Deliberation between PM1 and PM2.5 as air quality indicators based on comprehensive characterization of urban aerosols in Bangkok, Thailand--颗粒学报PARTICUOLOGY

Vejpongsa, I., Suvachittanont, S., Klinklan, N., Thongyen, T., Veres, M., & Szymanski, W. W. (2017). Deliberation between PM1 and PM2.5 as air quality indicators based on comprehensive characterization of urban aerosols in Bangkok, Thailand. Particuology, 35, 1-9. https://doi.org/10.1016/j.partic.2017.05.001

Deliberation between PM₁ and PM_2.5 as air quality indicators based on comprehensive characterization of urban aerosols in Bangkok, Thailand

Issariya Vejpongsa ^a, Sirikalaya Suvachittanont ^a, Natsuda Klinklan ^a, Thunyapat Thongyen ^b, Miklos Veres ^c, Wladyslaw W. Szymanski ^{a d *}

a Department of Chemical Engineering, Kasetsart University, Bangkok, Thailand
b Kasetsart University, Bangkok, Thailand
c Wigner Centre for Physics of the Hungarian Academy of Sciences, Budapest, Hungary
d Faculty of Physics, University of Vienna, Vienna, Austria

10.1016/j.partic.2017.05.001

Volume 35, December 2017, Pages 1-9

Received 29 December 2016, Revised 17 May 2017, Accepted 18 May 2017, Available online 18 July 2017, Version of Record 30 November 2017.

E-mail: w.szym@univie.ac.at

Highlights

• Separation of PM₁ and PM_2.5–1 showed evident differences regarding their quantity and composition.

• Ratios of various carbonaceous compounds in PM-fractions indicated the benefit of PM₁ sampling.

• Results suggest that PM₁ measurement together with PM_2.5 mirrored better the actual air pollution.

• Elevated sampling air temperatures (>50 °C) influenced mass concentration of PM₁ fraction.

Abstract

Urban ambient aerosols in the size range below 10 μm were measured and sampled for further evaluation (by Raman and Thermal-Optical analysis) of the collected material. The presented data shows that monitoring number and/or surface area concentrations besides the mass concentration provides valuable information for a meaningful assessment of the actual ambient air quality. The aim of the study was to characterize the urban aerosols using various instruments, methods, and sampling conditions, and to determine whether a split of the PM_2.5 size fraction at PM₁ may deliver a more sensible indication of the actual air quality than the current standard of monitoring PM_2.5. We found substantial differences relating to this split. PM_2.5 data frequently include particles from both mechanical and combustion processes. PM₁ measurements can be used to better distinguish particles derived from these two sources. We measured number concentrations of PM₁ with PM_2.5–1 concurrently with particle mass concentration and found that the typical average particle diameter by mass in the urban aerosols investigated was in the range of 120 nm; this corresponded well with the particle number size distributions measured in real time. Raman spectral analysis and thermal-optical evaluation of the sampled material also suggested that it would be sensible to split the measurement of the PM_2.5 fraction into PM₁ and PM_2.5–1 size fractions, especially for analysis of carbonaceous aerosol components using the DRI thermal/optical reflectance carbon analysis system

Graphical abstract

Keywords

Urban aerosol; PM-fractions; Carbonaceous particles; Raman spectroscopy; Thermal-optical analysis

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