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| Titel |
Spectroscopic characterization of porewater and water-extractable organic matter along a peat bog profile |
| VerfasserIn |
C. Zaccone, V. D'Orazio, T. M. Miano |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250019375
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| Zusammenfassung |
| The aim of the present study was to identify and compare chemical, physical and
spectroscopic features of porewaters and corresponding water-extractable organic matter
(WEOM) samples taken from a 105 cm ombrotrophic peat bog profile. The peat core was
collected in 2005 from a Swiss bog and divided into 91 slices of 1 cm of thickness. Extracted
porewater samples were filtered (0.45 μm), analyzed for pH and dissolved organic
carbon (DOC) concentration and characterized by means of UV-Vis (E4/E6 ratio) and
fluorescence spectroscopies. The same analyses were carried out also on the WEOM of
peat.
Spectroscopic data underline that DOCwe presents a more aromatic character, a higher
molecular weight, a higher degree of polycondensation and extent of conjugated fluorophore
systems, and thus a more “humic” character with respect to porewater samples.
Furthermore, E4/E6 values slightly increase with depth thus indicating that the organic
matter of both porewaters and WEOM samples is characterized by a decreasing in
aromaticity, molecular weights and degree of polycondensation throughout the
profile.
Moreover, although DOC generally represents the most active and mobile form of the
organic matter, the significant correlations between DOCpw with both DOCwe (R2 = 0.81,
p |
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