Search Results (8,623)

The rising volume of sludge production poses significant environmental threats. Sludge has a high moisture content (MC), which increases its disposal and transport expenses. On the other hand, sludge has low dewaterability due to its high concentration of soluble organic compounds. To reduce sludge production, understanding and improving preconditioning and mechanical dewatering are crucial for breakthroughs in advanced sludge dewatering. The sludge samples used in this analysis were obtained from the Sarabium municipal wastewater treatment plant, with a moisture content of 97% and a specific filtration resistance (SRF) of 9.15463 × 10¹⁵ m/kg. Sludge dewatering was enhanced by treating the samples chemically with ferric chloride, aluminum sulfate, Moringa olifera, and cationic polyacrylamide CPAM and physically with wood chips, slag, rice husk, and wheat straw. The experiments examined the sludge’s initial characterization (specific resistance to filtration (SRF) and time to filtrate (TTF)). To verify the structural characteristics (density), elemental composition, and the presence of various functional groups, a characterization investigation was conducted using scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and energy-dispersive X-ray spectroscopy (EDS). The results showed that chemical conditioning with ferric chloride is better than aluminum sulfate and Moringa. Wood chips also provide better results for physical conditioning than rice husk, wheat straw, and slag. The reaction occurred at the carbonyl group, where FTIR showed more activated sites during SEM analysis, as evidenced by the FTIR results. Still, when CPAM was added to conditioned sludge, there was no difference in sludge dewatering performance, and the activated sites remained unchanged. Hence, this research found that mechanical sludge dewatering was improved by conditioning with ferric chloride (pH of 6 and dose of 0.12 g/g of dry solid) and wood chips (dose of 1.5 g/g of dry solid), which reduced sludge volume after dewatering by 82.5% under low pressure, which in turn minimizes transportation, energy, and handling costs. This study supports SDG 3 and SDG 6 by improving sludge dewatering efficiency and promoting sustainable wastewater management using natural wood chips. Full article

The pressing need for sustainable, plant-based alternatives is highlighted by the growing resistance of agricultural pests to synthetic pesticides. This study examined the pesticidal potential of phytocompounds from C. tora discovered by GC–MS analysis against important tomato insect (T. absoluta) and fungal pathogen (A. solani). The binding stability and interaction dynamics of specific metabolites with fungal virulence (polygalacturonase, MAP kinase HOG1, and effector AsCEP50) and insect neuromuscular (ryanodine receptor and sodium channel protein) targets were assessed using molecular docking and 100 ns molecular dynamics simulations. Among the screened compounds, squalene and 4,7,10,13,16,19-docosahexaenoic acid, methyl ester (DHAME) exhibited the strongest binding affinities and conformational stability, with MM-GBSA binding free energies of −38.09 kcal·mol⁻¹ and −52.81 kcal·mol⁻¹ for squalene complexes in T. absoluta and A. solani, respectively. Persistent hydrophobic and mixed hydrophobic–polar contacts that stabilised active-site residues and limited protein flexibility were found by ProLIF analysis. These lively and dynamic profiles imply that DHAME and squalene may interfere with calcium signalling and stress-response pathways, which are essential for the survival and pathogenicity of pests. Hydrophobic interactions were further confirmed as the primary stabilising force by the preponderance of van der Waals and nonpolar solvation energies. The findings show that C. tora metabolites, especially squalene and DHAME, are promising environmentally friendly biopesticide candidates that have both insecticidal and antifungal properties. Their development as sustainable substitutes in integrated pest management systems are supported by their stability, binding efficacy and predicted biosafety. Full article

This perspective provides a multidisciplinary assessment of the use of lithium-ion batteries from electric vehicles (EVs) for second-life applications, motivated by the need to improve resource efficiency, reduce environmental impacts, and support a circular battery economy. Second-life deployment requires the integrated consideration of technical performance, legal compliance, and economic viability. The analysis combines a technical evaluation of battery aging mechanisms, operational load effects, and qualification strategies with a legal assessment of the EU Batteries Regulation (EU) 2023/1542 and an economic analysis of market potential and business models (BM). From a technical perspective, the limitations of State of Health (SOH) as a standalone indicator are demonstrated, highlighting the need for multiple health indicators and degradation-aware qualification. A scalable two-step qualification approach, combining qualitative inspection with a standardized quantitative measurement protocol, is discussed. From a legal perspective, regulatory requirements and barriers related to repurposing, waste classification, and conformity assessment are analyzed. From an economic perspective, business model patterns and market dynamics are evaluated, identifying Automated Guided Vehicles (AGVs) and industrial Energy Storage Systems (ESSs) for renewable firming as particularly promising applications. The paper concludes with recommendations for action and key research needs to enable safe, economically viable, and legally compliant second-life deployment. Full article

Hot dry rock (HDR), characterized by high temperature, vast reserves, and significant development potential, is one of the most important clean energy sources for the future. This study focuses on the Jianhu Uplift and Dongtai Depression in the southern part of the Subei Basin as the research area, conducting systematic target optimization research on HDR geothermal resources within the Cambrian–Ordovician carbonate strata. By systematically compiling regional geothermal geological data, an evaluation index system for target optimization of geothermal resources was established, incorporating two categories of indicators: resource conditions (thermal reservoir temperature and roof burial depth) and environmental impact (urban area safety distance and fault safety distance). Using the Analytic Hierarchy Process (AHP) and GIS spatial overlay analysis, the study area was evaluated for HDR geothermal resource exploration zoning, ultimately delineating three levels of preferred zones. The evaluation results indicate that the target area of the Cambrian–Ordovician geothermal reservoir is extensive, with the Dongtai Depression exhibiting a larger distribution of preferred zones. This study provides a reference for the optimization of target areas in geothermal resource exploration and development. Full article

Growing water scarcity, climate change, and increasingly stringent environmental regulations have intensified the need for advanced wastewater treatment technologies capable of removing emerging contaminants and enabling safe water reuse. This review provides an integrated assessment of recent trends in membrane bioreactors (MBRs) and advanced oxidation processes (AOPs), including their role in hybrid treatment systems, with emphasis on contaminant removal efficiency, energy demand, operational complexity, and transformation product formation. In parallel, an exploratory statistical analysis of EUROSTAT indicators—population connected to wastewater treatment plants, Water Exploitation Index (WEI), freshwater availability, and sludge production—was conducted to examine relationships between treatment infrastructure and pressures on water resources across Europe. Correlation and principal component analyses reveal weak to moderate and predominantly indirect relationships between infrastructure expansion and water stress, highlighting that connectivity alone does not reduce resource pressure in the absence of water reuse and advanced treatment. The combined technological and statistical evidence demonstrates that reuse-oriented MBR–AOP systems are critical for improving effluent quality, mitigating emerging pollutant risks, and supporting circular, climate-resilient water management strategies under European policy frameworks. Full article

This study addresses the management and optimization of decentralized bioresource energy generation under conditions of political instability, using Ukraine as a representative case. The research aims to enhance energy security and operational resilience where centralized energy infrastructure is vulnerable to disruption. A high-efficiency technology for decentralized heat generation is proposed, based on the direct combustion of non-standard agricultural biomass with a one-year renewal cycle. The methodology combines experimental and statistical analysis of biomass feeding processes with advanced three-dimensional modeling of mixture formation and combustion, as well as the development of an artificial intelligence-driven automated control system. The system enables the use of sunflower, rapeseed, wheat, corn, and other agricultural residues with variable particle size and moisture content of up to 40%, without the need for pre-drying or pelletization. An original jet–vortex bioheat generator and optimized dosing systems were designed to ensure continuous and stable combustion. An operational algorithm allowing stable performance within 25–100% of nominal capacity was formulated based on statistical evaluation of screw feeder behavior and optimization of adjustable electric drive parameters, ensuring thermal carrier temperature stability within ±1–2 °C. The main novelty lies in the integrated optimization framework combining unconventional biomass utilization, adaptive electric drive control, and AI-based automation to achieve high energy efficiency and environmental performance. The results indicate that such decentralized systems can substantially strengthen national energy security and support sustainable energy supply in unstable political environments. Full article

The interaction between small organic molecules and coal macerals plays a critical role in regulating fluid retention and transport in coal-related energy and environmental systems. However, the microscopic mechanisms governing adsorption selectivity and interfacial dynamics on different maceral surfaces remain insufficiently understood. In this study, molecular dynamics simulations were employed to investigate the adsorption and desorption behaviors of toluene (TOL) and tetrahydrofuran-2-ol (FUR) on inertinite (INE) and vitrinite (VIT) surfaces at the molecular level. Time-dependent variations in adsorption number, residence time, molecular mobility, interaction energies, and hydrogen-bond characteristics were systematically analyzed. The results reveal strong maceral- and molecule-dependent adsorption preferences. TOL exhibits the most stable adsorption on the INE surface, characterized by rapid surface accumulation, minimal desorption, and a long residence time of 0.43547 ns, which is mainly driven by strong van der Waals interactions and aromatic stacking effects. In contrast, TOL adsorption on VIT is highly dynamic, with frequent desorption events and a markedly reduced residence time of 0.1077 ns. FUR shows relatively weaker and more reversible adsorption on INE, accompanied by enhanced molecular mobility and a shorter residence time of 0.31354 ns. Notably, FUR demonstrates stronger surface retention on VIT, with an extended residence time of 0.34439 ns, which can be attributed to increased electrostatic contributions and intermittent hydrogen bonding. Hydrogen-bond analysis indicates that FUR forms longer-lived hydrogen bonds with VIT (22.05 ps) than with INE (17.86 ps), providing additional stabilization at the interface. These findings elucidate the distinct adsorption mechanisms of aromatic and polar molecules on heterogeneous coal macerals and offer molecular-scale insights into organic matter–coal interfacial processes relevant to energy extraction and subsurface transport. Full article

The purpose of this paper is to analyze recent publications in scientific journals on the circular economy and energy through a systematic review using the PRISMA method and to propose a framework. In recent years, the circular economy has been widely recognized as a viable solution to address environmental and economic challenges. The transition to renewable sources, such as solar, wind, and biomass, is essential for a clean and balanced energy market. The methodology adopted was a systematic review of the scientific literature using the PRISMA method, which aims to categorize published research, evaluating it in terms of its objectives, methodologies, results, and conclusions. To this end, full articles published in scientific journals between 2021 and 2025 on the subject were identified. The analysis of the selected studies reveals an intrinsic relationship between the circular economy and sustainable energy, particularly in the context of Sustainable Development Goals (SDGs) 7 and 12. The results highlight that circular economy practices, such as waste recovery, bioenergy generation, and gasification, not only demonstrate their ability to create sustainable value chains but also contribute to reducing environmental impacts, promoting energy efficiency, and present a proposed framework for analysis and proposition. Full article

Powder metallurgy processes manufacture products from metal powders, which can be produced using various methods. When customer requirements permit, powder metal processes can produce products in an additive rather than a subtractive fashion. Thus, this approach reduces the waste associated with traditional subtractive metallurgical forming processes such as machining. In addition to lowering material waste, enhancing design flexibility, and improving process efficiency, additive manufacturing of powder metallurgy products can also reduce environmental impact by reducing energy consumption, raw material use, emissions, transportation, and waste generation. Furthermore, the use of alternative methods for manufacturing metal powders can further reduce environmental impact. In this study, an energy-based limited-scope global warming potential life cycle assessment is presented that compares the carbon intensities of manufacturing critical products made of oxygen-free high-conductivity copper powder via two different powder production routes: electrode induction melting gas atomization, and the DirectPowder^TM System, within additive manufacturing supply chains. Instead of relying on single-point estimates, this study uses a Monte Carlo simulation to account for uncertainty and variation in input data. Results indicated that the DirectPowder^TM manufacturing pathway had a 39.4% lower global warming potential per kg of usable powder when parts were manufactured via laser powder bed fusion. When only the powder manufacturing methods were included in the analysis, the DirectPowder^TM method demonstrated the potential to reduce global warming impact by 92.9% when compared to the electrode induction melting gas atomization process. In total, 11.44 kg CO₂-eq per kg of OFHC copper produced is saved when using the DirectPowder^TM process. This research provides new insights into the tradeoffs between the environmental impact and functional capabilities of these methods. It offers valuable guidance on process selection for product designers and supply chain professionals seeking to optimize product performance, energy use, and environmental footprint. Full article

The revised Energy Performance of Buildings Directive (EPBD) has introduced ambitious targets aimed at accelerating the decarbonization of the building sector. In parallel, the forthcoming implementation of the Emission Trading System for buildings and road transport (ETS2) in January 2027 adds a further dimension to the policy landscape. This study investigates three renewable energy retrofit strategies (Scenarios A, B, and C) for a hotel building in northern Italy, assessing their effectiveness in meeting the decarbonization objectives set by the EPBD and ETS2. Scenario A couples photovoltaic generation with an existing gas boiler, Scenario B integrates PV with an electric heat pump for space heating, and Scenario C implements the full electrification of both heating and domestic hot water. The results of the three scenarios are evaluated using selected metrics, such as renewable primary energy consumption (EPren), non-renewable primary energy consumption (EPnren), CO₂ emission (CO₂), carbon avoidance cost (CAC), levelized cost of energy (LCOE), net present value (NPV), and Emission Trading System (ETS)2. The results show that PV deployment alone provides economic benefits but yields limited reductions in CO₂ emissions and non-renewable primary energy consumption due to continued reliance on natural gas. The introduction of a heat pump significantly enhances environmental performance, with reduced fossil fuel consumption, increased renewable energy use, and improved cost-effectiveness of carbon avoidance. The ETS2 has no impact in the case of full electrification, as fossil fuel consumption is completely eliminated. Full electrification achieves the greatest emission reductions and the lowest non-renewable primary energy demand while offering the strongest long-term economic performance. Overall, the analysis demonstrates that combining PV systems with building electrification is essential to achieving deep decarbonization, and that fully electrified configurations present the most robust pathway for compliance with emerging ETS2 policies. Full article

This study provides a detailed technical and sustainability comparison of the conventional CNC machining and additive manufacturing routes for an aerospace bearing bracket. The work integrates material selection, process parameterization, build simulation, and environmental–economic assessment within a single framework. For the CNC route, machining of Al 7175-T7351 is characterized through process sequencing, tooling requirements, and waste generation. For the Laser Powder Bed Fusion (LPBF) route, two build strategies, single-part distortion-minimized and multi-part volume-optimized, are developed using Siemens NX for orientation optimization and Atlas3D for thermal and recoater collision simulations. The mechanical properties of Al 7175-T7351 and Scalmalloy^® are compared to justify material selection for aerospace applications. Both the experimental and simulation-derived process metrics are reported, including the build time, support mass, energy consumption, distortion tolerances, and buy-to-fly (B2F) ratio. CNC machining exhibited a B2F ratio of 1:7, with cradle-to-gate CO₂ emissions of ~11,000 g and an energy consumption exceeding 100 kWh per component. In contrast, both LPBF strategies achieved a B2F ratio of 1:1.2, reducing CO₂ emissions by over 90% and energy consumption by up to 63%. Build volume optimization further reduced the LPBF unit cost by over 50% relative to the CNC machining. Use-phase analysis in an aviation context indicated estimated lifetime fuel savings of 776,640 L and the avoidance of 2328 tons of CO₂ emissions. The study demonstrates how simulation-guided build preparation enables informed sustainability-driven decision-making for manufacturing route selection in aerospace applications. Full article

Cemented tailings backfill (CTB) is widely used in mining operations due to its operational simplicity, reliable performance, and environmental benefits. However, the poor consolidation of fine tailings with ordinary Portland cement (OPC) remains a critical challenge, leading to excessive backfill costs. This study addresses the utilization of modified manganese slag (MMS) as a supplementary cementitious material (SCM) for fine tailings from an iron mine in Anhui, China. Sodium silicate (Na₂SiO₃) modification coupled with melt-water quenching was implemented to activate the pozzolanic reactivity of manganese slag (MS) through glassy structure alteration. The MMS underwent comprehensive characterization via physicochemical analysis, X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR) to elucidate its physicochemical attributes, mineralogical composition, and glassy phase architecture. The unconfined compressive strength (UCS) of the CTB samples prepared with MMS, OPC, tailings, and water (T-MMS) was systematically evaluated at curing ages of 7, 28, and 60 days. The results demonstrate that MMS predominantly consists of SiO₂, Al₂O₃, CaO, and MnO, exhibiting a high specific surface area and extensive vitrification. Na₂SiO₃ modification induced depolymerization of the highly polymerized Q⁴ network into less-polymerized Q² chain structures, thereby enhancing the pozzolanic reactivity of MMS. This structural depolymerization facilitated formation of stable gel products with low calcium–silicon ratios, conferring upon the T-MMS10 sample a 60-day strength of 3.85 MPa, representing a 94.4% enhancement over the T-OPC. Scanning electron microscopy–energy dispersive spectroscopy (SEM-EDS) analysis revealed that Na₂SiO₃ modification precipitated extensive calcium silicate hydrate (C-S-H) gel formation and pore refinement, forming a dense networked framework that superseded the porous microstructure of the control sample. Additionally, the elevated zeta potential for T-MMS10 engendered electrostatic repulsion, while the aluminosilicate gel provided imparted lubrication, collectively improving the flowability of the composite slurry exhibiting a 26.40 cm slump, which satisfies the requirements for pipeline transportation in backfill operations. Full article

Sour rot is a significant postharvest disease affecting citrus fruit, causing sourness and decay in various cultivars, particularly lemons. How the pathogen, Geotrichum citri-aurantii, adapts to the highly acidic environment of citrus fruit remains inadequately understood. In this study, the growth characteristics, morphological and structural changes, gene expression profiles, and adaptive mechanisms of G. citri-aurantii under highly acidic conditions were elucidated. The findings indicated that G. citri-aurantii modified the environmental pH by either alkalizing (pH < 3.00) or acidifying (pH > 3.00) the host tissue. It exhibited strong adaptability at pH 2.2, showing shortened and aggregated hyphae, delayed spore germination, and increased vacuoles. Transcriptomic analysis and qRT-PCR identified the significant regulation of key differentially expressed genes involved in cell wall remodeling, cell membrane component synthesis, carbon metabolism, and signal transduction. These regulatory changes enable the pathogen to prevent an influx of external acids and maintain the energy supply under acid stress conditions. Additionally, the Pal/Rim pH signaling pathway genes exhibit distinct response patterns in citrus cultivars with different acidities. These findings enrich the comprehension of the pathogenic process of G. citri-aurantii and offer a theoretical foundation for preventing and managing citrus sour rot. Full article

Slovakia’s biomethane production potential represents up to 10% of Slovakia’s natural gas consumption, which is largely unexploited. The aim of this paper is to develop a model of each available technology (continuous, dry batch, and wet batch) as well as that of a biogas treatment unit and evaluate the energetic, economic, and environmental potential of building a new anaerobic digestion plant in Slovakia, considering four plant locations with feedstock abundance within a 30 km perimeter. Feedstock composition and availability, energy integration, and product usability are evaluated. The applied multi-criteria decision analysis (MCDA) considers four evaluation criteria: return on investment (ROI), CO₂ emissions production, potential industrial biowaste revenue, and municipal density within the operational region. Biogas plant deployment analysis yielded the Levice facility as top-ranked, primarily due to its minimal environmental impact and superior logistical performance, closely followed by the Žilina, Michalovce, and Prešov facilities. When comparing biomethane production facilities, the Levice plant was excluded due to economic infeasibility, and the Žilina facility emerged as the optimal choice, particularly due to its superior ROI performance and the largest biomethane production potential of over 1 million m³ biomethane per year. Thus, biomethane station deployment in Slovakia has proved feasible and can enhance the energy self-sustainability of the country and contribute to meeting the decarbonization goals. Full article

Children’s responses to the climate crisis range from mistrust and helplessness to activism and eco-anxiety, highlighting the need for early educational experiences that foster constructive engagement. At the same time, the persistent underrepresentation of women in science highlights the importance of integrating gender awareness into science education. While hands-on activities and storytelling are widely recognized as effective educational strategies, less attention has been given to how these approaches can be meaningfully combined within a single learning experience. This exploratory study investigates the integration of hands-on environmental science activities and theatrical storytelling as an interdisciplinary, gender-aware educational design for children aged 6 to 11. The intervention included clean energy and greenhouse effect experiments guided by two actresses portraying pioneering scientists, Eunice Newton Foote and Susan Solomon, situating scientific concepts within narrative, historical, and social contexts. Qualitative observations and an exploratory analysis of children’s drawings indicate that narrative and embodied approaches can support cognitive and emotional engagement while fostering more inclusive representations of scientific practice. The study proposes a preliminary, interdisciplinary approach of engagement and inclusion, providing a starting point for future research on integrated, gender-aware environmental education. Full article