeep of recycling facilities contribute to waste inefficiency and contradict the European Union (EU) waste directives. Such a study uses a combined methodology framework in determining the economic, environmental, and policy implications of municipal waste management in 4,341 municipalities. We present a comprehensive comparison of recycling, landfilling, and energy-from-waste (EfW) approaches using descriptive statistics, cost-benefit analysis, regression models, and optimization methods. The evidence suggests that there is much heterogeneity of efficiency: the diseconomies of scale are in smaller cities, dumping in landfills has long-term environmental costs and short-run affordable costs, and recycling has high environmental and social costs, but higher financial costs. The population density, the institutions of governance, and the design of the collection systems are established to be key contributors to the cost efficiency through the application of regression analysis. The optimization situations also demonstrate that the financial viability and environmental performance can be significantly improved through the use of well-targeted measures such as subsidies, carbon pricing, and pay-as-you-throw schemes. This paper is the first national evidence base on the alignment of the municipal waste management in Italy with the EU circular economy objectives through multilevel analyses. Besides enlightening policymakers about the design of affordable, socially conscious waste regimes, these findings also give a model that can be replicated in other settings in evaluating the shift towards sustainability in Europe.
The object of our research was the low-grade quartzite ore with a gold content (0.7-0.8 g/t) from the Bolnisi-Kazreti gold mining enterprise located in the industrial region of Georgia. The aim was to extract gold from the abovementioned ore using microbiological methods which are mainly applied through two approaches: heap leaching and percolation leaching. In this study, both methodologies were investigated. The heap leaching process of gold (grinding fineness of 0.074 mm) was carried out for 30 days, until the gold content was concentrated in the solution. The liquid-to-solid ratio was 1:2. The recovery reached 92%. Activated carbon was used as a sorbent. The heap leaching methodology is cost-effective, simple, and environmentally safe. Its main drawback is the long duration of the leaching process. Under the percolation methodology, gold leaching (grinding fineness of 0.074 mm) was carried out over a period of 35 days. The liquid-to-solid ratio was 1:1. Gold recovery in the solution reached 97%. Activated carbon and zinc powder were used as sorbents. Based on the results, preference was given to activated carbon. The aim of the study was to replace the cyanide method for processing low-grade quartzite ores with a microbiological process employing a strain of autotrophic silicate bacteria, which is a safe, cost-effective and environmentally sound approach. The actuality of the research lies in the fact that, the minimum quantity of ingredients was determined for both methodologies, specifically with regard to the liquid-to-solid ratio, gold ore, bacterial culture, and nutrient medium. As a result, optimal conditions were established for both methodologies. The percentage of gold recovery complies with internationally accepted standards. Modern physicochemical analytical methods were used in the study: atomic absorption spectrometry (Perkin Elmer), X-ray fluorescence spectrometry (Sky-ray Instruments USA- EDX3600H X-ray), electron microscopy (NSX-100), biological microscopy (MI-5200STD), and quantitative chemical analysis.
As the development speed of automobiles accelerates, the amount of used tyres has risen sharply; as a result, environmental problems related to these old tyres have become more severe. Used-tire Rubber is now one of the main secondary materials for urban sports Construction that Artificial Turf and Running Tracks are made from because it can provide good Wear Resistance and Shock Absorption. Most existing life-cycle assessments (LCAs) have focused more on the recycling technology than other aspects of production process or downstream usage scenario so far. A cradle-to-grab LCA based on ISO 14040 and ISO 14044 is carried out here to assess the environmental effect of recycled tyre rubber applied in urban sports facilities. The System Boundary consists of ELT collection, Mechanical Recycling, Material Substitution, Use-Phase Maintenance, End-of-Life Treatment, etc. Multiple scenarios were examined based on secondary data from peer-reviewed literature and an existing LCA database to determine GWP and CED for a global warming impact assessment; It was found that there would be little difference among them. The result showed that recycled tire rubber-based sport infrastructures have lower Life Cycle Greenhouse Gas emissions and Energy Consumption compared with traditional Materials primarily because of Material Substitution effect, Extended Service Lifespan, etc., whereas an integrated value recovery Scenarios appeared most environmentally favourable. This result is supported by previous LCA studies. Akhtar and Tsang (2024) reported that incorporating 30% recycled tire rubber into infrastructure systems can reduce energy consumption by approximately 153.50 MJ/m 3 and decrease carbon emissions by 30.75 kg CO 2 eq/m 3 , demonstrating the significant environmental advantages of recycled rubber compared with conventional materials. By integrating waste tire recycling into long-lasting urban Infrastructure Applications in one Unified LC A System; This Study Bridges the gap of Recycling Processes to downstream Material Utilisation; And provides a Systems-Level View on Circular Urban Development.
Nowadays, almost all of the wooden composites are connected with thermos reactive adhesive resins. The commonly used binders are phenolformaldehyde, carbamide-formaldehyde, melamine-formaldehyde and diisocyanate resins. From widespread timber and wood sawdust are made the tiles composite materials, which are obtained from wood flour and binders by hot pressing at 120-1400C. In composites biding agents are urea [1], melamine [2, 3] or phenol-formaldehyde [4,5] resins. By the same composition is characterized today widely used high, medium and low-density fiberboards [6-8], which is composed of phenol-formaldehyde resins that is the class of carcinogenic substances, due to formaldehyde emissions. These materials nowadays have a number of shortcomings, the most important of which is that emissions from these materials contain cancerogenic harmful formaldehyde for the human organism. Ecologically friendly new composite materials with high-technical characteristics are made on the basis of wood sawdust and organic/inorganic binders. These composite materials are obtained on the basis of a new binders phenylethoxysiloxane (PhES-50, PhES-80), liquid glass, polyethylene and colophony (at different pressures and temperatures). The binder used simultaneously acts as both a binder and a reinforcement agent. The surface structure of the new composite materials was studied by means of optical microscopy, Scanning Electron Microscopy and Energy Dispersive X-ray Micro-analysis. For composites tensile strength at bending, impact viscosity, thermogravimetric stability and water absorption coefficient have been examined. Optimal conditions for obtaining new, ecologically friendly composites have been established. The obtained composites are characterized by high mechanical properties, thermal resistance, ecological purity and low water absorption capacity, which is one order of magnitude smaller than the water absorption of existing particle board.
Landfilling remains the most widely used disposal method, during which greenhouse gases such as methane, carbon dioxide, and nitrous oxide are released, contributing to climate change. Landfilling remains the most widely used disposal method, during which greenhouse gases such as methane, carbon dioxide, and nitrous oxide are released, contributing to climate change. This study addresses three key research questions: how scientific research on landfill-related greenhouse gas emissions has evolved over time, which thematic and geographical gaps persist in the existing literature, and what policy-relevant insights can be derived to support sustainable landfill management. To answer these questions, a bibliometric analysis was conducted on 1313 peer-reviewed articles published between 2010 and 2025 and indexed in the Scopus database. Publication trends, citation patterns, leading countries, institutions, journals, and emerging research themes were systematically examined using bibliometric mapping techniques. The results reveal a steady growth in scholarly output, with research predominantly concentrated in a limited number of countries and strongly focused on methane mitigation, landfill gas recovery, and waste-to-energy technologies. Beyond methane and carbon dioxide, increasing attention is also observed toward other landfill gases and associated environmental risks, indicating a gradual broadening of research scope. The novelty of this study lies in its extended temporal coverage, exclusive reliance on the Scopus database, and integrated assessment of research trends, gaps, and policy implications within a single analytical framework. The findings emphasize the importance of environmentally safe landfill management and greenhouse gas mitigation. The findings provide valuable scientific and policy-oriented insights that can support evidence-based decision-making, promote environmentally sound landfill practices, and contribute to climate change mitigation and societal well-being.
The increasing use of carbon fibre reinforced polymers (CFRPs) in the automotive industry has led to a rapid growth of production scrap and end-of-life composite waste, creating significant environmental and resource challenges. Although multiple recycling technologies for automotive CFRP have been developed, the lack of high-value downstream applications remains a key barrier to achieving a closed-loop circular economy. Sports equipment casings, which require lightweight, stiffness-dominated and impact-resistant materials rather than primary structural strength, represent a promising but underexplored reuse pathway for recycled carbon fibre composites. This study addresses the research questions of whether recycled automotive CFRP can meet the functional performance requirements of sports equipment casings and whether its adoption can deliver meaningful environmental benefits compared with virgin CFRP. The research objective is to evaluate the performance suitability and sustainability implications of recycled automotive carbon fibre composites for casing applications. A systematic secondary-data methodology is employed, synthesising published mechanical property data and life-cycle assessment (LCA) results from recent peer-reviewed studies. Mechanical feasibility is assessed using stiffness and strength retention ratios relative to virgin composites, while sustainability performance is evaluated using cumulative energy demand and global warming potential indicators under different material substitution scenarios. The results indicate that recycled CFRP typically retains more than 80% of the elastic modulus of virgin materials, with sufficient strength for non-primary casing applications, while achieving 35–45% reductions in energy use and greenhouse gas emissions. The novelty of this study lies in its integrated, application-oriented analysis that links recycled automotive CFRP waste streams with sports equipment casings, providing a structured decision-support perspective for cross-sector reuse within a circular economy framework.
The Supsa River basin, located in the humid subtropical climate zone of western Georgia, is characterized by diverse climatic zones and frequent meteorological hazards. Based on the meteorological observation data of the National Environmental Agency for 1960-2024, the catalog of natural disasters created at the M. Nodia Institute of Geophysics of Ivane Javakhishvili Tbilisi State University, and other literary sources, including the results of regional climate modeling, the climatic conditions and meteorological hazards of the Supsa River basin were studied. The temperature in the study area varies from 4°C (in mountainous areas) to 14°C (in the lowlands), and the annual precipitation is within 1,400–2,400 mm. The meteorological hazards common in the basin are fog, thunderstorms, hail, and blizzards. Droughts are not typical for the basin due to high humidity and significant precipitation. The paper analyzes the damage and waste generation associated with these meteorological hazards. Preventive measures, including early warning systems, windbreaks, and hail protection nets, are recommended to minimize the damage caused and reduce the generation of organic and construction wastes.
Marine ecological aquaculture serves as a vital industry for ensuring food security and driving blue economy development. However, marine fishery waste discharge poses significant threats to its sustainable development. To scientifically assess this impact, this study takes Sanmen Bay as the study area, constructing a multi-level evaluation index system based on the driving forces-pressures-state-impact-response (DPSIR) model and introducing a barrier degree model to quantify key constraints. Dynamic trend prediction employs nonlinear fitting. The study’s novelty lies in optimizing quantitative accuracy by integrating subjective (AHP) and objective (entropy) weights, solving the problem that traditional methods insufficiently characterize land-sea collaborative pollution interactions and marine fishery waste discharge mechanisms. By collecting water quality parameters and socio-economic data from 2014 to 2024, this study analyzed impacts of marine fishery waste (feed residue, feces, abandoned fishing gear, etc.) on ecological aquaculture, identified main obstacle factors and predicted future trends. Results showed the comprehensive evaluation index rose to 0.453 (2014-2024), remaining in the early warning zone. Heavy metal pollution, marine debris density, and sewage outfall distribution are key barriers causing nitrogen/phosphorus excess, eutrophication, and sediment pollution. Projections indicate these stressors will persist with fluctuating pressure and status indices until 2030. The evaluation system provides a multidimensional and quantifiable assessment tool for marine fisheries ecological aquaculture, proposing three countermeasures: intelligent bait reduction, sedimentation tank + artificial wetland treatment, and waste resource utilization, providing scientific decision-making basis for ecological management in semi-enclosed bays.
Scientific discoveries do not always come from carefully planned laboratory experiments; sometimes they begin with simple observations. This study started when Alkali-Activated Fly Ash Concrete (AAFAC) blocks were placed on a backyard lawn, without realizing their unintended impact on vegetation. Over time, the vegetation near the blocks became pale, weak, and eventually disappeared. Further observation suggested that alkaline compounds slowly leached from the AAFAC into the soil, increasing the pH to levels (10–12) that most plants cannot tolerate. To investigate this observation, three plots of land were prepared with different amounts of crushed AAFAC (0 kg/m 2 , 1 kg/m 2 , and 3 kg/m 2 ). The results were clear: after three months, the untreated plot showed normal weed and grass growth (average weed height 7 cm), the moderate treatment plot showed reduced growth (2 cm weeds and weak grass), and the high treatment plot was nearly bare (about 1 cm weeds and no grass). Since outdoor conditions include environmental variability (rain, temperature, insects, and soil differences), a controlled indoor experiment was conducted to isolate the effect of AAFAC. Six identical pots of alfalfa were grown for six weeks under the same conditions using three soil mixtures: 0% AAFAC, 10% AAFAC, and 25% AAFAC by weight. Plant growth and overall health decreased steadily as the AAFAC content increased. Both the outdoor and indoor results show that crushed AAFAC creates a high-pH soil environment that prevents vegetation growth. This finding highlights a simple and previously overlooked application of AAFAC for long-term vegetation control, while also offering a practical way to reuse large amounts of coal ash that would otherwise be landfilled.
Traditional methods for municipal solid waste (MSW) forecasting rely mainly on simplistic models that fail to capture complex urban dynamics, particularly during disruptive events like pandemics. Current machine learning approaches do not include policy-driven variables and real-time adaptability for municipal automation systems. How can machine learning models be enhanced with interrupted-time-series analysis to quantify pandemic impacts and provide automation-ready MSW forecasting for smart city governance? In order to find the solution, this study compiled 199 months of MSW data (2009-2024) from Surat Municipal Corporation (SMC). A rigorous preprocessing is employed by engineering temporal lag features (1-12 months) and creating a COVID-19 binary indicator (March 2020-March 2022). In our study, six supervised regression models were evaluated: Linear Regression, Random Forest, XGBoost, Support Vector Regression, Stacking Regressor, and Multilayer Perceptron, using rigorous interrupted-time-series comparison with and without pandemic indicators. Random Forest achieved highest accuracy (R 2 = 0.85), with lag_1 and residential waste as strongest predictors. The COVID-19 dummy reduced RMSE by 16% in Linear Regression and 10% in XGBoost thus demonstrating measurable pandemic impact quantification. SHAP analysis confirmed temporal dependencies and residential consumption patterns as the primary drivers. Our study systematically integrates interrupted-time-series methodology with the machine learning modeling for MSW forecasting which provides explicit pandemic impact measurement and automation-ready frameworks for municipal decision-making for their operations. Results we obtained demonstrate that hybrid ML + policy variable approaches enable resilient and interpretable forecasting systems capable of adapting to urban disruptions while supporting data-driven smart city waste management automation.
This study addresses the challenges of surface residues, structural disorder, and poor electrochemical performance in regenerated spent graphite anodes. We propose a one???step pyrolysis strategy using sodium lignosulfonate (SLS) as both a carbon source and a self-doping agent for S/O heteroatoms. Spent graphite was purified via sulfuric-acid curing and acid leaching, then coated with SLS and carbonized at 1000 °C under Ar. At an optimal SLS loading of 5 wt%, the regenerated graphite (HM5) exhibits a low ID/IG ratio (0.123) and successful S/O incorporation, as confirmed by Raman and XPS. In Li half-cells, HM5 delivers an initial Coulombic efficiency of 66.44% and a discharge capacity of 363.65 mAh g −–1 at 0.1 C, with 80.35% capacity retention after 150 cycles. The novelty lies in the dual role of SLS – enabling simultaneous carbon coating and heteroatom doping – offering a sustainable, biomass-derived route for high-performance regeneration of spent graphite anodes.
