Secondary and Primary Energy Minimum Interactions of Colloids in Porous Media: A Novel Binomial Modeling Approach
Abstract
Aqueous transport of colloids in porous media is significantlyaffected by interactions with grain surfaces associated with theprimary and secondary energy minimum at colloid-surface separationdistances within a few to hundreds of nanometers, respectively. Nearsurface fluid domain colloids experience relatively low fluid drag andrelatively strong colloidal forces that slow their down-gradienttranslation relative to colloids in bulk fluid. Near surface fluiddomain colloids may re-enter into the bulk fluid via diffusion(nanoparticles) or expulsion at rear flow stagnation zones, or theymay immobilize (attach) via strong primary minimum interactions.Our new model accounts for all possible permutations of mass transferwithin a dual pore and grain network. The primary phenomena therebyrepresented in the model are mass transfer of colloids between thebulk and near-surface fluid domains and immobilization. A previouslydeveloped pore-scale model provides likelihoods and time scalesassociated with the above pore-scale colloid mass transfer processes,whereas the network-scale model employs fluid flow field and graintopology to determine probabilities of transfer from up-gradient bulkand near-surface fluid domains to down-gradient bulk and near-surfacefluid domains. We used the model to make predictions of colloid fateand transport at the column scale based on independently determinedpore-scale parameterizations. The models allows separating theeffects of hydrodynamic dispersion and colloid attachment anddetachment on breakthrough elution curves.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFM.H34D..03H
- Keywords:
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- 1829 Groundwater hydrology;
- HYDROLOGYDE: 1832 Groundwater transport;
- HYDROLOGYDE: 1839 Hydrologic scaling;
- HYDROLOGYDE: 1846 Model calibration;
- HYDROLOGY