Speaker
Description
Biofilms profoundly alter flow and transport in porous media, yet their growth and clogging dynamics remain difficult to predict because biofilms behave neither as rigid solids nor as Newtonian fluids. Here we combine microfluidic experiments in well-defined porous architectures with rheology-informed modeling to reveal how fluid shear stress controls biofilm morphology and deformation. Using homogeneous microfluidic porous media with porosities ranging from 24% to 96.5% and pore sizes from 60 to 570 μm, we systematically vary the imposed flow rate (0.01–2.5 mL h⁻¹), corresponding to shear rates spanning more than two orders of magnitude (≈0.01–100 s⁻¹). Time-resolved microscopy of Bacillus subtilis biofilms reveals distinct growth regimes: uniform coating, heterogeneous patchy growth, streamer-dominated clogging, and flow-reopening by biofilm yielding. These regimes collapse onto a single shear-controlled phase diagram, demonstrating that the balance between nutrient supply and biofilm visco-elasto-plastic resistance governs pattern formation across different porosities and geometries. To rationalize these observations, we interpret biofilms as living visco-elasto-plastic materials subjected to pore-scale shear. We quantify deformation, detachment, and critical yielding thresholds, which are then incorporated into a pore-network framework and direct numerical simulations to upscale pore-scale dynamics into macroscopic permeability and intermittency. This multiscale approach links microbial growth, biofilm rheology, and flow heterogeneity within a unified physical picture. Our results provide a predictive framework for when biofilms grow, deform, clog, or reopen flow pathways in porous media, with direct implications for filtration, groundwater remediation, and subsurface energy technologies such as hydrogen or CO₂ storage.
| Country | Sweden |
|---|---|
| Green Housing & Porous Media Focused Abstracts | This abstract is related to Green Housing |
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