Evaluation of long-term performance of a continuously operated flow-electrode CDI system for salt removal from brackish waters

Abstract While flow-electrode capacitive deionization (FCDI), one of the most popular CDI variants, possesses a number of advantages over conventional fixed-electrode CDI (including large salt adsorption capacity, high flow efficiency and convenient management of the electrodes), challenges remain in constructing and operating an FCDI system such that it can operate continuously. Here we achieve effective continuous removal of salt from a brackish feed stream using flowing carbon electrodes which are regenerated in a closed-loop manner by using our previously introduced integrated FCDI/MF strategy. The performance of the FCDI/MF system is characterized over a two week period of operation with key factors influencing the desalination performance identified. Results show that the FCDI/MF system is capable of continuously desalinating brackish water (∼2 g L−1) to portable levels (