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| Titel |
Dynamics of hydraulic properties due to biological clogging |
| VerfasserIn |
R. Rosenzweig, U. Shavit, A. Furman |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250060241
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| Zusammenfassung |
| Classic treatment of soil-water flow is described by the unsaturated version of Darcy’s law
and Richards’ equation, assuming time invariant hydraulic properties, e.g. the saturated
hydraulic conductivity, Ks, and van Genuchten-Mualem’s α and n. However, when bacteria
is present the soil is quite far from being time invariant and biological activity constantly
alters the pore-scale structure, leading to macro-scale alteration of the hydraulic properties.
This may be of high relevance to processes such as subsurface bioremediation,
soil aquifer treatment, wastewater irrigation, and more. In this work we explore
the dynamic alteration of soil hydraulic properties by a combination of column
experiments and pore-network modeling. We experimentally demonstrate how biological
activity clogs an unsaturated soil column and reduces its hydraulic conductivity, while
a similar column where biological activity is limited does not clog. Further, we
demonstrate that the clogging is preferential to the nutrient input. Next, we develop a
pore-network model that uses triangular shape channels. This allows a dual occupancy
(water-air) of each channel and high connectivity. The model solves the flow of water,
nutrient transport, and biological dynamics. It includes biofilm growth and decay,
attachment and detachment, and nutrient exchange between the water and biofilm phases.
We perform a sensitivity analysis of the model and qualitatively show through the
loss of connectivity how the clogging that was observed in our experiment can be
explained. |
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