Electrofiltration

Electrofiltration represents a modification of dead-end membrane micro- or ultrafiltration. It targets a significant reduction of the filtration time and focuses especially on the filtration and/or concentration of colloidal substances that otherwise rapidly build up a deposit of colloidal particles on the surface of the membrane, which strongly hinders permeation of the fluid phase. The basic principle is that colloidal particles usually carry an electric charge. Hence, by applying an appropriate electric field, colloidal particles can be moved in the direction opposite to the fluid flow, thus keeping the surface of the filtrating membrane free of the deposit (Henry et al. 1977). A schematic sketch of this arrangement is shown in the Fig. 1.

Electrofiltration, Fig. 1

Schematic sketch of electrofiltration principle, F_w stands for driving force due to the friction between the particle and flowing solvent molecules and F_estands for driving force resulting from action of the applied...