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| Titel |
Source apportionment of carbonaceous aerosols in a megacity of northwest China: insights from radiocarbon measurement |
| VerfasserIn |
Haiyan Ni, Rujin Huang, Ulrike Dusek |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250148680
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| Publikation (Nr.) |
 EGU/EGU2017-12959.pdf |
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| Zusammenfassung |
| Fine particulate matter (PM2.5) samples were collected from 5 July 2008 to 27 June 2009 at
Xi’an, a very polluted megacity in Northwest China. The 24 h averaged PM2.5concentrations
(ranged from 32 μg m−3 to 339 μg m−3) were 1-14 times higher than the WHO guideline for
24 h PM2.5(25 μg m−3).
In this work, we unambiguously quantify fossil (e.g., vehicle emissions, coal burning etc.)
and non-fossil (e.g., biomass burning, cooking, biogenic emissions etc.) contributions to
organic carbon (OC) and elemental carbon (EC) of PM2.5using radiocarbon (14C)
measurement. In addition, we measured PM2.5 major components and source markers,
including OC and EC, ions, trace elements, polycyclic aromatic hydrocarbons (PAHs),
oxygenated PAHs (o-PAHs), anhydrous sugars and hopanes.
The preliminary results of radiocarbon measurements in OC and EC show that the
annual mean contributions from fossil-fuel combustion to EC was 76 ± 8% (6 ±
2 μg m−3). The remaining 24 ± 8% (2 ± 1 μg m−3) was attributed to biomass
burning, with higher contribution in the cold period (∼33%) compared to the warm
period (∼21%), due to enhanced emissions from local biomass burning activities in
winter. In contrast with EC, OC was dominated by non-fossil sources, with an annual
average of 54 ± 8 % (13 ± 10 μg m−3). Clear seasonal variations were seen in OC
concentrations both from fossil fuel (OCff), and from non-fossil sources (OCnf), with
maxima in the cold period and minima in the warm period, because of enhanced
fossil and non-fossil activities in winter, mainly biomass burning and domestic coal
burning.
Further source apportionment of OC, including primary/secondary fossil OC,
primary/secondary non-fossil OC, will be conducted by combining 14C results with positive
matrix factorization (PMF) analysis of organic matter (OM). |
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