THE SCALE-UP PROBLEM FOR ION TRANSPORT IN KAOLINITE CLAYS INCLUDING PH-DEPENDENCE

Summary

We propose a new multiscale computational model to simulate electrokinetic remediation processes in clayey soils. The macroscopic governing equations are derived using the homogenization procedure applied to the pore-scale description consisting of micro-pores saturated by an aqueous solution containing four monovalent ionic species (Na ⁺, H ⁺, Cl ⁻, OH ⁻) and charged solid particles surrounded by thin electrical double layers. The homogenized equations are discretized by the finite element method and applied to numerically simulate an electroosmosis experiment for decontamination of a clay sample by electrokinetics. Boundary conditions of Dankwerts type are postulated at the electrodes, which bring additional complexity to the iterative algorithm for solving the discrete model.