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Atmosphere ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 124
Author(s):  
Farooq Usman ◽  
Bahadar Zeb ◽  
Khan Alam ◽  
Zhongwei Huang ◽  
Attaullah Shah ◽  
...  

The current study investigates the variation and physicochemical properties of ambient particulate matter (PM) in the very important location which lies in the foothills of the Hindu Kush ranges in northern Pakistan. This work investigates the mass concentration, mineral content, elemental composition and morphology of PM in three size fractions, i.e., PM1, PM2.5 and PM10, during the year of 2019. The collected samples were characterized by microscopic and spectroscopic techniques like Fourier transform infrared spectroscopy, X-ray diffraction spectroscopy and scanning electron microscopy (SEM) coupled with energy-dispersive X-ray (EDX) spectroscopy. During the study period, the average temperature, relative humidity, rainfall and wind speed were found to be 17.9 °C, 65.83%, 73.75 mm and 0.23 m/s, respectively. The results showed that the 24 h average mass concentration of PM10, PM2.5 and PM1 were 64 µgm−3, 43.9 µgm−3 and 22.4 µgm−3, respectively. The 24 h concentration of both PM10 and PM2.5 were 1.42 and 2.92 times greater, respectively, than the WHO limits. This study confirms the presence of minerals such as wollastonite, ammonium sulphate, wustite, illite, kaolinite, augite, crocidolite, calcite, calcium aluminosilicate, hematite, copper sulphate, dolomite, quartz, vaterite, calcium iron oxide, muscovite, gypsum and vermiculite. On the basis of FESEM-EDX analysis, 14 elements (O, C, Al, Si, Mg, Na, K, Ca, Fe, N, Mo, B, S and Cl) and six groups of PM (carbonaceous (45%), sulfate (13%), bioaerosols (8%), aluminosilicates (19%), quartz (10%) and nitrate (3%)) were identified.


Author(s):  
Karolina Bralewska ◽  
Wioletta Rogula-Kozłowska ◽  
Dominika Mucha ◽  
Artur Jerzy Badyda ◽  
Magdalena Kostrzon ◽  
...  

This study aimed to evaluate the mass concentration of size-resolved (PM1, PM2.5, PM4, PM10, PM100) particulate matter (PM) in the Wieliczka Salt Mine located in southern Poland, compare them with the concentrations of the same PM fractions in the atmospheric air, and estimate the dose of dry salt aerosol inhaled by the mine visitors. Measurements were conducted for 2 hours a day, simultaneously inside (tourist route, passage to the health resort, health resort) and outside the mine (duty-room), for three days in the summer of 2017 using DustTrak DRX devices (optical method). The highest average PM concentrations were recorded on the tourist route (54–81 µg/m3), while the lowest was in the passage to the health resort (49–62 µg/m3). At the same time, the mean outdoor PM concentrations were 14–20 µg/m3. Fine particles constituting the majority of PM mass (68–80%) in the mine originated from internal sources, while the presence of coarse particles was associated with tourist traffic. High PM deposition factors in the respiratory tract of children and adults estimated for particular mine chambers (0.58–0.70), the predominance of respirable particles in PM mass, and the high content of NaCl in PM composition indicate high health benefits for mine visitors.


Geofluids ◽  
2022 ◽  
Vol 2022 ◽  
pp. 1-14
Author(s):  
Teng Lu ◽  
Faqiang Dang ◽  
Haitao Wang ◽  
Qingmin Zhao ◽  
Zhengxiao Xu

Nanoparticle-assisted microwave heating of heavy oil has the advantages of fast temperature rise and high thermal efficiency. Compared with traditional heating methods, it can reduce viscosity in a shorter time. In addition, the heavy components in the heavy oil are cracked into light components at high temperatures (this high temperature cannot be reached by conventional heating methods). This process is irreversible and avoids the problem of viscosity recovery of heavy oil after the temperature is reduced. Through absorbing microwave heating experiments, study the effect of nanoparticles on the improvement of the ability of heavy oil to absorb waves and raise temperature; through the heavy oil upgrading experiment and the four-component analysis experiment, the effect of adding hydrogen donor to assist microwave on the viscosity reduction of heavy oil upgrading by nanoparticles was studied, and the problem of viscosity recovery was determined; Through the gravity drainage experiment, the mechanism of nanoparticle-assisted microwave to improve the recovery of heavy oil is studied, and the influence of water content, nanocatalyst, and microwave power on the production of drainage is analyzed. The results show that nanoparticles can improve the wave absorption and heating capacity of heavy oil, and adding 0.6 wt% of nanomagnetic iron oxide catalyst can increase the heating rate of heavy oil in microwave by 60.6%; nanoparticle-assisted microwave heating method can effectively upgrade heavy oil and reduce viscosity. The experimental conditions are 2 wt% tetralin mass concentration, 0.5 wt% nano-Fe3O4 particle mass concentration, microwave heating time 50-60 min, and microwave power 539 W. Under this experimental condition, the viscosity is reduced by 40%. This method has viscosity recovery problems, but final viscosity reduction effect is still very significant. Obtaining the mechanism of nanoparticle-assisted microwave to enhance oil recovery, one of which is that nanoparticles improve the wave absorption and heating capacity of heavy oil and increase the heating speed of heavy oil; the second is that the nanoparticles form local high temperature under the action of microwave, which catalyzes the hydrocracking reaction between the heavy components in the heavy oil and the hydrogen donor, upgrading and reducing the viscosity of the heavy oil, and accelerating the production of heavy oil.


2022 ◽  
Author(s):  
Lauriane Chuzeville ◽  
Frank Boury ◽  
David Duday ◽  
Resmi Anand ◽  
Enzo Moretto ◽  
...  

New understandings in the amorphous calcium carbonate nanoparticle synthesis lead to a final mass concentration increase by a factor of 3.5. The stabilisation in aqueous media is achieved by a 2-minute scalable process using bio-sourced stabilisers.


2022 ◽  
Author(s):  
Angelo Robotto ◽  
Secondo Barbero ◽  
Roberto Cremonini ◽  
Enrico Brizio

A better air quality has led to a significant reduction of premature deaths over the past decade in Europe, as emissions of many pollutants declined considerably in the EU-27 Member States: SOx emissions by 76%, NOx by 42%, NMVOCs by 29% and PM2.5 by 29%. The present paper reports an in-depth analysis of the reasons why the regions of the Po valley, Northern Italy, still have difficulties to comply with EU air quality standards, in particular for PM10 and NO2, in spite of strong emission reductions carried out through careful Air Quality Plans put in practice during the last 2 decades. The analysis includes a consistent comparison of emission inventories for different European regions in Italy, Germany and Poland, the measured air quality trends and PM source apportionment in these areas, and, most of all, a thorough investigation of meteorological parameters influencing atmospheric pollutant dispersion and transport. The study reports that in the colder seasons, wind speed, PBL height and atmospheric pressure occurring in the Po basin are three to five times less efficient in diluting and dispersing pollutant if compared to regions north of the Alps. Due to the extremely disadvantageous orographic and climatic configuration of the Po Valley, only radical emission reductions could bring air quality into EU limit values with a questionable cost-benefit ratio of due policies. Provided that air quality standards (particularly for PM10 and PM2.5) aim at protecting people from adverse health effects arising from air pollution, it is however necessary to also consider the toxicity of atmospheric particulate in addition to PM10/PM2.5 mass concentration as a limit value. Based on existing toxicological studies and reports, a discussion is reported about PM toxicity factor depending on toxicity scores for source-specific aerosols and PM composition determined by Source Apportionment. Provided that PM components profiles are strongly different across Europe, the obtained PM toxicity factors range from 0.3 (for areas where the main PM contribution is referable to sea salts or inorganic matter) to 3.5 (where Elemental and Organic Carbon prevail), suggesting that, even at the same mass concentration, the effects of PM10/2.5 on human health are significantly variable and limit values should take into account differential toxicity. Modern PM Source Apportionment techniques, along with reliable toxicity and epidemiological analyses, represent the right tools to overcome the shortcomings of the current regulation standard and build a new consistent health metric for ambient PM in the future, helping policy makers impose effective air quality measures to protect people health.


MAUSAM ◽  
2021 ◽  
Vol 42 (4) ◽  
pp. 367-374
Author(s):  
SAYED M. EL-SHAZLY ◽  
ABDELAZEEM M. ABDELMAGEED ◽  
GAMILY HASSAN ◽  
BADRY NOBI

The dependence of the atmospheric extinction on aerosols concentration, temperature and wind speed is demonstrated. The atmospheric extinction was determined by measuring the transmission loss of radiation from alight source across 36 cm path with a photocell detector Conclusion include a general association of high extinction with high aerosols concentration, temperature and wind speed, but there are no one-to-one relationships. A correlation study between the extinction coefficient and each of these parameters was performed.  


Author(s):  
Boris N. Filatov ◽  
Natalya I. Latyshevskaya ◽  
Natalya V. Krylova ◽  
Irina K. Gorkina ◽  
Yulya I. Velikorodnaya ◽  
...  

The presence of grinding, mixing, and fractionation of solid components of formulations leads to the formation of aerosols in the air of the working area with a wide range of dispersion of the solid phase - all this characterizes the organization of technological processes for the production of energy-intensive materials. The study aims to give a qualitative assessment of possible air pollution of the working area of energy-intensive materials production by nanoscale aerosols with a solid dispersed phase. The researchers carried out the sampling of the working area air and flushes from solid horizontal surfaces to produce energy-intensive materials. We carried out the sampling by forced circulation of the test air through the absorption devices of Polezhaev. Scientists used Triton TX-114 solution with a mass concentration of 2.0 mg/dm3 as an absorption medium. The researchers performed flushing from surfaces using cloth tampons moistened with Triton TX-114 solution with a mass concentration of 2.0 mg/dm3. We determined the particle sizes in the samples using NanotracULTRA (Microtrac). Scientists found aluminum and nitrocellulose particles with sizes from 36 to 102 nm in the air of the working area and flushes from horizontal surfaces. The study of the fractional composition of RDX and aluminum powders of the ASD-1 brand showed the presence of nanoscale particles in them. Nanoscale dust particles pollute the air of the working area and solid horizontal surfaces at certain stages of the production of energy-intensive materials. There are nanoscale particles in the composition of powders of some standard components of formulations. Flushes from solid horizontal surfaces are an adequate qualitative indicator of the presence of nanoaerosols in the air of the working area.


Atmosphere ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 21
Author(s):  
Ioana Elisabeta Popovici ◽  
Zhaoze Deng ◽  
Philippe Goloub ◽  
Xiangao Xia ◽  
Hongbin Chen ◽  
...  

We present the mapping at fine spatial scale of aerosol optical properties using a mobile laboratory equipped with LIDAR (Light Detection And Ranging), sun photometer and in situ instruments for performing on-road measurements. The mobile campaign was conducted from 9 May to 19 May 2017 and had the main objective of mapping the distribution of pollutants in the Beijing and North China Plain (NCP) region. The highest AOD (Aerosol Optical Depth) at 440 nm of 1.34 and 1.9 were recorded during two heavy pollution episodes on 18 May and 19 May 2017, respectively. The lowest Planetary Boundary Layer (PBL) heights (0.5–1.5 km) were recorded during the heavy pollution events, correlating with the highest AOD and southern winds. The transport of desert dust from the Gobi Desert was captured during the mobile measurements, impacting Beijing during 9–13 May 2017. Exploring the NCP outside Beijing provided datasets for regions with scarce ground measurements and allowed the mapping of high aerosol concentrations when passing polluted cities in the NCP (Baoding, Tianjin and Tangshan) and along the Binhai New Area. For the first time, we provide mass concentration profiles from the synergy of LIDAR, sun photometer and in situ measurements. The case study along the Binhai New Area revealed mean extinction coefficients of 0.14 ± 0.10 km−1 at 532 nm and a mass concentration of 80 ± 62 μg/m3 in the PBL (<2 km). The highest extinction (0.56 km−1) and mass concentrations (404 μg/m3) were found in the industrial Binhai New Area. The PM10 and PM2.5 fractions of the total mass concentration profiles were separated using the columnar size distribution, derived from the sun photometer measurements. This study offers unique mobile datasets of the aerosol optical properties in the NCP for future applications, such as satellite validation and air quality studies.


Energies ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 59
Author(s):  
Alexander Balitskii ◽  
Myroslav Kindrachuk ◽  
Dmytro Volchenko ◽  
Karol F. Abramek ◽  
Olexiy Balitskii ◽  
...  

The article is devoted to the following issues: boiling of fluid in the cooling jacket of the engine cylinder head; agents that influenced the thermal conductivity coefficient of nanofluids; behavior of nanoparticles and devices with nanoparticles in the engine’s cylinder head cooling system. The permissible temperature level of internal combustion engines is ensured by intensification of heat transfer in cooling systems due to the change of coolants with “light” and “heavy” nanoparticles. It was established that the introduction of “light” nanoparticles of aluminum oxide into the water in a mass concentration of 0.75% led to an increase in its thermal conductivity coefficient by 60% compared to the base fluid at a coolant temperature of 90 °C, which corresponds to the operating temperature of the engine cooling systems. At the indicated temperature, the base fluid has a thermal conductivity coefficient of 0.545 W/(m °С), for nanofluid with particles its value was 0.872 . At the same time, a positive change in the parameters of the nanofluid in the engine cooling system was noted: the average movement speed increased from 0.2 to 2.0 m/s; the average temperature is in the range of 60–90 °C; heat flux density 2 × 102–2 × 106 ; heat transfer coefficient 150–1000 . Growth of the thermal conductivity coefficient of the cooling nanofluid was achieved. This increase is determined by the change in the mass concentration of aluminum oxide nanoparticles in the base fluid. This will make it possible to create coolants with such thermophysical characteristics that are required to ensure intensive heat transfer in cooling systems of engines with various capacities.


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