HR: 1340h
AN: H23D-1627    [Abstracts]
TI: UPSCALING REACTIVE TRANSPORT USING A PORE-NETWORK MODEL
AU: * Raoof, A
EM: raoof@geo.uu.nl
AF: Department of Earth Sciences Utrecht University, P.O. Box 80021, UTRECHT, 3508 TA, Netherlands
AU: Hassanizadeh, S
EM: hassanizadeh@geo.uu.nl
AF: Department of Earth Sciences Utrecht University, P.O. Box 80021, UTRECHT, 3508 TA, Netherlands
AU: Leijnse, T
EM: Toon.Leijnse@wur.nl
AF: Soil Physics, Ecohydrology and Groundwater Management Group, Wageningen University, PO Box 47, Wageningen, 6700 AA, Netherlands
AB: The main objective of this research is a better understanding of the relations between the reaction rate constants and Darcy scale velocity using a 3D pore scale network model. First, we carry out numerical "experiments" in a single tube imposing a diffused concentration front moving into the tube and assuming equilibrium adsorption at its wall. We have found that the form of volume-averaged concentration breakthrough curves can be described only by a linear kinetic model. The numerical data are used to determine the rate constants of the linear kinetic adsorption equation as functions of tube geometry, subscale adsorption parameters, and average flow velocity. Next, we have constructed a 3D pore-network model which is composed of a large number of interconnected tubes. Transport equations for kineticly-adsorbed solutes are solved within each tube. Single tube results are used in these equations. The pore-network model is used to simulate core-scale solute transport. Numerical data are used to calculate flux-averaged concentration to determine upscaled kinetic rate coefficients. In this way, we have been able to develop a relationship between core-scale adsorption rate constants and local-scale equilibrium coefficient and average flow velocity.
DE: 1832 Groundwater transport
SC: Hydrology [H]
MN: 2007 Fall Meeting