 |
| Titel |
Molecular characterization of urban organic aerosol in tropical India: contributions of primary emissions and secondary photooxidation |
| VerfasserIn |
P. Q. Fu, K. Kawamura, C. M. Pavuluri, T. Swaminathan, J. Chen |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 10, no. 6 ; Nr. 10, no. 6 (2010-03-19), S.2663-2689 |
| Datensatznummer |
250008249
|
| Publikation (Nr.) |
 copernicus.org/acp-10-2663-2010.pdf |
|
|
|
|
|
| Zusammenfassung |
| Organic molecular composition of PM10 samples, collected at Chennai in
tropical India, was studied using capillary gas chromatography/mass
spectrometry. Fourteen organic compound classes were detected in the
aerosols, including aliphatic lipids, sugar compounds, lignin products,
terpenoid biomarkers, sterols, aromatic acids, hydroxy-/polyacids, phthalate
esters, hopanes, Polycyclic Aromatic Hydrocarbons (PAHs), and photooxidation
products from biogenic Volatile Organic Compounds (VOCs). At daytime,
phthalate esters were found to be the most abundant compound class; however,
at nighttime, fatty acids were the dominant one. Di-(2-ethylhexyl)
phthalate, C16 fatty acid, and levoglucosan were identified as the most
abundant single compounds. The nighttime maxima of most organics in the
aerosols indicate a land/sea breeze effect in tropical India, although some
other factors such as local emissions and long-range transport may also
influence the composition of organic aerosols. However, biogenic VOC
oxidation products (e.g., 2-methyltetrols, pinic acid, 3-hydroxyglutaric
acid and β-caryophyllinic acid) showed diurnal patterns with daytime
maxima. Interestingly, terephthalic acid was maximized at nighttime, which
is different from those of phthalic and isophthalic acids. A positive
relation was found between 1,3,5-triphenylbenzene (a tracer for plastic
burning) and terephthalic acid, suggesting that the field burning of
municipal solid wastes including plastics is a significant source of
terephthalic acid. Organic compounds were further categorized into several
groups to clarify their sources. Fossil fuel combustion (24–43%) was
recognized as the most significant source for the total identified
compounds, followed by plastic emission (16–33%), secondary oxidation
(8.6–23%), and microbial/marine sources (7.2–17%). In contrast, the
contributions of terrestrial plant waxes (5.9–11%) and biomass burning
(4.2–6.4%) were relatively small. This study demonstrates that, in
addition to fossil fuel combustion and biomass burning, the open-burning of
plastics in urban area also contributes to the organic aerosols in South
Asia. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|