Can capacitive deionization outperform reverse osmosis for brackish water desalination?

Capacitive deionization has received significant attention as an energy-efficient technology for brackish water desalination. The capacitive deionization suffers from lower water recovery and high electrode discharge time, that hampers its economics. The low recovery ratio increases the brine disposal cost and is also environmentally polluting. In this paper, the feasibility of capacitive deionization as a brackish water desalination technology is studied. The capacitive deionization performance is first optimized and is later compared with the state-of-the-art reverse osmosis. Both modeling and experimental studies are carried out to optimize the performance of capacitive deionization. A new cost correlation as a function of the capacitive deionization system size is proposed. By optimally designing the system, the treated water cost for capacitive deionization is reduced by 36%. A feas…