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| Titel |
Humic-like substances in fresh emissions of rice straw burning and in ambient aerosols in the Pearl River Delta Region, China |
| VerfasserIn |
P. Lin, G. Engling, J. Z. Yu |
| 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 ; 10, no. 14 ; Nr. 10, no. 14 (2010-07-16), S.6487-6500 |
| Datensatznummer |
250008630
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| Publikation (Nr.) |
 copernicus.org/acp-10-6487-2010.pdf |
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| Zusammenfassung |
| HUmic-LIke Substances (HULIS) are an abundant unresolved mixture of organic
compounds present in atmospheric samples. Biomass burning (BB) has been
recognized as an important primary source of HULIS, but measurements of
HULIS in various fresh BB particles are lacking. In this work, HULIS in
emissions of rice straw burning was measured in a number of field and
chamber experiments. The average HULIS/OC ratio was 0.34±0.05 in
μg/μgC, showing small variance among emissions under different burning
conditions. The influence of BB on ambient HULIS levels was investigated by
examining the spatial and temporal variation of HULIS and other aerosol
constituents and interspecies relations in ambient PM2.5. The
PM2.5 samples were collected at an urban and a suburban location in the
Pearl River Delta (PRD), China over a period of one year. The HULIS
concentrations in the ambient PM2.5 were significantly higher in air
masses originating from regions influenced by BB. Significant correlations
between HULIS and water-soluble K+ concentrations at both sites further
support that BB was an important source of HULIS. Ambient concentrations of
HULIS also correlated well with those of sulfate, oxalate, and oxidant (the
sum of O3 and NO2). The HULIS/OC ratios in BB-influenced ambient
aerosols (~0.6) were much higher than those in the fresh BB emissions
(0.34), implying that secondary formation was also an important source of
HULIS in the atmosphere. The annual average HULIS concentrations were 4.9 μg m−3
at the urban site and 7.1 μg m−3 at the suburban
site while the annual average concentrations of elemental carbon were 3.3 μg m−3 and
2.4 μg m−3, respectively. The urban-suburban
spatial gradient of HULIS was opposite to that of elemental carbon, negating
vehicular exhaust as a significant primary emission source of HULIS. |
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