Multiscale Modeling of Uranium Bioreduction in Porous Media by One-Dimensional Biofilms

Area of Science:

• Environmental Science
• Biogeochemistry
• Mathematical Modeling

Background:

• Uranium contamination in porous media poses environmental risks.
• Bioreduction is a key process for uranium remediation.
• Existing models often neglect thermodynamic effects in biofilm dynamics.

Purpose of the Study:

• To develop a multiscale mathematical model for uranium bioreduction.
• To investigate the role of thermodynamic inhibition in biofilm growth.
• To analyze the impact of attachment and detachment rates on reactor performance.

Main Methods:

• Formulation of a multiscale mathematical model from mesoscale to macroscale.
• Incorporation of a multispecies one-dimensional biofilm model with suspended bacteria.
• Inclusion of thermodynamic growth inhibition and analysis of attachment/detachment processes.

Main Results:

• Thermodynamic inhibition quantitatively alters bioreduction dynamics.
• Neglecting thermodynamic effects can lead to inaccurate concentration predictions.
• Increased attachment or decreased detachment rates result in thicker biofilms, but reactor performance is unaffected.

Conclusions:

• Multiscale modeling provides a comprehensive understanding of uranium bioreduction.
• Thermodynamic effects are crucial for accurate simulation of uranium bioreduction systems.
• Biofilm thickness is sensitive to attachment/detachment rates, but reactor efficiency is robust.