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| Titel |
Modeling of microbiological growth in the capillary fringe |
| VerfasserIn |
Pavel Hron, Peter Bastian, Olaf Ippisch, Daniel Jost |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250078347
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| Zusammenfassung |
| The capillary fringe (CF) is a highly dynamic soil zone, which is located above the
groundwater level. It results from the capillary water rise into the unsaturated soil
zone and therewith offers a broad range of growth conditions for microorganisms.
These conditions change from aerobic (good oxygen supply) at the top of the CF
to anaerobic (no available oxygen) at the bottom of the CF and under the water
table.
In recent years, a lot of earth scientists and microbiologists worked together to deepen the
understanding of the physical, geochemical and biological processes in the CF. But there is
still a lack in knowledge on both sides, since the water content changes in the CF from
saturated to almost unsaturated which hampers determination of biological parameters as
well as modeling.
In the DFG-project “Dynamic Capillary Fringes - A Multidisciplinary Approach
(DyCap)” researchers started to simulate growth of microorganisms in the CF. The biological
parameters like growth rates, saturation constants for substrate and oxygen, yield coefficients
and maintenance rate were determined in batch assays using parameter estimation. A flow
through cell filled with fine sand was used to establish a CF and to investigate the growth
of microorganisms in this zone. In order to allow non-invasive visualization and
quantification, facultative anaerobic Escherichia coli) cells which can grow under
aerobic and anaerobic conditions and which produce a green fluorescent protein were
used.
We developed a numerical simulator for multiphase multicomponent reactive flow in
porous media, which is able to consider simultaneously multiphase flow, component
transport, phase exchange and microbiological processes. This tool was used to simulate the
E. coli growth in the CF with nutrient supply under steady-state condition and the results are
finally compared to the experimental data. |
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