Layered electrodeionization device with discreet cation chamber

An electrodeionization apparatus comprising:

• a. an anode chamber 601, including an anode therein;
• b. a cathode chamber 608, including a cathode therein;
• i. wherein, an electric field is formed as a result of a voltage applied between the anode and the cathode;
• c. an anion membrane 602 contiguous with the anode chamber 601;
• d. a dual layer depletion chamber comprising;
• i. an anion exchange material layer 603 contiguous with the anion membrane 602, the anion exchange material layer including therein anion exchange materials;
• ii. a composite anion-cation exchange material layer 604 contiguous with the anion exchange material layer 603, the composite anion-cation exchange material layer including therein one of a mixed ion exchange material, or a doped anion exchange material, or a doped cation exchange material;
• iii. wherein an interface between the anion exchange material layer 603 and the composite anion-cation exchange material layer 604 is substantially transverse to the applied electric field, so that a direction of fluid flow across the interface is substantially perpendicular to the interface;
• e. a first cation membrane 605 is contiguous on a first side of the composite anion-cation exchange material layer 604 of the dual layer depletion chamber;
• f. a cation exchange material layer 606 is contiguous on a second side of the first cation membrane 605, the cation exchange material including therein cation exchange materials;
• g. a second cation membrane 607 is contiguous with the cation exchange material layer 606 on a first side and is contiguous with the cathode chamber 608 on a second side.