working paper 
Coupling of COMSOL and PHREEQC for the Simulation of Environmental Flow and Transport Processes with Geochemical Reactions
 2013 
COMSOL_PHREEQC is a software tool that couples the generic finite element solver COMSOL Multiphysics® with the geochemical modeling framework PHREEQC to simulate a wide variety of environmental flow and transport processes (COMSOL) together with comprehensive geochemical reactions (PHREEQC).