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| Titel |
Sources of humic-like substances in the Pearl River Delta, China: positive matrix factorization analysis of PM2.5 major components and source markers |
| VerfasserIn |
B. Y. Kuang, P. Lin, X. H. H. Huang, 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 ; 15, no. 4 ; Nr. 15, no. 4 (2015-02-24), S.1995-2008 |
| Datensatznummer |
250119455
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| Publikation (Nr.) |
 copernicus.org/acp-15-1995-2015.pdf |
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| Zusammenfassung |
| Humic-like substances (HULIS), the hydrophobic part of water-soluble organic
carbon (WSOC), account for a significant fraction of PM2.5 mass. Their
source studies are so far largely qualitative. In this study, HULIS and WSOC
were determined in 100 PM2.5 samples collected in 2009 at an urban site
(Guangzhou) and a suburban site (Nansha) in the Pearl River Delta in South
China. The annual average concentration of HULIS was 4.83 and
4.71 μg m−3, constituting 8.5 and 10.2% of the PM2.5 mass, while
HULIS-C (the carbon component of HULIS) contributed 48 and 57% of
WSOC at the two sites, respectively. HULIS were found to correlate with
biomass burning (BB) tracers (i.e., levoglucosan and K) and secondary
species (e.g., SO42− and NH4+), suggesting its
association with BB emissions and secondary formation processes. Sources of
HULIS were investigated using positive matrix factorization analysis of
PM2.5 chemical composition data, including major components and
source markers. In addition to secondary formation process and BB emissions,
residual oil combustion related to shipping was identified for the first
time as a significant source of HULIS. Secondary formation process
contributed the most, accounting for 49–82% of ambient HULIS at the two
sites in different seasons. BB emissions contributed a seasonal average of
8–28%, with more contributions observed in the winter months
(November–February) due to crop residue burning during harvest season.
Residual oil combustion was revealed to be an important source at the
suburban site in summer (44% of HULIS-C) due to its proximity to one of
the ports and the shipping lane in the region. Vehicle emissions were found
to contribute little to HULIS, but had contributions to the hydrophilic WSOC
fraction. The contrast in contributions from different combustion sources to
HULIS and hydrophilic WSOC suggests that primary sources of HULIS are linked
to inefficient combustion. This source analysis suggests further study of
HULIS be focused on secondary formation process and source characteristics
of HULIS from BB and residual oil combustion. |
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