Characterization Of Atmospheric Particles Research Articles

Multiple Models Used to Deconstruct the Characteristics of Atmospheric Particles in Arid Region of Northwest China

Northwest China has a desert, arid and semi-arid climate that makes outdoor air sampling challenging. The region is also affected by intense dust storms. Monitoring challenges from the harsh climate have limited supplies of the data needed to inform appropriate regulatory actions to address air pollution in the region. Here we combine a comprehensive set of state-of-the-art offline analytical approaches and multiple models to deconstruct the chemical nature and sources of particulate matter at arid city in northwestern China. We collected 972 samples in Jiuquan during the period March 2019 through January 2020. The annual levels of PM10 (73.7 μg/m3) exceeded the Chinese Ambient Air Quality Standard (CAAQS) Grade II of 70 μg/m3. The percentages of the sum of sulfate, nitrate and ammonium, inorganic elements, organic carbon and elemental carbon in PM10 mass ranged 6.8–15.8%, 9.9–12.2%, 9.0–27.7%, and 1.5–4.7%, respectively. Analyses of sources indicated that soil dust was a major contributor to PM10 levels in Jiuquan city accounting for 24.8–30.5%. Fugitive dust and coal combustion were the second and third largest contributors to PM10, respectively. Our results suggest that natural emissions can make air quality regulation futile. In this comprehensive particulate pollution analysis, we present the view that the sizeable regional particulate sources warrant national and regional mitigation strategies to ensure compliance with air quality requirements.

The characteristics of atmospheric particles and metal elements during winter in Beijing: Size distribution, source analysis, and environmental risk assessment

In order to investigate the pollution characteristics of size-segregated particles and metal elements (MEs) after the Chinese Air Pollution Prevention Action Plan was released in 2013, an intensive field campaign was conducted in the suburban area of Chaoyang District, Beijing in winter 2016. The size distributions of particle mass concentrations were bimodal, with the first peak in the fine fraction (0.4–2.1 µm) and the second peak in the coarse fraction (3.3–5.8 µm). Moreover, the proportion of fine particles increased and the proportion of coarse particles decreased as the pollution level was more elevated. It was found that the composition of coarse particles is as important as that of fine particles when pollution of aerosol metals in the atmosphere in 2016 were compared to 2013. In addition, according to the size distribution characteristics, 23 MEs were divided into three groups: (a) Fe, Co, Sr, Al, Ti, Ba, and U, which concentrated in coarse mode; (b) Zn, As, Cd, Tl, and Pb, which concentrated in fine mode; and (c) Na, K, Be, V, Cr, Mn, Ni, Cu, Mo, Ag, and Sn, showing bimodal distribution. Under clean air, slight pollution and moderate pollution conditions, most elements maintained their original size distributions, while under severe pollution, the unimodal distributions of most MEs became bimodal distributions. The factors analysis combined with size distributions indicated that Na, Zn, Mo, Ag, Cd, and Tl, showing the moderate to severe contamination on environment, were significantly influenced by diffuse regional emissions or anthropogenic source emissions (vehicle exhaust emissions and combustion process). The environmental risk assessment revealed that the heavy metal loading in the atmospheric particles collected had a high potential for ecological risk to the environment during sampling period because of the high contribution of Cd, Tl, Zn and Pb.

Morphological and chemical characteristics of atmospheric particles in the Metropolitan Zone of Toluca Valley (Mexico)

Scanning electron microscopy with energy-dispersive spectroscopy has been used for both morphological and elemental chemistry analyses of atmospheric particles. This technique allows the in situ observation of individual aerosol particles in the sample chamber. Aerotransported particles were analysed from seven monitoring stations located in the Metropolitan Zone of Toluca Valley (MZTV). Several different morphologies were identified: aggregates, porous spheres, rough and smooth compact material. The elemental composition included C, Na, Mg, Al, Si, S, Cl, K, Mn, Ca, Ti, V, Cr, Fe, Ni, Cu, Zn and Ce. These are semiquantitative analyses considering the bulk sample or individual particles. It was possible to correlate or confirm some chemical associations such as C–S, Ca–S–O and Si–Al–O, probably due to the presence of compounds derived from incomplete combustion, building tailing materials and aluminosilicates of cortical origin. Bioaerosols such as pollen, spores, brochosomes and diatoms were identified in the zone; all these types of particles have a natural origin too. Several types of suspended particles were identified in the MZTV, they were from different sources (natural and anthropogenic) to which the population can be potentially exposed, and may cause harm in the short- and long-term, according to their chemical element composition and size.

Characterization of Atmospheric Particles in Seoul, Korea Using SEM-EDX

Atmospheric particles in Seoul, Korea were investigated by scanning electron microscopy (SEM) equipped with energy dispersive X-ray analysis (EDX). Particles were identified and characterized by their morphology and elemental compositions. The morphology of particles was closely coupled with elemental compositions, which provided information on sources and transport processes of aerosols. There were various types of combustion-derived particles identified such as fly ashes, soot, organic matters, tar balls, chars, and sulfur-containing particles. These anthropogenic particles mainly have spherical shape with nano- to micro-meter size. Char was, however, distinguished by irregular shape with varying size up to several micrometers. The sulfur-containing aggregates show a wide range of size, shape, and elemental composition. In addition, bioaerosol and mineral dust were the most abundant particles from natural sources.

Size Distribution and Elemental Characteristics of Atmospheric Particles during Winter in Harbin

In order to investigate the characteristic of atmospheric particles, TSP, PM10 and PM2.5 were collected in winter and non-winter. This study investigates the size distribution and elemental characteristics of atmospheric particles. The results show that PM2.5 makes a great contribution to TSP, which changes with the concentration of TSP. PM2.5/ PM10 specially reaches the highest value, increased from 53.5% to 87.2%. It can indicate that the main pollution sources are fine particles from man-made pollution. Others, PM2.5/TSP and TSP are not strictly proportional relationship. The concentration of the elements in TSP is higher than in PM2.5, which are primarily present in coarse particles. While the contribution of S is the highest among them, in particular the contribution of S in PM2.5 reaches 33.8%. This is mainly due to coal-fired in winter, and fine particulate accounts for large percentage in coal dust.

Characterization of atmospheric particles by electron probe X-ray microanalysis.

Microchemical glass standards were used to validate a quantitation method based on peak-to-background (P/B) ratios from electron probe x-ray microanalysis spectra. This standardless method was applied to the determination of concentrations of individual particles from Malpha or Lalpha lines, as well as from Kalpha lines. The algorithm was tested on particulate glass samples for diameters ranging from 1 to 20 microm. The determined concentrations did not depend on particle size. The certified values for elements were well matched, except for Na, which may migrate under electron bombardment. Finally, classification of qualitative results obtained for aerosol particles was completed by the P/B quantitative method.

Characterization of atmospheric particles using bipolar on-line laser mass spectrometry and multivariate classification

Characterization of atmospheric particles using bipolar on-line laser mass spectrometry and multivariate classification

Characteristics of atmospheric particles (airborne and in snowpack)at Khumbu glacier in the Nepalese Himalayas (EV-K2-CNR project)

Atmospheric aerosol samplings taken at 5000 and 5650 m asl in a remote region of Nepalese Himalayas were determined by scanning electron microscopy for size distribution and by X-ray spectrometry for elemental composition. While the particles at both sites showed the same size distribution and elemental composition, many also had a high incidence of Si and Al, a fact suggesting their crustal origin. A stratigraphic study of a section of a high altitude glacier was then made to gain information concerning prevailing air mass trajectories and removal episodes. Periodicities in the chemical composition of melted ice and in residual microparticles are also reported.