Abstract: Pretreatment method and apparatus to remove matrix ions from a liquid sample, prior to separation of the sample analytes (e.g. by chromatography), by flowing the liquid sample into a sample compartment and stopping the flow. The sample compartment has a wall comprising an ion exchange membrane having exchangeable ions of the same charge as the matrix ions to be removed. A regenerant liquid stream flows through a regenerant flow compartment on the other side of the membrane from said parked liquid sample. Matrix ions in the parked liquid sample are transported across the membrane into the regenerant flow compartment. Suppression may be performed electrolytically and/or chemically. A concentrator column may also be used.

Abstract: Pretreatment method and apparatus to remove matrix ions from a liquid sample, prior to separation of the sample analytes (e.g. by chromatography), by flowing the liquid sample into a sample compartment and stopping the flow. The sample compartment has a wall comprising an ion exchange membrane having exchangeable ions of the same charge as the matrix ions to be removed. A regenerant liquid stream flows through a regenerant flow compartment on the other side of the membrane from said parked liquid sample. Matrix ions in the parked liquid sample are transported across the membrane into the regenerant flow compartment. Suppression may be performed electrolytically and/or chemically. A concentrator column may also be used.

Abstract: The invention comprises novel apparatuses and testing methods for evaluating a fluid diffusion component. The apparatus includes a fluid capable of undergoing oxidation or reduction, a half-cell electrode assembly able to receive the fluid, and a change in acidity indicator in communication with the assembly. An inventive method of the invention includes the steps of passing a fluid capable of undergoing oxidation or reduction through a half-cell electrode assembly to form a sample, contacting the sample with an indicator, and detecting a change in acidity in the indicator.

Abstract: An apparatus for industrial wastewater treatment and the electrolytic recovery of metals from solutions is disclosed. It comprises two or more plates with electricity conducting surfaces arranged in parallel and separated by insulating gaskets, two heads and a hydraulic ram or other mechanical means to press the group of plates between the heads. Plates and gaskets pressed together form chambers where metal recovery and other electrochemical reactions take place. Holes bored on the plates or on the gaskets separating them allow the solutions to flow in and out of the chambers. The solutions in the chambers close the electrical circuit between the conducting surfaces of the plates and allow an electrical current to flow from one plate to the other closing also a circuit between the terminals of an electrical current source.

Abstract: An electrokinetic method and apparatus for discretely collecting ionic contaminants from a variety of media, with an ionic current there across in which an ion collection compartment has been positioned. Each compartment preferably compromises of an anion or cation exchange membrane and a solution that provides an accumulation zone for ions that permeate into the compartment. After the collection period, the solution is extracted from the compartment, and the concentration of ionic contaminants is determined using standard analytical methods. The preferred apparatus embodiment for use in conjunction with such a method has a direct-push probe configuration. The apparatus can be used (a) to detect low concentrations of ionic contaminants, (b) to evaluate cleanup efficiencies, and (c) to monitor the transport of ionic contaminants.

Abstract: Filter or filter-element designated for Modified Electro-Dialysis (MED) purposes characterized in that the filter or filter-element comprises a porous, ceramic, mainly uniform material with functional, preferably ion selective groups grafted onto the inner, porous surface of the ceramic body. The outer surface of the filter or filter-element may be completely or partly covered by layers of porous, ceramic membranes with a pore size of less than 1 ?m and thickness less than 1 mm, and/or anion, cation or bipolar groups or membranes. The thickness of the filter-element is larger than 1 mm and has pores of size larger than 1 ?m. The invention also relates to a method for the manufacture of such a filter either continuously by tape-casting, extruding, rolling or calendaring or single-bodied by casting, pressing or forging, of a paste containing a non-conductive, ceramic material.

Abstract: An generator of pure pressurized high pressure hydrogen comprising a molten hydroxide or eutectic mixture electrolyte pressurizing chamber bounded by a hydrogen-selective anode and a hydrogen-selective otherwise gas impermeable cathode respectively connected to a D.C. power supply, with the pressurizing chamber maintained at a temperature between the melting point of the electrolyte and about 600° C., wherein, upon passing D.C. current between the anode and cathode, pure hydrogen arriving on the electrolyte bounding with the anode substantially instantaneously reacts with hydroxyl ions from the electrolyte to form water and electrons and evolves pressurized pure hydrogen gas on the cathode, and with such substantially instantaneous reaction at the anode creating a suction effect which effectively pumps pure hydrogen permeating through said anode.

Abstract: An electrophoresis system for removing or reducing concentration of a metabolic component from blood or plasma of a subject is provided. A method for removing or reducing concentration or amount of a metabolic component in blood or plasma of a subject is also provided. The system and method include use of a set of ion permeable barriers and the application of an electrical potential across these barriers to selectively remove metabolic components from blood or plasma.

Abstract: The invention relates to a composite or a composite membrane consisting of an ionomer and of an inorganic optionally functionalized phyllosilicate. The isomer can be: (a) a cation exchange polymer; (b) an anion exchange polymer; (c) a polymer containing both anion exchanger groupings as well as cation exchanger groupings on the polymer chain; or (d) a blend consisting of (a) and (b), whereby the mixture ratio can range from 100% (a) to 100% (b). The blend can be ionically and even covalently cross-linked. The inorganic constituents can be selected from the group consisting of phyllosilicates or tectosilicates.

Abstract: An electrolytic bath is divided into an anodic chamber and a cathodic chamber by a cation-exchange membrane. A base alkaline solution of high impurity concentration is supplied into the anodic chamber from a tank of a base material as well as a circulating anolyte overflowed from the anodic chamber is supplied and circulated from an anode circulating tank, and NaOH solution of low impurity concentration is supplied and circulated into the cathodic chamber through a tank of a refined solution. The concentration of the circulating anolyte is detected, and based on this detected value the supplying amount of the base NaOH solution is controlled and electrolysis is performed. Thus, the concentration of NaOH solution in the anodic chamber is kept stable, and the refined NaOH solution of low impurity concentration can be obtained in the cathodic chamber.

Abstract: An electro-osmotic cell capable of substantially reducing zero-current transport is disclosed, wherein the cell includes a cell housing having a first half cell and a second half cell, with an ion selective membrane therebetween, a first electrode positioned within the first half cell, a second electrode positioned within the second half cell, an electrolyte in electrical communication with the first electrode and the second electrode, and a wiring apparatus electrically connecting the first electrode and the second electrode, wherein the wiring apparatus has one or more structures used for counteracting salt concentration increases within the electro-osmotic cell. Such a cell may be used within an electro-osmotic fluid delivery device, along with a fluid inlet, a piston member adjacent the electro osmotic cell, and a drug reservoir adjacent the piston member, wherein the drug reservoir includes a sealed compartment having an exit port. A method for using such a device is similarly disclosed.

Abstract: Flow-through capacitors are provided with one or more charge barrier layers. Ions trapped in the pore volume of flow-through capacitors cause inefficiencies as these ions are expelled during the charge cycle into the purification path. A charge barrier layer holds these pore volume ions to one side of a desired flow stream, thereby increasing the efficiency with which the flow-through capacitor purifies or concentrates ions.

Abstract: A microfabricated device employing a bridging membrane and methods for electrokinetic transport of a liquid phase biological or chemical material using the same are described. The bridging membrane is deployed in or adjacent to a microchannel and permits either ionic current flow or the transport of gas species, while inhibiting the bulk flow of material. The use of bridging membranes in accordance with this invention is applicable to a variety of processes, including electrokinetically induced pressure flow in a region of a microchannel that is not influenced by an electric field, sample concentration enhancement and injection, as well as improving the analysis of materials where it is desired to eliminate electrophoretic bias. Other applications of the bridging membranes according to this invention include the separation of species from a sample material, valving of fluids in a microchannel network, mixing of different materials in a microchannel, and the pumping of fluids.

Abstract: An electrodeionization apparatus comprising an endblock formed from a resilient material, and method for making the same. The resilient material may include various types of thermoplastic elastomers, such as, styrene block copolymers, copolyesters, plolyurethanes, polyamides, thermoplastic elastomeric olefins, and thermoplastic vulcanizates. The resilient material may have a Shore A hardness of between about 40 and about 90.

Abstract: The present invention provides a cation exchange membrane which has excellent durability, a high limiting current density, a low direct current membrane resistance and excellent selectivity to monovalent cations. In the present invention, a cation exchange membrane excellent in selective permeability to monovalent cations is produced by bringing high molecular cations into contact with a surface of a cation exchange membrane in the presence of anions of an oxyacid or anions of an organic sulfonic acid.

Abstract: An electrodeionization apparatus and method of use includes an expanded conductive mesh electrode. The expanded conductive mesh electrode may be formed from any conductive material that is dimensionally stable and may be coated with conductive coating suitable for use in anode or cathode service. The expanded conductive mesh electrodes are formed by slitting a sheet of metal and pulling its sides in a direction perpendicular to the slits. The fabricated mesh may be flattened after stretching. The expanded conductive mesh electrodes typically have a diamond-shaped pattern of any size that provides support for an adjacent ion-permeable membrane while allowing an electrode or fluid stream to flow through. The mesh size typically has a long-wise dimension and a short-wise dimension. The conductive mesh electrode may also be placed against an endblock having fluid channels. These channels may be serpentine or parallel channels, which allow fluid flow to wash away any accumulation.

Abstract: An electrodialysis cell (40) suitable for removal of paint solubilizer from electrocoat paint ultrafilter permeate includes a tubular, non-conductive housing (42), a substantially cylindrical, hollow object electrode (48) in the housing, a substantially cylindrical counter electrode (52) situated within the hollow object electrode, and a tubular ion exchange membrane (50) around the counter electrode but spaced from the counter electrode as well as the object electrode. The counter electrode and the tubular membrane together define an annular electrolyte passageway while the object electrode and the tubular membrane together define an annular ultrafilter permeate passageway. The object electrode-to-counter electrode area ratio is at least about 6.

Abstract: For dosing lithium in cooling water containing cationic impurities or for reducing cationic impurities, the invention guides cooling water cycle through a first side of an electrodialysis unit and guides a concentration cycle through a second side of the electrodialysis unit. Cationic impurities are filtered out of the medium of the concentration cycle with a selective ion exchanger that is disposed in the concentration cycle.

Abstract: The invention relates to a composite or a composite membrane consisting of an ionomer and of an inorganic optionally functionalized phyllosilicate. The isomer can be: (a) a cation exchange polymer; (b) an anion exchange polymer; (c) a polymer containing both anion exchanger groupings as well as cation exchanger groupings on the polymer chain; or (d) a blend consisting of (a) and (b), whereby the mixture ratio can range from 100% (a) to 100% (b). The blend can be ionically and even covalently cross-linked. The inorganic constituents can be selected from the group consisting of phyllosilicates or tectosilicates.

Abstract: Feed water, fed through an inlet 6 into a desalting compartment 8, flows around the end 4a of a anion-exchange membrane 4 surrounding an anode 2a. The feed water enters into a portion defined between the anion-exchange membrane 4 and a cation-exchange membrane 5, and flows around the end 5a of the cation-exchange membrane 5 surrounding a cathode 3a. Then, the water to be treated further flows around the ends 4b, 5b of ion-exchange membranes 4, 5 surrounding an anode 2b and a cathode 3b, respectively, and then flows out through a product water outlet 7. A part of product water is supplied to the concentrated water circulating within the concentrating compartment 30, 40. A part of the concentrated water flowing out of the concentrating compartment 30, 40 is added to concentrated water circulating within the concentrating compartment 10, 20. The diffusion of silica from the concentrating compartment is restricted. As a result, final product water containing extremely low silica concentration is obtained.

Abstract: Bipolar membrane electrodialysis methods for salt splitting polyvalent metal salts, where the metal cation can form substantially insoluble precipitates in the presence of hydroxyl ions can now be used in recovering acid and base values from a salt streams without precipitates fouling cell operation and causing shutdown. The introduction of an acid to the chamber where metal hydroxides would form inhibits their development or neutralizes formed solids, allowing salt splitting to continue. Salt splitting methods of the invention performed with a three compartment bipolar electrodialysis cell are useful in producing concentrated and purified acid forms, such as 2-keto-L-gluconic acid, H(KLG), a key intermediate in the production of ascorbic acid.

Abstract: An apparatus and the process produces salts by an electrodialysis operation. The basic electrodialysis apparatus is a cell having a number of compartments separated by membranes. A DC source is connected to drive a current through a feed stream passing through the cell which splits the salt stream into an acid and a base. The incoming feed may be nanofiltered to remove divalent metal. The base loop may be in communication with an ion exchange column packed with a material that removes multivalent cations. Depending upon the material being processed and the desired end result either or both the nanofiltration and the ion exchanged column may be used in the apparatus.

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: 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: 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: The present invention concerns methods for masking inhomogeneity of a member of a specific binding pair (sbp) employed in a capillary electroseparation. The method comprises binding the sbp member to synthetic particles that become localized during capillary electroseparation. Also disclosed is one embodiment of the present invention, which is a method for conducting a capillary electroseparation specific binding assay. The method involves the electroseparation of a labeled first member of a specific binding pair that is bound in a complex from labeled first member that is not bound in the complex. The complex comprises the first member and a second member of a specific binding pair. A combination is provided comprising a sample suspected of containing an analyte, a labeled first member of a specific binding pair, and a second member of a specific binding pair under conditions for forming a complex between labeled first member and the second member.

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: 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: The invention relates to an electrochemical process for the production of sodium hydroxide and sulfuric acid from aqueous sodium sulfate solutions, said process comprising the feeding of an aqueous sodium sulfate solution into a salt splitter device comprising at least three compartments including a middle feed compartment which is between an anode compartment and a cathode compartment, wherein the feed compartment is separated from the anode compartment by a chemically-functionalized anion exchange membrane, and wherein the feed compartment is separated from the cathode compartment by a chemically-functionalized cation exchange membrane. Specifically, the chemically-functionalized anion exchange membrane of the present invention is a perfluorohydrocarbon polymer material to which has been grafted a plurality of benzo-crown ether groups which have been complexed with a metal ion selected from sodium, potassium and lithium.

Abstract: A charge-flow separation apparatus (CFS) for enriching rare cell populations, particularly fetal cells, from a whole blood sample by separating the rare cell fractions from whole fractions according to the relative-charge density and/or the relative binding affinity for a leukocyte depletion solid phase matrix is described. The apparatus having an internal cooling system allows for dissipating heat generated by the electric field of the apparatus. The internal cooling system, consisting of a plurality of cooling tubes to circulate coolant material, prevents cellular degradation typically associated with the high heat generated by the electric field and permits the use of a higher voltage gradient to shorten separation times.

Abstract: Describes a method of electrochemically converting amine hydrohalide, e.g., ethyleneamine hydrochloride, into free amine, e.g., free ethyleneamine. A three compartment electrolytic cell is provided having (1) a catholyte compartment containing a cathode assembly comprising a cathode and an anion exchange membrane, (2) an anode compartment containing an anode assembly comprising either (a) a hydrogen consuming gas diffusion anode and a current collecting electrode or (b) a hydrogen consuming gas diffusion anode which is fixedly held between a hydraulic barrier and a current collecting electrode, and (3) an intermediate compartment separated from the catholyte and anode compartments by the anion exchange membrane and either (i) the hydrogen consuming gas diffusion anode or (ii) the hydraulic barrier respectively.

Abstract: Describes a method of electreochemically converting amine hydrohalide, e.g., amine hydrochloride, into free amine, e.g., free ethyleneamine. An electrolytic cell is provided having (1) a catholyte compartment containing a cathode assembly comprising a cathode and a bipolar ion exchange membrane, (2) an anode compartment containing an anode assembly comprising either (a) a hydrogen consuming gas diffusion anode and a current collecting electrode or (b) a hydrogen consuming gas diffusion anode which is fixedly held between a hydraulic barrier and a current collecting electrode, and (3) at least one pair of intermediate compartments separating the catholyte and anode compartments and separated from each other by an anion exchange membrane.

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: A gas-diffusion cathode disposed in contact with an ion-exchange membrane partitioning an electrolytic cell into an anode chamber and a cathode chamber, wherein at least one guide piece is disposed in the gas-diffusion cathode and a salt water electrolytic cell using the above-described gas-diffusion cathode. By using the above-described gas-diffusion cathode for salt water electrolysis, an aqueous caustic alkali solution formed descending in the direction of gravity in the cathode changes direction of movement by contact with a guide piece, whereby the decreased electrode performance resulting from the hindrance of the supply of raw material gas and the discharge of the gas formed caused by the retention of the descending caustic alkali solution is prevented and a large-sized electrolytic cell can be used without problems generally encountered in conventional electrolytic systems.

Abstract: The present invention relates to an electrochemical cell and a process for producing a hydroxide solution, sulfuric acid and a halogen gas from a hydrogen halide and a sulfate solution. In particular, the sulfate solution may be an alkali metal sulfate solution, such as sodium or potassium sulfate solution, an alkaline earth metal sulfate solution or an ammonium sulfate solution. The cell and the process may use either an anhydrous or an aqueous hydrogen halide, namely, hydrogen chloride, hydrogen fluoride, hydrogen bromide and hydrogen iodide, to a respective dry halogen gas, such as chlorine, fluorine, bromine, or iodine, to produce hydrogen ions in order to split the alkali metal solution and form the sulfuric acid. The cell has two membrane-electrode assemblies, where an anode is disposed in contact with one membrane, and a cathode is disposed in contact with another membrane. The sulfate solution is fed in between the membrane-electrode assemblies.

Abstract: In an electrolyzer provided according to this invention, the polarity of electrodes is periodically inverted at very short intervals. This has the effect of allowing gases to be generated uniformly all over the surface of each electrode in the form of extremely small bubbles instead of being formed in specific positions in the form of large bubbles as is the case with a conventional electrolyzer in which a direct current is allowed to flow without changing the flow direction. Thus the surfaces of electrodes are prevented from being covered with bubbles, and the flow of liquids along the surfaces of electrodes is not disturbed by the bubbles any more.

Abstract: In a process for an electrochemical treatment of cellulose waste lye, mass transport takes place through a diaphragm or membrane between a cathode chamber and an anode chamber, and optionally through a middle chamber. Cationogenic components are removed from cellulose waste lye containing lignin sulfonates and being located in at least one of the chambers. Lignin sulfonic acids are produced from the waste lye. In an installation for an electrochemical treatment of cellulose waste lye, at least one diaphragm divides at least one reaction vessel into at least one cathode chamber and at least one anode chamber. At least one cathode electrode is disposed in the at least one cathode chamber, and at least one anode electrode is disposed in the at least one anode chamber. The at least one cathode electrode is formed of iron or aluminum and the at least one anode electrode is formed of special steel, in particular V4A steel.

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: The present invention relates to an electrochemical cell and a process for using a halogen halide and splitting a sulfate solution and producing a hydroxide solution, sulfuric acid and a halogen gas. In particular, the sulfate solution may be an alkali metal sulfate solution, such as sodium or potassium sulfate solution, an alkaline earth metal sulfate solution or an ammonium sulfate solution. The cell and the process may use either an anhydrous or an aqueous hydrogen halide, namely, hydrogen chloride, hydrogen fluoride, hydrogen bromide and hydrogen iodide, to a respective dry halogen gas, such as chlorine, fluorine, bromine, or iodine, to produce hydrogen ions in order to split the sulfate solution and form the sulfuric acid. The cell has two membrane-electrode assemblies, where an anode is disposed in contact with one membrane, and a cathode is disposed in contact with another membrane. The sulfate solution is fed in between the membrane-electrode assemblies.

Abstract: A system for pretreating sample streams including a concentrated matrix compound to neutralize the compound. The system includes an electrochemical membrane device in which sample flows through a sample flow channel of the device separated from a matrix ion receiving flow channel by an ion exchange membrane preferentially permeable to ions of the opposite charge to the ions to be analyzed. The ionic species in the thus-pretreated sample are directed to an analytical system such as an ion chromatograph.

Abstract: An electrodialyzer for desalinating an aqueous solution comprises a plurality of parallel chambers (5, 6, 7, 8) formed alternately of anion exchange membranes (3) and cation exchange membranes (2, 4) arranged in a non-linear flow path the aqueous solution so that the solution passes successively across a surface of each of the membranes. The two end chambers (5, 8) house an anode (9) and a cathode (18) connected to a source of electrical bias (11) and this causes ions to form and to migrate from the flow path into a concentration chamber (6) separated from the flow path by membranes (2, 3) from which the concentrated fluid can be drawn off. A process is also described for desalinating aqueous solutions.

Abstract: Method and apparatus for flow injection analysis (FIA) using an electroosmotic pump. The apparatus includes: an electroosmotic pump having a grounding joint; a sample injection valve for introducing a sample into a carrier stream which valve is in fluid communication with the grounding joint by way of a conduit; a dispersion coil in fluid communication with the sample injection valve; and a detector which is in fluid communication with the dispersion coil. The grounding joint couples the electroosmotic pumping system and the FIA system but electrically isolates them.Generally, the method utilizes one fluid which is electroosmotically pumped to propel a carrier for flow injection analysis at a controllable flow rate. More specifically, the method includes the steps of: adding a sample to a liquid carrier stream to form a sample zone in the carrier stream; flowing a liquid pumping stream by electroosmosis; and connecting the pumping stream with the carrier stream to propel the carrier stream.

Abstract: Electrodialysis ("ED") stacks are disclosed having components selected from the group:a) cation exchange ("CX") membranes and/or CX granules having in at least a surface a predominant amount of sulfonate exchange groups and a minor amount of weakly ionized exchange groups;b) anion exchange ("AX") membranes and/or AX granules having in at least a surface substantially only quaternary ammonium and/or phosphonium exchange groups which upon decomposition leave almost no amine or phosphine groups bound to the membranes or granules;c) AX and/or CX granules which are selective to monovalent ions at currents which are fractions of the limiting current of such granules;d) AX and/or CX membranes and granules, such membranes and granules selective to monovalent ions at currents which are fractions of the limiting current of such membranes and granules;e) ion exchange ("IX") granules in which the concentration of IX groups in the inner regions is a fraction (including zero) of the concentration in the outer regions;f) AX