Review on Capacitive Deionization: A Novel Method of Water Purification

Abstract

Shortage of potable water in remote communities and rapid depletion of ground water have led to development of pressure driven and electrochemical technologies like reverse osmosis, electro dialysis and capacitive deionization. Capacitive deionization is a promising process technology to purify brackish and saline water. Though the concept of capacitive deionization was initiated in 1960’s, the last decade has seen rapid development of process and material technology. Commercially viable plants are now available for applications ranging from potable water production to treatment of cooling tower makeup. This article discusses the concept, process design principles, electrode materials and energy requirement for this novel process. Operating problems including fouling and scaling are dealt with. A brief note on environmental impact of this process is given.