The feasibility of using capacitive deionization (CDI) was investigated for the desalination of brackish water containing on compound The reproducibility, salt removal efficiencies, and current efficiencies were examined at various cell potentials and cell configurations. For the CDI cell constructed with only porous carbon electrodes, the results showed stable and reproducible adsorption and desorption characteristics But the current efficiency was low at 49.3% at the cell potential of 14 V The low current efficiency was attributed to the dissolved salt present in the pore volume of the carbon electrode To increase the current efficiency, desalination experiments were performed using a membrane capacitive deionization (MCDI) unit cell, which employed ion-exchange membranes as ion selective layers in a CDI cell The current efficiency increased to 90.2% under the same experimental conditions. MCDI tests were conducted using all influent containing octane to elucidate the effect of on Compounds on desalination efficiency The experimental results showed that the MCDI System Could be successfully applied to the desalination of brackish water containing on compounds. (C) 2009 Elsevier B V All rights reserved.