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| Titel |
Characteristics of atmospheric mercury deposition and size-fractionated particulate mercury in urban Nanjing, China |
| VerfasserIn |
J. Zhu, T. Wang, R. Talbot, H. Mao, X. Yang, C. Fu, J. Sun, B. Zhuang, S. Li, Y. Han, M. Xie |
| 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 ; 14, no. 5 ; Nr. 14, no. 5 (2014-03-03), S.2233-2244 |
| Datensatznummer |
250118456
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| Publikation (Nr.) |
 copernicus.org/acp-14-2233-2014.pdf |
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| Zusammenfassung |
| A comprehensive measurement study of mercury wet deposition and
size-fractionated particulate mercury (HgP) concurrent with
meteorological variables was conducted from June 2011 to February 2012 to
evaluate the characteristics of mercury deposition and particulate mercury
in urban Nanjing, China. The volume-weighted mean (VWM) concentration of
mercury in rainwater was 52.9 ng L−1 with a range of 46.3–63.6 ng L−1.
The wet deposition per unit area was averaged 56.5 μg m−2 over
9 months, which was lower than that in most Chinese cities, but much
higher than annual deposition in urban North America and Japan. The wet deposition
flux exhibited obvious seasonal variation strongly linked with the amount of
precipitation. Wet deposition in summer contributed more than 80% to the
total amount. A part of contribution to wet deposition of mercury from
anthropogenic sources was evidenced by the association between wet
deposition and sulfates, as well as nitrates in rainwater. The ions correlated most
significantly with mercury were formate, calcium, and potassium, which
suggested that natural sources including vegetation and resuspended soil
should be considered as an important factor to affect the wet deposition of
mercury in Nanjing. The average HgP concentration was 1.10 ± 0.57 ng m−3.
A distinct seasonal distribution of HgP concentrations was
found to be higher in winter as a result of an increase in the PM10
concentration. Overall, more than half of the HgP existed in the particle
size range less than 2.1 μm. The highest concentration of HgP in
coarse particles was observed in summer, while HgP in fine particles
dominated in fall and winter. The size distribution of averaged mercury
content in particulates was bimodal, with two peaks in the bins of < 0.7 μm
and 4.7–5.8 μm. Dry deposition per unit area of HgP was
estimated to be 47.2 μg m−2 using meteorological conditions and
a size-resolved particle dry deposition model. This was 16.5% less than
mercury wet deposition. Compared to HgP in fine particles, HgP in
coarse particles contributed more to the total dry deposition due to higher
deposition velocities. Negative correlation between precipitation and the
HgP concentration reflected the effect of scavenging of HgP by
precipitation. |
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