Radial deionization – RDI™ – is a proprietary form of capacitive deionization (CDI). In radial deionization, an aqueous stream containing salt is passed between two oppositely charged supercapacitors. As the liquid passes through the dielectric spacer separating the capacitors, ions are attracted to the oppositely-charged capacitor layers. The ions leave the water within the dielectric layer, pass through a charge specific membrane coating, and are adsorbed onto the surface area of the carbon supercapacitor.
When the capacitors have filled with ions, the polarity is reversed and the ions are discharged back into the dielectric spacer and removed from the system. A 3-way valve is situated at the outlet of the device(s), directing brine away from the cleaned water.