Simulation of Reactive Transport in Porous Media: A Benchmark for a COMSOL-PHREEQC-Interface

D. Müller[1], H. Francke[1], G. Blöcher[1], H. Shao[2]
[1]Helmholtz-Zentrum Potsdam Deutsches GeoForschungsZentrum GFZ, Potsdam, Brandenburg, Germany
[2]Helmholtz-Zentrum für Umweltforschung UFZ, Leipzig, Saxony, Germany

The reactive transport simulation interface COMSOL-PHREEQC, developed by Wissmeier & Barry (2011), provides a MATLAB®-based coupling interface to combine COMSOL Multiphysics® for flow and heat transport simulations and PHREEQC as a geochemical batch reaction simulator. The functionality of the coupling tool is tested using the “calcite” example (Shao et al. 2010) as a benchmark. The results of COMSOL-PHREEQC are compared to OpenGeoSys, coupled with PHREEQC. In the example, a column initially contains calcite and water. During the experiment, the column is flushed with a MgCl2 solution. At the front of the plume, calcite dissolves and dolomite precipitates temporarily. OpenGeoSys and COMSOL Multiphysics® yield similar results for non-reactive transport and reactive transport in capillaries, but differ in porous media.