在线阅读

在线阅读

Partic. vol. 35 pp. 1-9 (December 2017)
doi: 10.1016/j.partic.2017.05.001

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

Issariya Vejpongsaa, Sirikalaya Suvachittanonta, Natsuda Klinklana, Thunyapat Thongyenb, Miklos Veresc, Wladyslaw W. Szymanskia, d, *

Show more

w.szym@univie.ac.at

Highlights

    • Separation of PM1 and PM2.5-1 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 PM2.5 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 PM2.5 size fraction at PM1 may deliver a more sensible indication of the actual air quality than the current standard of monitoring PM2.5. We found substantial differences relating to this split. PM2.5 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 PM2.5-1 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 PM2.5 fraction into PM1 and PM2.5-1 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