ABSTRACT
This chapter focuses on the theory and methods of applying electric fields during membrane separations (MS) to reduce concentration polarization and fouling. Several attempts have been made to reduce concentration polarization and fouling and to increase the performance of MS processes. MS processes are based on the ability of a membrane to separate two liquids and to act as a semipermeable barrier. The liquid to be treated enters the separation module and a portion passes through the membrane free of suspended or dissolved solids. At higher transmembrane pressures, the permeate flux in ultrafiltration and microfiltration processes becomes independent of pressure and is controlled by the phenomenon of concentration polarization. Electrically assisted MS processes have many potential applications. In the food industry, they can be used to increase the performance of concentration or purification processes of liquid foods. MS have certain advantages over other separation techniques, especially in biochemical applications.
