Energy consumption in membrane capacitive deionization and electrodialysis of low salinity water.

Membrane capacitive deionization (MCDI) is a promising new technology for brackish water treatment. Although many authors show the advantages of MCDI by comparing its energy consumption with pressure driven-methods, such as reverse osmosis or nanofiltration, membrane capacitive deionization should rather be compared to electrodialysis (ED), widely considered the most economical desalination technology for low salinity brackish water treatment. In this paper, MCDI is compared with ED by desalting model sodium chloride solutions (0.7-1.0 g/dm3). The results show higher energy consumption of MCDI than of ED when generating 0.5 g/dm3 product: 0.428-0.499 kWh/m3 for MCDI and 0.034-0.230 kWh/m3 for ED, depending on the feed concentration and used membrane. [ABSTRACT FROM AUTHOR]