Pore-network modeling of solute transport and biofilm growth in porous media

Abstract

In this work, a pore-network (PN) model for solute transport and biofilm growth in porous media was developed. Compared to previous studies of biofilm growth, it has two new features. First, the constructed pore network gives a better representation of a porous medium. Second, instead of using a constant mass exchange coefficient for solute transport between water phase and biofilm, a variable coefficient as a function of biofilm volume fraction and Damköhler number was employed. This PN model was verified against direction simulations. Then, a number of case studies were conducted, in order to illustrate the temporal evolutions of medium permeability and biomass content under different operating conditions. Finally, we explored the effects of biofilm morphology and permeability on biofilm growth, as well as non-unique relationship between medium permeability reduction and its porosity change.