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| Titel |
Chemical characterization and source apportionment of PM2.5 in Beijing: seasonal perspective |
| VerfasserIn |
R. Zhang, J. Jing, J. Tao, S.-C. Hsu, G. Wang, J. Cao, C. S. L. Lee, L. Zhu, Z. Chen, Y. Zhao, Z. Shen |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7316
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 13, no. 14 ; Nr. 13, no. 14 (2013-07-25), S.7053-7074 |
| Datensatznummer |
250018780
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| Publikation (Nr.) |
 copernicus.org/acp-13-7053-2013.pdf |
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| Zusammenfassung |
| In this study, 121 daily PM2.5 (aerosol particle with aerodynamic
diameter less than 2.5 μm) samples were collected from an urban site in
Beijing in four months between April 2009 and January 2010 representing the
four seasons. The samples were determined for various compositions,
including elements, ions, and organic/elemental carbon. Various approaches,
such as chemical mass balance, positive matrix factorization (PMF),
trajectory clustering, and potential source contribution function (PSCF),
were employed for characterizing aerosol speciation, identifying likely
sources, and apportioning contributions from each likely source. Our results
have shown distinctive seasonality for various aerosol speciations
associated with PM2.5 in Beijing. Soil dust waxes in the spring and
wanes in the summer. Regarding the secondary aerosol components, inorganic
and organic species may behave in different manners. The former
preferentially forms in the hot and humid summer via photochemical
reactions, although their precursor gases, such as SO2 and NOx,
are emitted much more in winter. The latter seems to favorably form in the
cold and dry winter. Synoptic meteorological and climate conditions can
overwhelm the emission pattern in the formation of secondary aerosols. The
PMF model identified six main sources: soil dust, coal combustion, biomass
burning, traffic and waste incineration emission, industrial pollution, and
secondary inorganic aerosol. Each of these sources has an annual mean
contribution of 16, 14, 13, 3, 28, and 26%,
respectively, to PM2.5. However, the relative contributions of these
identified sources significantly vary with changing seasons. The results of
trajectory clustering and the PSCF method demonstrated that regional sources
could be crucial contributors to PM pollution in Beijing. In conclusion, we
have unraveled some complex aspects of the pollution sources and formation
processes of PM2.5 in Beijing. To our knowledge, this is the
first systematic study that comprehensively explores the chemical
characterizations and source apportionments of PM2.5 aerosol speciation
in Beijing by applying multiple approaches based on a completely seasonal
perspective. |
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