Abstract: A cross flow filtration apparatus for nanofiltration or reverse osmosis has pressure vessels with a plurality of filter cartridges in each vessel. A feed port is provided at an intermediate position on the side of the vessel, and two permeate flows or branches exit opposite ends of the vessel, and the first branch has a characteristically high “upstream” flux and quality, while the second is of lesser flux and/or quality. The system provides a high degree of moduarity, enhancing flux or yield at a reduced driving pressure or overall pressure drop. Centered or off-center port, and a stop or valve in the permeate stream may apportion flows between the two outlets. Staged systems may employ a first stage bypass to achieve a target quality with increased yield. A flow divider or adaptor permits the cartridges to fit and seal in the vessel and an installation tool or sleeve may facilitate installation or replacement of cartridges having a directional perimeter seal.

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: 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: 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: 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

Abstract: Apparatus and method for introducing ion-exchange and other particulates into certain compartments of an assembled electrodeionization stack comprising flowing a slurry of said particulates into the compartments while employing strainers for particulate retention so as to form a packed bed in the compartments; also apparatus and method for flowing said particulates out of said stack in the form of a slurry.

Abstract: Apparatus and method for introducing ion-exchange and other particulates into certain compartments of an assembled electrodeionization stack comprising flowing a slurry of said particulates into the compartments while employing strainers for particulate retention so as to form a packed bed in the compartments; also apparatus and method for flowing said particulates out of said stack in the form of a slurry.

Abstract: Apparatus and method for introducing ion-exchange and other particulates into certain compartments of an assembled electrodeionization stack comprising flowing a slurry of said particulates into the compartments while employing strainers for particulate retention so as to form a packed bed in the compartments; also apparatus and method for flowing said particulates out of said stack in the form of a slurry.

Abstract: An electrodeionization polarity reversal apparatus is employed for the removal of dissolved salts from liquids. The preferred embodiment comprises the use of a fluid permeable filler of an equinormal mixture of anion and cation exchange material in both the ion-depleting and ion-concentration chambers while employing periodic symmetrical polarity reversal.

Abstract: A corrosion resistant electrode connector assembly suitable for use in electrodialysis cells is disclosed, in which a jacket of titanium pipe is closely and mechanically fitted over an electrically conducting pipe comprised, for example, of copper. The assembly is flattened, closed at one end, and drilled to receive a plurality of connecting bolts. In use, an electrical conductor cable is attached to the assembly at the open end and the connector assembly securely bolted to an electrode.