Leonard Paul Seed

The Desel System – Capacitive Deionization for the Removal of Ions From Water

Capacitive deionization (CDI) represents a new approach to the treatment of a variety of water/wastewater streams contaminated with inorganic compounds. ENPAR Technologies Inc. of Canada has developed its DesEL System, which combines high water recoveries with high ion removal efficiencies. The system operates on the principle of capacitive deionization to remove ionic compounds referred to as total dissolved solids (TDS). The results of several bench and pilot tests of capacitive deionization systems are presented. In addition to the removal of general TDS, the system can be configured to preferentially remove monovalent ions. This alternative approach has been used to selectively remove nitrate from groundwater with only minor reductions in overall TDS. Pilot testing of the DesEL system has been conducted on groundwater containing high arsenic levels (0.210 to 0.820 mg/L). The DesEL system was effective at removing the As from the groundwater stream to less than the detection limit of 0.005 mg/L. The DesEL system has proven to be an effective technology for a variety of water and wastewater treatment applications.