ABSTRACT Conventional reduction of copper slag emits ∼450 kg CO₂ per ton, threatening the climate. Therefore, this study aims to reduce CO2 emissions while recovering iron metal from the pyro-hydrometallurgical reduction of copper slag. Through Aspen Plus simulation, chemical additives, temperature, reductant amount, solid/liquid ratio, leach time and temperature were evaluated. Results showed that 2M CaCO3 in the pyrometallurgical approach, along with 2M NaOH +1M Na2CO3 salts in the hydrometallurgical approach, give 70 and 0.2 wt.% CO2 emissions along with 91% and 98.7% iron recoveries in the respective processes. High iron recoveries and low CO2 emissions predicted that CO2 played a part in the reaction to recover iron from copper slag. The optimised reductant amount was 13.3 wt.%, which indicated that high carbon in the reactants can cause high CO2 emissions. Simulation results indicated that a high molar ratio (>2M + 1M) of NaOH + Na2CO3 causes excess release of CO2 byproduct gas (up to 72.1 wt.%) that ultimately lowers the reaction rate, but when the amount of OH – (from 1-2) in the reaction increases, the CO2 emissions decrease. This study not only provides an optimised assembly for 98.7% iron recovery from copper slag but also develops a way for future studies to keep in mind minimum CO2 emissions.

The textile waste was disposed of in landfills or incinerated, which causes environmental pollution and resource depletion. Alternatively, dissolution is an alternative solution due to its potential for recycling and resource recovery. Due to the importance of sustainable assessment on introducing alternative solutions, the life cycle assessment was conducted to determine the environmental impacts and feasibility of the dissolution. This study specifically uses an equal ratio of blended polyester and cotton textile waste via solvent dissolution with dimethyl sulfoxide (DMSO). A Life Cycle Assessment (LCA) framework based on International Organization for Standardization (ISO 14044:2006) and International Organization for Standardization (ISO 14040:2006) was used to identify environmental hotspots, estimate energy and resource needs, and recommend process improvements. Life Cycle Impact Assessment (LCIA) was conducted in terms of ReCiPe, both midpoint and endpoint indicators, and Cumulative Energy Demand (CED) impact categories. The assessment encompasses key stages, including raw material extraction, processing, and dissolution, focusing on energy consumption, greenhouse gas emissions, and resource efficiency. Findings show that dissolution recycling promises a sustainable solution because the dissolution method uses lower energy utilities and lower carbon emissions than the incineration process (Nordahl, 2023). In conclusion, this study helps to solve knowledge gaps in advanced recycling technologies for blended textiles and promotes the adoption of sustainable practices in textile waste management and circular economy activities.

Regulatory gaps in restart and cold/hot start emissions overlooked by current periodic technical inspection (PTI), and driving behaviors significantly impact plug-in hybrid electric vehicle (PHEV) particle number (PN) emissions under real driving conditions. Using portable emissions measurement systems (PEMS), this study builds cumulative PN emissions by key segments (cold-start, restart) and instantaneous high-emission events across four distinct behaviors. Key findings reveal that calm and normal driving elevate cold-start PN (up to 6.2 ×1011 #/km) due to prolonged engine-off intervals and slow warm-up. Aggressive driving's frequent restarts yield lower per-event emissions owing to thermal advantages. Adaptive cruise control (ACC) minimizes total PN by combining thermally efficient engine operation with extended zero-emission phases (16-17% duration). Crucially, instantaneous high-emission analysis shows > 80% of PN concentrates in < 20% of driving duration, with emission thresholds varying dramatically (82-1366%) across behaviors-primarily due to divergent dominant modes favored by each behavior. To quantify these behavior-specific modes and their parametric signatures, k-means clustering was applied, and found distinct behavioral associations: aggressive driving predominantly linked to high-load/high-rpm operation (> 2800rpm or > 80% load), while calm/normal driving elevates cold-start and restart contributions. Consequently, real-world emission monitoring necessitates behavior-adaptive dynamic scenarios, tailoring test focus and parametric design informed by clustered thresholds.

Grain byproducts can serve as cost-effective alternatives to corn, but may lead to reduced production performance and increased greenhouse gas emissions. This study aimed to investigate the effects of replacing corn with the grain byproducts (wheat bran, sprayed corn bran) subjected to bacterial-enzymatic fermentation treatment or not in Hu sheep, mainly focusing on production performance, energy-nitrogen metabolism, rumen fermentation and greenhouse gas emissions. A total of fifty-four 6-month-old Hu sheep were divided into three groups, with 6 pens per group and 3 sheep per pen, and then randomly allocated to one of the three dietary groups for 60 days, i.e., a control group (CON), a group (RC) that corn was partially (~42%) replaced with grain byproducts, and a group (BF) that corn was partially replaced by fermented grain byproducts. Compared with the CON group, the RC group showed numerically lower rumen total volatile fatty acid (TVFA) concentration and its propionate proportion, nitrogen retention content (NR; -10.22%) and its retention ratio (NR/NI decreased by 4.27 percentage points, absolute reduction from 24.30% to 20.04%), corresponding to a relative decrease of 17.6%.) as well as a numerically reduced net profit (-2.18%) with a decreased feed price (-¥0.16/kg TMR). Meanwhile, the RC group showed a significant increase in the relative abundance of Methanobrevibacter (p < 0.05), accompanied by numerically higher daily methane emissions (+6.14%) and emission intensity (+4.08%), although these methane-related differences did not reach statistical significance (p > 0.05). Compared to the RC group, the BF group resulted in a numerical increase in feed price (+¥0.03/kg TMR), net profit (+27.93%), TVFA concentration, propionate proportion, NR (+28.17%), NR/NI (an increase of 5.38 percentage points), the relative abundance of Prevotella, Shuttleworthia and Succinivibrio as well as the decrease of fecal nitrogen (FN; -12.29%), daily methane emissions (-8.75%), emission intensity (-5.83%) and the relative abundance of Methanobrevibacter. In summary, replacing dietary corn by 42% with wheat bran and sprayed corn bran numerically reduced formula cost and nitrogen utilization, while increasing methane emissions and methanogens abundance, without significantly affecting growth performance. This combination led to no improvement in economic returns for fattening Hu sheep. Bacterial-enzymatic fermentation treatment of these byproducts could mitigate these drawbacks, being superior energy-nitrogen metabolism and lower greenhouse gas emissions intensity, presenting a potential strategy for cost reduction and efficiency enhancement. Further research with larger sample sizes is warranted to confirm these findings and support broader application.

Organic waste management represents a systemic sustainability challenge within linear production–consumption regimes. Black soldier fly (Hermetia illucens) bioconversion has emerged as a bio-based pathway capable of simultaneously reducing waste volumes and generating value-added outputs. This systematic review synthesizes 156 studies (2010–2025) using PRISMA-guided methods and integrates meta-analysis with thematic analysis. Results indicate significantly lower greenhouse gas emissions compared to landfilling, composting, and incineration (Hedges’ g = −2.84; 95% CI: −3.21 to −2.47), despite high heterogeneity (I² = 78.4%). Mean waste reduction reached 82.3%, with strong scale effects in economic performance. Regulatory fragmentation remains a structural constraint. Situated within circular economy and industrial ecology frameworks, these findings suggest that BSF systems function as context-dependent mechanisms for material recirculation and bio-based substitution. Their contribution to circular bioeconomy transitions depends on regulatory harmonization, methodological standardization, and locally embedded implementation strategies.

This study examines the asymmetric and nonlinear effects of heating and cooling degree days (HDD and CDD) on environmental sustainability in Germany over the period 1979-2024. Using the recently developed Cross Quantile Regression (CQR) framework and its multivariate extension (m-CQR), the analysis captures distributional heterogeneity in the temperature-emissions relationship across conditional quantiles of CO2 emissions per capita (CO2PC). The empirical framework controls for GDP per capita, energy consumption, ecological footprint, and urbanisation to isolate the climatic-emissions nexus. The results indicate that HDD and CDD exert statistically significant but asymmetric effects on emissions. Higher CDD intensifies CO2 emissions, particularly in upper emission quantiles, reflecting rising cooling-related energy demand during heat extremes. In contrast, HDD exhibits a dual effect: moderate winters are associated with lower emissions, while severe cold conditions increase heating-related CO2 output. Welfare estimates suggest that extreme temperature regimes (τ > 0.7) are associated with annual welfare losses of approximately €110-€250 per capita. These findings imply that uniform mitigation strategies may be ineffective when temperature-emissions sensitivities are heterogeneous. Integrating degree-day variability into climate and energy planning, such as Germany's Klimaschutzplan 2050, can improve climate adaptation and emissions management.

Driven by the construction industry’s “dual carbon” goals, prefabricated buildings are a key path for low-carbon transformation. This study addresses the complexity of carbon emissions in the production of prefabricated concrete components by developing a calculation model based on process-based inventory analysis and the carbon emission factor method. Carbon emissions for five types of prefabricated components—composite slabs, prestressed composite slabs, interior wall panels, columns, and stairs—were calculated using actual energy consumption data and compared with results from the quota method. The study also developed a carbon emission prediction model using the Extreme Gradient Boosting (XGBoost) algorithm, achieving an R 2 of 0.966 on the test set. Results showed that the energy consumption measurement method calculated lower carbon emissions compared to the quota method, with differences up to 54.675 kgCO2e for composite slabs. Material production accounted for approximately 90% of carbon emissions in the production phase. The most significant predictor in the XGBoost model was component volume. These findings provide theoretical support and data references for low-carbon design and process optimization in the prefabricated concrete industry.

Farmers for Climate Solutions started the Farm Resilience Mentorship (FaRM) Program in 2021 as a peer-to-peer, regionally adaptive, education and knowledge sharing program. The program is designed to support farmers and ranchers in adopting low emissions, high resilience Beneficial Management Practices (BMPs), specifically: improved nitrogen management, cover cropping, and rotational grazing.&lt;br/&gt;With partner organizations across the country, FaRM supports in-person and virtual learning events, with farmers and ranchers, agrologists, agronomists, Certified Crop Advisers and agricultural researchers as knowledge sharers. It also includes the FaRM Learning Hub where farmers, ranchers and agronomists can take online self-directed courses to build their knowledge on how to adapt BMPs to their farm or ranch.&lt;br/&gt;With an adaptive approach to knowledge mobilization and a desire to support behaviour change, FaRM has developed a rigorous monitoring, evaluation and learning framework that has allowed FaRM to pivot to serve the needs of regional communities while still achieving program objectives. Of the farmers and ranchers responding to the 2024 FaRM Impact Survey, 89% indicated that they had implemented, expanded, and/or enhanced a BMP to some extent as a result of participating in the FaRM Program, with an additional 11% of farmer/rancher respondents indicating that they had yet to undertake a BMP, but intended to. However, despite this strong uptake, cross-country sector consultations have noted that without local, regional data, producers and agronomists are hesitant to implement practices. In 2025, in response to this, and to build engagement with agronomists, FaRM launched Phase 2, which focuses in part on increasing regional support and knowledge transfer by engaging agricultural professionals, in partnership with farmers and ranchers, to run field trials to overcome regional barriers to BMP adoption and to troubleshooting BMP adoption through practical, hands-on experience.

Terrestrial ecosystems are vital for achieving carbon neutrality, yet the distinction between their biophysical limits and realizable potential remains unclear. Here, we developed an integrated framework to quantify China's terrestrial theoretical carbon sequestration potential (CSP) and actual CSP under diverse climate and management scenarios, incorporating vegetation dynamics and soil carbon stocks through 2100. We estimated current terrestrial carbon stock at 95.3 Pg C, with a theoretical CSP of 166.4 Pg C. By the 2060s, afforestation could expand by 77.5 Mha, representing 8% of China's land area. For actual CSP, peak CSP is projected to reach 0.35 Pg C yr-1 during 2020-2060, declining to 0.12 Pg C yr-1 from 2060 to 2100 under the SSP119 scenario combined with forest expansion. Actual CSP remains significantly below the theoretical limit. Speciafically, a gap of 51.5-57.9 Pg C remains between actual and theoretical CSP across all scenarios. However, strategic reforestation coupled with low emissions could reduce this gap by approximately 15 Pg C by 2100. These findings differentiated the theoretical and actual CSP, providing quantitative baselines for China's carbon sink capacity and actionable guidance for achieving carbon neutrality through optimized land use.

Abstract The goal of reducing aerodynamic drag is crucial for improving vehicle fuel efficiency and lowering emissions, particularly in bluff-body vehicles undergoing significant wake-induced drag. This research explores the aerodynamic characteristics of a modified Ahmed body model through computational fluid dynamics (CFD) simulations conducted in ANSYS Fluent. The main objective is to assess the impact of passive flow control by embedding a vortex generator at the rear of the vehicle, with inclination angles ranging from 0° to 30°. The baseline model shows considerable wake formation due to early flow separation, leading to a high drag coefficient of 0.864 and a notably negative rear pressure coefficient of -0.306. Implementing the vortex generator effectively delays separation, reduces the wake size, and enhances rear pressure recovery. The best aerodynamic performance is observed at a vortex generator inclination angle of 20°, where the drag coefficient decreases by 8.68% and the average rear pressure coefficient improves to -0.1936. Beyond 20°, the effectiveness declines due to increased flow disturbances and turbulence, causing a rise in drag. These results confirm the angle-dependent behavior of vortex generators and their potential for passive drag reduction, aligning with existing literature. The findings provide valuable insights for optimizing the aerodynamics of ground vehicles using cost-effective, energy-efficient flow control methods.

Revealing the unrecognized climate burden of aquaculture systems: A global insight into greenhouse gas emissions and mitigation strategies.

Abstract There is limited understanding of how human development influences non–greenhouse gas (non-GHG) air pollutant emissions, particularly within the Arab world—a region of significant geopolitical importance. Addressing this gap is crucial to determining who pollutes more, a key issue in distributing environmental harm and responsibility, and central to environmental sustainability and justice. This study contributes to filling that gap by analyzing data on five non-GHG air pollutants—carbon monoxide (CO), nitrogen oxides (NOₓ), non-methane volatile organic compounds (NMVOCs), ammonia (NH₃), and sulfur dioxide (SO₂)—together with four human development indicators: the Human Development Index (HDI), a composite measure of overall development; the Gross National Income Index (GNII), reflecting economic progress; the Education Index (EI), representing educational attainment; and the Life Expectancy Index (LEI), measuring health outcomes. Using panel data from 16 Arab countries spanning 1990 to 2022, the study applies compound annual growth rate analysis and fixed effects econometric modeling. The main objectives are twofold: (1) to examine the temporal evolution of total emissions per capita alongside human development indicators, and (2) to assess the influence of human development indicators on total emissions per capita. The results show wide disparities in total emissions per capita and human development indicators across Arab countries, with fixed effects models explaining part of the variation but also highlighting the complex, multidimensional nature of the emissions–development relationship. Higher overall human development is generally associated with lower emissions; however, its components exert distinct effects. Economic growth tends to increase emissions, whereas improvements in education and health contribute to reducing them. Countries experiencing strong economic growth but weaker social development emit more, while those with balanced progress across income, education, and health emit less. These findings highlight the importance of integrated and equitable development strategies to advance environmental sustainability and justice in the Arab region.

Enhancing combustion temperature for improved biochar ignition and combustion rates in high-altitude regions with low NOx emissions

Reducing dietary cation-anion difference to mitigate ammonia emissions from manure without compromising production of lactating cows.

Large-area flexible thermal control films via balancing low solar absorptivity and low infrared emissivity

Drivers of CO2 and CH4 fluxes from shallow lakes and prediction based on climate factors under global warming.

Unraveling and overcoming ammonium toxicity in haloalkaliphilic methanotrophs for economic biomanufacturing and methane mitigation.

In the European Union, between 14 and 18% of current passenger cars are made of plastic materials. Despite all advantages that plastics bring to the production of vehicle components, there are also decisive disadvantages at the vehicle's end-of-life. Plastics end up as automotive shredder residues and are mainly utilized thermally as refuse-derived fuels. Mechanical recycling of automotive plastics from end-of-life vehicles is not common practice. We assessed the circularity potential of plastics in passenger cars through mechanical recycling of automotive shredder residues. We developed a sensor-based sorting process to separate polypropylene, polyamide, polycarbonate, and acrylonitrile butadiene styrene. Our process yields a 13.3% recovery rate for thermoplastics from end-of-life vehicles. 26.1% polypropylene, 31.2% polycarbonate, 5.3% acrylonitrile butadiene styrene, and 22.1% polyamide were recovered. We developed a dynamic simulation model to theoretically extrapolate those results and calculate the closed-loop recycled content of plastic in new cars from post-consumer end-of-life vehicle waste. We simulated total and polymer-specific closed-loop rates for six scenarios and performed a sensitivity analysis. In our MIX scenario, a closed-loop recycled content rate of 3.1-4.8% can be reached in 2035, based on our study setting. An environmental assessment shows that our developed sorting process results in 29.5% lower greenhouse gas emissions than the usual incineration of the automotive shredder residues sorted. Although additional efforts will be required to effectively close material loops for plastics in the automotive sector, our results indicate the technical potential of concentrating polymers from automotive shredder residue to contribute to meeting closed-loop recycled content quotas.

Pediatric minor procedure rooms generate less waste compared to similar procedures in operating rooms.

Mechanism research and process design for the separation of dimethyl carbonate and n-propanol by extractive distillation using ionic liquid.