Abstract: An electrodeionization apparatus is provided comprising an ion-concentrating compartment partially bounded by an anion permeable membrane and also partially bounded by a cation permeable membrane, and a first ion exchange material domain disposed within the ion-concentrating compartment, wherein the first ion exchange material domain is contiguous with at least a portion of an ion-concentrating compartment side surface of one of the anion permeable membrane and the cation permeable membrane, and is spaced apart from the other one of the one of the anion permeable membrane and the cation permeable membrane. In the case where the one of the anion permeable membrane and the cation permeable membrane, having the at least a portion of an ion-concentrating compartment side surface with which the first ion exchange material domain is contiguous, is an anion permeable membrane, the first ion exchange material domain is an anion exchange material predominant domain.

Abstract: An electrodeionization apparatus is provided comprising an ion-concentrating compartment partially bounded by an anion permeable membrane and also partially bounded by a cation permeable membrane, and a first ion exchange material domain disposed within the ion-concentrating compartment, wherein the first ion exchange material domain is contiguous with at least a portion of an ion-concentrating compartment side surface of one of the anion permeable membrane and the cation permeable membrane, and is spaced apart from the other one of the one of the anion permeable membrane and the cation permeable membrane. In the case where the one of the anion permeable membrane and the cation permeable membrane, having the at least a portion of an ion-concentrating compartment side surface with which the first ion exchange material domain is contiguous, is an anion permeable membrane, the first ion exchange material domain is an anion exchange material predominant domain.

Abstract: An electrodeionization apparatus is provided comprising an ion-concentrating compartment partially bounded by an anion permeable membrane and also partially bounded by a cation permeable membrane, and a first ion exchange material domain disposed within the ion-concentrating compartment, wherein the first ion exchange material domain is contiguous with at least a portion of an ion-concentrating compartment side surface of one of the anion permeable membrane and the cation permeable membrane, and is spaced apart from the other one of the one of the anion permeable membrane and the cation permeable membrane. In the case where the one of the anion permeable membrane and the cation permeable membrane, having the at least a portion of an ion-concentrating compartment side surface with which the first ion exchange material domain is contiguous, is an anion permeable membrane, the first ion exchange material domain is an anion exchange material predominant domain.

Abstract: an electrodeionization apparatus is provided comprising an ion-concentrating compartment partially bounded by an anion permeable membrane and also partially bounded by a cation permeable membrane, and a first ion exchange material domain disposed within the ion-concentrating compartment, wherein the first ion exchange material domain is contiguous with at least a portion of an ion-concentrating compartment side surface of one of the anion permeable membrane and the cation permeable membrane, and is spaced apart from the other one of the one of the anion permeable membrane and the cation permeable membrane. In the case where the one of the anion permeable membrane and the cation permeable membrane, having the at least a portion of an ion-concentrating compartment side surface with which the first ion exchange material domain is contiguous, is an anion permeable membrane, the first ion exchange material domain is an anion exchange material predominant domain.

Abstract: An electrodeionization apparatus is provided comprising an ion-concentrating compartment partially bounded by an anion permeable membrane and also partially bounded by a cation permeable membrane, and a first ion exchange material domain disposed within the ion-concentrating compartment, wherein the first ion exchange material domain is contiguous with at least a portion of an ion-concentrating compartment side surface of one of the anion permeable membrane and the cation permeable membrane, and is spaced apart from the other one of the one of the anion permeable membrane and the cation permeable membrane. In the case where the one of the anion permeable membrane and the cation permeable membrane, having the at least a portion of an ion-concentrating compartment side surface with which the first ion exchange material domain is contiguous, is an anion permeable membrane, the first ion exchange material domain is an anion exchange material predominant domain.

Abstract: An electrodeionization apparatus is provided comprising an ion-concentrating compartment partially bounded by an anion permeable membrane and also partially bounded by a cation permeable membrane, and a first ion exchange material domain disposed within the ion-concentrating compartment, wherein the first ion exchange material domain is contiguous with at least a portion of an ion-concentrating compartment side surface of one of the anion permeable membrane and the cation permeable membrane, and is spaced apart from the other one of the one of the anion permeable membrane and the cation permeable membrane. In the case where the one of the anion permeable membrane and the cation permeable membrane, having the at least a portion of an ion-concentrating compartment side surface with which the first ion exchange material domain is contiguous, is an anion permeable membrane, the first ion exchange material domain is an anion exchange material predominant domain.

Abstract: A spacer mesh is provided and is configured to separate a first ion conducting membrane from a second ion conducting membrane to define a space between the membranes, comprising a plurality of strands consisting essentially of a polymer having a heat distortion temperature of at least 90° C. at 66 psi, and a melt flow index within the range of 3 g/10 min to 6 g/10 min, and being chemically stable at pH>13 or pH<2. The spacer mesh includes a first plurality of spaced apart substantially parallel strand elements, and a second plurality of spaced apart substantially parallel strand elements, wherein the first plurality of strand elements and the second plurality of strand elements are connected to define a netting having a plurality of apertures, each of the apertures having a plurality of vertices defined by a pair of intersecting strands, and a distance between non-adjacent vertices in an aperture is less than 10/1000 of an inch.

Abstract: An apparatus for producing deionized water, comprising an electrodialyzer having cation exchange membranes and anion exchange membranes alternately arranged to form demineralizing compartments and concentrating compartments and having ion exchangers accommodated in the demineralizing compartments, and designed to conduct an electric current while supplying water to be treated to the demineralizing compartments, wherein a spacer is arranged in each concentrating compartment to maintain the thickness of the concentrating compartment, and the cation exchange membranes or the anion exchange membranes are incorporated in their dry state in the electrodialyzer, whereby water is supplied to the electrodialyzer, while each ion exchange membrane is brought in contact with the spacer by a pressure from the demineralizing compartment side.

Abstract: An apparatus for producing deionized water consisting essentially of an electrodialyzer having cation exchange membranes and anion exchange membranes alternately arranged between a cathode and an anode to form demineralizing compartments and concentrating compartments, and ion exchangers accommodated in the demineralizing compartments, wherein a pressure of from 0.1 to 20 kg/cm2 is exerted between the ion exchangers accommodated in the demineralizing compartments and the cation exchange membranes and anion exchange membranes defining the demineralizing compartments.

Abstract: The invention provides a method and apparatus for electrodeionizing water, whereby the water to be purified is passed through diluting compartments in an electrodeionization unit having an anode compartment at one end of the unit and a cathode compartment at the other end of the unit, and a plurality of diluting compartments alternating with concentrating compartments defined by anion and cation exchange membranes. Each of the diluting compartments contains ion exchange material. Importantly, the ion exchange material comprises at least one mixed bed phase of anion exchange material and cation exchange material and at least one single phase, adjacent to the mixed bed phase, of anion exchange material or cation exchange material, or anion exchange and cation exchange material.

Abstract: A modular sysTem for the demineralization of aqueous liquids comprising a plurality of modular units, each of the modular units being encapsulated and having a cathode proximate a first end of the modular unit and an anode proximate the opposite end of said modular, a plurality of alternating diluting compartments and concentrating compartments positioned between the cathode and the anode, and ion exchange material positioned within the diluting compartments. Each of the diluting compartments has a compartment spacer with an elongated central cavity and a plurality of fine slit openings at each end adjacent the cavity. The ion exchange means comprise a porous and permeable continuous phase of cation or anion exchange resin particles and a porous and permeable dispersed phase of clusters of the other of the cation or anion exchange resin particles.

Abstract: An electrodeionization apparatus adapted to remove ions from a liquid, the apparatus having a cathode proximate a first end of the apparatus and an anode proximate the opposite end of the apparatus and having a plurality of alternating diluting compartments and concentrating compartments positioned between the cathode and the anode, the diluting and concentrating compartments defined by anion and cation permeable membranes, and ion exchange material positioned within the diluting compartments, the diluting compartments having therein a continuous phase of a first ion exchange material containing a dispersed phase of clusters of a second ion exchange material. The method of removing ions from a liquid in such an electrodeionization apparatus comprises passing an aqueous liquid to be purified through the diluting compartments in which the diluting compartments have the continuous phase of a first ion exchange material with the dispersed phase of a second ion exchange material.

Abstract: A method and apparatus is provided for inhibiting scaling in an electrodeionization system and, more particularly, for increasing tolerance to hardness in the feed water to an electrodeionization unit by inhibiting precipitation of scale-forming metallic cations contained in the feed water and thereby increasing efficiencies of the electrodeionization system. Water to be purified is passed through an electrodeionization unit in which the flow in the diluting compartment is countercurrent to the flow in the concentrating compartment. This is to impede the migration of scale-forming metallic cations from the diluting compartment, through the cation exchange membrane, into the concentrating compartment and towards the concentrating compartment side of the anion exchange membrane, thereby preventing scale formation on the anion exchange membrane.

Abstract: A method and apparatus for inhibiting scaling in an electrodeionization system or in a combined reverse osmosis/electrodeionization system for water treatment and, more particularly, for increasing tolerance to hardness in the feed water to an electrodeionization unit to inhibit precipitation of metal cations contained in the feed water and for increasing efficiency of the electrodeionization system. Water to be purified is passed through a electrodeionization unit in which a concentrate stream recycling through concentrating compartments and anode and cathode compartments contains effective amounts of an antiscalant to inhibit precipitation of scale. One or more preliminary reverse osmosis units in series with the electrodeionization unit preferably receives a portion of the antiscalants in the concentrate stream. The antiscalant in the water fed to the reverse osmosis unit can be supplemented and adjusted.

Abstract: An apparatus for producing deionized water consisting essentially of an electrodialyzer having cation exchange membranes and anion exchange membranes alternately arranged between a cathode and an anode to form demineralizing compartments and concentrating compartments, and ion exchangers accommodated in the demineralizing compartments, wherein a pressure of from 0.1 to 20 kg/cm.sup.2 is exerted between the ion exchangers accommodated in the demineralizing compartments and the cation exchange membranes and anion exchange membranes defining the demineralizing compartments.

Abstract: A method for producing deionized water by self-regenerating type electrodialysis deionization, which comprises (i) using a deionized water-producing apparatus containing an electrodialyzer comprising cation exchange membranes and anion exchange membranes alternately arranged between an anode compartment provided with an anode and a cathode compartment provided with a cathode, demineralizing compartments compartmentalized with anion exchange membranes on the anode side and compartmentalized with cation exchange membranes on the cathode side, and concentrating compartments compartmentalized with cation exchange membranes on the anode side and compartmentalized with anion exchange membranes on the cathode side, the electrodialyzer having ion exchangers accommodated in the demineralizing compartments, and (ii) applying a voltage while supplying water to be treated to the demineralizing compartments to remove impurity ions in the water to be treated, wherein at least a part of the untreated water or already treate