Numerical experiments for bioclogging in porous media.

Area of Science:

• Environmental Science
• Biotechnology
• Geosciences

Background:

• Bioclogging, the reduction of permeability in porous media due to microbial activity, poses challenges in various subsurface applications.
• Understanding the mechanisms of bacterial attachment, growth, and extracellular polymeric substances (EPS) formation is crucial for managing these processes.

Purpose of the Study:

• To develop and validate a macroscopic mathematical model describing bioclogging in saturated porous media.
• To investigate the impact of bacterial growth and attachment on porous media permeability and porosity.
• To analyze the influence of key model parameters on bioclogging behavior.

Main Methods:

• Development of a macroscopic mathematical model incorporating bacterial growth, attachment, and EPS production.
• Simulation of column experimental data from existing literature to validate the model.
• Numerical experiments to assess the effects of biomass accumulation on permeability and porosity.
• Sensitivity analysis to identify critical parameters influencing model predictions.

Main Results:

• The developed model accurately simulated experimental data on permeability changes.
• Simulation results demonstrated that biomass growth and attachment significantly alter porous media permeability and porosity.
• Extracellular polymeric substances (EPS) were identified as a potentially significant factor in the bioclogging process.
• Sensitivity analyses revealed that parameters like maximum substrate utilization rate and yield coefficient strongly influence permeability and porosity.

Conclusions:

• The mathematical model provides a valuable tool for understanding bioclogging phenomena in porous media.
• Biomass deposition and growth, along with EPS production, are key drivers altering the physical properties of porous media.
• The model's findings highlight the importance of microbial processes in subsurface flow and transport.