Pore-scale modeling and microfluidics experimental studies of coupled geochemical and biological reactions along transverse mixing zones
Abstract
Transverse mixing-limited reactions in porous media play an important role in many practical engineering problems. Transverse mixing along the fringes of a contaminant plume can be the limiting step controlling overall degradation rate during natural or engineered in situ bioremediation. Similar mixing processes can promote precipitation/dissolution reactions during geological sequestration of carbon dioxide. Field and laboratory investigations have demonstrated that the length scale of transverse mixing zones can be very small, often on the order of centimeters or less. We have studied coupled processes at this scale over the past 15 years using pore-scale numerical simulation models and microfluidics laboratory experiments. In this presentation, I summarize our methods and findings, emphasizing cases of coupled geochemical/biological reactions resulting in precipitation and biofilm growth that alters porosity and permeability. Comparisons between direct numerical simulations and microfluidics experiments will be presented in order to quantify feedbacks between flow and reaction processes. Pore-scale models will be compared with simpler continuum models at the Darcy scale. Based on this comparison, I discuss challenges for upscaling nonlinear coupled reactions from pore scale to the continuum and larger field scales.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.H14I..02V
- Keywords:
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- 0496 Water quality;
- BIOGEOSCIENCES;
- 1009 Geochemical modeling;
- GEOCHEMISTRY;
- 1847 Modeling;
- HYDROLOGY