(333k) Comparison Of Convective-Dispersive Aspects In Electrokinetic Cells Of Rectangular And Cylindrical Geometry

The occurrences of flow reversals during EK processes has been explained by Oyanader et al (2003); Oyanader et al. (2005a&b) using different geometrical models for the soil porous matrix. The conjunction of three competing driving forces (pressure, buoyancy and electrostatic) have an affect on the motion of the solute species that need further understanding. The different driving forces need to be studied in term of how they promote mixing or separation of solute species in an EK cell. Most EK technologies, i.e. Cation Selective Membrane, Ceramic Casting, Lasagna, Electrochemical ion exchange, etc., have reported low removal efficiency. In this contribution, the main focus is on unveiling the possible reasons for EK pitfalls from a fundametal point of view. The approach is based on modeling and fundamental principles applied, first, to the hydrodynamic part of the system and, later, to the species/analytes transport. An area averaging technique has been used to capture the main parameters of the system such as effective mixing, and diffusivity. Furthermore, an approach has been applied to describe the capillary aspect of the soil matrix. This approach involves the characterization of the capillary channels as of rectangular and/or cylindrical aspect to present and discuss several limiting cases related to the influence of flow regimes on the transport of solute in an EK for removal purposes. Optimal operating conditions are highlighted to introduce design criteria and protocols.

Oyanader, M., P. Arce, and A. Dzurik, ?Avoiding Pitfalls In Electrokinetic Remediation: Robust Design And Operation Criteria Based On First Principles For Maximizing Performance In A Rectangular Geometry?, Electrophoresis, 2003. Oyanader, M., P. Arce, And A. Dzurik, "Design Criteria For Soil Cleaning Operations In Electrokinetic Remediation. Hydrodynamic Aspects In A Cylindrical Geometry", Electrophoresis, 2005a. Oyanader, M., P. Arce and A. Dzurik "Design Criteria For Soil Cleaning Operations In Electrokinetic Remediation. Hydrodynamic Aspects In An Annular Geometry", I&ECh Research, 2005b.