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| Titel |
Hygroscopic behavior of atmospherically relevant water-soluble carboxylic salts and their influence on the water uptake of ammonium sulfate |
| VerfasserIn |
Z. J. Wu, A. Nowak, L. Poulain, H. Herrmann, A. Wiedensohler |
| 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 ; 11, no. 24 ; Nr. 11, no. 24 (2011-12-15), S.12617-12626 |
| Datensatznummer |
250010268
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| Publikation (Nr.) |
 copernicus.org/acp-11-12617-2011.pdf |
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| Zusammenfassung |
| The hygroscopic behavior of atmospherically relevant water-soluble
carboxylic salts and their effects on ammonium sulfate were investigated
using a hygroscopicity tandem differential mobility analyzer (H-TDMA). No
hygroscopic growth is observed for disodium oxalate, while ammonium oxalate
shows slight growth (growth factor = 1.05 at 90%). The growth factors at
90% RH for sodium acetate, disodium malonate, disodium succinate,
disodium tartrate, diammonium tartrate, sodium pyruvate, disodium maleate,
and humic acid sodium salt are 1.79, 1.78, 1.69, 1.54, 1.29, 1.70, 1.78, and
1.19, respectively. The hygroscopic growth of mixtures of organic salts with
ammonium sulfate, which are prepared as surrogates of atmospheric aerosols,
was determined. A clear shift in deliquescence relative humidity to lower RH
with increasing organic mass fraction was observed for these mixtures. Above
80% RH, the contribution to water uptake by the organic salts was close to
that of ammonium sulfate for the majority of investigated compounds. The
observed hygroscopic growth of the mixed particles at RH above the
deliquescence relative humidity of ammonium sulfate agreed well with that
predicted using the Zdanovskii-Stokes-Robinson (ZSR) mixing rule. Mixtures
of ammonium sulfate with organic salts are more hygroscopic than mixtures
with organic acids, indicating that neutralization by gas-phase ammonia
and/or association with cations of dicarbonxylic acids may enhance the
hygroscopicity of the atmospheric particles. |
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