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, which has an ion exchanger accommodated in demineralizing compartments of an electrodialyzer having cation exchange membranes and anion exchange membranes alternately arranged between an anode and a cathode, wherein the ion exchanger is a composite ion exchanger comprising a first porous ion exchanger having a mixture of 60 to 95 wt % of cation exchange resin particles and 5 to 40 wt % of anion exchange resin particles bonded to each other and a second porous ion exchanger having a mixture of 60 to 95 wt % of anion exchange resin particles and 5 to 40 wt % of cation exchange resin particles bonded to each other.

Abstract: A method and apparatus for increasing the current efficiency of suppressor and suppress-like pretreatment devices is disclosed for the purpose of suppressing a high concentration of eluent without the detrimental effects of excess heat generation. The method and apparatus may be used in ion chromatography.

Abstract: A continuous electrodeionization apparatus and method. The continuous electrodeionization apparatus and method provide improved removal of weakly ionized ions, particularly silica. The apparatus and method involves using macroporous ion exchange resins that are both highly crosslinked and have a high water content. In preferred embodiments, the ion exchange resin beads also have a substantially uniform diameter.

Abstract: First and second stages are used in electrodeionization to purify water including calcium and carbon dioxide and its hydrates. The diluting flow channels of the first stage include only anion exchange material or cation exchange material, and thus remove either carbon dioxide and its hydrates (and other anions) or calcium (and other cations) but not the other. The diluting flow channels of the second stage receive the diluting channel effluent from the first stage and include the other type of exchange resin (or a mixed resin) and remove the oppositely charged ions. The brine effluent from the concentrating flow channels in the first stage is isolated from the second stage, and calcium and total inorganic carbon tend to be removed in different stages so as to deter calcium carbonate precipitation in any of the concentrating flow channels.

Abstract: Electrodeionization apparatus and method. The electrodeionization apparatus includes an ion-depleting compartment in which alternating layers of an electroactive media are positioned. One of the alternating layers is doped to provide a more balanced current distribution through the apparatus. The method involves reducing the difference in conductivity between the alternating layers positioned in the ion-depleting compartment by adding a dopant material to one of the layers.

Abstract: A method of treating an ion exchange material, the method including: (a) positioning at least two regions of ion exchange material between an anode and cathode electrode, wherein at least a portion of the two regions being in electrical contact and being separated by a non-ion specific permeable interface; (b) supplying water to the at least two regions; (c) applying an electric potential between the electrodes thereby causing generation of hydrogen ions at the anode and hydroxide ions at the cathode, which ions are caused to move through each region towards the oppositely-charged electrode and thereby displacing at least a portion of any anions or cations associated with the ion exchange material in each region such that the displaced anions and cations are also caused to move through the regions towards the oppositely charged electrode; and (d) removing at least some of the cations and/or anions formed during step (c) which reach the interface.

Abstract: Water to be treated (feed water) flows through a series of desalination chambers filled with ion exchange resins on which impurity ions in the feed water are removed. Each desalination chamber consists of a cation-permeable membrane on one side with an anion-permeable membrane on the other side. The space between the two membranes is filled with the ion exchange resins and there are concentrate chambers on either side of the membranes. There is a cathode chamber or an anode chamber each located at either end of the assembly of alternating desalination and concentrate chambers. By circulating the concentrate water while adding acid to the concentrate water to maintain its acidity, scale deposition within the concentrating chambers and the electrode chamber is prevented so that deionizing capability of the entire assembly can be maintained.

Abstract: Two sub-desalination chambers d1 and d2 are defined by a cation exchange membrane 3 on one side, an anion exchange membrane 4 on the other side, and an intermediate ion exchange membrane 5 in between and are filled with ion exchange materials 8 to construct a desalination chamber D. Concentrating chambers 1 are provided via the cation exchange membrane 3 and the anion exchange membrane 4 on both sides of the desalination chamber D. The desalination chambers D and the concentrating chambers 1 are provided between an anode 7 and a cathode 6. While a voltage is applied between the anode 7 and the cathode 6, water is supplied to one of the two sub-desalination chambers d2 and then, water discharged from the first sub-desalination chamber d2 is supplied to a second sub-desalination chamber d1. Concentrate water is supplied to the concentrate chambers.

Abstract: The present invention relates to methods in which ion exchange resins are used to reduce the amount of substances which interfere with nucleic acid hybridization in samples. The methods also stabilize the samples. Kits containing the ion exchange resins render the methods convenient to use.

Abstract: A process and apparatuses for producing hydrogen peroxide which provides good current density and production efficiency from an electrolytic liquid having an exceedingly low conductivity, such as ultrapure water. An electrolytic cell main body containing an anode 5 and a cathode 6 which are electrically connected to each other via ion-exchange resin particles 9 is used to conduct electrolysis while maintaining the electrical connection. High-purity, high-concentration hydrogen peroxide is produced at a high current efficiency even when the electrolytic liquid has an exceedingly low conductivity.

Abstract: Electrodeionization apparatus for purifying water includes a cathode, an anode, and a plurality of alternating anion permeable membranes and cation permeable membranes between the cathode and anode that define concentrating and diluting flow channels between adjacent pairs of membranes. Each concentrating flow channel includes a first guard channel adjacent to the anion permeable membrane, a second guard channel adjacent to the cation permeable membrane, and a brine channel between the first and second guard channels. The first and second guard channels have water with lower concentration of dissolved ions than water in the brine channel so as limit parasitic transfer from a concentrating flow channel to a diluting flow channel.

Abstract: In producing deionized water by electrodeionization according to the present invention, feed water and concentrating water are flowed into the ion depletion compartments and the concentration compartments, respectively, in such a way that the current direction of feed water being fed into the ion depletion compartments is opposite to the current direction of concentrating water being fed into the concentration compartments. Further, feed water flowed into each ion depletion compartment is first passed through an anion exchange material layer, and subsequently passed through other ion exchange material layer(s). The migration of anions into the concentration compartments is promoted in the portions of such anion exchange material layers through which feed water is first passed. As a result, the silica removal rate is improved.

Abstract: Electrodeionization packing including one or more macrostructural elements made up of smaller, microstructural elements. The microstructural elements are in fixed, close contacting position with respect to each other in the macrostructural elements so as to provide porosity in the macrostructural elements. A majority of the microstructural elements have a characteristic dimension between 10 and 50 micrometers, and the macrostructural elements have a void fraction between about 25% and 50%.

Abstract: Electrodeionization apparatus for purifying water that includes a cathode, an anode, and a plurality of alternating anion permeable membranes and cation permeable membranes between the cathode and anode that define concentrating and diluting flow channels between adjacent pairs of membranes. The diluting channels include cation exchange materials and anion exchange materials that are fixed in close contacting position with respect to each other and provide conductive paths for cations and anions to the adjacent membranes and provide flow passages for water between the materials. The anion exchange materials and cation exchange materials each have a characteristic dimension that is smaller than the characteristic dimensions of the flow passages.

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: A bipolar membrane, usable for electrodialysis of aqueous electrolytes, comprises two ion exchange membranes, respectively anionic and cationic, juxtaposed along a common surface, wherein, along said common surface, a gel based on hydrated metal sulpate and/or sulphite, including less than 0.01 mol % of indium, cerium, manganese and copper sulphates gel, is formed.

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: A helical electrodeionization apparatus is adapted to purify aqueous liquids to effect the production of high purity water. An insulated net-separating wall is positioned between a pair of anion and cation exchange membranes to form a special membrane bag type flow unit I, each flow unit I is linked up with a group of slots on the side walls of central pipe, and is rolled up to form cylinder structure which centers on central pipe as the helical axis, a conductive crust is formed by winding metal strip or wire outside the cylinder. Ion exchange resin is filled up between the adjacent membrane bags to form flow unit II. The present invention has less pressure drop and needs less power, and is suited to multiple-device series operation. Preferably, daily maintenance and renewal of the resin is convenient, and production cost is lower.

Abstract: First and second stages are used in electrodeionization to purify water including calcium and carbon dioxide and its hydrates. The diluting flow channels of the first stage include only anion exchange material or cation exchange material, and thus remove either carbon dioxide and its hydrates (and other anions) or calcium (and other cations) but not the other. The diluting flow channels of the second stage receive the diluting channel effluent from the first stage and include the other type of exchange resin (or a mixed resin) and remove the oppositely charged ions. The brine effluent from the concentrating flow channels in the first stage is isolated from the second stage, and calcium and total inorganic carbon tend to be removed in different stages so as to deter calcium carbonate precipitation in any of the concentrating flow channels.

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: Improved electrodialysis (ED) stacks are disclosed having one or more components selected from the group:a) cation exchange membranes having ion exchange groups predominantly sulfonic acid groups and a minor amount of weakly acidic and/or weakly basic groups or membranes which are selective to monovalent cations and simultaneously therewith, cation exchange granules selective to monovalent cations as packing in the dilute compartments;b) anion exchange membranes having as ion exchange groups only quaternary ammonium and/or quaternary phosphonium groups and substantially no primary, secondary and/or tertiary amine and/or phosphine groups or membranes which are selective to monovalent anions simultaneously therewith, anion exchange granules selective to monovalent anions as packing in the dilute compartments;c) as packing in the dilute compartment, anion exchange granules which are selective to monovalent anions, or cation exchange granules which are selective to monovalent cations, or cation exchange granules

Abstract: A gasket for an electrodeionization cell assembly has a serpentine series flow path comprising a plurality of flow path sections joined by restrictor sections to form a series flow path. The series flow paths are packed with ion exchange material. Manifold holes are located at opposite ends of the series flow path. A rigid port is positioned between each of the manifold holes and the ends of the series flow path. A plurality of the gaskets are stacked in a face to face relationship so that the manifold holes form conduits for fluid to flow to and from each of the series flow paths.

Abstract: An integral, monolithic frame-membrane is disclosed, such frame-membrane having a semi-permeable membrane portion and integral therewith a frame portion, the frame portion having one or more cavities, each cavity juxtaposed to the membrane portion, each cavity having at least one fluid entrance conduit communicating with an entrance manifold aperture and at least one fluid exit conduit communicating with an exit manifold aperture. The integral, monolithic frame-membrane may be used in apparatus for carrying out gas-separation; microfiltration; ultrafiltration; nanofiltration; reverse osmosis (i.e. hyperfiltration); diffusion dialysis; Donnan dialysis; electrodialysis (including filled-cell electrodialysis; i.e. electrodeionization); pervaporation; piezodialysis; membrane distillation; osmosis; thermo osmosis; and electrolysis with membranes.

Abstract: An apparatus for producing deionized water comprising 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 exchange resin particles packed in the demineralizing compartments, wherein the ion exchange resin particles are a mixture of at least two groups of ion exchange resin particles having a particle size distribution such that particles having particle sizes of from 75 to 125% of the average particle size, are at least 85 wt % of the total amount, and the average particle size of a group of ion exchange resin particles having the maximum average particle size, is at least 1.5 times the average particle size of a group of ion exchange resin particles having the minimum average particle size.

Abstract: Sweet whey is demineralized by an electrodeionization process by passing sweet whey to be demineralized through a resin bed of strong cationic exchange resin contained in an electrodeionization dilution compartment or through a resin bed of weak anionic and of cationic, particularly strong cationic, exchange resins in the compartment, and in the process, the pH of the wash solution present in the electrodionization cation and anion concentration compartments is maintained so that the solution present in each concentration compartment has a pH value less than 5.

Abstract: Low conductivity cooling water for a fuel cell body is obtained by a water treatment apparatus which removes dissolved carbon dioxide gas in the exhaust gas condensate by a decarbonation column. Iron oxide is eliminated from the condensate as well as blowdown water by a MF membrane separator device. Iron ions are removed by a chelate resin column. Deionization occurs with an electrodeionizer which has an internal ion exchange resin.

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: In an electrochemical cell arrangement for the deionization of aqueous solutions by ion exchange including cathode and anode chambers having electrodes disposed therein, a brine chamber is disposed between, and directly adjacent to, the cathode and anode chambers which are filled with anion and cation exchanger materials such that the electrodes are directly in contact therewith and means are provided for conducting the aqueous solution to be treated through the cathode and anode chambers and means for passing brine through the brine chamber to be charged therein by the ions removed from the aqueous solution in the cathode and anode chambers.

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

Abstract: An assembly consisting of at least one seal layer and a solid polymer ion exchange layer wherein the seal layer covers essentially only the region of the ion exchange layer which is to be sealed. The seal layer is made of porous polytetrafluoroethylene film having one surface coated and partially impregnated with a solid polymer ion exchange material. The seal layer provides support and masking functions for the solid polymer ion exchange layer during intermediate manufacturing steps, and reinforcement and effective sealing when assembled in an electrochemical apparatus.

Abstract: An integral, monolithic frame-membrane is disclosed, such frame-membrane having a semi-permeable membrane portion and integral therewith a frame portion, the frame portion having one or more cavities, each cavity juxtaposed to the membrane portion, each cavity having at least one fluid entrance conduit communicating with an entrance manifold aperture and at least one fluid exit conduit communicating with an exit manifold aperture. The integral, monolithic frame-membrane may be used in apparatus for carrying out gas-separation; microfiltration; ultrafiltration; nanofiltration; reverse osmosis (i.e. hyperfiltration); diffusion dialysis; Donnan dialysis; electrodialysis (including filled-cell electrodialysis; i.e. electrodeionization); pervaporation; piezodialysis; membrane distillation; osmosis; thermo osmosis; and electrolysis with membranes.

Abstract: Describes a method of electrochemically converting amine hydrohalide, e.g., ethyleneamine hydrochloride, into free amine, e.g., free ethyleneamine, by charging an aqueous solution of amine hydrohalide to the catholyte compartment of an electrolytic cell, which contains a cathode, charging hydrogen gas to the anode compartment of the cell, which contains an anode assembly comprised of a hydrogen consuming gas diffusion anode fixedly held between a current collecting electrode and an anion exchange membrane. The catholyte and anode compartments of the cell are separated by the anion exchange membrane. An amine hydrohalide solution containing free amine is removed from the catholyte compartment.

Abstract: An improved electrodeionization apparatus and method are provided. The electrodeionization apparatus includes electrolyte compartments, ion-concentrating, and ion-depleting compartments, having electroactive media therein. The electroactive media can be induced to have a reversible change in its chemical or electrical properties upon imposition of an external electrical field or the presence of an electrically charged substance. The change in chemical or electrical properties of the media results in a desired change in the transport or chemical properties of the media. The incorporation of the improved electroactive media also provides for an improved, and more reliable electrodeionization process in applications requiring chemical and temperature resistance media, where localized pH shifts would be harmful to the product being deionized, under temperature and chemical conditions of the liquid to be processed, or under circumstances where traditional media would tend to foul.

Abstract: An improved electrodeionization apparatus and method are provided. The electrodeionization apparatus includes an ion-concentrating compartment, an ion-depleting compartment, and electrolyte compartments, wherein alternating layers of anion exchange resins and cation exchange resins are positioned in the ion-depleting compartment, and the anion exchange resins comprise Type II anion resins. The incorporation of Type II anion material, alone or with Type I anion material, in anion permeable membranes and/or resins improves the electric current distribution, degree of resin regeneration, and deionization performance.

Abstract: A method for treating waste nitrocellulose, the method comprising the steps f treating nitrocellulose with acid in a hydrolysis process to break the nitrocellulose down to glucose, recovering a majority of the acid by electrodialysis, neutralizing a remainder of the acid, and fermenting the glucose to convert the glucose to a useful product. The invention further comprises a system for performing the above method.

Abstract: An improved apparatus for detecting anions in water includes an electrical continuous ion-exchange unit comprising an anode compartment and a cathode compartment which are spaced apart by an alkali removing compartment packed with a cation exchanger defined by two cation-exchange membranes. Each of the said anode compartment, cathode compartment and alkali removing compartment is provided with a passageway through which water is admitted and a passageway through which the treated water is discharged. The passageway through which the treated water is discharged from the alkali removing compartment is equipped with an instrument for measuring the specific resistance or electrical conductivity of the treated water.

Abstract: A electrochemical cell for removing ions from a solution stream comprises a housing having first and second electrodes. At least one water-splitting ion exchange membrane is positioned between the electrodes, the water-splitting membrane comprising (i) a cation exchange surface facing the first electrode, and (ii) an anion exchange surface facing the second electrode. A solution stream pathway is defined by the water-splitting membrane. The solution stream pathway comprises (i) an inlet for influent solution stream, (ii) at least one channel that allows influent solution stream to flow past at least one surface of the water-splitting membrane to form one or more treated solution streams, and (iii) a single outlet that combines the treated solution streams to form a single effluent solution.

Abstract: A method of manufacturing an apparatus for the electrodeionization of a fluid includes determining the flow rate of the fluid to be deionized, its initial concentration of ionic impurities, a desired post-processing concentration of ionic impurities and appropriately selecting the number of diluting compartments for use in the apparatus and the electrical current to be applied between the anode and cathode in the apparatus and manufacturing the apparatus accordingly.

Abstract: A porous ion exchanger which has a porous structure having ion exchange resin particles bound by a binder polymer, and which has a water permeability of at least 30 kg.multidot.cm.sup.-1 .multidot.hr.sup.-1 under a pressure of 0.35 kg/cm.sup.2.

Abstract: Electrically regenerable desalting apparatus having the desalting compartment packed with ion exchangers produced by utilizing radiation-initiated graft polymerization, in which said ion exchangers are nonwoven fabrics in the form of a fiber assembly and a cation exchanger and an anion exchanger are disposed in a face-to-face relationship, with a porous material being interposed between the two ion exchangers. Having the ability to reject ions from liquids, the apparatus is particularly suited to the production of pure water in the electrical power generating industries (including the nuclear industry), electronic industry and the pharmaceuticals manufacturing industry, as well as to the desalting of thick fluids encountered in food and chemical manufacturing processes.

Abstract: Apparatus for selecting connections from each of two or more inlet streams, at least two of which flow simultaneously, to one or more exit streams of a group of at least two. The apparatus has at least one rotatable first body, a first surface of which is adjacent to a first surface of a second body. The first body provides at least first and second fluid conduits, at least one end of each conduit terminating at the first surface of the first body. The second body also provides at least first and second fluid conduits, at least one end of each conduit terminating at the first surface of the second body. The first ends of each conduit provided by the first body and the first ends of each conduit provided by the second body are in such predetermined positions that the first conduit of the first body communicates with the second conduit of the second body.

Abstract: A membrane module in which non-porous membranes are bonded to spacer elements, which elements are in turn bonded to each other to create a membrane support zone as a result of contact with the surface of the membrane opposite the surface to which the membrane is bonded. The membrane is restrained from peeling from the membrane bond by the support zone under opposing pressure as may be caused by fluid flowing past the membrane. The preferred use of such a membrane module is for continuous electrodeionization processes.

Abstract: An electrolytic ionized water (EIW) producing apparatus comprises an anode, a cathode, an electrolyzer which includes an anode chamber, a cathode chamber and an intermediate chamber, inlet lines for supplying an influent water to the three chambers, and outlet lines for discharging effluent water from the chambers. Further, an acidic electrolyte supplying unit is connected to the outlet line from the anode chamber, and an alkaline electrolyte supplying unit is connected to the outlet line from the cathode chamber. The electrolyte supplying units can selectively control at least the dosage level of elelctrolyte(s) to be supplied, the composition and concentration of the electrolyte(s) or pH of EIW after the addition of the electrolyte(s).

Abstract: In an electrolytic ionized water (EIW) producing apparatus, a three-chamber electrolyzer includes an anode chamber, a cathode chamber and an intermediate chamber. An influent such as deionized water is supplied to these chamber via inlet lines. Further an electrolyte supplying units are connected to the inlet lines of the anode chamber and the inlet line of the cathode chamber.

Abstract: An electrochemical cell (50) for deionizsation utilizes electrochemical ion-exchange to remove ions from a feed solution. Under the influence of an electric field, ions are adsorbed into, are scored within and pass through a permeable layer (54, 64) of particulate ion-absorbing material and binder, the sheet being several millimeters thick. Water from the feed solution also permeates through the layer (54, 64), so a concentrated solution of the ions emerges from the rear (58) of the layer. The cell does not require separate sources of feed and eluant solutions and can be operated substantially continuously. In a modified cell (70) the flow path for the feed solution passes through a highly porous ion exchanger structure (77), which may be located between two such microporous layers (54, 64). Absorption in such a cell may be effective in the absence of an electric field, elution requiring the periodic application of the electric field.

Abstract: An ultra-thin composite membrane is provided which includes a base material and an ion exchange resin. The base material is a membrane which is defined by a thickness of less than 1 mil (0.025 mm) 0.8 mils and a microstructure characterized by node interconnected by fibrils, or a microstructure characterized by fibrils with no nodes present. The ion exchange resin substantially impregnates the membrane such that the membrane is essentially air impermeable.

Abstract: A process is provided for removing ions from water which is passed through an ion depletion compartment of an electrodeionization apparatus. The electrodeionization apparatus contains an ion depletion compartment containing mixed ion exchange resin beads and an ion concentration compartment which may contain ion exchange resin beads in a given separation stage having an anode and a cathode. The anion resin beads and cation resin beads utilized each comprise beams of substantially uniform size. A second liquid is passed through the ion concentration compartment to collect ions under the influence of DC potential which pass from the depletion compartments into the concentration compartments through ion permeable membranes. The electrodeionization apparatus can be operated continuously since resin regeneration is not required.