Rocking-Chair Capacitive Deionization for Continuous Brackish Water Desalination

Capacitive deionization (CDI) is considered an alternative desalination technology due to its easy operation, high energy efficiency, and environmentally friendly process. However, a separate regeneration step is required in typical CDI technologies that releases the absorbed ions on the electrodes which results in an inefficient and cost-intensive process. This study proposed a novel CDI system referred to as rocking-chair capacitive deionization (RCDI) that has a continuous brackish water desalination process which consists of a pair of Nafion-coated activated carbon electrodes and an anion-exchange membrane. The coated Nafion contributed to the cation selectivity of the carbon electrode, and it enabled a continuous desalination process during constant-current operation through a rocking-chair ion movement. From the desalination tests that included the analysis of the CDI Ragone plot, …