Effects of the operating parameters on the reverse osmosis-electrodeionization performance in the production of high purity water

An RO-CEDI (Reverse osmosis-continuous electrodeionization) hybrid process was investigated to produce high purity water. The RO system, with an effective membrane area of 1.1 m(2), was operated using tap water with conductivity of 64 mus (.) cm(-1), and the CEDI system experiments were carried out in a cell-pair stack consisting of 3 compartments. During the parametric study of the RO-CEDI hybrid system, the optimal operating conditions were determined based on the water purity. The electrical resistivity and water dissociation of the ion exchange resins and ion exchange membrane were verified as the key mechanisms of the CEDI system in the water purification. The produced water met the quality requirements as a make-up water in a nuclear power plant with a resistivity of 10-16.7 MOmega (.) cm.