The Dependence of the Desalination Performance in Capacitive Deionization Processes on the Electrodes PZC

Abstract

Capacitive deionization (CDI) is a method in which charged species can be electro-adsorbed by imposed electrostatic forces formed by polarization of high surface carbon electrode. An important parameter that may have pronounced effect on the desalination performance in CDI processes is the potential of zero charge (PZC) of the carbon electrodes in the cell. In this work we examined the influence of the relation between the electrodes’ PZC and the electrodes’ potential (Vs. Ref. electrode) when the cell is being short-circuited (E0) at dynamic steady state, on the salt removal effectiveness. A flow through CDI cell, which solution's concentration could be continuously measured in the course of the periodic charge-discharge processes was employed for this purpose. The paper outlines guidelines for CDI cells optimization by choosing appropriate carbon electrodes.