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Secondary formation and source analysis of carbonaceous components in PM1 in a typical city, Southwest of China.
- Source :
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Atmospheric Environment . Apr2023, Vol. 299, pN.PAG-N.PAG. 1p. - Publication Year :
- 2023
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Abstract
- Carbonaceous components are major components of PM 1 , which have a significant impact on climate change, air quality and human health. However, the secondary formation and source analysis of carbonaceous components in PM 1 are still unclear. Therefore, in order to study the secondary formation and sources of carbonaceous components in PM 1 , PM 1 samples were collected in Chengdu, a typical city located in southwest of China, from 2018 to 2019. The concentrations of organic carbon (OC), elemental carbon (EC) and isotopic compositions of carbon (δ13C) in PM 1 were determined using a thermal/optical carbon analyzer and elemental analyzer-isotope ratio mass spectrometer. In addition, the δ13C values from relevant potential sources (C3 plants, C4 plants, vehicle exhaust and coal) were also determined. The results showed that the annual average concentrations of OC and EC in PM 1 in Chengdu were 6.43 ± 3.30 μg·m−3 and 1.99 ± 0.98 μg·m−3, accounting for 13.83% and 4.28% of the PM 1 mass concentration, respectively. The concentrations of OC in PM 1 ranked in the order of winter > summer > spring > autumn, while the concentrations of EC varied in the order of winter > spring > autumn > summer. The concentrations of OC and EC in PM 1 reached the maximum in winter, mainly due to the special meteorological conditions and significantly higher pollutant emissions. The correlations of OC and EC were higher in spring, autumn and winter, and lower in summer. It showed that OC and EC might have the same sources in spring, autumn and winter, while the sources of OC and EC were relatively complex in summer. The annual average concentration of secondary organic carbon (SOC) in PM 1 was 2.23 ± 1.22 μg·m−3. The concentrations of SOC were higher in autumn and winter and lower in spring and summer. The special meteorological conditions and significantly higher pollutant emissions are important reasons for the higher SOC concentrations in winter. On the other hand, the low temperature in winter can also promote the formation of SOC. The results of carbon isotopic compositions indicated that the carbonaceous components in PM 1 were mainly derived from vehicle exhaust (52.4%), C3 plants combustion (26.2%), coal burning (16.2%) and C4 plants combustion (5.2%). The findings help to deepen the understanding of the secondary formation and sources of carbonaceous components in PM 1 and provide theoretical guidance for environmental management. [Display omitted] • The concentrations of OC and EC in PM 1 reached the maximum in winter. • OC and EC might have the same sources in spring, autumn and winter. • The concentrations of SOC were higher in autumn and winter. • The contribution ratios of vehicle exhaust exceeded 50% in all four seasons. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 13522310
- Volume :
- 299
- Database :
- Academic Search Index
- Journal :
- Atmospheric Environment
- Publication Type :
- Academic Journal
- Accession number :
- 162177733
- Full Text :
- https://doi.org/10.1016/j.atmosenv.2023.119671