Search Results (425)

Livestock farming is a vital component of global food security, yet it remains a major contributor to greenhouse gas (GHG) emissions, particularly methane (CH₄), which has a global warming potential 28 times greater than carbon dioxide (CO₂). This review provides a comprehensive synthesis of current knowledge surrounding the sources, biological mechanisms, and mitigation strategies related to CH₄ emissions from ruminant livestock. We first explore the process of methanogenesis within the rumen, detailing the role of methanogenic archaea and the environmental factors influencing CH₄ production. A thorough assessment of both direct and indirect methods used to quantify CH₄ emissions is presented, including in vitro techniques (e.g., syringe method, batch culture, RUSITEC), in vivo techniques (e.g., respiration chambers, Greenfeed, laser CH₄ detectors), and statistical modeling approaches. The advantages and limitations of each method are critically analyzed in terms of accuracy, cost, feasibility, and applicability to different farming systems. We then examine a wide range of mitigation strategies, organized into four core pillars: (1) animal and feed management (e.g., genetic selection, pasture quality improvement), (2) diet formulation (e.g., feed additives such as oils, tannins, saponins, and seaweed), (3) rumen manipulation (e.g., probiotics, ionophores, defaunation, vaccination), and (4) manure management practices and policy-level interventions. These strategies are evaluated not only for their environmental impact but also for their economic and practical viability in diverse livestock systems. By integrating technological innovations with sustainable agricultural practices, this review highlights pathways to reduce CH₄ emissions while maintaining animal productivity. It aims to support decision-makers, researchers, and livestock producers in the global effort to transition toward climate-smart, low-emission livestock farming. Full article

The cement industry, a foundation of global infrastructure development, significantly contributes to environmental pollution. Key sources of pollution include dust emissions; greenhouse gases, particularly carbon dioxide; and the release of toxic substances such as heavy metals and particulate matter. These pollutants contribute to air, water, and soil degradation and are linked to severe health conditions in nearby populations, including respiratory disorders, cardiovascular diseases, and increased mortality rates. Noise pollution is also a significant issue, inducing auditory diseases that affect most workers in cement plants, and disturbing the population living in the neighborhoods and fauna behavior. This review explores the pollution paths and the multifaceted impacts of cement production on the environment. It also highlights the social challenges faced by communities, underscoring the urgent need for stricter environmental policies and the adoption of greener technologies to mitigate the adverse effects of cement production on both the environment and human health. Full article

This paper explores the implementation of battery electric vehicles (BEVs) in underground mining operations, focusing on their benefits, challenges, and safety considerations. The study examines the shift from traditional diesel-powered machinery to BEVs in response to increasing environmental concerns and stricter emission regulations. It discusses various lithium-ion battery chemistries used in BEVs, particularly lithium–iron–phosphate (LFP) and nickel–manganese–cobalt (NMC), comparing their performance, safety, and suitability for underground mining applications. The research highlights the significant benefits of BEVs, including reduced greenhouse gas emissions, improved air quality in confined spaces, and potential ventilation cost savings. However, it also addresses critical safety concerns, such as fire risks associated with lithium-ion batteries and the emission of toxic gases during thermal runaway events. The manuscript emphasises the importance of comprehensive risk assessment and mitigation strategies when introducing BEVs to underground mining environments. It concludes that while BEVs offer promising solutions for more sustainable and environmentally friendly mining operations, further research is needed to ensure their safe integration into underground mining practices. This study contributes valuable insights to the ongoing discussion on the future of mining technology and its environmental impact. Full article

Dietary protein levels greatly influence gut microbial ecosystems; however, their effects on gut archaea and associated functions in ruminants require further elucidation. This study evaluated the impact of varying dietary protein levels on gut archaeal composition, antimicrobial resistance (AMR) genes, virulence factors, and functional capacities in sheep. Eighteen ewes (Yunnan semi-fine wool breed, uniparous, 2 years old, and averaging 50 ± 2 kg body weight) were randomly assigned to diets containing an 8.5 (low; H_1), 10.3 (medium; H_m), or 13.9% (high; H_h) crude protein level from the 35th day of pregnancy to the 90th day postpartum. The total duration of the experiment was approximately 202 days. A total of nine fecal samples (three from each group) were analyzed via 16S rRNA and metagenomics sequencing. Higher archaeal alpha diversity and richness were observed in the H_m and H_h groups compared to the H_l group (p < 0.05). A Beta diversity analysis revealed the archaeal community’s distinct clustering mode based on protein levels. The methanogenic genera Methanobrevibacter and Methanocorpusculum were dominant across the three groups, and their abundance was influenced by protein intake. A functional prediction analysis indicated moderate changes in amino acid and carbohydrate metabolism, which are particularly associated with methane production, an important source of greenhouse gases. AMR genes (e.g., tetA (60), patA, vat, and Erm methyltransferase) and virulence factors (Bacillibactin, LPS) were significantly enriched when animals were fed high-protein diets. Our results demonstrated that dietary protein levels significantly influence gut archaeal composition, AMR gene enrichment, and related functional pathways. Medium-protein diets promoted greater archaeal diversity, whereas high-protein diets favored resistance gene proliferation and enhanced methanogenic activity. Optimizing dietary protein intake may enhance gut health, mitigate antimicrobial resistance risk, and reduce methane emissions, thereby supporting livestock sustainability and environmental protection. Full article

Climate change, driven by rising atmospheric concentrations of greenhouse gases (GHGs) such as CO₂, poses the most pressing environmental challenges today. Soil carbon (C) sequestration emerges as a crucial strategy to mitigate this issue by capturing atmospheric CO₂ and storing it in soil organic carbon (SOC), thereby reducing GHG levels and enhancing soil health. Although soil is the largest terrestrial C sink, capable of storing between 1500–2400 petagrams (Pg) of C, the practical potential for SOC sequestration through regenerative practices is still widely debated. This review examines the biotic, abiotic, structural, physical, and chemical limitations that constrain soil C sequestration, along with the human dimensions that influence these processes. It explores the role of plant physiology, root architecture, microbial interactions, and environmental factors in determining the efficacy of SOC sequestration. Furthermore, it discusses the potential innovative strategies, including photosynthetic modifications, root system engineering, microbial bioengineering, and the application of advanced materials such as C-capturing minerals, poly-carboxylic compounds, and nanomaterials, to enhance C capture and storage in soils. By providing a comprehensive understanding of these factors, this review aims to inform future research and policy development, offering pathways to optimize soil C sequestration as a viable tool for climate change mitigation. Full article

The reduction of environmental pollutant emissions—including greenhouse gases, particulate matter, and other harmful substances—represents one of the foremost challenges in climate policy, economics, and industrial management today. Excessive emissions of CO₂, NO_X, and suspended particulates exert significant impacts on climate change as well as human health and welfare. Consequently, numerous studies and regulatory and technological initiatives are underway to mitigate these emissions. One critical area is intra-plant transport within manufacturing facilities, which, despite its localized scope, can substantially contribute to a company’s total emissions. This paper aims to assess the potential of computer simulation using FlexSim software as a decision-support tool for planning inter-operational transport, with a particular focus on environmental aspects. The study analyzes real operational data from a selected production plant (case study), concentrating on the optimization of the number of transport units, their routing, and the layout of workstations. It is hypothesized that reducing the number of trips, shortening transport routes, and efficiently utilizing transport resources can lead to lower emissions of carbon dioxide (CO₂) and nitrogen oxides (NO_X). The findings provide a basis for a broader adoption of digital tools in sustainable production planning, emphasizing the integration of environmental criteria into decision-making processes. Furthermore, the results offer a foundation for future analyses that consider the development of green transport technologies—such as electric and hydrogen-powered vehicles—in the context of their implementation in the internal logistics of manufacturing enterprises. Full article

Understanding the trends and drivers of greenhouse gases (GHGs) is vital to making effective climate mitigation strategies and benefiting human health. In this study, we investigate carbon dioxide (CO₂) trends in the top three emitting states in the U.S. (i.e., Texas, California, and Florida) using column-averaged CO₂ concentrations (XCO₂) from the Greenhouse Gases Observing Satellite (GOSAT) from 2010 to 2022. Annual XCO₂ enhancements are derived by removing regional background values (XCO_{2, enhancement}), and their interannual changes (ΔXCO_{2, enhancement}) are analyzed against key influencing factors, including population, gross domestic product (GDP), nonrenewable and renewable energy consumption, and normalized vegetation difference index (NDVI). Overall, interannual changes in socioeconomic factors, particularly GDP and energy consumption, are more strongly correlated with ΔXCO_{2, enhancement} in Florida. In contrast, NDVI and state-specific environmental policies appear to play a more influential role in shaping XCO₂ trends in California and Texas. These differences underscore the importance of regionally tailored approaches to emissions monitoring and mitigation. Although renewable energy use is increasing, CO₂ trends remain primarily influenced by nonrenewable sources, limiting progress toward atmospheric CO₂ reduction. Full article

Food security and environmental quality related to food production are global issues that need urgent solutions. Proteins are crucial for diets, and demand is growing for innovative and more environmentally sustainable sources of protein, like vegetables, microorganisms, and insects, and lab-grown food that can meet nutritional and environmental goals. This study analyzes a time series to assess the sustainability of different protein sources by evaluating their effects on emissions of greenhouse gases and the use of agricultural land while accounting for the carbon sink potential across the supply chain. The study also explores future trends in global protein sources, emphasizing shellfish as a key to achieving food security from both nutritional and environmental perspectives. By reviewing terrestrial livestock, farmed seafood, vegetal proteins, and alternative sources like insects and cultured cells, the study assesses sustainability, food security potential, and challenges from nutritional, environmental, and consumer viewpoints. We conclude that shellfish aquaculture, particularly oysters, mussels, clams, and scallops, has significant potential in enhancing food security, fostering sustainable protein consumption, reducing land use, and contributing to climate change mitigation by sequestering significant amounts of atmospheric carbon. Full article

Natural gas purification and the mitigation of carbon dioxide (CO₂) emissions from flue gases are critical steps in alleviating the greenhouse effect and significantly mitigate multiple environmental challenges associated with global warming. Hypercrosslinked polymers (HCPs) have become a hot topic as prospective adsorbents for gas purification and separation, owing to their low cost and scalability. Hence, TPB-Ben, TPB-Nap, and TPB-Ant were synthesized through a solvent knitting strategy, with the modification in the size of the monomers serving as a distinctive feature. This alteration aimed to explore the impact of phenyl ring quantity on the polymers’ gas adsorption and separation efficiency. All HCPs showed outstanding selective separation capability of CO₂ from CO₂/CH₄ and CO₂/N₂ mixtures, such as TPB-Ben-3-2 (CO₂/CH₄: 10.77; CO₂/N₂: 59.72), TPB-Nap-3-2 (CO₂/CH₄: 9.12; CO₂/N₂: 61.31), and TPB-Ant-3-2 (CO₂/CH₄: 10.00; CO₂/N₂: 62.89), which could be potential candidate adsorbents for natural gas purification and CO₂ capture. Considering the mild reaction conditions, low cost, efficient gas adsorption, and the potential for scalable production, these polymers are considered ideal selective solid adsorbents for capturing CO₂. This further highlights the significance of the solvent knitting strategy. Full article

Carbon dioxide, the primary greenhouse gas responsible for global warming, represents today a critical environmental challenge for humans. Mitigating CO₂ emissions and other greenhouse gases is a pressing global concern. The primary goal of this study is to investigate the potential of particular ionic liquids (ILs) in capturing CO₂ for the sweetening of natural and other gases. The solubility of CO₂ was measured in three distinct ILs, which shared a common anion (triflate, TfO) but differed in their cations. The selected ionic liquids were {1-butyl-3-methylimidazolium triflate [BMIM][TfO], 1-butyl-1-methylpyrrolidinium triflate [BMP][TfO], and 1-butyl-4-methylpyridium triflate [MBPY][TfO]}. The solvents were screened based on results from a molecular computational study that predicted low CO₂ Henry’s Law constants. Solubility measurements were conducted at 303.15 K, 323.15 K, and 343.15 K and pressures up to 1.5 MPa using a gravimetric microbalance (IGA-003). The CO₂ experimental results were modeled using the Peng–Robinson Equation of state with three mixing rules: van der Waals one (vdWI), van der Waals two (vdWII), and the non-random two-liquid (NRTL) Wong–Sandler (WS) mixing rule. For the three ILs, the NRTL-WS mixing rule regressed the data with the lowest average deviation percentage of 1.24%. The three solvents had similar alkyl chains but slightly different polarities. [MBPY][TfO], with the largest size, exhibited the highest CO₂ solubility at all three temperatures. Calculation of its relative polarity descriptor (N) shows it was the least polar of the three ILs. Conversely, [BMP][TfO] showed the highest Henry’s Law constant (lowest solubility) across the studied temperature range. Comparing the results to published data, the study concludes that triflate-based ionic liquids with three fluorine atoms had lower capacity for CO₂ compared to bis(trifluoromethylsulfonyl) imide (Tf2N)-based ionic liquids with six fluorine atoms. Additionally, the study provided data on the enthalpy and entropy of absorption. A final comparison shows that the ILs had a lower CO₂ capacity than Selexol, a solvent widely used in commercial carbon capture operations. Compared to other ILs, the results confirm that the type of anion had a more significant impact on solubility than the cation. Full article

The extensive use of coal in the steel metallurgy sector has resulted in significant greenhouse gas emissions. Hydrogen-rich gases have been introduced to partially replace coal in the blast furnace reduction process to mitigate this issue. This research explores using abundant coalbed methane (CBM) resources near steel plants for metallurgical applications. Addressing the challenge of determining optimal process parameters in hydrogen-rich blast furnace smelting, this project first develops an energy and mass balance model for the hydrogen-rich blast furnace, providing a foundation for process analysis. Using this model, the substitution ratio and oxygen enrichment rate of the blast furnace are calculated under varying preheating temperatures of coalbed methane. Additionally, this study assesses carbon dioxide emission patterns based on the elemental balance principle, emphasizing the potential of coalbed methane to reduce carbon emissions and support low-carbon metallurgical development. Full article

Estimating leaks in urban gas distribution systems is crucial for reducing greenhouse gas emissions from fugitive losses and mitigating costly waste. This study aimed to use a simplified methodology to estimate pipeline leakage in gas distribution systems and validate these estimations against established benchmarks or other gases globally. The estimation encompassed sources including third-party damage, long-term permeation, flaring, and purging during pipeline commissioning and decommissioning, as well as fugitive leakage, each requiring respective evaluation. Results showed that the total town gas leakage volume was around 695,044 m³ to 2,009,991 m³, accounting for 0.045% to 0.13% of the total town gas sales in 2022. Among the five leakage sources, fugitive leakage was the major contributor with the leakage volume of 1,938,914 m³. To comprehensively benchmark all emission factors (EFs), those from previously reported studies were adapted to the town gas scenario and combined with the current activity factors (AFs) in Hong Kong to calculate the leakage amounts. Comparing our results with different models, we observed variations in estimated leakage amounts based on years, regions, and sampling methods. Upgrades in pipeline materials led to reduced EFs and subsequently lower total gas leakage. Our findings support efforts to reduce greenhouse gas emissions by providing actionable data for policymakers and utility companies to address gas leakage issues. Full article

This paper presents a review of current developments in port pollution prevention and mitigation. A systematic categorization of the sources of pollution in the development and operation phases of ports and terminals is first presented. The paper then considers in detail technological and regulatory measures currently being applied to limit port pollution in the operation phase. This review is combined with that of relevant academic research and aims to fill a research gap by identifying the current and emerging port pollution themes and the latest trends in measures for pollution prevention and mitigation. A comprehensive approach is taken in this review by including not only academic research but also the industry’s research and development initiatives and the regulatory authority’s legislation. This paper identifies more than thirty different technological, regulatory, or organizational measures to limit pollution, although details on company-based research and development were found to be scarce. Mitigation of greenhouse gases and air-polluting emissions is identified as the most important field of research, but it is affected by regulatory uncertainties. Further research is needed on topics such as increased alternative fuel provision, digitalization potential for sustainability enhancement, and strategies for engaging stakeholders in greening ports. Full article

Carbon capture, utilization and storage (CCUS) represents a vital technological strategy for mitigating greenhouse gas emissions and facilitating sustainable development. Supercritical CO₂ (SC-CO₂) pipeline transportation serves as an essential intermediary step towards attaining the “Dual Carbon Goals” and CCUS, representing the optimal and most cost-effective solution for ultra-long distance transport. In the CO₂ capture process, trace amounts of impurities, such as H₂O, O₂, H₂S, NO_x and SO_x, are inevitable. These gases react to form acidic compounds, thereby accelerating pipeline corrosion. With the progression of CCUS initiatives, corrosion within supercritical CO₂ pipeline transportation has become a critical challenge that significantly affects the safety and integrity of pipeline infrastructure. This review paper provides an in-depth analysis of the corrosion behavior of pipeline materials in a supercritical CO₂ environment, with particular attention to the effects of impurity, temperature, and pressure on corrosion rates, corrosion products, and corrosion morphology. Furthermore, an analysis of the corrosive behavior of welded joints in supercritical CO₂ transport pipelines is performed to provide valuable reference data for research and construction projects related to these pipelines. Full article

Energy-saving device (ESD) plays an important role in mitigating the emission of greenhouse gases in ship industry. It is necessary to study a promising ESD, a gate rudder, for its great potential in promoting energy efficiency. In the present study, ship resistance and self-propulsion simulations were conducted to investigate the energy-saving effects of gate rudder using a viscous in-house CFD solver. First, verification and validation studies were performed to estimate the accuracy and reliability of the numerical method and the results are in good agreement with experimental data. Afterward, resistance and self-propulsion simulations of a crude carrier equipped with the conventional rudder and the gate rudder were carried out respectively. Ship resistance and self-propulsion characteristics with different sailing velocities and propeller revolution rates were compared to study the energy-saving ability of the gate rudder as well as its effects on ship hydrodynamic performance. The results indicate that the gate rudder can greatly optimize the energy efficiency of the ship. Meantime, the ship equipped with the gate rudder shows better resistance and propulsion performance in a self-propelled state. Full article