• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.11
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• pp.4664-4670
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• 2010

Comparison of the classical mobile-immobile zone (MIM) model to the derived model led to several conclusions. If the MIM model is to be applied, the initial concentration in the immobile zone has to be down-scaled by a correction factor that is a function of pore geometry. The MIM model was valid only after sufficiently long time has passed, i.e., only after the diffusion front reaches the deepest pore wall in the immobile zone. The MIM mass-transfer coefficient $\alpha$, was inversely proportional to the square of the pore depth. Also it did not depend on the mobile-zone flow velocity, contrary to the number of laboratory and field observations. The classical MIM model displayed a rapid exponential decay of immobile-zone concentration. Meanwhile at large times, the newly derived model displayed similar exponential decay. This was contrary to the mounting evidence of power-law BTC tails observed in laboratory and field settings.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.2
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• pp.99-103
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• 2010

A new analytic solution was derived for the diffusion into or from an immobile zone of a rectangular 2-D pore. For a long time, the new solution converges to a traditional mobile-immobile zone (MIM) model, but only if the latter is used with an apparent initial concentration that is smaller by almost 20% than the true one. This is the tradeoff for using a simple MIM model instead of an exact model based on the diffusion equation. The mass-transfer coefficient was found to be constant for a sufficiently long time; it was proportional to the molecular diffusion and inversely proportional to the square of the pore depth. The mass-transfer coefficient was time-dependent for a sufficiently short time and may be significantly larger than its asymptotic value.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.04a
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• pp.393-396
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• 2005

The reactive transport model on the biologically mediated sequential nitrate transformation and its subsequent transport was developed and tested. This model was coded as a reaction module within the RT3D framework (Clement, 1997). Transports of the reasonable six mobile solutes (dissolved organic carbon, $O_2,\;{NO_3}^-,\;{NO_2}^-,\;N_2O,\;N_2$) and two immobile microbes were simulated. The simulation results gave a reasonable match with supposed transport pattern. For the next step, the developed model will be validated against experimental data.