Working Theory
Electrodeionization uses electrical current to force a continuous migration of contaminant ions out of the feed water and into the reject stream while continuously regenerating the resin bed with H+ (hydrogen) and OH- (hydroxyl) ions that are derived from water splitting. The patented flow process of the dilute and concentrate streams make the Omexell module completely unique .
Feed water (dilute stream) enters the Omexell module from below and is diverted into vertically spiraled cells known as the 'D' (dilute) chambers. The dilute stream flows vertically through ion-exchange resins located between two membranes (an anion membrane specifically designed to allow migration of only anions, and acation membrane specifically designed to allow migration of only cations).
Concentrate enters the module through the center pipe from below and is diverted into spirally flowing cells known as the 'C' (concentrate) chambers.
DC current is applied across the cells. The DC electrical field splits a small percentage of water molecules (H2O) into Hydrogen (H+) and Hydroxyl (OH-) Ions. The H+ and OH- Ions attach themselves to the cation and anion resin sites, continuously regenerating the resin. Hydrogen ions have a positive charge and Hydroxyl ions have a negative charge and each will migrate through its respective resin, then through its respective permeable membrane and into the concentrate chamber due to their respective attraction to the cathode or anode. Cation membranes are permeable only to cations and will not allow anions or water to pass, and anion membranes are permeable only to anions and will not allow cations or water to pass.
Contaminate ions dissolved in the feed water, attach to their respective ion-exchange resin displacing H+ and OH- ions. Once within the resin bed, the ions join in the migration of other ions and permeate the membrane into the 'C' chambers. The contaminant ions are trapped in the 'C' chamber and are swept away. The feed water continues to pass through the dilute chamber and is purified and is collected on the outlet of the "D" chambers and exits the EDI module. All EDI module product flows are collected and exit the system.