scholarly journals Single-particle chemical characterization and source apportionment of iron-containing atmospheric aerosols in Asian outflow

2011 ◽  
Vol 116 (D18) ◽  
Author(s):  
Hiroshi Furutani ◽  
Jinyoung Jung ◽  
Kazuhiko Miura ◽  
Akinori Takami ◽  
Shungo Kato ◽  
...  
Keyword(s):  
Source Apportionment ◽  
Atmospheric Aerosols ◽  
Single Particle ◽  
Chemical Characterization

scholarly journals Comparative study of chemical characterization and source apportionment of PM2.5 in South China by filter-based and single particle analysis

Elem Sci Anth ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Jingying Mao ◽  
Liming Yang ◽  
Zhaoyu Mo ◽  
Zongkai Jiang ◽  
Padmaja Krishnan ◽  
...  
Keyword(s):  
Source Apportionment ◽  
Single Particle ◽  
Southern China ◽  
Control Strategies ◽  
Chemical Characterization ◽  
Number Concentration ◽  
Relative Advantage ◽  
Particle Analysis ◽  
High Time Resolution ◽  
Single Particle Analysis

Single particle aerosol mass spectrometers (SPAMS) have created significant interest among atmospheric scientists by virtue of their ability to provide real-time size-resolved information on the chemical composition of aerosols. The objective of this study is to evaluate the newly developed single particle analysis technique in terms of chemical characterization and source apportionment of ambient aerosols by comparing it with traditional filter-based methods. In this study, an air quality monitoring campaign was conducted over a period of 25 days at an urban area in Yulin city, southern China, by employing both SPAMS and traditional filter-based measurements to establish the performance of SPAMS. It was observed that the chemical characterization of particles based on SPAMS did not agree well with the filter-based analysis. Based on the filter analysis, sulfate was the most abundant component in PM2.5 (23.5%), followed by OC (18.1%), while for single particle analysis (number concentration), EC-containing particles showed the largest contribution to PM2.5 (>40%), followed by OC (15.7%). In terms of source apportionment via positive matrix factorization, six sources were identified by each of the two approaches. Both the approaches showed relatively good agreements for secondary species, traffic, and dust sources; however, discrepancies were noted for industry, fossil fuel, and biomass burning sources. Finally, investigation of diurnal profiles and two specific emission episodes monitored during the Chinese New Year and traffic activities demonstrated the relative advantage of single particle analysis over filter-based methods. Overall, single particle analysis can provide source apportionment with a high time resolution, which is helpful for policy makers to analyze and implement emergency control strategies during air pollution episodes. However, SPAMS performs quantification of number concentration rather than mass concentration and is limited to particles larger than 200 nm, which leads to discrepancies between the two methods. SPAMS measurements can therefore not simply replace traditional filter-based analyses, which needs to be carefully considered in the selection of the monitoring implementation.

Chemical characterization and source apportionment of PM2.5 personal exposure of two cohorts living in urban and suburban Beijing

2019 ◽  
Vol 246 ◽  
pp. 225-236 ◽  
Author(s):  
Jing Shang ◽  
Reza Bashiri Khuzestani ◽  
Jingyu Tian ◽  
James J. Schauer ◽  
Jinxi Hua ◽  
...  
Keyword(s):  
Source Apportionment ◽  
Chemical Characterization ◽  
Personal Exposure

scholarly journals Chemical characterization of fine particular matter in Changzhou, China and source apportionment with offline aerosol mass spectrometry

2016 ◽  
Author(s):  
Zhaolian Ye ◽  
Jiashu Liu ◽  
Aijun Gu ◽  
Feifei Feng ◽  
Yuhai Liu ◽  
...  
Keyword(s):  
Trace Elements ◽  
Organic Matter ◽  
Organic Carbon ◽  
Source Apportionment ◽  
Major Ions ◽  
Chemical Properties ◽  
Chemical Characterization ◽  
Water Soluble ◽  
Traffic Emissions ◽  
Aerosol Mass

Abstract. Knowledge on aerosol chemistry in densely populated regions is critical for reduction of air pollution, while such studies haven't been conducted in Changzhou, an important manufacturing base and polluted city in the Yangtze River Delta (YRD), China. This work, for the first time, performed a thorough chemical characterization on the fine particular matter (PM2.5) samples, collected during July 2015 to April 2016 across four seasons in Changzhou city. A suite of analytical techniques were employed to characterize organic carbon / elemental carbon (OC / EC), water-soluble organic carbon (WSOC), water-soluble inorganic ions (WSIIs), trace elements, and polycyclic aromatic hydrocarbons (PAHs) in PM2.5; in particular, an Aerodyne soot particle aerosol mass spectrometer (SP-AMS) was deployed to probe the chemical properties of water-soluble organic aerosols (WSOA). The average PM2.5 concentrations were found to be 108.3 μg m−3, and all identified species were able to reconstruct ~ 80 % of the PM2.5 mass. The WSIIs occupied about half of the PM2.5 mass (~ 52.1 %), with SO42−, NO3− and NH4+ as the major ions. On average, nitrate concentrations dominated over sulfate (mass ratio of 1.21), indicating influences from traffic emissions. OC and EC correlated well with each other and the highest OC / EC ratio (5.16) occurred in winter, suggesting complex OC sources likely including both secondarily formed and primarily emitted OA. Concentrations of eight trace elements (Mn, Zn, Al, B, Cr, Cu, Fe, Pb) can contribute up to 6.0 % of PM2.5 during winter. PAHs concentrations were also high in winter (140.25 ng m−3), which were predominated by median/high molecular weight PAHs with 5- and 6-rings. The organic matter including both water-soluble and water-insoluble species occupied ~ 20 % PM2.5 mass. SP-AMS determined that the WSOA had an average atomic oxygen-to-carbon (O / C), hydrogen-to-carbon (H / C), nitrogen-to-carbon (N / C) and organic matter-to-organic carbon (OM / OC) ratios of 0.36, 1.54, 0.11, and 1.74, respectively. Source apportionment of WSOA further identified two secondary OA (SOA) factors (a less oxidized and a more oxidized OA) and two primary OA (POA) factors (a nitrogen enriched hydrocarbon-like traffic OA and a cooking-related OA). On average, the POA contribution overweighed SOA (55 % vs. 45 %), indicating the important role of local anthropogenic emissions to the aerosol pollution in Changzhou. Our measurement also shows the abundance of organic nitrogen species in WSOA, and the source analyses suggest these species likely associated with traffic emissions, which warrants more investigations on PM samples from other locations.

scholarly journals A new method for measuring optical scattering properties of atmospherically relevant dusts using the Cloud and Aerosol Spectrometer with Polarization (CASPOL)

2013 ◽  
Vol 13 (3) ◽  
pp. 1345-1356 ◽  
Author(s):  
A. Glen ◽  
S. D. Brooks
Keyword(s):  
Cross Sections ◽  
Atmospheric Aerosols ◽  
Single Particle ◽  
Global Climate ◽  
Optical Scattering ◽  
Measurement Tool ◽  
Optical Signature ◽  
New Instrument ◽  
The Difference ◽  
Atmospherically Relevant

Abstract. Atmospheric aerosols have major impacts on regional and global climate through scattering and absorption of solar radiation. A new instrument, the Cloud and Aerosol Spectrometer with Polarization (CASPOL) from Droplet Measurement Technologies measures light scattered by aerosols in the forward (4° to 12°) and backward (168° to 176°) directions, with an additional polarized detector in the backward direction. Scattering by a single particle can be measured by all three detectors for aerosols in a broad range of sizes, 0.6 μm < diameter < 50 μm. The CASPOL is a unique measurement tool, since unlike most in-situ probes, it can measure optical properties on a particle-by-particle basis. In this study, single particle CASPOL measurements for thirteen atmospherically relevant dusts were obtained and their optical scattering signatures were evaluated. In addition, Scanning Electron Microscopy (SEM) was used to characterize the shape and morphology of each type of dust. The total and polarized backscatter intensities varied with particle size for all dust types. Using a new optical signature technique all but one dust type could be categorized into one of three optical scattering groups. Additionally, a composite method was used to derive the optical signature of Arizona Test Dust (ATD) by combining the signatures of its major components. The derived signature was consistent with the measured signature of ATD. Finally, calculated backscattering cross sections for representative dust from each of the three main groups were found to vary by as much as a factor of 7, the difference between the backscattering cross sections of white quartz (5.3 × 10−10 cm−2) and hematite (4.1 × 10−9 cm−2).

scholarly journals Volatility and hygroscopicity of aging secondary organic aerosol in a smog chamber

2011 ◽  
Vol 11 (22) ◽  
pp. 11477-11496 ◽  
Author(s):  
T. Tritscher ◽  
J. Dommen ◽  
P. F. DeCarlo ◽  
M. Gysel ◽  
P. B. Barmet ◽  
...  
Keyword(s):  
Atmospheric Aerosols ◽  
Volume Fraction ◽  
Chemical Characterization ◽  
Mass Gain ◽  
Heterogeneous Reactions ◽  
Oh Radicals ◽  
Smog Chamber ◽  
Chemical Aging ◽  
Aerosol Mass ◽  
Significant Mass

Abstract. The evolution of secondary organic aerosols (SOA) during (photo-)chemical aging processes was investigated in a smog chamber. Fresh SOA from ozonolysis of 10 to 40 ppb α-pinene was formed followed by aging with OH radicals. The particles' volatility and hygroscopicity (expressed as volume fraction remaining (VFR) and hygroscopicity parameter κ) were measured in parallel with a volatility and hygroscopicity tandem differential mobility analyzer (V/H-TDMA). An aerosol mass spectrometer (AMS) was used for the chemical characterization of the aerosol. These measurements were used as sensitive parameters to reveal the mechanisms possibly responsible for the changes in the SOA composition during aging. A change of VFR and/or κ during processing of atmospheric aerosols may occur either by addition of SOA mass (by condensation) or by a change of SOA composition leading to different aerosol properties. The latter may occur either by heterogeneous reactions on the surface of the SOA particles, by condensed phase reactions like oligomerization or by an evaporation – gas-phase oxidation – recondensation cycle. The condensation mechanism showed to be dominant when there is a substantial change in the aerosol mass by addition of new molecules to the aerosol phase with time. Experiments could be divided into four periods based on the temporal evolution (qualitative changes) of VFR, κ and organic mass: O3 induced condensation, ripening, and OH induced chemical aging first with substantial mass gain and then without significant mass gain. During the O3 induced condensation the particles' volatility decreased (increasing VFR) while the hygroscopicity increased. Thereafter, in the course of ripening volatility continued to decrease, but hygroscopicity stayed roughly constant. After exposing the SOA to OH radicals an OH induced chemical aging with substantial mass gain started resulting in the production of at least 50 % more SOA mass. This new SOA mass was highly volatile and oxidized. This period was then followed by further OH induced chemical aging without significant mass gain leading to a decrease of volatility while hygroscopicity and SOA mass stayed roughly constant.

scholarly journals The real part of the refractive indices and effective densities for chemically segregated ambient aerosols in Guangzhou measured by a single-particle aerosol mass spectrometer

2016 ◽  
Vol 16 (4) ◽  
pp. 2631-2640 ◽  
Author(s):  
Guohua Zhang ◽  
Xinhui Bi ◽  
Ning Qiu ◽  
Bingxue Han ◽  
Qinhao Lin ◽  
...  
Keyword(s):  
Mass Spectrometer ◽  
Atmospheric Aerosols ◽  
Single Particle ◽  
Refractive Indices ◽  
Chemical Compositions ◽  
Aerosol Mass Spectrometer ◽  
The Real ◽  
Aerosol Mass ◽  
Wide Range ◽  
The Impact

Abstract. Knowledge on the microphysical properties of atmospheric aerosols is essential to better evaluate their radiative forcing. This paper presents an estimate of the real part of the refractive indices (n) and effective densities (ρeff) of chemically segregated atmospheric aerosols in Guangzhou, China. Vacuum aerodynamic diameter, chemical compositions, and light-scattering intensities of individual particles were simultaneously measured by a single-particle aerosol mass spectrometer (SPAMS) during the fall of 2012. On the basis of Mie theory, n at a wavelength of 532 nm and ρeff were estimated for 17 particle types in four categories: organics (OC), elemental carbon (EC), internally mixed EC and OC (ECOC), and Metal-rich. The results indicate the presence of spherical or nearly spherical shapes for the majority of particle types, whose partial scattering cross-section versus sizes were well fitted to Mie theoretical modeling results. While sharing n in a narrow range (1.47–1.53), majority of particle types exhibited a wide range of ρeff (0.87–1.51 g cm−3). The OC group is associated with the lowest ρeff (0.87–1.07 g cm−3), and the Metal-rich group with the highest ones (1.29–1.51 g cm−3). It is noteworthy that a specific EC type exhibits a complex scattering curve versus size due to the presence of both compact and irregularly shaped particles. Overall, the results on the detailed relationship between physical and chemical properties benefits future research on the impact of aerosols on visibility and climate.

Chemical characterization of PM10 samples collected simultaneously at a rural and an urban site in the Caribbean coast: Local and long-range source apportionment

2018 ◽  
Vol 192 ◽  
pp. 182-192 ◽  
Author(s):  
Yasser Morera-Gómez ◽  
David Elustondo ◽  
Esther Lasheras ◽  
Carlos Manuel Alonso-Hernández ◽  
Jesús Miguel Santamaría
Keyword(s):  
Source Apportionment ◽  
Long Range ◽  
Chemical Characterization ◽  
Urban Site ◽  
Caribbean Coast ◽  
The Caribbean
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