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Aerosol Science and Engineering
Number of Followers: 2  Hybrid journal (It can contain Open Access articles)ISSN (Print) 2510-375X - ISSN (Online) 2510-3768 Published by Springer-Verlag  [2468 journals]
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- Burning of Municipal Solid Waste: An Invitation for Aerosol Black Carbon
and PM2.5 Over Mid–Sized City in India-
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Abstract: Waste management is the main concern of most cities in developing countries. The proper procedure is needed to reduce Municipal solid waste, that’s why burning is the cheaper way to decrease solid waste. The main aim of this study is to assess the concentration of Black Carbon and PM2.5 during the MSW burning sites in Jamshedpur. The continuous measurement was taken during the burning period in three phases at Industrial, Urban, and Rural waste burning sites having respective average BC concentrations observed as 145 ± 46, 101 ± 33 & 95 ± 33 μg m−3, and PM2.5 as 1391 ± 358, 998 ± 319, 957 ± 313 μg m−3. BC and PM2.5 concentrations show significant diurnal variations with maximum average concentration at the midnight phase due to large temperature fluctuation (lower mixed layer height) in the atmosphere. This evaluation during burning period exceeds regular day estimates by around 5–6 times. The rate distinction of BC by the Aethalometer model indicates that source apportionment of BC is more sensitive in assessing BCBB (biomass burning) with an average fraction of 82% at 880 nm because waste trash burning in the dump yard was mostly solid. Pearson correlation analysis shows strong correlations between BC and PM2.5 concentration that is primarily attributable to well-known nearby sources such as vehicular emissions.
PubDate: 2023-05-26
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- Investigating the Impression of National Clean Air Programme in
Enhancement of Air Quality Characteristics for Non-attainment Cities of
Uttarakhand-
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Abstract: Developmental activities have become sweet poison nowadays. Such activities degrade local air quality status, which can severely impact human health and their surrounding environment. The present study examines Uttarakhand’s air quality characteristics in non-attainment cities (Dehradun, Rishikesh, and Kashipur) to understand its cleansing processes. Under National Air Quality Monitoring Programme (NAMP), concentration of air pollutants (such as PM, SOx and NOx) was regularly monitored between 2015 and 2019 to evaluate the air quality status in the state. The NAMP highlights the higher concentration of PM10 in Dehradun, Rishikesh, and Kashipur, and hence it is imperative to reduce the concentration of PM10 under the permissible limit. State has 30.2% urbanisation rate, and annual urban growth rate of 4.0% much higher than the rural growth rate (1.2%) of the state, which results in 3 times higher amount of PM10 to the permissible limit. Moreover, 1.5–2-time higher amount of PM10 were recorded in Rishikesh, and Kashipur. In making sustainable future, various sector-specific strategies and sustainable approaches under National Clean Air Programme (NCAP) were launched to combat this critical situation. While comparing with the present air quality status, Dehradun experienced 12% reduction in PM10; whereas for Rishikesh and Kashipur, only 4.1% and 0.866% reduction were observed. The effective implementation of sector-specific action points will be the key factor in improvement of air quality of the Uttarakhand state. Graphical
PubDate: 2023-04-06
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- Impact of COVID-19 Lockdown on Ambient Air Quality in the Southwest
Coastal Urban Regions of India-
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Abstract: The rapid growth of urban areas and population as well as associated development over recent decades have been a major factor controlling ambient air quality of the urban environment in Kerala (India). Being located at the southwestern fringe of the Indian peninsula, Kerala is one of the regions that has been significantly influenced by the activities in the Indian Ocean. The present study focuses on the effect of the COVID-19 lockdown (in 2021) on ambient air quality in the selected coastal metropolitan areas of Kerala. Although previous research studies reported improvement in ambient air quality in Kerala during the lockdown period, this study demonstrates the potential of onshore transport of air pollutants in controlling the air quality of coastal urban regions during the lockdown period. Data from the ambient air quality monitoring stations of the Kerala State Pollution Control Board in the urban areas of Thiruvananthapuram (TM), Kollam (KL), Kozhikode (KZ), and Kannur (KN) are used for the analysis. Temporal variation in the concentration of air pollutants during the pre-lockdown (PRLD), lockdown (LD), and post-lockdown (PTLD) periods (i.e., 1 March to 31 July) of 2021 is examined to assess the effect of lockdown measures on the National Air Quality Index (AQI). Results indicate a significant decline in the levels of air pollutants and subsequent improvement in air quality in the coastal urban areas. All the effect of lockdown measures has been evident in the AQI, an increase in the concentration of different pollutants including CO, SO2, and NH3 during the LD period suggests contributions from multiple sources including onshore transport due to marine traffic and transboundary transport.
PubDate: 2023-04-05
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- The Influence of Fine-Mode Aerosols on MODIS–AERONET Aerosol Optical
Depth Disparities in the Sahel West Africa-
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Abstract: In the present paper, the disparities between aerosol optical depths (AOD) retrieved using the Moderate Resolution Infrared Spectro-radiometer (MODIS) and AErosol RObotic NETwork (AERONET) are presented for five Sahel sites based on the R2 correlation metric of their multiyear data. The sites are Banizoumbou (13.54N; 2.66E), Dakar (14.39N; 16.95 W), Djougou (9.76N; 1.59E), Ilorin (8.32N; 4.34E), and Ouagadougou (12.2N; 1.4 W). The overall and seasonal MODIS–AERONET AOD disparities for the locations were evaluated and compared with aerosol parameters associated with fine-mode prevalence at the sites, namely, total AOD (AOD500nm), precipitable water (PW), Angstrom derivative (α1), and fine mode fraction (FMF) for the seasons MAM, JJA, SON, and DJF. The largest overall disparity (least R2) was found for Ilorin (R2 = 0.021 ± 0.295), while the least overall disparity (largest R2) was found for Banizoumbou (R2 = 0.660 ± 0.132). The FMF was found to have the strongest correlations with the overall and seasonal disparities (R2*FMF = – 0.626 (overall), R2*FMF = – 0.350 (MAM), R2*FMF = – 0.9 (JJA), R2*FMF = – 0.602 (SON), R2*FMF = 0.084 (DJF). The largest seasonal disparity occurred at Ilorin in JJA (R2 = 0.014) when very low AOD500nm (0.352) was associated with significant fine-mode occurrence (α1 = 0.433; FMF = 0.581), while the least seasonal disparity occurred in Djougou in MAM (R2 = 0.866) when very high AOD500nm (0.814) was associated with the least fine-mode occurrence (α1 ~ 0.00; FMF = 0.278). In Banizoumbou, Dakar, Djougou, and Ouagadougou, fine-mode aerosols occurred more significantly in the dry period (low PW), suggesting a biomass burning source, and at Ilorin, the fine-mode occurred more significantly in the monsoon season (high PW), suggesting a non-biomass burning source. Since the AOD at Ilorin correlated strongest with monsoon-season meridional wind (AOD500nm*MWwet = 0.611), compared to other seasonal wind fields, it is inferred that the large monsoon-season MODIS–AERONET AOD disparities at the site were due to southwesterly wind, which transports fine-mode aerosols from coastal industrial sites, as indicated in previous studies.
PubDate: 2023-03-16
DOI: 10.1007/s41810-023-00177-6
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- Investigation of Changes in Atmospheric Pollutants due to the Cessation of
Anthropogenic Activities: Spatial Heterogeneity and Complex Atmospheric
Chemistry-
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Abstract: The current study examines the air quality trends in response to Covid-19-induced lockdowns at various locations in Delhi. The primary pollutants like NO2, CO, and PM10 have shown reductions during the lockdown phase, but the magnitude varied significantly in different places. Also, during the lockdown, air quality in some areas of Delhi exceeded National Ambient Air Quality Standards. Secondary pollutants like O3 have shown mixed trends due to complex atmospheric processes and dependence on relative proportions of VOC and NOx levels. A total of six sites, including traffic, industrial, and residential sites, have been studied. The diurnal behavior of pollutants also differed significantly around different places. During the lockdown, Ashok Vihar, a traffic-influenced area, showed a decrease in O3 (~ 40%), while at DTU (Traffic site), O3 levels increased (~ 48%). The industrial sites Okhla and Wazirpur also showed different trends during the lockdown; O3 in Wazirpur decreased by 50%, whereas Okhla increased by 25%. NOx concentration was lesser in 2020 at all the stations compared to 2019, indicating the positive impact of the lockdown on air pollution due to vehicular emissions. The Approximate Envelope Method estimates the secondary fraction of PM2.5. This fraction of PM is dominated in the lockdown year in the residential site, while it remains unchanged in the traffic site and increased by 11% in the industrial area. Despite being not so far from each other, these sites show very different patterns of pollutants during lockdown episodes.
PubDate: 2023-03-13
DOI: 10.1007/s41810-023-00175-8
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- Air Pollution Control Technologies for Indoor Particulate Matter
Pollution: A Review-
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Abstract: Indoor air quality is one of the major concerns in the modern environment since urban residents spend 80–90% of their time staying indoors. Pollutant exposure could be relatively higher indoors due to the increased number of sources along with activities that cause re-suspension of pollutants back into the air stream. Several existing and emerging technologies for indoor particulate matter (PM) control are available; however, there is a lack of a comprehensive review of these technologies for the end-users. Therefore, current study presents a techno-commercial comparison of the existing indoor air pollution control technologies based on several metrics such as particle removal efficiency, cost-commercialization, energy consumption, and by-product emission. Additionally, recent advancements and applications of the aforementioned technologies in real indoor environments have also been reviewed. The study suggests that for efficient particle removal, either high-efficiency particulate air (HEPA) filters or ESP should be preferred. Likewise, for the removal of multiple pollutants like particles, gases and volatile organic compounds simultaneously, emerging technologies can be integrated with pre- or post-stages of conventional technologies. The cost performance index is lowest for HEPA filters and ESP, indicating that they provide a better value for money in terms of performance. Ionization based and emerging PM control technologies should be avoided in case of sensitive populations due to health concern associated with emission of hazardous by-products. Graphical
PubDate: 2023-03-09
DOI: 10.1007/s41810-023-00178-5
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- Characteristics of Remotely Sensed Urban Pollution Island (UPI) & its
Linkage with Surface Urban Heat Island (SUHI) over Eastern India-
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Abstract: The urbanisation and its detrimental impact on climate is a well-documented phenomenon in today’s world, but research documenting the Urban Pollution Island (UPI) especially over South Asia is seldom found. With the advancement of the satellite datasets, the quantification of UPI has become possible only in recent years. When measured using satellite data, the UPI is the spatial anomaly of Aerosol Optical Depth (AOD) over an urban area with reference to a nearby non-urban zone. UPI may influence energy budget, precipitation patterns and human health over the city. In the present research, it has been attempted to analyse the climatology and characteristics of UPI and its association with the Surface Urban Heat Island (SUHI) over six cities (Patna, Gaya, Ranchi, Jamshedpur, Bardhaman and Siliguri) from eastern India, which is a highly populated region and infamous for climatic concerns. Alongside, a Surface PM2.5 data is also investigated further, to find heat and pollution island links. The UPI–SUHI interactions have been evaluated and found to be very distinct for each city. It is found that high urban AOD value can be noticed irrespective of the UPI magnitude over Patna. Bardhaman has exhibited very high AOD (> 3.0) even in very low UPI conditions. Jamshedpur’s urban loadings found to be contributing somewhere to UPI formations. UPII has also shown a clear sign of a seasonal cycle across the cities. In Patna, increase in PM2.5 may be linked to SUHII in medium loading cases and very high PM2.5 loadings (> 200 μg/m3) result in low average SUHII. It may be summarised that Patna, Gaya and Bardhaman are exhibiting high surface PM2.5 loads over urban zones, whilst Ranchi, Siliguri and Jamshedpur have much cleaner urban air. The Mann–Kendall test and Pettitt’s test also detected significant increasing trend and change point in recent times for UPI intensity. The well-developed UPI system shows an exigency of more in-depth studies to mitigate the detrimental effects of UPI–SUHI in upcoming times.
PubDate: 2023-03-02
DOI: 10.1007/s41810-023-00176-7
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- A Comprehensive Review on the Classification, Uses, Sources of
Nanoparticles (NPs) and Their Toxicity on Health-
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Abstract: Nanotechnology (NT) refers to the generation and application of nanoparticles (NPs). Research in NT has been ongoing for several decades and has resulted in a wide range of materials at the nano-scale. Globally, NPs serve various domestic, pharmaceuticals, aviation, textiles, and other industrial purposes. These particles are currently used in kitchen utensils, medical applications, energy-related research, aircraft, etc. The future of our planet depends on NT. Numerous molecular indicators of genetic and autoimmune diseases, malignant tumors, and a wide range of other disorders can currently be diagnosed using NPs. Drug delivery to specific tissues and organs with controlled drug release and accumulation parameters is achieved through NPs. In addition, NPs have been used as active components in some cases. For example, photodynamic therapy’s incorporation and heating are photosensitizers and hyper-thermic tumor killing through NPs. Despite numerous beneficiary use and economic success of NPs, their toxic effects on terrestrial and aquatic ecosystems have also gained attention. Excessive exposure to NPs in sectors, such as agriculture, industry, etc. has generated negative health effects in humans. The review highlights about NPs in great detail. The paper discusses their sources, usage, toxicity and health effects, transportation, analysis, and treatment. It represents a summary of recent research developments and achievements in the field of NT and substantial gap areas that need to be addressed.
PubDate: 2023-03-01
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- Temporal and Spatial Variations of Satellite-Based Aerosol Optical Depths,
Angstrom Exponent, Single Scattering Albedo, and Ultraviolet-Aerosol Index
over Five Polluted and Less-Polluted Cities of Northern India: Impact of
Urbanization and Climate Change-
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Abstract: It is widely acknowledged that factors such as population growth, urbanization's quick speed, economic growth, and industrialization all have a role in the atmosphere's rising aerosol concentration. In the current work, we assessed and discussed the findings of a thorough analysis of the temporal and spatial variations of satellite-based aerosol optical parameters such as Aerosol Optical Depth (AOD), Angstrom Exponent (AE), Single Scattering Albedo (SSA), and Ultraviolet-Aerosol Index (UV-AI), and their concentration have been investigated in this study over five polluted and less-polluted cities of northern India during the last decade 2011–2020. The temporal variation of aerosol optical parameters for AOD ranging from 0.2 to 1.8 with decadal mean 0.86 ± 0.36 for Patna region shows high value with a decadal increasing trend over the study area due to rise in aerosols combustion of fossil fuels, huge vehicles traffic, and biomass over the past ten years. The temporal variation of AE ranging from 0.3 to 1.8 with decadal mean 1.72 ± 0.11 for Agra region shows high value as compared to other study areas, which indicates a comparatively higher level of fine-mode aerosols at Agra. The temporal variation of SSA ranging from 0.8 to 0.9 with decadal mean 0.92 ± 0.02 for SSA shows no discernible decadal pattern at any of the locations. The temporal variation of UV-AI ranging from -1.01 to 2.36 with decadal mean 0.59 ± 0.06 for UV-AI demonstrates a rising tendency, with a noticeable rise in Ludhiana, which suggests relative dominance of absorbing dust aerosols over Ludhiana. Further, to understand the impact of emerging activities, analyses were done in seasonality. For this aerosol climatology was derived for different seasons, i.e., Winter, Pre-Monsoon, Monsoon, and Post-Monsoon. High aerosol was observed in Winter for the study areas Patna, Delhi, and Agra which indicated the particles major dominance of burning aerosol from biomass; and the worst in Monsoon and Post-Monsoon for the Tehri Garhwal and Ludhiana study areas which indicated most of the aerosol concentration is removed by rainfall. After that, we analyzed the correlation among all the parameters to better understand the temporal and spatial distribution characteristics of aerosols over the selected region. The value of r for AOD (550 nm) for regions 2 and 1(0.80) shows a strong positive correlation and moderately positive for the regions 3 and 1 (0.64), mostly as a result of mineral dust carried from arid western regions. The value of r for AE (412/470 nm) for region 3 and (0.40) shows a moderately positive correlation, which is the resultant of the dominance of fine-mode aerosol and negative for the regions 5 and 1 (− 0.06). The value of r for SSA (500 nm) for regions 2 and 1 (0.63) shows a moderately positive correlation, which explains the rise in big aerosol particles, which scatters sun energy more efficiently, and the value of r for UV-AI for regions 1 and 2 shows a strong positive correlation (0.77) and moderately positive for the regions 3 and 1 (0.46) which indicates the absorbing aerosols present over the study region.
PubDate: 2023-03-01
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- Aerosol Deposition in 90° Circular Tube Bends with Laminar Flows: Effects
of Inertial Impaction and Gravitational Settling-
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Abstract: As studied by many authors, the behavior of particles in aerosol flow through bent tubes is relevant to a variety of technological developments for practical applications. The present work is no exception, motivated by the need of understanding ink droplet loss during mist transport in Aerosol Jet® printing. While the majority of works in the literature have considered particle deposition in tube bends with the tube-flow Reynolds number Re > 1000, the mist flow in transport channels of Aerosol Jet® printer often has Re < 100. Here, the effects of inertial impaction and gravitational settling with laminar flows in 90° bends are examined using an OpenFOAM® CFD package, for Re ~ 50 to 1000. The computational code is verified by comparing with the experimental result of Pui et al. for Re = 1000. Besides inertial impaction due to the centrifugal forces in bends, the effect of gravitational settling is shown to become increasingly significant with reduction of tube-flow velocity, which can also be quite sensitive to the bend orientation when the mist flow rate is low. For situations of downward bend or upward inlet, where the gravitational force and centrifugal force oppose each other, the effect of gravitational settling appears relatively insignificant. However, the particle deposition efficiency is generally enhanced in upward bends or bends with downward inlet, where the gravitational force and centrifugal force reinforce each other, exhibiting large deviations from the zero-g case, especially at lower flow velocities (i.e., smaller Froude number).
PubDate: 2023-03-01
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- Alternative High-Performance Fibers for Nonwoven HEPA Filter Media
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Abstract: Continual research, development, and advancement in air filtration technology is important to abate the ever increasing health hazards of air pollution and global pandemics. The purpose of this review is to survey, categorize, and compare mechanical and thermal characteristics of fibers to assess their potential applicability in air filter media. The history of high-efficiency particulate air (HEPA) filter development explains how we arrived at the current state of the art nonwoven fibrous borosilicate glass filter paper. This review explores the history and practical uses of particular fiber types and explains fiber production methods in general terms. The thermal and mechanical properties of particular fibers are examined using the codes and standards produced by the American Society of Mechanical Engineers (ASME) to generalize the applicability of fiber categories for HEPA filter units within the nuclear air cleaning industry. This review discusses common measurements for specific strength and tenacity used by the textile and construction industries. Particular fibers are selectively compared for density, tensile strength, tensile stiffness, flexural rigidity, moisture regain, decomposition temperature, and thermal expansion. This review concludes with a subjective assessment of which types of fibers may be appropriate to study for HEPA filtration.
PubDate: 2023-03-01
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- Risk Assessment and Source Analysis of Atmospheric Heavy Metals Exposure
in Spring of Tianjin, China-
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Abstract: With the rapid development of the social economy and the frequent occurrence of haze, heavy metals in atmospheric particulates have been shown harmful to human health. In this paper, the samples of atmospheric particulate matter (PM10 and PM2.5) were collected in two typical sites of Tianjin in spring. The concentration of 6 heavy metals in PM10 and PM2.5 were analyzed by microwave digestion inductively coupled plasma mass spectrometry method. The enrichment factor (EF) method was used to identify the sources of heavy metals in particulate matter. The results showed that the daily average concentrations of PM10 and PM2.5 in Tianjin were notably influenced by building construction, traffic-related emission and meteorological condition. The heavy metals in the atmospheric particulate matter were as follows: ρ(Mn) > ρ(Pb) > ρ(Ni) > ρ(V) > ρ(Cd) > ρ(Co) and more easily enriched in fine particles PM2.5. The result of EF analysis suggested that the V, Mn, Co and Ni were not enriched, and the source of them in the atmospheric particulate matter samples was mainly nature. Cd and Pb were typical pollution elements in spring of Tianjin, and predominantly derived from human activities. Health risk assessment demonstrated that the carcinogenic risk levels of heavy metals in the atmospheric particulate matter samples were generally followed the order of men > women > children. Cd and Pb in the atmospheric particulate matter had no carcinogenesis risk. The potential carcinogenic risk of Ni was evaluated as acceptable and tolerable. This study could provide a scientific reference for the prevention and control of atmospheric particulate pollution.
PubDate: 2023-03-01
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- Spatial and Temporal Analysis of Particulate Matter and Gaseous Pollutants
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Abstract: Vehicles are one of the main contributors to outdoor air pollution in urban areas of developing nations. Addis Ababa is experiencing the fastest rate of urbanization with increasing heavy traffic across the city. Megenagna is one of the city’s busiest transportation hubs, connecting traffic to most of Addis Ababa’s lower town via major highways and railways. The ever-increasing air pollution from heavy traffic in the area is an alarming environmental problem for the city. This research aimed to assess and evaluate traffic-related particulate and gaseous pollutants in Megenagna. There were 41 sampling points, 16 of which were near the root of the Megenagna bus station, and the rest 25 were taken on the six main road lines. The samples were collected for the 2-month variations of January and February during the rush hour. Sampling was done using the hand-held portable air test equipment (Model-CW-HAT2005) and Aeroqual Series 500 (2016). Geo-statistical analysis and descriptive and inferential statistical analysis were used. The mean values of PM2.5, PM10, SO2, and NO2 in the Megenagna area were 30.3 ± 2.2 µg/m3, 58.6 ± 3.1 µg/m3, 777.5 ± 151.2 µg/m3, and 58.6 ± 3.04 µg/m3, respectively. The difference between sampling locations was statistically significant (p < 0.05), suggesting that there is significant spatial variation between different parts of the study site. Individual comparisons, however, revealed that they are not significantly different from one another on some sites. The hotspot analysis also confirmed that there are hot and cold spots in the distribution of pollution over space and time.
PubDate: 2023-03-01
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- Quantification of Fine Particulate Matter (PM2.5) and Its Correlation with
Meteorological Parameters Within the Ambient Air of Automobile Workshops
in Benin City-
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Abstract: This study explores the quantification of PM2.5 (particles with an aerodynamic diameter of less than or equal to 2.5 µm) and how it is impacted by meteorological parameters. The study was conducted in Benin City between January and December 2019. The city was divided into four zones, namely, North West (NW), North East (NE), South East (SE), and South West (SW). A total of 180 representative samples for PM2.5 were collected from artisans’ workshops in both wet and dry seasons, using an Apex2IS Casella standard pump fitted with a conical inhalable sampling (CIS) head at a flow rate of 3.5 L/min for 8 h. Meteorological parameters were collected simultaneously with PM2.5. The PM2.5 levels range from 37.9 to 735.1 (µg/m3) and 60.6 to 313.9 (µg/m3) during the dry and wet seasons, respectively. The estimated PM2.5 concentration exceeded the World Health Organization (WHO) and National Ambient Air Quality Standard (NAAQS) of 25 and 250 ug/m3, respectively. The meteorological parameters were estimated to be 27.9–33.4 (°C), 59.8–78.9 (%), 748.4–754.3 (mmHg), 2.8–6.9 (km/h), 154.9–205.4 (o), 425.1–1,073.4 (W/m2), and 717.3–1,133.7 (µW/m2) for temperature, relative humidity, pressure, wind speed, wind direction, solar radiation, and ultra-violet radiation, respectively. A significant positive correlation was observed between PM2.5, temperature, solar radiation, and ultra-violet radiation. However, a negative correlation was observed for pressure. This positive correlation may influence the poor dispersion of PM2.5, particularly in the wet season when we experience low temperatures and low wind speeds, and consequently impact negatively on human health.
PubDate: 2023-03-01
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- Numerical Prediction of the Effect of Thermal Plume of a Standing Human on
the Airborne Aerosol Flow in a Room: Assessment of the Social Distancing
Rule-
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Abstract: The purpose of the study is to investigate the dispersion of droplet nuclei/aerosol which are produced during coughing and continuous talking to quantify the risk of infection due to airborne disease transmission. A three-dimensional modelling of aerosol transport due to human respiratory activities such as coughing and talking within a room environment has been simulated using CFD technique. An inert scalar transport equation was used to represent aerosol cloud, while turbulence was modelled with the \(k-\epsilon \) turbulence model. A modified Wells–Riley equation was used to calculate the risk of infection based on quanta emission concept. The spatial and temporal distribution of aerosol cloud within the room is initially driven by the upward flowing thermal plume surrounding the human, but later driven by the flow field constrained by the walls and cooler air movement. While the cough generated aerosols are concentrated in a smaller space within the room, the continuous talk generated aerosols are distributed throughout the room. Within an indoor environment, 2 m distancing will not be enough to protect healthy people from aerosols coming from an infected person due to continuous talking with prolonged exposure.
PubDate: 2023-03-01
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- Aerosol Load-Cloud Cover Correlation: A Potential Clue for the
Investigation of Aerosol Indirect Impact on Climate of Europe and Africa-
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Abstract: Aerosol optical depth (AOD) is a key parameter in atmospheric pollution and climate processes. In this paper, we compared the aerosol loading (550 nm) from 2000–2001 to 2017–2018 and total cloud cover using seasonal, latitudinal and solar activity cycle data from the Moderate Resolution Imaging Spectroradiometer (MODIS) and determined the spectral optical range from the region of relatively clear air (Europe) to the region of more considerable biomass burning activity (Africa). To remove the large annual cycle influence, the data were deseasonalized, allowing exploration of inter-annual variability. Deseasonalization obtains the time series AOD monthly average anomaly over the years for each grid cell. We employ the solar flux index over the regions by correlating the absolute percentage mean difference of aerosol and cloud interactions and validate the result by modeling aerosol and cloud data from 2020 to 2021 using a neural network. AOD and solar flux for Africa show correlations of − 0.638 for 2000–2001 and − 0.218 for Europe, and at the same time, AOD with cloud cover for Africa shows correlations of − 0.129 and 0.360 for Europe. The analysis confirmed an inverse weak correlation of aerosols with cloud cover. This would help resolve the knowledge gap by demonstrating that aerosol and cloud interactions are not only dependent on region but also more dependent on the solar activity cycle and seasons. We observed dependence by the latitude of the aerosol load and solar flux index.
PubDate: 2023-03-01
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- Size-Resolved Characteristics and Sources of Inorganic Ions, Carbonaceous
Components and Dicarboxylic Acids, Benzoic Acid, Oxocarboxylic Acids and
α-Dicarbonyls in Wintertime Aerosols from Tianjin, North China-
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Abstract: Size-resolved aerosols collected at Tianjin, North China in winter were studied for inorganic ions, carbonaceous components, dicarboxylic acids, benzoic acid, oxocarboxylic acids and α-dicarbonyls. Na+ found to be the dominant ions, while sum of SO42−, NO3− and NH4+ was almost more than half of the total ionic mass in all size fractions. Both inorganic anions and carbonaceous components showed a bimodal distribution. Water-soluble organic carbon (WSOC) accounted for 53.9% to total OC, with 36.0% in fine- and 17.9% in coarse-mode fractions (≤ 2.1 and ≥ 2.1 μm particles, respectively) of aerosols. Most of dicarboxylic acids and related compounds peaked at 0.43–0.65 μm size bin followed by a gradual decrease, except for few species. Average concentrations of total dicarboxylic acids were 1223 and 516 ng m−3 in fine and coarse mode fractions, respectively. Oxalic acid found to be the most abundant species followed by phthalic and azelaic acids in fine- and coarse-mode fractions, except the third most abundance of glyoxylic acid in the coarse mode fraction. Based on size-resolved distributions, correlations and mass ratios of selected marker species, we found that inorganic aerosols were mainly derived from sea salt and vehicular exhaust and coal combustion emissions rather than biomass burning and soil dust in winter over the Tianjin region, North China. While dicarboxylic acids and related compounds were mainly originated from fossil fuel including coal combustion and their contributions from biomass burning and marine and terrestrial biogenic emissions were minor. Their in situ secondary formation and transformations were intensive at local and regional scales.
PubDate: 2023-02-08
DOI: 10.1007/s41810-022-00159-0
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- Distribution and variability of Black Carbon Aerosol and its response to
specific Meteorological Occurrences: A case study on the Indian city of
Ranchi-
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Abstract: The black carbon (BC) aerosol is the organic remanence of the incomplete burning of various fuels. The study attempts to analyse the temporal variability of BC over Ranchi, Jharkhand, India using ground based measurements of aethalometer. The diurnal variation reveals two prominent sharp peaks throughout the year, one in the morning hours (0130-0330 UTC) and other in the evening hours (1330-1530 UTC). The results show a marked seasonal variation in BC concentration, with highest value during the pre-monsoon (7.24 µg/m3) and least in the monsoon (2.01 µg/m3) season. The relationship of meteorological variables such as temperature, precipitation, aerosol optical depth (AOD), organic carbon and vegetation represented via Normalized Difference Vegetation Index (NDVI) with BC is also computed using satellite-based measurements. A significant correlation is in the spatial pattern of organic carbon (r = 0.927), AOD (r = 0.86) and temperature (r = 0.748) with BC, whereas precipitation (r = − 0.146) and NDVI (r = − 0.203) shows insignificant correlation with BC. Significantly higher level of BC concentration (11.95 µg/m3) in response to the fog event is observed throughout the day against lower (6.5 µg/m3) BC in winter. The morning peak is increased by 4.71 µg/m3 and delayed by two hours on foggy day than the winter mean. During the thunder squall event, mean BC is reduced to 3.84 µg/m3 from 7.24 µg/m3 in pre-monsoon. Similar reduction is also observed in mean BC (1.2 µg/m3) in response to a rainy day during monsoon. The variability in BC is key to the changes in AOD that impacts the air quality, energy balance, cloud-precipitation processes, global warming and climate change.
PubDate: 2023-01-27
DOI: 10.1007/s41810-023-00174-9
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- Characterization from Diesel and Renewable Fuel Engine Exhaust:
Particulate Size/Mass Distributions and Optical Properties-
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Abstract: Combustion of fossil fuel produces emissions and is one of the major environmental problems leading to climate change. Diesel engines are highly efficient but produce particulate emissions. These particulate emissions are considered dangerous to human health because inhaling particulates may cause respiratory and heart disease. Substituting fossil diesel fuel with renewable diesel fuel and using diesel particulate filters is one possibility to meet stringent legislative requirements. With this motivation, the present experimental investigation aimed to evaluate the particle size distribution (PSD), optical properties of particulate matter (PM) emitted, and the outcome of using an after-treatment system comprising of a diesel particle filter (DPF). This investigation aimed to make a comparative analysis of particulate emission upstream and downstream of the DPF with and without ultraviolet (UV) light (405 nm and 781 nm wavelength) turned on/off. Experiments were performed at (a) engine idle with a torque of 6 Nm at 750 rpm, IMEP of 1.35 bar and power of 0.5 kW, (b) engine at part load with a torque of 32 Nm at 1200 rpm, IMEP of 8.5 bar and power of 4.5 kW. Diesel engine was operated on two fuels (a) Diesel and (b) EHR7. Results showed that as and when UV light was turned on, a distinct nucleation mode that dominated the number concentration for both test fuels were observed. Downstream of the filter had relatively higher AAE values which show the contribution to climate change. Present experimental research is important for renewable fuel industries, industrial innovation's future, and the exhaust gas after-treatment system (EATS) community. The results contribute to knowledge for occupational exposure, human health, and the environment.
PubDate: 2023-01-25
DOI: 10.1007/s41810-023-00172-x
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- Insights on Air Pollution During COVID-19: A Review
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Abstract: Air quality improved due to a sudden reduction in the mass concentration of criteria pollutants (PM2.5, PM10, NOx, CO, SO2) except ozone (O3) over cities of the world during the novel coronavirus diseases (COVID-19) lockdown. Such reduction in pollutants concentration during the lockdown period is an indicator of pollutants contributed from human-induced sources. The elevated ozone level during the lockdown period is explained by shifted NOx-mediated reaction towards volatile organic carbon (VOCs) mediated reaction. The reduction in pollutants concentration and improved air quality is not uniform for outdoor and indoor environments. The indoor air quality is quite poor compared to outdoor throughout the lockdown period. The degradation in indoor air quality is associated with increased human activities and the degree of ventilation inside the home. The number of active COVID-19 cases is associated with air quality over a region. The improved air quality helped in a reduction in COVID-19 virus transmission among the people. Present review articles provide detailed insight into current research progress, the impact of lockdowns on outdoor and indoor air quality in different cities of the world. Further, this review articles provide a detailed overview of an elevated O3 level during the lockdown period and the mechanism of formation.
PubDate: 2023-01-19
DOI: 10.1007/s41810-023-00173-w
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