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| Titel |
Dicarboxylic acids, ketocarboxylic acids, α-dicarbonyls, fatty acids and benzoic acid in PM2.5 aerosol collected during CAREBeijing-2007: an effect of traffic restriction on air quality |
| VerfasserIn |
K. F. Ho, R.-J. Huang, K. Kawamura, E. Tachibana, S. C. Lee, S. S. H. Ho, T. Zhu, L. Tian |
| 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 ; 15, no. 6 ; Nr. 15, no. 6 (2015-03-19), S.3111-3123 |
| Datensatznummer |
250119562
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| Publikation (Nr.) |
 copernicus.org/acp-15-3111-2015.pdf |
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| Zusammenfassung |
| Thirty water-soluble organic species, including dicarboxylic acids,
ketocarboxylic acids, α-dicarbonyls, fatty acids and benzoic acid
were determined as well as organic carbon (OC), elemental carbon (EC) and
water-soluble organic carbon (WSOC) in PM2.5 samples collected during
the Campaign of Air Quality Research in Beijing 2007 (CAREBeijing-2007) in
the urban and suburban areas of Beijing. The objective of this study is to
identify the influence of traffic emissions and regional transport to the
atmosphere in Beijing during summer. PM2.5 samples collected with or
without traffic restriction in Beijing are selected to evaluate the
effectiveness of local traffic restriction measures on air pollution
reduction. The average concentrations of the total quantified bifunctional
organic compounds (TQBOCs), total fatty acids and benzoic acid during the
entire sampling period were 1184±241, 597±159
and 1496±511 ng m−3 in Peking University (PKU), and 1050±303,
475±114 and 1278±372 ng m−3 in
Yufa, Beijing. Oxalic acid (C2) was found as the most abundant dicarboxylic acid
at PKU and Yufa followed by phthalic acid (Ph). A strong even carbon number
predominance with the highest level at stearic acid (C18:0), followed
by palmitic acid (C16:0) was found for fatty acids. According to the
back trajectories modeling results, the air masses were found to originate
mainly from the northeast, passing over the southeast or south of Beijing (heavily
populated, urbanized and industrialized areas), during heavier pollution
events, whereas they are mainly from the north or northwest sector (mountain
areas without serious anthropogenic pollution sources) during less pollution
events. The data with wind only from the same sector (minimizing the
difference from regional contribution) but with and without traffic
restriction in Beijing were analyzed to evaluate the effectiveness of local
traffic restriction measures on the reduction of local air pollution in
Beijing. The results suggested that the traffic restriction measures can
reduce the air pollutants, but the decrease of pollutants is generally
smaller in Yufa compared to that in PKU. Moreover, an enhancement of
EC value indicates more elevated primary emissions in Yufa
during restriction periods than in non-restriction periods. This study
demonstrates that even when primary exhaust was controlled by traffic
restriction, the contribution of secondary organic species formed from
photochemical processes was critical with long-range atmospheric transport
of pollutants. |
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