Search Results (1,241)

Lignite particles generate considerable dust during drying due to structural damage, which increases the dust removal costs of the drying system, pollutes the environment, and raises the risk of combustion and explosion, thereby posing a threat to the safety of the drying system. Moisture plays a crucial role in the structural damage of lignite particles during drying. In this study, lignite samples with moisture contents of 60%, 36%, and 18% were prepared and dried in hot air at 200 °C. The transfer behavior of moisture in the pore structure was investigated, and the evolution of the pore structure was observed. The relationship between pore structure evolution and moisture transfer behavior was correlated, and the mechanism of structural damage under the action of moisture during the drying process was proposed. The results demonstrated that the moisture in large pores was transported rapidly in the form of a gas–liquid mixture; the liquid moisture in the pores boiled into water vapor, and the water vapor pressure was the main reason for the destruction of the pore structure. For raw lignite, the total pore volume decreased sharply from 0.92 to 0.37 mL/g within the first 360 s of drying, and the fractal dimension dropped from 2.701 to 2.545, indicating severe pore collapse. However, the moisture in small pores migrated by molecular diffusion, which is nondestructive to the lignite structure. Full article

Kuwait experiences persistently high levels of air pollution driven by industrial emissions, transportation, oil-related activities, and frequent desert dust storms. This study aims to synthesize and critically evaluate the available evidence on the relationship between air pollution, Air Quality Index (AQI), and health outcomes in Kuwait using a guided narrative review approach. A guided literature search identified 26 peer-reviewed studies published between 2014 and 2026 about Kuwait air pollution, which were assessed for methodological characteristics, pollutant types, health outcome categories, and vulnerable populations. The most frequently examined pollutants were particulate matter (PM_2.5: 69%; PM₁₀: 38%), followed by NO₂ (23%), multi-pollutant and AQI-based (19%), O₃ (12%), SO₂ (12%), VOCs and PAHs (8%). Health-related investigations most commonly addressed mortality and respiratory morbidity, while cardiovascular, metabolic, biomarker-based, and cancer-related outcomes were less frequently represented. Among studies reporting direct health outcomes, elevated PM_2.5 exposure was generally associated with increased risks of respiratory hospitalizations, cardiovascular events, and all-cause mortality. Susceptible populations identified across the literature include children, older adults, individuals with pre-existing chronic conditions, and outdoor workers, who may experience higher exposure levels and greater health vulnerability. However, a substantial proportion of the included studies focused primarily on exposure characterization or pollutant modeling without direct assessment of health outcomes. These studies nonetheless indicate consistently elevated pollutant levels and seasonal variability, which may plausibly contribute to population health risks. Overall, while the available Kuwait-specific evidence suggests potential adverse health effects linked to air pollution, the strength of direct epidemiological evidence remains limited. Important gaps persist, including the scarcity of long-term cohort studies, limited multi-pollutant analyses, and insufficient integration of AQI categories with health outcomes. These limitations highlight the need for more robust and longitudinal research to better quantify health risks and inform public health policy in Kuwait. Full article

To comprehensively investigate the aerosol optical properties and vertical structures over the northeastern Tibetan Plateau (TP), a field campaign was conducted from January to August 2023 in the Hainan Tibetan Autonomous Prefecture. Ground-based sunphotometer measurements yielded a mean aerosol optical depth (AOD) of 0.18 and an Ångström exponent (AE) of 1.20 over the study period. The lowest AE, observed in April alongside the highest aerosol loading, suggests a predominance of dust aerosols during this period. This finding is further supported by the elevated vertical extinction profiles derived from LiDAR measurements, indicating long-range transboundary transport of dust aerosols from northern desert regions. Ground-based AOD measurements were used to validate satellite-derived MODIS retrievals and the assimilated MERRA-2 reanalysis product. Among the aerosol types examined, dust aerosols exhibited the highest accuracy in both AOD and AE validation. MERRA-2 was found to systematically underestimate AOD by 22% and AE by 35%. Nevertheless, due to its tighter expected error envelope, lower overall errors, and superior temporal continuity and spatial coverage, MERRA-2 remains a reliable data source for subsequent analyses. A long-term analysis spanning 2006 to 2025 identifies 2011 as a turning point, after which AOD declined at a rate of 0.0022 per year. This sustained reduction highlights the effectiveness of China’s air pollution prevention and control policies. Collectively, these findings provide essential insights for refining satellite retrieval algorithms and aerosol–climate models over the TP. Full article

Nanoparticles (NPs) of urban dust can be hazardous to human health due to the possibility of a high accumulation of potentially toxic elements (PTEs), high penetration ability into organisms, and their ability to cause injury to cells, tissues, and organs. The composition of NPs of urban dust may vary during the year; however, there are so far no studies on the seasonal changes in their elemental composition and related ecological and health risks. The current work was carried out using samples of urban dust from Moscow, the largest megacity in Europe, collected in spring, summer, and autumn. It was found that NPs of urban dust are polluted by PTEs, namely W, Bi, Hg, P, S, Sn, Mo, Cu, Cd, Pb, Sb, and Zn. The highest pollution and ecological risks were found in NPs of urban dust collected in summer (RI = 592) as compared to autumn (RI = 399) and spring (RI = 231). The same regularity was observed for health risks. The highest possible cancerogenic risk was found in summer NPs (CTCR = 3.0 × 10⁻⁴) followed by autumn NPs (CTCR = 2.5 × 10⁻⁴) and spring NPs (CTCR = 3.5 × 10⁻⁵). However, the difference between mean values obtained for the three seasons was not statistically significant. Additionally, it was demonstrated that vehicle emissions are one of the main sources of pollution of NPs, and their intensity does not significantly change throughout the year in Moscow. The results obtained offer new insights into the regularities of seasonal variations in elemental composition, pollution, and related ecological and health risks of NPs of urban dust. Full article

With the continuous promotion of the dual carbon target, effective control of high-concentration dust pollutants in industrial sites is of great value for the healthy creation of healthy industrial environments and efficient energy utilization. In this study, we used the spraying method to improve and prepare the dust removal material, polyphenylene sulfide (PPS) fiber filter material, and test the filtration performance, resistance characteristics, and dust-cleaning effect of the improved rGO-PPS material. The results showed that, compared with PPS filter material, rGO-PPS material significantly improved particle filtration efficiency, with a filtration efficiency 0.058–19.417% higher in the particle size range of 0.265–5.75 μm. The higher the spraying concentration of the composite filter material, the higher the filtration efficiency at the same particle size. The comprehensive filtration performance of rGO-PPS composite filter material with a concentration of 3 g/L was better, as it better met the requirements of “high efficiency and low resistance”. With an increase in dust load, the filtration resistance of the filter material showed a continuous upward trend. The dust peeling rate increased with an increase in blowback wind speed. When the blowback wind speed reached 0.3 m/s, the dust-cleaning effect of the filter material tended to stabilize. Under this condition, the dust peeling rate of PPS filter material was 61.58%, and the dust peeling rate of 3 g/L rGO-PPS composite filter material reached 74.52%. These research results provide an experimental basis and technical support for the development and engineering application of high-efficiency purification filter materials for industrial multi-source pollutants. Full article

Large-section tunnels produce a large amount of dust after drill-and-blast construction. If not removed in a timely manner, the dust will seriously endanger workers’ health. For the purpose of enhancing the working conditions within the tunnel during construction, this investigation employs an integrated methodology that combines computational simulations with on-site measurements. Drawing upon the principles of gas–solid two-phase flow theory, the coupled diffusion law of airflow and dust in large-section tunnels is investigated. A two-factor orthogonal experiment combined with economic analysis is employed to determine the optimal ventilation parameters for the forced ventilation system. The findings indicate that, when the initial ventilation configuration is applied, the airflow field is divided into three stages, and dust diffusion is primarily driven by airflow. The average dust concentration in the 1.6 m breathing zone at 600 s post-blasting is measured to be 36.8 mg/m³. While satisfying the ventilation demand stipulated for the tunnel, the optimal ventilation parameters are determined as an outlet air velocity of 18 m/s and a duct-to-face distance of 40 m. Under these conditions, the dust concentration is reduced to 1.5 mg/m³, representing a 95.9% improvement in dust removal efficiency. Additionally, the hourly electricity cost at 18 m/s is USD 4.39 lower than that at 20 m/s. This study provides valuable insights for optimizing forced ventilation parameters in large-section tunnels, significantly reducing pollutant levels while saving costs. Full article

Atmospheric particulate matter poses a high risk by carrying potentially toxic components such as polycyclic aromatic hydrocarbons (PAHs). The major sources of these potentially toxic compounds include traffic-related emissions and winter heating, implying the combustion of fossil fuels or biomass. Air pollution, especially chronic exposure, poses the most serious human health hazard in childhood, and several studies emphasise the importance of research on the potential impacts of air pollution in school environments. While indoor air quality studies are already available in Hungary, investigations on outdoor air pollution in school environments are missing. To fill this gap, in a medium-sized Hungarian town, Veszprém, six schools were selected to assess air quality in the outdoor environments where schoolchildren spend their breaks and have physical training. These schools represent different locations and conditions, from high-trafficked sites to suburban environments. Using resuspended dust samples, environmental quality was assessed based on PAH contents of the samples and ecotoxicity tests (Vibrio fischeri bacterial bioassay). Ecotoxicity of the samples moved in a wide range, from highly toxic to non-toxic. PAH measurements indicated considerable contamination in the case of one sample taken from a suburban area. Source apportionment demonstrated that winter heating is also an important pollution source. Full article

Microplastic (MP) pollution has emerged as a significant environmental crisis across the Arabian Gulf, driven by rapid urbanization, industrialization, and infrastructure challenges in waste management. Studies indicate that MPs are ubiquitous in nature and are present in different environmental compartments, including coastal waters, sediments, marine biota, and the atmosphere. The region is characterized by high salinity, high UV index, and frequent dust storms that can affect the physical and chemical behavior of plastic debris. A consistent finding across regional studies highlights the fibrous polyethylene (PE) and polypropylene (PP) polymer types as dominant microplastic particles. This prevalence of fibrous MPs highlights the role of secondary microplastics that are derived from the fragmentation of larger plastic items and textile-derived materials as a major contaminant source. Ecological impacts are increasingly observed, with studies reporting MP ingestion in commercially important fish species and the potential for biomagnification into the human food web. However, there exist key knowledge gaps regarding the long-term toxicological impacts on human health. This review synthesizes existing data to improve the understanding of microplastic distribution in Qatar and the Arabian Gulf while highlighting the need for standardized monitoring approaches and appropriate waste management strategies. Full article

Dust pollution induced by blasting during tunnel construction via the drill-and-blast method poses a severe threat to workers’ health and construction safety. To address this issue, a wet chord grid dust removal and purification device adaptable to deep-buried long tunnels was developed in this study. The device integrates dust control and removal functions, featuring mobility, high purification efficiency, and water recycling capability. Through experimental tests, the optimal operating parameters of the system were determined: the dust removal efficiency reached a peak of 94.3% (laboratory optimal value from the basic parameter optimization test) when the frequency of the extraction axial flow fan was set to 30 Hz and the cross-sectional wind speed of the chord grid reached 3.34 m/s. The circulating water tank achieved the optimal water treatment performance under the conditions of a relative buried depth of 0.42 for the water inlet, a volume ratio of 1:2 for the sedimentation area to the clear water area, and a relative baffle height of 0.65. Numerical simulations based on CFD software (2021) revealed that the on-site dust removal efficiency of the device reached 79.86% and 87.9% under the working conditions where the tunnel face was 10 m and 100 m away from the connecting passage, respectively, which are in good agreement with the field measurement results. In the practical application at the Shierpo Tunnel of the Guangxi Tianba Expressway, the device achieved an average total dust removal efficiency of 78.4%, with 81.2% removal efficiency for PM₁₀ and 76.5% for PM_2.5, demonstrating excellent engineering applicability and dust removal performance for respirable dust. This study provides effective technical support and a theoretical basis for improving the construction environment of drill-and-blast tunnels. Full article

PM_2.5 is a major air pollutant characterized by complex sources and strong spatiotemporal heterogeneity. However, accurately quantifying the relative contributions of different factors remains difficult due to the lack of long-term datasets and the strong correlations between meteorological factors and emissions. To address this problem, the study utilizes the China long-term particulate matter (CLPM) dataset developed in previous research to investigate the dominant drivers and regional disparities of PM_2.5 concentration variations from 1980 to 2022. The analysis employs Gaussian Convolution (GC) to model pollutant diffusion, Partial Least Squares (PLS) regression to address multicollinearity, and the Lindeman-Merenda-Gold (LMG) method to quantify the relative contributions of each driver. The results reveal that as the convolution scale increased from 0.25° to 10°, dominant PM_2.5 sources shifted from local anthropogenic emissions to regional biomass burning and large-scale dust transport, highlighting the scale-dependent transition of pollution drivers. Furthermore, PM_2.5 concentrations are predominantly explained by emissions, which account for over 60% of the total variance and exceed 80% in eastern China, while meteorological factors are associated with 12–26%. Among these, total precipitation and downward surface solar radiation have the strongest influences on pollutants. It is important to note that these results reflect the statistical explanatory power of emissions and meteorological variables within the regression model. Overall, this research provides a method for separating the statistical influences of emissions and meteorological factors, offering methods for multi-scale explanatory power of PM_2.5 and other atmospheric pollutants. Full article

Electricity production is one of the most significant sources of environmental pollution. Traditional energy sources involve environmental devastation associated with the extraction of fossil fuels, greenhouse gas emissions, dust, and the byproducts of ash and other harmful substances. Therefore, the choice of energy source directly impacts the environmental impact of technological processes. Obtaining energy from sources that do not generate such a significant negative impact on the environment, such as hydroelectric power plants or wind farms, is not always possible, as it depends on the location of a given enterprise near rivers or areas with regularly strong winds. Therefore, the aim of our study was to assess the environmental impact of switching the power source for the technological process of mass bottle packaging from grid-connected to photovoltaic power. To this end, a 1 MW photovoltaic PV installation was designed to replace traditional grid-connected power. The design was carried out using PVsyst 7.4 software. An analysis of the monthly yields from the PV installation showed that it could power the analyzed technological process independently for ten months of the year, excluding January and December. Using Simapro 9.6 software and the Ecoinvent database, an environmental impact analysis of the change in electricity source was conducted. The study showed that powering the process with energy from the proposed photovoltaic farm reduces the potential environmental impact by approximately 75% in terms of human health, approximately 65% in terms of ecosystems, and approximately 50% in terms of resources. Full article

Parabens, a prevalent class of endocrine-disrupting chemicals (EDCs), are ubiquitous in consumer products; however, their role in linking pediatric allergic phenotypes remains poorly understood. This case-control study analyzed paraben levels in urine and indoor dust as proxies for internal and external exposures and investigated their associations with allergic rhinitis only (AR Only), asthma only (AS Only), and comorbidities (AR&AS) among children in Shanghai. The concentrations for each of four paraben compounds were quantitatively measured, and multi-pollutant frameworks—including Bayesian Kernel Machine Regression (BKMR) and Weighted Quantile Sum (WQS) regression—were employed to characterize the mixture exposure and risk. Propylparaben (PrP) was detectable in 100% of urine samples and over 90% of dust samples, and the concentrations ranked the highest out of the four compounds in both samples. Benzylparaben (BzP) was detected in >70% of urine samples and over 50% of dust samples at relatively lower levels. Urinary PrP exhibited significantly positive associations with all phenotypes (OR in 2.18–2.92) and BzP with the AR&AS Comorbidity (OR = 3.55, 95% CI: 1.32–9.55). Dust-borne PrP was associated with AR Only (OR = 2.26, 95% CI: 1.16–4.43), indicating a potential “Portal of Entry” effect via direct nasal deposition. According to BKMR and WQS analyses, urinary PrP and BzP emerged as two primary risk drivers. Using interaction analysis, an additive synergistic effect was observed between urinary PrP and BzP with parental history of allergy, suggesting heightened vulnerability to paraben exposure in genetically predisposed subgroups. In conclusion, children with respiratory allergies were associated with higher exposure to PrP and BzP and exhibited higher susceptibility in those with a parental history of allergy. Full article

Straw substitution for coal in direct-fired power generation can significantly reduce pollutant emissions. However, there are numerous challenges to using straw in direct-burning power generation, and the question of benefits also looms large. In this study, an environmental benefit assessment model for the straw power supply chain was developed using the life cycle assessment method from an environmental emission cost perspective. Pollutant emissions and environmental benefits were analyzed for four straw power supply chain models under the assumptions of this study. The results indicates that the CO₂ in the straw power generation supply chain system mainly comes from the straw collection and transport stages, which account for 29% and 70%, respectively. The SO₂ and PM₁₀ emissions mainly originate from the power generation stage. The environmental benefits of substituting straw for coal-fired power generation range from 1,859,895.02 to 1,875,326.36 USD. Further sensitivity analysis suggests that fertilizer application rates and transport distance are negatively correlated with the system’s environmental benefit, whereas the adoption of advanced dust removal technologies, increases in the charge standards and improvements in energy efficiency are positively correlated. These results can promote the sustainable development of the biomass power generation industry. Full article

Textile wastewater pollution is a global issue that requires attention due to its potential negative environmental impacts. Therefore, in the present investigation, Inga feuilleei seed (IFS) powder was used as a potential adsorbent of Direct Red 80 (DR80) dye in synthetic water. The results showed that the highest removal efficiency was achieved at pH = 2 and an IFS powder particle size of 150 μm. ART-FTIR analysis of IFS dust showed the presence of -OH, C=C, and C-H groups. The kinetic study revealed a better fit of the experimental adsorption data to the pseudo-second-order kinetics, suggesting that the mechanism governing the adsorption process is chemisorption. The maximum adsorption capacity of DR80 on IFS powder was 133.11, 146.78, 152.78, and 183.51 mg/g at 20, 30, 40, and 50 °C, respectively. According to the thermodynamic study, the process is endothermic and spontaneous. Finally, the use of IFS powder is a cost-effective alternative since the project approach for the development of the production process of this adsorbent is feasible and profitable. In conclusion, IFS powder is a cost-effective adsorbent for removing DR80 in water, and the process could be scaled up in removal studies on textile wastewater. Full article

This study presents the engineering design and system-level modeling of a high-frequency power supply architecture for electrostatic precipitators intended to improve particulate removal efficiency and operational stability. Atmospheric air pollution by fine particulate matter (PM2.5) remains one of the most critical challenges in environmental protection and public health. Although electrostatic precipitators (ESPs) are widely used for industrial gas cleaning, the efficiency and stability of conventional 50 Hz power supplies are limited under conditions of strongly nonlinear corona discharge and high-resistivity dust. This paper presents the development and investigation of an advanced high-frequency power supply system for electrostatic precipitators based on a coupled electrical–electrophysical mathematical model. The work follows an engineering design methodology that integrates converter topology selection, electrophysical modeling of corona discharge, and control-oriented system optimization. The proposed model provides a unified description of electric field formation, space charge accumulation, ion transport, and particle motion in the corona discharge region. The simulation results show that in the operating voltage range of 10–100 kV, the electric field strength reaches (2–5)·10⁶ V/m, the ion concentration stabilizes in the range of 10¹³–10¹⁵ m⁻³, and the particle drift velocity increases from approximately 0.05 to 0.3 m/s, leading to an increase in collection efficiency from about 55% to 93%. It is demonstrated that the proposed system ensures stable output voltage regulation within ±2.5–5% even under strongly nonlinear load conditions. The use of an LC output filter (C = 1–10 nF, L = 10–100 mH) reduces the voltage ripple from about 14% to 1.4–4.8% and significantly improves the transient response. In addition, adaptive adjustment of the pulse repetition frequency in the range of 10–200 kHz makes it possible to reduce energy consumption by 12–18% while simultaneously increasing the collection efficiency by 8–15%. The obtained results confirm that the proposed high-frequency power supply architecture provides a physically well-founded and energy-efficient solution for improving the environmental performance and operational stability of electrostatic precipitators. Full article