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| Titel |
The exchange of SVOCs across the air-sea interface in Singapore's coastal environment |
| VerfasserIn |
J. He, R. Balasubramanian |
| 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. 4 ; Nr. 10, no. 4 (2010-02-17), S.1837-1852 |
| Datensatznummer |
250008119
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| Publikation (Nr.) |
 copernicus.org/acp-10-1837-2010.pdf |
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| Zusammenfassung |
| Coastal areas are vulnerable to the accumulation of semivolatile organic
compounds, such as PAHs, OCPs and PCBs from atmospheric inputs. Dry
particulate and wet depositions, and air-water diffusive exchange in the
Singapore's south coastal area, where most of chemical and oil refinery
industries are situated in, were estimated. Based on a yearly dataset, the
mean annual dry particulate deposition fluxes of ∑16-PAHs, ∑7 OCPs and ∑21 PCBs
were 1328.8±961.1 μg m−2 y−1,
5421.4±3426.7 ng m−2 y−1 and 811.8±578.3 ng m−2 y−1, and the wet deposition of ∑16-PAHs
and ∑7 OCPs were 6667.1±1745.2 and 115.4±98.3 μg m−2 y−1,
respectively. Seasonal variation of atmospheric
depositions was influenced by meteorological conditions. Air-water gas
exchange fluxes were shown to be negative values for PAHs, HCHs and DDXs,
indicating Singapore's south coast as a sink for the above-mentioned SVOCs.
The relative contribution of each depositional process to the total
atmospheric input was assessed by annual fluxes. The profile of dry
particulate deposition, wet deposition and gas exchange fluxes seemed to be
correlated with individual pollutant's properties such as molecular weight
and Henry's law constant, etc. For the water column partitioning, the
organic carbon-normalized partition coefficients between particulate and
dissolved phases (KOC) for both PAHs and OCPs were obtained. The
relationships between KOC of PAHs and OCPs and their respective
octanol-water partition coefficient (KOW) were examined. In addition,
both adsorption onto combustion-derived soot carbon and absorption into
natural organic matter for PAHs in marine water column were investigated.
Enrichment factors in the sea-surface microlayer (SML) of the particulate
phase were 1.2–7.1 and 3.0–4.9 for PAHs and OCPs, and those
of dissolved phase were 1.1–4.9 and 1.6–4.2 for PAHs and
OCPs, respectively. These enrichment factors are relatively higher than
those reported for nearby coastal areas, which are most likely due to more
organic surfactants floating in the south coastal surface of Singapore. |
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