Search Results (4,115)

To mitigate the environmental footprint of the aviation sector, this study proposes an integrated cascading biorefinery scheme to produce Sustainable Aviation Fuel (SAF) precursor bloodstock via enzymatic transesterification of coconut oil. Utilizing a synergistic binary alcohol system (ethanol-butanol) and the liquid lipase Eversa Transform 2.0, a strategic molecular reconfiguration of fatty acid esters was achieved. Optimization through Response Surface Methodology (RSM) identified critical parameters—5% catalyst loading, total binary alcohol-to-oil molar ratio of 7:1 (specifically comprised of a 2.5:4.5:1 ethanol/butanol/coconut oil matrix), and an operation temperature of 57.5 °C—yielding a 97% conversion efficiency. A sequential vacuum fractional distillation process was implemented to partition the ethyl-butyl esters into high-value streams. Notably, the light distillate fraction, characterized by a specific carbon chain distribution (C6: 27.2%, C8: 52.5%, C10: 6%, and C12: 13.6%), perfectly aligns with the molecular window of aviation kerosene. This fraction exhibits excellent cold-flow properties, viscosity, and volatility profiles, positioning it as an ideal high-performance SAF precursor blendstock to increase the renewable content of current aviation fuels. Simultaneously, the remaining C16–C18 residue serves as a high-density energy source for internal refinery processes, while C8–C14 species are recovered as high-purity chemical feedstocks. This circular model maximizes carbon atom economy and economic viability by cogenerating high added-value biochemicals alongside jet-grade blendstocks. These findings provide a scalable, enzymatic framework for the next generation of decarbonized aviation fuels. Full article

Multispectral satellite imagery is a very useful technique to identify altered wall rocks around orogenic gold systems. In this study in the Akzhal–Vasilyevskoye district, Kazakhstan, we show that a geology-based ASTER band-ratio workflow is a useful technique to trace metasomatic footprints of mineralization. In the West Kalba camp, beresite and listvenite both produce usable ASTER SWIR signals, while pyrite and arsenopyrite are largely featureless at multispectral resolution. Five ratios on AST_07XT surface-reflectance data, screened with upper-tail anomaly masks, have enabled identification of sericitic cores, chloritic and carbonate halos, ferric caps, and zones containing mixtures of ferrous phyllosilicates. We show that district-scale Al–OH sericitic anomalies occur within Mg–OH and carbonate shells. At Vasilyevskoye the pattern is due to beresite nuclei within listvenite rims, while at Tokum the sericitic centres remain compact within wider Mg–OH and carbonate halos. Mean polygon spectra differ between the two footprints across Bands B4–B6 and across the SWIR tail (B7–B9). SEM–EDS at Vasilyevskoye links the mapped anomalies to chlorite, sericite, and carbonate gangue assemblages with sulfide-bearing volumes. The data also allow identification of subordinate REE, phosphate, and Ti enrichment within carbonaceous and polymineralic host lithologies. Full article

The Milano Cortina 2026 Winter Olympic Games represent a significant departure from traditional mega-event models due to their markedly polycentric territorial structure. This study investigates the sustainability of this “decentralized” model by analyzing the environmental impact of mobility flows across a vast geographic area. Adopting a methodological approach, the research integrates historical attendance data from previous Winter Games with official projections and travel time simulations to model the event’s carbon footprint. Specifically, the framework quantifies gas emissions by categorizing mobility flows into external international travel and internal inter-cluster transit. The analysis highlights a significant discrepancy between the stated sustainability objectives and the actual implementation of the infrastructural plan. Findings reveal that the total carbon debt is heavily driven by international travel, yet the localized impact on Alpine clusters remains critical due to a persistent reliance on road infrastructure over rail systems. The results suggest a “paradox of decentralized sustainability”, where the benefits of reusing existing sporting venues are offset by the environmental costs of connecting geographically fragmented sites. We conclude that without a robust and efficient public transport network, territorial dispersion acts as a catalyst for widespread anthropogenic pressure on fragile mountain ecosystems, challenging the long-term ecological legacy of the event. By empirically exposing these dynamics, this study offers a novel evaluative framework for assessing the true sustainability of distributed governance in future mega-events. Full article

Silage additives enhance forage preservation and resource efficiency by reducing dry matter (DM) losses and limiting aerobic spoilage. This study evaluated crop-specific lactic acid bacteria (LAB) inoculants by comparing treated (T) silage with untreated (U) controls for maize and grass. Silage quality was assessed using nutritional, fermentation, and microbial indicators, alongside aerobic stability (ASTA) and biogas yield. Additionally, a carbon footprint (CF) assessment, based on primary data from a farm in northern Germany with background datasets, quantified the implications for the biogas-to-electricity pathway. Two scenarios were modelled, with Scenario II accounting for changes in soil organic carbon (SOC). LAB additives improved preservation, with DM losses decreased from 18.48% in untreated grass (UG) to 13.17% in treated grass (TG) and from 21.53% in untreated maize (UM) to 5.21% in treated maize (TM). ASTA increased to 223 h for TM and 218 h for TG, alongside a lower presence of yeasts and moulds. In Scenario I, CF decreased by 5.00% for TG (293.53 g CO₂-eq kWh_el⁻¹) and 6.89% for TM (229.05 g CO₂-eq kWh_el⁻¹). Under Scenario II (including SOC), TG showed a value of 135.43 g CO₂-eq kWh_el⁻¹, and TM 321.48 g CO₂-eq kWh_el⁻¹. Overall, the additive improved silage stability and reduced climate impacts. Full article

This work evaluates the transition from grey to green hydrogen in the Haber–Bosch process through a case study of the Fertial ammonia plant. An integrated assessment per ton of NH₃ was conducted using coupled process simulation with system-level mass, energy, and emission accounting, which link the electrolyser dynamics with ammonia loop operation under variable renewable conditions. The results show an electrical demand of 8.9 MWh/t NH₃ and significant water consumption potential of 27–34 m³/t NH₃. Compared with grey ammonia produced via SMR hydrogen (3.65–4.63 t CO₂/t NH₃), renewable electrolysis reduces total emissions by up to 64% and fossil resource use by approximately 71% (case of 100% PV), depending on electricity carbon intensity. While renewable electricity enables ammonia decarbonization, high water consumption potential represents a challenge. Additionally, hydrogen purity fluctuations and intermittent electrolyser output affect loop conversion and process stability, highlighting the need for heat integration and storage strategies to maintain steady operation. Full article

This study provides a comprehensive systematic review and bibliometric mapping of artificial intelligence and machine learning applications within sustainability research. A bibliometric analysis was conducted on 2981 publications retrieved from the Scopus database, covering the period from 2003 to 2025 and tracing the field’s evolution from fragmented early studies to rapid growth after 2018. The findings reveal a robust methodological core centered on deep learning and neural networks, increasingly applied to energy efficiency, precision agriculture, and smart urban ecosystems. A critical contribution of this review is the identification of the emergence of Green AI, highlighting the dual challenge of using artificial intelligence for environmental goals while mitigating the carbon footprint of computational processes themselves. Ultimately, this study offers a strategic roadmap for researchers and policymakers to align algorithmic innovation with global sustainable development goals. Full article

Background/Objectives: Hygiene theatre describes a diverse array of cleaning and sanitation protocols (such as the use of disinfectant sprays, or plexiglass dividers) that may provide a false sense of safety/security without actually or meaningfully reducing the risk of transmission of pathogens. Initially viewed as a humorous, but harmless, contrivance, the carbon footprint implications and climate impacts of unnecessary and unhelpful performative clinical activities is increasingly being scrutinized. This study examined primary health care providers’ perspectives on hygiene theatre and how to mitigate or reduce both its prevalence and its impact. Methods: Semi-structured interviews with 17 family physicians, nurses, nurse practitioners, and pharmacists were conducted. Results: The findings suggest that pervasive and persistent hygiene theatrics may reflect primary care providers’ inability to critically self-reflect on routinized clinical practices due to a lack of time, the inaccessibility of clinical evidence, and a lack of workplace supports. Conclusions: Addressing hygiene theatre may benefit from direction, guidance or regulation from external groups such as employers, unions, or licensing bodies. The further education of patients (who may have come to expect these theatrics) may also be necessary to better manage their expectations. Full article

Energy-related carbon emissions in the residential sector have emerged as a critical focal point in global climate change mitigation efforts, given the sector’s significant contribution to overall carbon footprints and its close ties to daily human activities. This study presents a systematic bibliometric analysis of energy-related carbon emissions in the residential sector over the last four years (2023–2026), aiming to unravel the latest trends, driving factors, and potential implications for sustainable development, with a particular focus on major carbon-emitting countries and regions, such as China and the United States. By integrating national statistical data, household energy consumption surveys, and relevant policy documents, the analysis first quantifies the temporal and spatial variations in residential carbon emissions across different regions and urban–rural divides. Subsequently, it delves into the key determinants influencing these emissions, including changes in energy consumption patterns (such as the penetration of clean energy sources), household income levels, demographic shifts, and the implementation of energy efficiency measures. Furthermore, this analysis explores the intricate relationships between residential energy choices, carbon emissions, and broader socioeconomic contexts, shedding light on the challenges and opportunities in transitioning toward low-carbon residential lifestyles. The findings are anticipated to provide valuable insights for policymakers, researchers, and stakeholders involved in formulating targeted strategies to curb residential carbon emissions and promote the adoption of sustainable energy practices in the household domain. Full article

Environmental gradients associated with continentality shape terrestrial ecosystems by modifying biodiversity patterns, community structure, and ecosystem functioning. In arid ecosystems, where water and thermal constraints are pronounced, soil organisms represent sensitive indicators of environmental change. Soil nematodes, due to their functional diversity encompassing bacterivores, fungivores, herbivores, omnivores, and predators, constitute effective bioindicators of soil health. We hypothesized that increasing continentality (thermal amplitude) would progressively reduce nematode diversity and functional complexity while altering CUE and metabolic footprints through community compositional shifts. A total of 130 soil samples were collected across three bioclimatic zones (island, coastal, and semi-continental) within the Arganeraie Biosphere Reserve, Morocco, and analyzed for nematode abundance, diversity, trophic structure, ecological indices, and functional traits. Nematode abundance and richness were significantly higher in the island zone compared to the coastal and semi-continental zones, while Shannon diversity did not differ significantly. The island zone exhibited a balanced trophic structure with higher proportions of bacteribores, fungivores, herbivores, and omnivores–predators, than the coastal and semi-continental zones. CUE values were consistently low (<0.5) across all zones, with the widest distribution in the island zone. Thermal amplitude was negatively associated with nematode biomass (R = −0.36), production (R = −0.27), and all trophic footprints, with herbivores showing the steepest decline (R = −0.51). Notably, total energy flux remained relatively stable despite reductions in diversity and trophic complexity, suggesting functional redundancy within dominant bacterivore guilds. These findings support the hypothesis that increasing continentality is associated with reduced nematode diversity and functional complexity, alongside altered carbon processing efficiency. This study underscores the value of integrating trophic, metabolic, and energetic approaches for assessing soil health vulnerability in Mediterranean agroecosystems under climate change. Full article

Considering the implementation of the circular economy and the concept of sustainable development, there is a growing need to reduce resource consumption and the environmental impact of industrial processes. This is particularly important in the sugar industry, which is characterized by high energy intensity and a complex process structure. The aim of this paper is to conduct a narrative review of the latest research from 2021–2026 on the assessment of technological processes in the sugar industry from an energy and environmental perspective. The analysis includes approaches such as life-cycle assessment, carbon footprint analysis, energy indicators, and methods related to the circular economy. The results of the review indicate that existing research focuses primarily on selected process aspects, such as greenhouse gas emissions, energy consumption, or by-product management. However, approaches integrating environmental, energy, cost, and process analysis are lacking. This paper identifies a significant research gap and proposes a direction for filling it by integrating dynamic life-cycle assessment, exergy analysis, material flow and energy costing (MFCA), and process–energy modeling. This approach provides a comprehensive framework for process evaluation and supports the identification of improvement strategies that minimize energy consumption, environmental burdens, and production costs while preserving process efficiency. Full article

In recent sustainability discussions, the link between policy uncertainty and environmental consequences has received significant attention. This study investigates the impact of sustainability uncertainty on the ecological footprint (EF) in G7 countries between 2002 and 2024. The recently developed ESG-Based Sustainability Uncertainty Index (ESGUI) is used as the primary explanatory variable. The control variables are economic growth, trade openness, and renewable energy consumption. Two complementary estimators capable of addressing cross-sectional dependence, slope heterogeneity, and degrees of mixed integration are applied: CS-ARDL and the AMG estimator. The CS-ARDL results demonstrate that the ESGUI and renewable energy have a weakly significant negative long-term effect on the EF, a result that reverses the positive raw correlation observed in the descriptive statistics, which is driven by the confounding effect of GDP. Moreover, economic growth has a strong positive effect on the EF. Nevertheless, the AMG estimator reveals that the ESGUI is negative but not statistically significant. Furthermore, economic growth contributes to environmental degradation by increasing the EF, while renewable energy and trade openness have a mitigating effect on this EF. Taken together, these results demonstrate that sustainability uncertainty plays only a limited role on average, while economic growth remains the dominant driver of EF. Consequently, policy efforts should focus on decoupling economic growth from resource use, strengthening carbon border regulation mechanisms, and prioritizing fossil fuel substitution rather than simply expanding renewable energy supply. Full article

The growing importance of embodied carbon (EC) in building decarbonisation requires transparent, context-specific Life Cycle Assessment (LCA) approaches. This study develops a practical framework for quantifying cradle-to-site EC (A1–A4), combining detailed post-construction material quantification with a structured data selection methodology. Carbon factors (CFs) are primarily sourced from geographically representative Environmental Product Declarations (EPDs) and evaluated through a reliability framework that incorporates material similarity, geographical proximity, and data completeness. An Analytic Hierarchy Process (AHP) is further applied to select representative values for key materials such as ready-mix concrete. The application of this framework highlights the critical influence of data representativeness on EC results and demonstrates a transparent and reproducible approach for reducing uncertainty in early-stage assessments. The case study yields a total EC of 228 kg CO₂e/m², with structural materials identified as the main carbon hotspots: ready-mix concrete accounts for approximately 40% of total impacts, reinforcing steel for around 11%, while masonry systems, infill, and levelling layers contribute a significant additional share. Together, these materials represent slightly more than 75% of total embodied emissions. Beyond the numerical results, the study shows that a limited number of material categories dominate the carbon footprint, enabling targeted decarbonisation strategies. The proposed framework is designed to be transferable to similar building contexts and supports more robust, data-driven decision-making in the Portuguese construction sector and beyond. It is particularly relevant in regions where locally representative environmental data are not necessarily sufficient, as it provides a structured approach for developing embodied carbon assessments under such condition. Full article

This study presents a comprehensive approach that combines the kinetic characterization of the activated sludge process with the application of microalgae culture systems to reduce direct and indirect greenhouse gas emissions in wastewater treatment plants (WWTPs). Based on experimental data obtained in laboratory reactors and real operating parameters extracted from a reference plant, the emission routes associated with secondary treatment were analyzed and the mitigation potential by microalgae in the tertiary stage was modeled. Comparative tables, CO₂ capture scenarios and integrated operation diagrams were developed. The results show that the integration of both technologies can significantly reduce BOD residual load, improve energy yield and capture up to 135 kgCO₂/day depending on the remaining substrate. The reduction in aeration demand reached 25%, and BOD removal increased from a range of 72 to 85% (conventional system) to 87–94% (hybrid system). The work supports the engineering plausibility and relevance of a hybrid sludge–microalgae system as an exploratory strategy for WWTP sustainability. Given the experimental design available in the historical laboratory record, the tertiary-stage outcomes are interpreted here as indicative algal–bacterial scenario responses. Because replicate runs under identical conditions and a parallel non-inoculated control reactor were not available, the manuscript does not present these results as definitive tertiary-performance validation. Complementary plant-scale records from the Canary Islands were considered solely as an external plausibility benchmark for the polishing-stage assumptions and were not interpreted as replicate evidence or as a substitute for a non-inoculated control reactor. The specific objective of this work is to derive activated sludge biokinetic parameters from laboratory assays and to use the experimentally constrained residual load framework to assess, at the scenario level, the mitigation potential of a tertiary algal–bacterial stage under Canary Islands conditions. Full article

The transition toward a net-zero economy requires buildings to evolve from passive consumers into Grid-Interactive Efficient Buildings (GEBs). Traditional Building Energy Management Systems (BEMSs) lack the dynamic intelligence needed to control stochastic energy flows and solve multi-objective optimization problems. To systematically map this technological shift, this study conducts a Systematic Literature Review (SLR) following PRISMA guidelines, analyzing a curated corpus of 144 studies (135 primary technical papers and 9 review articles). Due to the significant diversity in methodological approaches within cyber-physical testbeds and IoT architectures discovered through the literature review process, a qualitative narrative and architectural synthesis was conducted rather than a quantitative meta-analysis. Based on this framework, this review examines emerging paradigms for Cognitive Buildings based on Artificial Intelligence of Things (AIoT), edge computing, and semantic interoperability. This review discusses the evolution of algorithms from predictive Deep Learning (DL) and Deep Reinforcement Learning (DRL) to newer approaches such as Agentic AI and Physics-Informed Neural Networks (PINNs). These new methods address the fundamental “sim-to-real” gap while ensuring thermodynamic consistency and safety in physical actuation. It also presents strategic applications in multi-objective optimization of HVAC systems, demand response, energy arbitrage, and predictive maintenance. Moreover, this review tackles major real-world deployment issues by introducing Federated Learning for data privacy, Transfer Learning for portfolio scaling, and TinyML for overcoming the computational carbon paradox of “Green AI.” By quantifying this paradox, the review contrasts the massive computational carbon footprint of cloud-based model training against the milliwatt-class efficiency of localized edge deployments. Overall, this review outlines potential research directions toward the development of autonomous Cognitive Digital Twins (CDTs) and Human-Centric Personal Comfort Models (PCMs). Full article

This study aims to systematically evaluate the balancing mechanism between road performance, carbon emissions, and economic cost when selecting asphalt materials for severe cold regions, filling the gap in multi-criteria decision-making for composite chemical modifications. To address alternating temperatures, heavy traffic, and modified asphalt transport difficulties, this study presents a novel evaluation framework focusing on the performance–environmental–cost nexus of a desulfurized rubber powder composite SBS-modified asphalt mixture, which provides a clear technological breakthrough for high-ratio scrap tire recycling in seasonal frost zones. Two reference mixtures serve as comparisons: a conventional rubber powder composite SBS (styrene–butadiene–styrene triblock)-modified asphalt mixture (CR-SBS) and an SBS-modified asphalt mixture (SBS). A comparative experiment was conducted between the two materials and the SBS-modified asphalt mixture (ACR-SBS) compounded with desulfurized rubber powder. High-temperature stability was tested by the rutting test, low-temperature crack resistance by the beam bending test, and water stability by the immersion Marshall and freeze–thaw splitting tests. Life cycle carbon emissions and economic costs were quantified from raw material acquisition to construction. The results show that desulfurized rubber powder composite with ACR-SBS delivers the most superior overall road performance. However, it also generates the highest life cycle carbon footprint. Its total carbon emission reaches 162,800 kgCO₂eq, which is 13.7% (19,600 kgCO₂eq) higher than SBS (143,200 kgCO₂eq) and 7.7% (11,600 kgCO₂eq) higher than CR-SBS (151,200 kgCO₂eq). The total cost of ACR-SBS is 391,000 CNY, which is 1.5% (6000 CNY) higher than SBS (385,000 CNY) and 1.3% (5000 CNY) lower than CR-SBS (396,000 CNY). These findings provide a basis for the selection of high-performance, low-carbon, and economical composite-modified asphalt in severe cold regions. Full article