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| Titel |
X-ray fluorescence mapping of mercury on suspended mineral particles and diatoms in a contaminated freshwater system |
| VerfasserIn |
B. Gu, B. Mishra, C. Miller, W. Wang, B. Lai, S. C. Brooks, K. M. Kemner, L. Liang |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1726-4170
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| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 11, no. 18 ; Nr. 11, no. 18 (2014-09-30), S.5259-5267 |
| Datensatznummer |
250117616
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| Publikation (Nr.) |
 copernicus.org/bg-11-5259-2014.pdf |
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| Zusammenfassung |
| Mercury (Hg) bioavailability and geochemical cycling is affected by its
partitioning between the aqueous and particulate phases. We applied a
synchrotron-based X-ray fluorescence (XRF) microprobe to visualize and
quantify directly the spatial localization of Hg and its correlations with
other elements of interest on suspended particles from a Hg-contaminated
freshwater system. Up to 175 μg g−1 Hg is found on suspended
particles, but less than 0.01% is in the form of methylmercury. Mercury
is heterogeneously distributed among phytoplankton (e.g., diatoms) and
mineral particles that are rich in iron oxides and natural organic matter
(NOM). The diatom-bound Hg is mostly found on outer surfaces of the cells,
suggesting passive sorption of Hg on diatoms. Our results indicate that
localized sorption of Hg onto suspended particles, including diatoms and
NOM-coated oxide minerals, may play an important role in affecting the
partitioning, reactivity, and biogeochemical cycling of Hg in natural aquatic
environments. |
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