Numerical modeling of reactive transport in aquifers

Natural aquifers are heterogeneous. Their description for practical purposes such as regional groundwater management has to make use of averaged effective parameters. In linear transport a lot has been achieved, with macrodispersion expressing the effect of small scales. For non-linear processes virtually nothing is known yet. Here a fast non-linear adsorption process with a Freundlich isotherm was used as a prototype. Already in linear transport we showed that there are two different concepts of macrodispersion coefficients: a coefficient describing real mixing and a coefficient describing the variability between different realizations of the same random process. While in linear transport the difference between the two is often irrelevant it remains large and essential in nonlinear transport where reaction rates are concentration dependent and only real mixing is responsible for reaction. The ensemble dispersion can no longer be expressed as a local dispersion term, rather a non-local integral expression is required. Finally it could be shown that for spatially varying Freundlich exponents a new effective isotherm has to be used and dispersion coefficients become concentration dependent.

Main publications

Attinger, S., Dimitrova Micha, J. and Kinzelbach, W. (2003) Multiscale Modeling of Nonlinearly Adsorbing Solute Transport, SIAM Multiscale Modeling and Simulation, 1(3), p.408-431.

Contacts

W. Kinzelbach

Agency/Funding

German Ministry of Research and Development via GermanSociety for Reactor Safety/408 kCHF

Partners

IWR Heidelberg
University of Duisburg
University of Freiburg

Status

Finished in 2003

See other past research projects