Search Results (2,303)

The global food system (FS) contributes one-third of anthropogenic greenhouse gas (GHG) emissions, yet evidence remains heavily skewed toward temperate-climate cities, leaving cold-climate cities in the Northern Hemisphere understudied. Here, the GHG footprint (GHGF) of the entire FS in Ulaanbaatar, Mongolia, is assessed, accounting for six subsystems spanning food production, processing and storage, retail, transportation, consumption, and food waste. The baseline indicates that the food waste (FW) subsystem dominates the total GHGF (47.13 kg CO_2eq/kg), contributing 49.3% of overall emissions. It exceeds those from agricultural food production (AFP) (18.5%) and, food & food waste transportation (FFWT) (22.6%). We further evaluate two mitigation scenarios. (1) Under a dietary shift scenario aligned with national dietary guidance, the total GHGF decreases 14.4% while the FW subsystem remains the largest contributor, (2) but the food waste reduction scenario yields a comparable reduction of 15.9%. The findings revealed that decarbonisation lever efficiency can be done through food waste reduction while supporting a circular valorisation strategy, including waste-related GHG liabilities as an energy source in cold-climate cities. Full article

With the rapid development of the edible fungus industry, the environmental pressure and resource waste caused by the massive generation of fungal residue have become increasingly prominent. Meanwhile, heavy metal wastewater pollution and the growing demand for clean energy pose dual challenges to sustainable development. This study focuses on Auricularia cornea var. Li. fungal residue, exploring the establishment of a multi-level resource utilization pathway integrating “porous carbon material preparation—heavy metal adsorption—photocatalytic hydrogen evolution.” Firstly, the Auricularia cornea var. Li. residue-based porous carbon material was examined by combining hydrothermal carbonization, activation and slow pyrolysis. In optimal conditions, the porous carbon obtained yielded a surface area of 675.56 m²/g and formed a composite pore structure consisting of micropores with coexisting micropore and mesopore. Secondly, we performed batch adsorption experiments to study the effects of solution pH, adsorbent dosage and contact time and the adsorption behavior via fitting adsorbing kinetic models. Under optimal conditions, Cd(II) removal efficiency reached 92.36% and an equilibrium adsorption capacity of 92.47 mg/g. We used Cd(II) adsorbed porous carbon as a cadmium source and converted into a CdS photocatalyst using a hydrothermal sulfidation process. The CdS prepared using sodium sulfide as a sulfur source gave an average hydrogen evolution rate of 668.01 μmol·g⁻¹·h⁻¹ and showed higher photocatalytic performance for water splitting to produce hydrogen. Full article

Waste heat recovery from automotive exhaust gases represents an important strategy for improving vehicle energy efficiency. This study experimentally investigates the performance of a thermoelectric generator (TEG) system based on TEC1-12706 modules running under different cold-side cooling conditions and incorporating a Hot Rolled Steel (HRS) protective layer on the hot side. The HRS plate was used to ensure uniform heat distribution and protect the thermoelectric module against thermal shocks generated by a 250 °C heat source. Four cooling regimes were experimentally analyzed: natural convection and forced airflows equivalent to 40, 60, and 90 km/h. The results proved that increasing airflow intensity significantly improved the temperature difference across the module, from approximately 16 ± 2 °C under natural convection to nearly 40 ± 2 °C at the highest airflow velocity. Correspondingly, the steady-state voltage generated increased from approximately 0.25 ± 0.01 V to over 0.60 ± 0.01 V under an 82 Ω resistive load. The measured hot-side temperature remained below 75 °C in all experimental conditions, confirming the thermal protection capability of the HRS layer. The experimental data also revealed a near-linear relationship between voltage and temperature difference, consistent with the Seebeck effect. The proposed configuration shows the feasibility of combining thermal protection and forced convection cooling to improve the stability and electrical performance of thermoelectric waste heat recovery systems intended for low-power automotive auxiliary applications. Full article

The geographic and economic contexts play a major role in decision-making when it comes to municipal solid waste management. In the present study, simulations are carried out using the Waste and Resource Assessment Tool for the Environment (WRATE) software academic version 3.0.1, based on the Ecoinvent database (version 2) to assess the greenhouse gas emissions released by 1 ton of municipal solid waste with a typical composition characterizing upper middle-income countries, with an organic fraction of approximately 50% by weight. The variation over time (2000 to 2022) with no intended transformation in the management strategy is first analyzed, then several transformations are applied by varying the waste management routes (open dumping, landfilling, recycling and composting) as well as the energy recovery integration. The results are then discussed based on the waste categories and the performed operations (landfilling, recycling, transportation, treatment and recovery). The results revealed that the most promising scenario includes limited open dumping that does not exceed 10%, landfilling with at least 20% energy recovery, and major fractions addressed to composting and recycling. Overall, this scenario returns a negative carbon footprint with a value of approximately−0.35 tons of CO₂-Eq/ton of MSW. Results are mostly applicable to countries with similar waste composition and infrastructure levels; preconditions include source segregation, compost markets, and landfill gas infrastructure. Full article

This study aims to investigate the greenhouse gas (GHG) emissions and environmental footprint of BOCOM Petroleum, a mid-sized downstream oil company operating in Douala, Cameroon. In response to the critical need for empirical data on industrial emissions in Sub-Saharan Africa, a mixed-methods approach combining Life Cycle Assessment (LCA), carbon accounting, and stakeholder interviews was adopted. Emissions were categorised following the GHG Protocol into Scope 1 (direct), Scope 2 (energy-related), and Scope 3 (value chain). Results reveal total annual emissions of 51,734 CO₂, kg/year, with Scope 3 accounting for 38%, Scope 2 for 33%, and Scope 1 for 29%. Major emission sources include stationary combustion, laboratory processes, and the use of electricity-intensive heat-generating machines. An Environmental Management Plan (EMP) was developed, proposing actionable measures such as process optimisation, adoption of energy-efficient equipment, electrification of vehicle fleets, and improved waste management. Findings underscore the need for systemic decarbonisation strategies among mid-sized oil firms and highlight the alignment of corporate initiatives with Cameroon’s climate commitments. This study contributes a replicable methodological framework for emission auditing in industrial enterprises across the region and calls for further integration of environmental and financial planning in corporate sustainability strategies. Full article

The cement industry is one of the most energy- and emission-intensive sectors and plays a crucial role in achieving climate neutrality and sustainability objectives. This study examines waste management practices in cement production within the framework of the circular economy and low-carbon transition, with particular emphasis on Polish cement plants operating under EU environmental regulations. Particular attention is given to the use of waste as alternative fuels and secondary raw materials, as well as to the economic and environmental implications of EU climate policy instruments. The research methodology includes an analysis of key emission sources such as clinker production, fuel combustion, and raw material transport and an evaluation of technological and organizational measures aimed at improving energy efficiency and reducing emissions. The empirical analysis is based primarily on operational observations from selected Polish cement plants operating under EU ETS conditions and combines plant-level operational evidence with comparative sectoral data and scenario-based techno-economic assessments related to selected low-carbon technologies. The results suggest that increasing the use of waste-derived fuels and materials may contribute to emission reduction, lower reliance on non-renewable resources, and improved circularity in cement production systems operating under advanced regulatory conditions. Furthermore, the findings highlight the potential for synergies between environmental performance and economic competitiveness. The study underscores the importance of coherent regulatory frameworks and continued investment in low-emission and circular technologies to ensure the long-term sustainability and viability of the cement industry. Full article

Global urbanization is shifting from incremental expansion to stock optimization, and old residential communities have become important spatial units for low-carbon transition. However, in existing built environments, traditional process-based inventory methods face practical constraints, including missing original drawings, complex site conditions, and severe vegetation obstruction. As a result, systematic accounting of buildings, landscapes, and natural carbon sinks remains difficult. This study integrates life cycle assessment (LCA), BIM reverse modeling, 3D point clouds, DesignBuilder simulation, inventory-based accounting, and i-Tree Eco to construct a life cycle carbon emission accounting framework for old residential communities. The framework links current-condition data reconstruction, quantity take-off, operational energy simulation, landscape inventory accounting, and vegetation carbon sequestration assessment. It is applied to Nanyuan Xincun in Hefei to quantify the community-scale carbon source–sink structure. The results show that Nanyuan Xincun presents a clear operation-led emission pattern, with the operation and maintenance phase accounting for 82.52% of total positive emissions. Within architectural engineering, operation and maintenance accounts for 82.91%, while material production accounts for 13.28%. Landscape engineering shows a more mixed structure, with operation and maintenance accounting for 52.95% and material production accounting for 36.49%. Vegetation carbon sequestration analysis shows that mature trees and shrubs are the main ecological carbon assets. Annual sequestration reaches 16.95 t-CO₂e/a, and trees and shrubs contribute 92.85% of total vegetation carbon storage. Under current vegetation conditions, annual sequestration is equivalent to 32.99% of annual landscape operation emissions, indicating considerable ecological compensation potential. Based on these findings, this study proposes four optimization pathways: operational energy reduction, low-carbon material substitution, construction and demolition waste recycling, and mature tree protection. These pathways provide data support for refined carbon management and low-carbon renewal in existing communities. Full article

At present, human activity is the main source of water pollution. The tanning industry is a primary source of water contamination with Cr(III), which can cause various diseases if ingested. A circular economy approach proposes an effective, low-cost solution. The utilization of waste from the food industry is used for the removal of Cr(III) through biosorption. This study evaluated the adsorption capacity of orange peel (OP) and pineapple crown (PC) pretreated with H₂O₂ and NaOH was evaluated under different operating conditions. The physicochemical properties of the biosorbents were characterized using techniques such as Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). The results show that treatment with NaOH at 60 °C obtained an adsorption capacity of 61.63 mg/g and 64.19 mg/g for OP and PC, respectively. The combined biosorbents resulted in an approximately 50% increase in the adsorption capacity of Cr(III) compared to individual biosorbents. The isotherms that best fit the experimental data were Sips and Redlich–Peterson (RP) models, suggesting heterogeneous adsorption behavior in biosorbents. Thermodynamic parameters indicated that biosorption process was spontaneous and endothermic. Full article

The pollution of water, including salt and fresh water, has become an emergency problem. Pollutants come from different sources and have various characteristics, starting from industry and fertilizers used in agriculture, sewage related to human living, and other sources. Diverse sources of pollution require a comprehensive approach to water purification. One possible approach may be the use of appropriate sorbents. Currently, one of the most promising materials used is zeolites. This is because they can come from various sources, including waste raw materials such as fly ash, and, therefore, allow for the use of a circular economy approach. Moreover, these materials can be modified, which enables their selective use for selected types of pollutants. Eventually, these materials become economically viable options. The main aim of this article is to present and analyze possible solutions to water pollution based on zeolite materials. For this purpose, a critical literature review was prepared. The review reveals that zeolites perform particularly well in ion-exchange-driven removal of inorganic contaminants, while their effectiveness for organic micropollutants under realistic conditions is often limited. The identified trade-offs between removal efficiency, regeneration stability, and scalability indicate that zeolites are best applied as function-specific rather than universal sorbents. From a sustainability perspective, this targeted applicability is supported by advantages, such as low material cost, long service life, and the possibility of using naturally occurring or waste-derived precursors, which, together, enable resource-efficient water treatment processes, reduced reliance on energy-intensive technologies, and the valorization of industrial byproducts within circular economy frameworks. Full article

Despite the rapid expansion of photovoltaic (PV) installations over the past decade, challenges such as curtailments of renewable energy sources (RESs) and grid constraints continue to limit the capacity of Cyprus’ power system to accommodate higher solar penetration. In this context, grid reliability, defined as the ability to maintain stable operation by balancing supply and demand, minimizing curtailment, and reducing stress on the island network, has emerged as a critical concern. The deployment of PV-plus-storage systems offers a viable solution to enhance grid reliability while alleviating operational constraints. This paper presents a real-world case study of the first commercially deployed grid-connected PV-powered, battery-integrated electric vehicle (EV) charging station in Cyprus. Commissioned in May 2025, the system integrates a 60.32 kW_p rooftop PV array, a 100 kW/97 kWh battery energy storage system (BESS), and a 160 kW DC fast charger. A custom cloud-based energy management platform enables real-time monitoring, forecasting, and optimization under a zero-export scheme. High-resolution operational and weather data were collected between 15 May and 30 November 2025. Over this period, the integrated PV-battery system supplied 29% of the site’s total energy demand (self-sufficiency rate of 28.97%) and achieved a self-consumption rate of 98.69%. Such rates would not have been attainable with a pure PV system, given the depot’s evening-concentrated EV charging demand profile, which requires the BESS to time-shift daytime solar generation. The system reduced depot electricity costs by approximately 29%, generating €16,010 in savings and avoiding 26.47 tonnes of carbon dioxide (CO₂) emissions compared to a grid-only baseline. Beyond site-level performance, the system contributed to grid stress reduction by absorbing excess PV generation that would otherwise have been curtailed/wasted. Operational insights indicate minimal temperature-related issues, highlight the importance of automated fault detection and alerting to minimize downtime, and demonstrate how periodic operation strategies can optimize system performance and mitigate curtailment in Cyprus’s isolated grid. Full article

Large language model (LLM) serving has emerged as a major source of energy consumption in modern AI infrastructure. In current deployments, graphics processing units (GPUs) are typically operated at default high-frequency settings to maximize performance. However, under practical service-level objectives (SLOs), peak performance is often unnecessary, especially during the memory-bound decode stage, resulting in substantial power redundancy and avoidable energy waste. Existing studies that apply GPU dynamic voltage and frequency scaling (DVFS) to improve the energy efficiency of LLM serving have shown promising results. However, they generally rely on coarse-grained control, accurate output length prediction, or request-level resource management, which limits their effectiveness under highly dynamic workloads and strict SLO constraints. We present EcoInfer, a fine-grained DVFS framework for energy-efficient LLM serving. EcoInfer performs iteration-level, workload-aware GPU frequency control that adapts to the current inference phase and system state while preserving latency guarantees. It comprises three tightly integrated modules: a machine-learning-based frequency–latency predictor that estimates iteration latency across candidate GPU frequencies using lightweight iteration-level features; an SLO-aware frequency controller that selects the minimum feasible frequency within a sweet-spot-guided candidate range; and a low-overhead runtime optimization layer that combines adaptive decision caching with asynchronous execution to reduce and hide the overhead of online control. Implemented on top of vLLM, EcoInfer achieves up to 25.4% energy savings and 21.5% average energy savings and improves energy efficiency by 1.28× on average in terms of Tokens/J while maintaining a nearly unchanged SLO attainment rate compared with the default vLLM baseline. Full article

With the global emphasis on sustainable development, supply chain management is facing new challenges and opportunities. Enterprises often face a large number of suppliers when selecting suppliers, which makes the selection process complex. Considering the crucial role of supplier selection in sustainable supply chains, a sustainable supplier selection model based on multi-attribute utility analysis and a fuzzy approximation ideal solution ranking method is proposed to reduce carbon emissions and environmental pollution. This model helps companies scientifically evaluate and select suppliers by comprehensively considering three aspects: environment, economy, and society. Meanwhile, the study utilizes an optimized genetic algorithm-based order allocation model to raise the efficacy and fairness of order allocation. Reducing procurement costs often relies on improving resource utilization and reducing production waste, which directly lowers the energy consumption and carbon emission intensity per unit of product. At the same time, reducing product damage and delivery delay rates can avoid additional greenhouse gas emissions caused by rework, abandonment, and emergency transportation. By improving supplier productivity and optimizing order allocation, the developed model can not only reduce economic costs but also control environmental pollution and carbon footprints from the source of the supply chain. The outcomes indicate that technological level is a crucial factor influencing supplier selection, with a significant positive impact on supplier willingness to choose, and its standard path coefficient is 0.199, with a significance level of 0.001. Meanwhile, the optimized genetic algorithm exhibits strong stability and convergence in order allocation. This optimization model has high efficiency in handling large-scale orders. This provides strong support for the decision-making of enterprises in sustainable supply chain management and a valuable reference for China’s exploration and practice in the field of sustainable development. Full article

Achieving China’s green transition and its carbon peak and carbon neutrality goals requires joint efforts in low-carbon transformation across supply chain enterprises. This study constructs a supply chain low-carbon awareness (LCA) index using text analysis and examines, from a micro-perspective, the relationship between supply chain low-carbon awareness, corporate carbon emissions, and low-carbon behaviors. The results show that: (1) LCA significantly improves carbon reduction performance, especially in firms with higher supply chain concentrations, non-state ownership, and lower energy intensity. (2) LCA drives the adoption of three distinct mitigation strategies: source control, end-of-pipe treatment, and efficiency improvements. Specifically, downstream LCA is more effective in promoting environmentally beneficial products, circular economy practices, and waste reduction, while upstream LCA is more effective at advancing energy conservation and green office initiatives. (3) By encouraging proactive emission reduction strategies, LCA effectively lowers carbon intensity and enhances firm value. The findings provide micro-level evidence for understanding supply chain low-carbon synergy in China. The study contributes to the theory of supply chain low-carbon synergy and offers insights for promoting corporate low-carbon transition practices. Full article

Amid the global renewable energy transition and rural revitalization, efficient organic waste use is critical for circular economy and carbon neutrality—core pillars of global sustainability. This study addresses unrecovered biogas slurry waste heat and biomass boiler thermal instability in Lindian County’s agricultural waste project. Using a small-scale experiment with MATLABR2023a simulations, it analyzed key parameters’ influence on mesophilic dry anaerobic fermentation, validating waste heat recovery and heat source optimization—measures closely aligned with sustainability goals. A novel multi-energy system for biogas fermentation integrated solar, biomass, and carbonization furnace residual heat. Experiments and simulations assessed heat demand, heating allocation, and economic performance. Findings showed 17-fold peak–valley heat demand fluctuations with seasonal patterns; 200 MJ load increments captured system dynamics. The multi-energy system outperformed single-energy setups in investment and operational costs. Optimal cost-effectiveness came with a 50%, 35%, and 15% heat load distribution among the solar, charcoal furnace, and biomass subsystems, cutting operational expenses. Results provide a robust framework for optimized biogas project design, aiding cost reduction, competitiveness, and circular economy and supporting China’s energy transition, rural revitalization, and the achievement of the sustainable development goals. Full article

Fuel cell-based combined heat and power (CHP) systems enable cascade conversion of hydrogen chemical energy into electricity and heat, providing an effective pathway to enhance overall energy utilization efficiency. In this study, a system-level simulation model for a proton exchange membrane fuel cell CHP waste heat recovery system is developed, incorporating stack waste heat, auxiliary component heat dissipation, catalytic combustion heat, and air-source heat pump upgrading. The multi-source coupling characteristics and the effects of key operating parameters on system performance are quantitatively investigated. The results show that within the current density range of 0.2–1.2 A/cm², the fuel cell stack is the dominant heat source, with heat generation increasing linearly with current density. The catalytic combustion unit acts as a marginal heat source, contributing less than 2% of total heat. The performance of the heat pump system is primarily influenced by ambient temperature and compressor speed. The system energy distribution exhibits significant load dependence: as current density increases, the stack heat contribution rises from 35% to 78%, and the primary source of auxiliary power consumption shifts from the heat pump compressor to the stack air compressor. Although the heat pump COP continues to decline, the system COP first increases and then stabilizes. Sensitivity analysis indicates that ambient temperature improves CHP efficiency by 18% while increasing compressor speed enhances thermal efficiency by 51.7%, but reduces electrical efficiency by 25.2%, resulting in an overall CHP efficiency improvement of 11.0%. In contrast, cathode inlet pressure has a nearly neutral impact on system performance (<0.7% fluctuation). Full article