Articles techniques et présentations

We present a software tool for simulations of subsurface flow and solute transport in combination with comprehensive intra-phase and inter-phase geochemistry. The software uses PHREEQC as a reaction engine to COMSOL Multiphysics®. The coupling with PHREEQC gives major advantages over COMSOL’s built-in reaction capabilities, i.e., the soil solution is speciated from its element composition according to thermodynamic mass action equations with ion activity corrections.

State-of-the-art adsorption models such as surface complexation with diffuse double layer calculations as well as equilibrium and kinetic mineral reactions are accessible. PHREEQC provides a framework to integrate user-defined kinetic reactions with possible dependencies on solution speciation (i.e., pH, redox state, saturation indices, and ion activities). Extensive compilations of geochemical reactions are accessible through associated databases.