HR: 11:05h
AN: H32D-04 INVITED    [Abstracts]
TI: Lab-Scale Experiments and Numerical Modeling of Mixing and Degradation of Pollutants in Aquifers
AU: * Grathwohl, P
EM: grathwohl@uni-tuebingen.de
AF: Tuebingen University, Sigwartstr. 10, Tuebingen, 72076, Germany
AU: Rolle, M
EM: massimo.rolle@uni-tuebingen.de
AF: Tuebingen University, Sigwartstr. 10, Tuebingen, 72076, Germany
AU: Eberhardt, C
EM: christina.eberhardt@uni-tuebingen.de
AF: Tuebingen University, Sigwartstr. 10, Tuebingen, 72076, Germany
AU: Bauer, R
EM: robert.bauer@gsf.de
AF: GSF, Neuherberg, Munich, 80000, Germany
AU: Griebler, C
EM: chistian.giebler@gsf.de
AF: GSF, Neuherberg, Munich, 80000, Germany
AU: Meckenstock, R
EM: rainer.meckenstock@gsf.de
AF: GSF, Neuherberg, Munich, 80000, Germany
AB: Prediction of natural attenuation rates in groundwater requires process based modeling of the biogeochemical reactions involved and field effective parameters on mixing rates. For the validation of the models we measured high resolution concentration profiles and mixing rates in a sequence of lab-experiments performed in quasi two- dimensional flow-through systems. Transport of conservative and reactive tracers, undergoing both abiotic and microbially-mediated degradation reactions, was investigated. Transversal mixing and reactions under changing flow fields and in heterogeneous porous media were directly compared with analogous physical and numerical experiments carried out with steady state flow and in homogeneous sediments. The results show that flow focusing in heterogeneous porous media significantly enhances mixing and reaction rates. Changing flow fields, however, are of minor importance. Moreover, the comparison between measured and simulated concentrations clearly indicates that when transverse dispersion/mixing coefficients of dissolved reactants and reaction parameters are known, forward numerical modeling can accurately predict the transport of pollutants in groundwater systems.
DE: 2724 Magnetopause and boundary layers
SC: Hydrology [H]
MN: 2007 Fall Meeting