This is an entirely new procedure characterized through the interaction of membrane-technology, electro-dialysis and ion-exchange.
Pure water qualities of < 0.1 µS/cm can be achieved.
During the EDI-methode mixed bed ion-exchanger resins are placed between the membranes of the salt-removal-cells. Under the moving power of an electric field ionogenic remainder ingredients are removed from the water from which the salt has already been withdrawn (for example the so called UO-permeat).
It is within the electric field that anions, which are on their way to the anode, pass the membranes of the anion exchange-elements and that the cations pass the membranes of the cation-exchange elements on their way to the cathode. After that they are each kept back by the next membrane.
Out of this process originates a diluted solution ("dilulate") in every second cell and the concentrate in the intermediate chambers. In the dilulate-cells the ions shortly attach to the mixed bed resins and /or move along the resin's surface and thus through the entire dilulate-cell.
In addition to this the mixed bed resin is constantly regenerated through the OH- and H+-ions which can be found in the water dissociating on the resin's surface.