Search Results (63)

The current study predicts that there would be scaling relationships among atmospheric suspended particulate materials (PMs) with different diameters. Through sampling the particulate materials concentration over different types of land use in municipal areas in Chongqing, analyzing the respective data of the independent concentrations of particulate materials varying in sizes, and testing the predictions, it is found that: (1) there are generally a negative relationships between falling dust of large particulate size (diameter > 10 μm) and floating dust of small ones (diameter ≤ 10 μm); (2) there are positive correlations among the fine particulate materials varying in sizes of iPM10, iPM2.5, and iPM1; (3) there is a disproportionately increase between the particulate materials varying in sizes compared to the respective control; (4) there is a declining-and-rising tendency between the particulate materials reduction rate and the increase in particulate materials along a particulate-size-decline gradient. The results of this study may contribute to understanding the law of the interactions of particulate materials with different particle sizes in the atmosphere and lay a theoretical foundation for the elimination of the atmospheric suspended pollutants. Full article

Short-term control measures are often implemented during major events to improve air quality and protect public health. In preparation for the 11th National Traditional Games of Ethnic Minorities of China (denoted as “NMG”), held from 8 to 16 September 2019 in Zhengzhou, China, the authorities introduced several air pollution control measures, including traffic restrictions and dust control. In the study presented herein, we applied automated machine learning-based weather normalisation combined with an augmented synthetic control method (ASCM) to evaluate the effectiveness of these interventions. Our results show that the impacts of the NMG control measures were not uniform, varying significantly across pollutants and monitoring stations. On average, nitrogen dioxide (NO₂) concentrations decreased by 8.6% and those of coarse particles (PM₁₀) decreased by 3.0%. However, the interventions had little overall effect on fine particles (PM_2.5), despite clear reductions observed at the traffic site, where NO₂ and PM_2.5 levels decreased by 7.2 and 5.2 μg m⁻³, respectively. These reductions accounted for 56.3% of the NMG policy’s effect on NO₂ concentration and 73.2% of its effect on PM_2.5 concentration at the traffic site. Notably, the control measures led to an increase in ozone (O₃) concentrations. Our results demonstrate the moderate effect of the short-term NMG intervention, emphasising the necessity for holistic strategies that address pollutant interactions, such as nitrogen oxides (NO_X) and volatile organic compounds (VOCs), as well as location-specific variability to achieve sustained air quality improvements. Full article

PM_2.5 concentrations in major port cities in the Republic of Korea, such as Incheon and Busan, are as serious as those in land-based metropolises, such as Seoul, and fine dust generated in port cities is mainly emitted from ships. To identify the specific substances influencing local air quality, the occurrence and effects of high concentrations of PM_2.5 at the ports of Incheon and Busan were analyzed. To analyze the effects of improving air quality based on the Republic of Korea’s port and ship-related reduction measures, we calculated an emissions forecast for 2025 following the implementation/non-implementation of these measures and analyzed all impacts using the WRF-SMOKE-CMAQ modeling system. The ratio of ionic components constituting PM_2.5 at the ports of Incheon and Busan was generally high in nitrate composition; however, the ratio of sulfate was high on high PM_2.5 concentration days. When implementing measures to reduce emissions related to ports and ships, forecasted PM_2.5 and SO₂ emissions showed substantial decreases in port areas as well as nearby land and sea areas. The associated decrease in the PM_2.5 concentration was highly influential in reducing the concentration of sulfate. Full article

This study analyzed the factors influencing personal PM_2.5 exposure levels among adults with allergic diseases in Seoul using a linear mixed-effects (LMEs) model. The average personal PM_2.5 exposure concentration of the study participants was 17.38 μg/m³, exceeding the World Health Organization (WHO) daily recommended guideline (15.00 μg/m³), though it was relatively low compared to global levels. Inter-individual exposure variability was approximately 43.5%, with exposure levels varying significantly depending on microenvironments. Notably, 58% of participants exhibited higher exposure on weekends compared to weekdays, likely associated with increased outdoor activities. The LMEs model results identified smoking (90.81% higher in smokers), temperature, relative humidity, outdoor pollutants (PM_2.5, O₃, CO), indoor PM_2.5 and CO concentrations, and time spent in residential environments as factors increasing exposure, while rainfall (91.23% reduction), wind speed, and air purifier use were identified as factors reducing exposure. These findings suggest that individual activity patterns and environmental factors significantly influence exposure levels, highlighting the need for personalized mitigation strategies and national fine dust policies. This study is expected to provide scientific evidence contributing to the reduction in health risks and improvement of quality of life for individuals with allergic diseases. Full article

This study conducted a pilot test and field demonstration to analyze the feasibility of using rainwater for road surface sprinkling and its effectiveness in reducing fine dust to create sustainable cities. The pilot test results verified the effectiveness of rainwater sprinkling on road surfaces in reducing fine dust. Subsequently, to ensure field applicability, a test bed with different pavement sections was established along Ojeong-ro in Bucheon, Gyeonggi-do, and a circulatory system for reusing the runoff rainwater was installed and tested for its acceptable dust reduction effectiveness. The results showed that the section with porous pavement exhibited a significant reduction in acceptable dust levels, and a trend of decreasing pollutant levels due to the initial washing effect of rainwater was observed. However, the water quality and quantity analysis revealed that additional purification processes are necessary to reuse the water for road surface sprinkling. Based on these findings, this study suggests that expanding porous pavement and introducing purification systems are essential for installing rainwater utilization facilities to reduce fine dust in urban areas. This research provides critical foundational data that can contribute to urban environmental improvement and establish a sustainable water circulation system. Full article

In the present study with a novel two-chamber setup (TCS) for dustiness investigations, the relationship between pressure differences as well as air velocities and the resulting dust emissions is investigated. The dust emissions of six particle size fractions of acetaminophen at pressure differences between 0 and 12 Pa are examined. The results show that both simulated and measured air velocities increase with increasing pressure difference. Dust emissions decrease significantly with increasing pressure difference and air velocity. Fine particles cause higher dust emissions than coarse particles. A high goodness of fit is obtained with exponential and quadratic functions to describe the relationship between pressure difference and dust emission, indicating that even moderate increases in pressure may lead to a reduction in the emission. Average air velocities within the TCS simulated with Computational Fluid Dynamics are between 0.09 and 0.37 m/s, whereas those measured experimentally are between 0.09 and 0.41 m/s, both ranges corresponding to the recommended values for effective particle separation in containment systems. These results underline the ability of the novel TCS to control pressure and airflow, which is essential for reliable dust emission measurements and thus provide support for further scientific and industrial applications. Full article

As part of the Zero Pollution Action Plan of the Green Deal, the European Commission has set the goal of reducing the number of premature deaths caused by fine particulate matter (PM2.5) by at least 55% by 2030, compared to 2005 levels. To achieve this, the European Commission aims to introduce stricter limits. In urban areas, road transport is a significant source of PM emissions. Vehicle PM originates from engine exhaust and from tire, brake and road wear, as well as from road dust resuspension. In recent decades, the application of stringent emission limits on vehicle exhaust has led to the adoption of technologies capable of strongly reducing PM emissions at the tailpipe. Further, the progressive electrification of vehicle fleets will lead to near-zero exhaust PM emissions. On the other hand, non-exhaust PM emissions have increased in recent years following the proliferation of sport utility vehicles (SUVs), whose numbers have jumped nearly tenfold globally, and electric vehicles, as these vehicles tend to be heavier than corresponding conventional and older internal combustion engine light-duty vehicles. This shift has resulted in a more modest reduction in PM10 and PM2.5 emissions from the transport sector compared to other pollutants (−49% and −55%, respectively, from 1990 to 2020). This report aims to provide an up-to-date overview of non-exhaust PM characterization, drawing insights from the recent scientific literature to address this critical environmental and public health challenge. Full article

The pandemic lockdown of the year 2020 has been generally accompanied by an improvement in the air quality. Here, we report data on the effects of lockdown limitations on the air quality in the metropolitan area of Naples (Italy) by following the evolution of main atmospheric pollutants over a five-year period and comparing their concentrations in the pandemic year 2020 with the previous (2018 and 2019) and following (2021 and 2022) two years. In particular, NO₂ and PM10 concentrations registered by representative air quality sampling station network and the columnar features of the aerosol characterized by a sun-photometer are considered. To avoid the possible influence of Saharan dust transport, which generally affects the observational area, the analysis has been limited to the days free from such events. Our findings evidence a tendency towards pre-pandemic conditions, notwithstanding some differences related to partial and temporary restrictions imposed even in the year 2021. For both near-surface NO₂ and PM, the observations confirm a significant reduction induced by the lockdown in 2020, besides the seasonal changes, and a gradual tendency towards more typical values in the following years. Also, the columnar aerosol data clearly highlight a gradual recovery of typical conditions in 2021 and 2022, confirming a peculiar effect of the pandemic lockdown of the year 2020 on the atmospheric aerosol characteristics that evidences a striking predominance of the fine component. Full article

Among the economic sectors, mobility is showing significant environmental impacts, especially in the use phase of vehicles. By substituting fossil-fuelled propelling systems, environmental impacts such as the Global Warming Potential (GWP) can be reduced. The use of properly designed light electric vehicles (LEVs) significantly reduces further environmental impacts, as well as maintenance costs, which are relevant for a circular economy. For example, the use of low-voltage (42 V) propelling systems enables the maintenance of LEVs in a broader range of existing bicycle workshops. Regarding the environmental impacts, the described LCA results indicate the advantage of LEVs compared with EVs and ICVs, e.g., vehicle weight is found to be a main factor related to environmental impact for each type of vehicle. This implies a reduced need for battery capacity and lower emissions of particulate matter from tire and break abrasion. This study aims to present the application potential of LEVs and the related reduction in environmental impacts. Anonymised inventory lists of municipal vehicle fleets are analysed for quantifying the substitution potential of LEVs in specific use cases. For this purpose, the use phase of vehicles is analysed with a focus on product design for repair and recycling and supplemented by the results of a comparative environmental impact assessment of internal combustion engine vehicles (ICEVs), electric vehicles (EVs), and LEVs. The comparison is made on the premise of similar application requirements. These specifications are the ability of each of the vehicles to transport a maximum of three persons (driver included) or one driver and 250 kg of cargo in 3 m³ over a daily distance of 100 km in urban areas. On this basis, the municipal environmental benefits derived from substituting small vehicles in the form of ICEVs and EVs with LEVs are assessed. The results show that in the field of municipal mobility, a relevant number of conventional small vehicles can be substituted with LEVs. The environmental impacts in categories of the highest robustness level, RL I, that is, Global Warming Potential, fine dust emissions, and Ozone Depletion Potential, can be reduced by LEVs by 50% compared with EVs and by over 50% compared with ICEVs. The strong influence of vehicle weight on the abrasive conditions of tires and brakes is considerable, as shown by reduced fine dust emissions. Full article

Coal dust is one of the environmental factors that seriously affect the health of workers as well as the mining equipment in underground coal mines. At present, coal dust is commonly generated during drilling, blasting, excavation, and transportation processes in mining operations. During mining blasting processes, coal dust is generated with varying particle sizes and high concentration levels. High concentrations of dust will affect mining operations and increase the ventilation time required for mining faces. In addition, coal dust exists in suspended form in the roadway and is harmful to human health, especially fine dust particles that have a negative impact on work efficiency. To improve ventilation efficiency and eliminate coal dust, this article presents a CFD-DPM numerical modeling method that integrates a DEM collision model based on the finite element method to analyze the motion characteristics of airflow and dust particles in the mine tunnel, while considering collisions between particles and between particles and walls. The article analyzes the distribution of wind speed, the dispersion of dust in the space around the roadway, and dust concentrations at distances of 1 m, 3 m, and 6 m from the working personnel and at a position 1.5 m above the roadway floor, corresponding to the breathing zone of the workers, with varying parameters such as velocity and duct position. The results indicate that with a wind velocity of V = 18 m/s and an air duct height h = 3.0 m, the best dust reduction results are achieved, and they provide theoretical guidance for selecting and optimizing ventilation parameters in dust control. Full article

One of the most noticeable problems associated with the close location of piggeries is gaseous compounds emission. Ammonia and hydrogen sulfide emissions affect the quality of life of people living in the vicinity of such facilities. Among the diverse methods for managing and controlling malodorous substances, biological methods, which involve the utilization of microbiological agents, are widely employed. The use of bacterial strains is a relatively simple, low-cost, and ecological method. The study aimed to conduct a preliminary evaluation of the implementation of a novel consortium of deodorizing bacteria. The study involved the selection of bacteria, assessment of the antagonistic properties, implementation of the inoculum in a mesh-filled biofilter, and analysis of ammonia, hydrogen sulfide, and fine dust content in the air before and after passing through the mature biological bed. The results obtained demonstrate the effectiveness of the biofiltration bed in reducing ammonia levels, with a maximum decrease observed at 73.90%. For hydrogen sulfide, a removal efficiency of >72.08% was observed. Reduction in fine dust pollution also decreased from a level of 3.75 mg/m³ to 1.06 mg/m³. The study’s findings demonstrate the promising potential of utilizing a consortium of deodorizing bacteria as an effective approach to mitigating emissions from piggeries. Full article

Currently, solving global environmental problems is recognized as an important task for humanity. In particular, automobile exhaust gases, which are pointed out as the main cause of environmental pollution, are increasing environmental pollutants and pollution problems, and exhaust gas regulations are being strengthened around the world. In particular, when an engine is idling while a car is stopped and not running, a lot of fine dust and toxic gases are emitted into the atmosphere due to the unnecessary fuel consumption of the engine. These idling emissions are making the Earth’s environmental pollution more serious and depleting limited oil resources. Biodiesel, which can replace diesel fuel, generally has similar physical properties to diesel fuel, so it is receiving a lot of attention as an eco-friendly alternative fuel. Biodiesel can be extracted from various substances of vegetable or animal origin and can also be extracted from waste resources discarded in nature. In this study, we used biodiesel blended fuel (B20) in a CRDI diesel engine to study the characteristics of gases emitted during combustion in the engine’s idling state. There were a total of four types of biodiesels used in the experiment. New Soybean Oil and New Lard Oil extracted from new resources and Waste Soybean Fried Oil and Waste Barbecue Lard Oil extracted from waste resources were used, and the gaseous substances emitted during combustion with pure diesel fuel and with the biodiesels were compared and analyzed. It was confirmed that all four B20 biodiesels had a reduction effect on PM, CO, and HC emissions, excluding NOx emissions, compared to pure diesel in terms of the emissions generated during combustion under no-load idling conditions. In particular, New Soybean Oil had the highest PM reduction rate of 20.3% compared to pure diesel, and Waste Soybean Fried Oil had the highest CO and HC reduction rates of 36.6% and 19.3%, respectively. However, NOx was confirmed to be highest in New Soybean Oil, and Waste Barbecue Lard Oil was the highest in fuel consumption. Full article

The urban heat island (UHI) effect poses a significant challenge for cities like Pohang, South Korea, which suffer from environmental pollution. Integrating a ventilation corridor into city planning can mitigate this issue. Despite wind’s potential as a resource for urban areas, its role remains under-studied in urban planning and design. To address this gap, this study analyzes the wind environment of Pohang City to identify effective strategies for reducing the UHI effect through the implementation of wind corridors, thereby enhancing the city’s thermal environment and sustainability. We used the KLAM_21 model to simulate and analyze the cold airflow. The results indicate that the land cover of Pohang, including residential and commercial areas, consists of urbanized dry areas. The wind direction over the past 10 years (2013–2022) has generally been west–southwest (247.5°). The cold air height and flow direction range expanded around the Hyeongsan River, eventually affecting the central city after 5 h. In the simulations, cold air accumulated above 30 m at specific locations near the valley’s base. After 2 h, the flow range of the cold air height increased. The green area ratio (GAR) and cold air speed positively correlated (+0.153). Thus, creating a wind-corridor forest could effectively address Pohang’s fine dust and UHI phenomena. Full article

Quicklime is produced through the thermal processing of limestone in industrial kilns. During quarry operations, fine particulate quarry dust adheres to limestone lump surfaces, increasing the bulk concentration of impurities in limestone products. During thermal processing in a kiln, impurities such as Si, Mg, Al, Fe, and Mn react with Ca, reducing quicklime product quality. Which reactant phases are formed, and the extent to which these result in a reduction in quality, has not been extensively investigated. The present study investigated as-received and manually washed limestone product samples from two operational quarries using elemental compositions and a developed predictive multi-component chemical equilibrium model to obtain global phase diagrams for 1000–1500 °C, corresponding to the high-temperature zone of a lime kiln, identifying phases expected to be formed in quicklime during thermal processing. The results suggest that impurities found on the surface of the lime kiln limestone feed reduce the main quality parameter of the quicklime products, i.e., calcium oxide, CaO (s), content by 0.8–1.5 wt.% for the investigated materials. The results also show that, in addition to the effect of impurities, the quantity of CaO (s) varies greatly with temperature. More impurities result in more variation and a greater need for accurate temperature control of the kiln, where keeping the temperature below approximately 1300 °C, that of Hatrurite formation, is necessary for a product with higher CaO (s). Full article

The management of unutilized fly ash poses challenges due to concerns about storage and its potential groundwater contamination. Within the road industry, where the bulk utilization of fly ash is feasible, its unsuitability for use in the base and sub-base layers of pavements due to its low strength and a high proportion of fine particles has been a limitation. The incorporation of stone dust alongside fly ash, treated with lime or cement, yields superior strength and stiffness. Apart from strength, the stabilized mix’s durability, capillary rise, and water absorption properties are crucial for determining its suitability for pavement applications. Observations from this study reveal that fiber-reinforced cement-stabilized fly ash–stone aggregate specimens treated with 4% and 6% cement, with and without fibers, met the limiting mass loss of 20%, as specified in IRC SP: 89. The mass loss decreases with an increase in cement and fiber content. However, the capillary rise in the mixes increases with a higher percentage of fly ash and fiber content but decreases with increased cement content. Cement addition results in a reduction in water absorption; however, the addition of fibers results in an increase in water absorption. A linear correlation has been established between mass loss and UCS and IDT, which can be used to evaluate the suitability of materials for the structural layer without conducting a wet–dry durability test, which typically takes one month. This study proposes that cement-stabilized fly ash and stone aggregate mixtures with 4% and 6% cement can be used as the subbase and base of pavement based on wet–dry mass loss criteria and water absorption criteria. Observations from this study reveal that fiber-reinforced cement-stabilized fly ash–stone aggregate specimens treated with 4% and 6% cement, with and without fibers, met the limiting mass loss of 20%, as specified in IRC SP: 89. The mass loss decreases with an increase in cement and fiber content. However, the capillary rise in the mixes increases with a higher percentage of fly ash and fiber content but decreases with increased cement content. Cement addition results in reduction in water absorption. However, the addition of fibers results in increase in water absorption. A linear correlation is established between mass loss and UCS and IDT, which can be used to evaluate the suitability of materials for the structural layer without conducting wet–dry durability tests, which take one month. This study proposes that cement-stabilized fly ash and stone aggregate mixtures with 4% and 6% cement can be used as the subbase and base of pavement based on wet–dry mass loss criteria and water absorption criteria. Full article