Ultrafine Particles and PM2.5 at Three Urban Air Monitoring Stations in Northern Taiwan from 2011 to 2013

Lin, Guan-Bo; Lee, Guo Rui; Lin, Sih Fan; Hung, Yi Hung; Li, Shih Wei; Wu, Guo Jei; Ye, Huajun; Huang, Wei; Tsai, Chuen-Tinn

doi:10.4209/aaqr.2015.04.0271

Cited by 17 publications

(6 citation statements)

References 49 publications

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“…Previous study (Lin et al, 2015) in other megacities reported that 𝜒 of all particles was around 2 with Da at around 100 nm which is close to our results. Previous measurements (Zhang et al, 2016) transform to be more spherical-like by acquiring more secondary species (Ahern et al, 2016).…”

Section: Size-resolved Particle Morphologysupporting

confidence: 93%

Aerodynamic size-resolved composition and cloud condensation nuclei properties of aerosols in Beijing suburban region

Liu

Kang

et al. 2021

Preprint

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Abstract. The size-resolved physiochemical properties of aerosols determine their atmospheric lifetime, cloud interactions, and the deposition rate on human respiratory system, however most atmospheric composition studies tend to evaluate these properties in bulk. This study investigated size-resolved constituents of aerosols on mass and number basis, and their droplet activation properties, by coupling a suite of online measurements with an aerosol aerodynamic classifier (AAC) based on aerodynamic diameter (Da) in Pinggu, a suburb of Beijing. While organic matter accounted for a large fraction of mass, a higher contribution of particulate nitrate at larger sizes (Da > 300 nm) was found under polluted cases. By applying the mixing state of refractory black carbon containing particles (rBCc) and composition-dependent densities, aerosols including rBCc were confirmed nearly spherical at Da > 300 nm. Importantly, the number fraction of rBCc was found to increase with Da at all pollution levels. The number fraction of rBC is found to increase from ~3 % at ~90 nm to ~15 % at ~1000 nm, and this increasing rBC number fraction may be caused by the coagulation during atmospheric aging. The droplet activation diameter at a water supersaturation of 0.2 % was 112 ± 6 nm and 193 ± 41 nm for all particles with Da smaller than 1 μm (PM1) and rBCc respectively. As high as 52 ± 6 % of rBCc and 50 ± 4 % of all PM1 particles in number could be activated under heavy pollution due to enlarged particle size, which could be predicted by applying the volume-mixing of substance hygroscopicity within rBCc. As rBCc contributes to the quantity of aerosols at larger particle size, these thickly coated rBC may contribute to the radiation absorption significantly or act as an important source of cloud condensation nuclei (CCN). This size regime may also exert important health effects due to their higher deposition rate.

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Section: Size-resolved Particle Morphologysupporting

confidence: 93%

Aerodynamic size-resolved composition and cloud condensation nuclei properties of aerosols in Beijing suburban region

Liu

Kang

et al. 2021

Preprint

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“…It was justified by the need to separate local pollution sources, such as traffic, heating, or industrial emissions, which are also capable of generating nano-sized particles. Local pollution sources are very pertinent in a city, because vehicles generate large amounts of ultrafine particles (Wahlin et al, 2001;Gidhagen et al, 2005;Monkkönen et al, 2005;Lin et al, 2015) all over the city. Heating and industrial sources also generate large amounts of ultrafine particles.…”

Section: Discussionmentioning

confidence: 99%

Relationship between UV Energy and Formation of Secondary Particles in Santiago de Chile

Gramsch

Soto

Oyola³

et al. 2020

Aerosol Air Qual. Res.

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Despite reduction efforts, the concentration of PM 2.5 (particulate matter ≤ 2.5 µm in diameter) has remained steady or even grown slightly in Santiago, Chile, over the last few years. However, this potential increase may be due to the formation of secondary particles rather than a rise in primary emissions. Therefore, this study measured the size distribution of particulate matter with an Electrical Low Pressure Impactor (ELPI; Dekati) to investigate the generation of secondary ultrafine particles at several sites in this metropolitan area during 2013 and 2018. Little formation was detected during winter, but more activity was observed during fall, and the highest generation of these particles was found during summer, when the number of new particles between 10 and 20 nm in diameter displayed an obvious peak in the afternoon during periods of high solar radiation. Overall, no clear relationship was discerned between the secondary particle number and the UV radiation until the latter exceeded ~4.5 kJ m -2 , when an almost linear correlation (R 2 = 0.739) appeared. Additionally, the particle number exhibited a much lower correlation with the total solar energy, indicating that UV solar radiation plays the major role in ultrafine particle formation. However, these trends may only apply to polluted cities, which already contain elevated particulate matter concentrations. Also, the fact that secondary formation primarily occurs in Santiago during summer, when the PM 2.5 level is low, confirms that large numbers of pre-existing particles inhibit the creation of new ones.

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“…et al, 2014;Liu C.N. et al, 2015) and ultrafine particles (Chen S.C. et al, 2010a;Chen S.C. et al, 2010b), long-term measurement for PM 2.5 and ultrafine particles mass concentrations (Lin G.Y. et al, 2015), and the measurement of PM 10 , PM 2.5 and PM 0.1 for source characterization and apportionment (Gugamsetty B. et al, 2012).…”

Section: Application Of Inertial Impactorsmentioning

confidence: 99%

“…To determine the compliance with NAAQS, it is often desirable to fractionate particles into two size fractions simultaneously, one corresponding to the coarse particle mode (> 2.5 μm) and one corresponding to the fine particle mode (≤ 2.5 μm). The virtual impactor is very suitable for this application (Lin G.Y. et al, 2015;Landis M.S.…”

Section: The Inlet For Two Size Fractionsmentioning

confidence: 99%

Inertial Impaction Technique for the Classification of Particulate Matters and Nanoparticles: A Review

Tsai

2021

KONA

Self Cite

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Inertial impactors are applied widely to classify particulate matters (PMs) and nanoparticles (NPs) with desired aerodynamic diameters for further analyses due to their sharp cutoff characteristics, simple design, easy operation, and high collection ability. A few hundred papers have been published since the 1860s that addressed the characteristics and applications of the inertial impactors. In the last 30 years, our group has also carried out lots of studies to contribute to the design and the improvement of inertial impactors. With our understanding of inertial impactors, this article reviews previous studies of some typical types of the inertial impactors including conventional impactors, cascade impactors, and virtual impactors and the parameters for design consideration of these devices. The article also reviews some applications of the inertial impactors, which are mass concentration measurement, mass and number distribution measurement, personal exposure measurement, particulate matter control, and powder classification. The synthesized knowledge of the inertial impactor in this study can help researchers to design an inertial impactor with an accurate cutoff diameter, a sharp collection efficiency curve, and no particle bounce and particle overloading effects for long-term use for PM classification and control purposes.

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Ultrafine Particles and PM2.5 at Three Urban Air Monitoring Stations in Northern Taiwan from 2011 to 2013

Cited by 17 publications

References 49 publications

Aerodynamic size-resolved composition and cloud condensation nuclei properties of aerosols in Beijing suburban region

Aerodynamic size-resolved composition and cloud condensation nuclei properties of aerosols in Beijing suburban region

Relationship between UV Energy and Formation of Secondary Particles in Santiago de Chile

Inertial Impaction Technique for the Classification of Particulate Matters and Nanoparticles: A Review

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