Transcript Micro-scale numerical models for biofilm formation in porous media

The Environmental Fluid Dynamics Lecture Series
Presents a Seminar
Professor Cristian Picioreanu
Associate Professor
Biofilms Institute
Dept of Biotechnology
Delft University, The Netherlands
Tuesday, April 8
Dean’s Boardroom, 258 Fitzpatrick
11am-12noon
Micro-scale numerical models for biofilm formation in porous media
Biofilm formation in porous media is determined by a multitude of processes not
only different in nature, but also in spatial and temporal scales, making in general the whole system
challenging to study. This presentation will introduce concepts and approaches to biofilm modeling
at pore scale. On the whole, we couple two- or three-dimensional fluid dynamics models with solute
transport supplying nutrients for biofilm development in complex geometry media. The biofilm
formation can be described by particle-based models, with growth dependent of nutrient
concentrations and detachment as a function of shear stress induced by flow. Mineral precipitation
can also be introduced in the particle-based framework.
A first application evaluates the impact of biofilms on proppant packed fractures in
shale gas reservoirs. Simulations of two phase flow indicated that although hydrophobic proppant
grains provide better dewatering than hydrophilic surfaces, biofilms can worsen the dewatering.
Model extensions show how biofilm lysis can create flow paths continuously changing position even
after the medium permeability reached steady state.
The second example describes the effect of biofilm growth in spacer-filled channels of
reverse osmosis membrane devices for water desalination. The 3-d numerical simulations show how
biofilm accumulation strongly affects the feed channel pressure drop and liquid channeling.
Furthermore, accumulation of salts near the membrane and mineral precipitation is stimulated by the
biofilm.
Finally, computations of fluid-structure interaction and mass transfer enhancement in
flow-induced oscillating biofilm streamers will be presented.