Natural organic matter and iron export from the Tanner Moor, Austria

Author(s)
Franz Jirsa, Elisabeth Neubauer, Richard Kittinger, Thilo Hofmann, Regina Krachler, Frank von der Kammer, Bernhard Keppler
Abstract

Samples from a pristine raised peat bog runoff in Austria, the Tannermoor creek, were analysed for their iron linked to natural organic matter (NOM) content. Dissolved organic carbon <0.45 mu m (DOC) was 41-64 mg L-1, iron 4.4-5.5 mg L-1. Samples were analysed applying asymmetric field flow fractionation (AsFIFFF) coupled to UV-vis absorption, fluorescence and inductively coupled plasma mass spectrometry (ICP-MS). The samples showed an iron peak associated with the NOM peak, one sample exhibiting a second peak of iron independent from the NOM peak. As highland peat bogs with similar climatic conditions and vegetation to the Tanner Moor are found throughout the world, including areas adjacent to the sea, we examined the behaviour of NOM and iron in samples brought to euhaline (35%.) conditions with artificial sea salt. The enhanced ionic strength reduced NOM by 53% and iron by 82%. Size exclusion chromatography (SEC) of the samples at sea-like salinity revealed two major fractions of NOM associated with different iron concentrations. The larger one, eluting sharply after the upper exclusion limits of 4000-5000 g mol(-1), seems to be most important for iron chelating. The results outline the global importance of sub-mountainous and mountainous raised peat bogs as a source of iron chelators to the marine environment at sites where such peat bogs release their run-offs into the sea.

Organisation(s)
Department of Inorganic Chemistry
Journal
Limnologica
Volume
43
Pages
239-244
No. of pages
6
ISSN
0075-9511
DOI
https://doi.org/10.1016/j.limno.2012.09.006
Publication date
06-2013
Peer reviewed
Yes
Austrian Fields of Science 2012
104002 Analytical chemistry, 104023 Environmental chemistry
Sustainable Development Goals
SDG 14 - Life Below Water
Portal url
https://ucrisportal.univie.ac.at/en/publications/natural-organic-matter-and-iron-export-from-the-tanner-moor-austria(c5ce6f57-895c-4dea-bad7-da5fcbe60628).html