The present invention offers a forward osmosis composite hollow fiber membrane module having hollow fiber bundles comprising a plurality of hollow fibers, the hollow fibers having a separation layer composed of a macromolecular polymer thin film provided on the inner surface of a microporous hollow fiber supporting membrane, wherein the membrane area of the hollow fiber bundle is at least 1 m.sup.2, and a variation coefficient for the average thickness of the separation layer in the radial direction and the lengthwise direction of the hollow fiber bundles, as calculated by a method of measuring the mass of the separation layer portion in a scanning electron microscope image of a cross section of the separation layer in the thickness direction, is 0% to 60%.

The present invention offers a forward osmosis composite hollow fiber membrane module having hollow fiber bundles comprising a plurality of hollow fibers, the hollow fibers having a separation layer composed of a macromolecular polymer thin film provided on the inner surface of a microporous hollow fiber supporting membrane, wherein the membrane area of the hollow fiber bundle is at least 1 m.sup.2, and a variation coefficient for the average thickness of the separation layer in the radial direction and the lengthwise direction of the hollow fiber bundles, as calculated by a method of measuring the mass of the separation layer portion in a scanning electron microscope image of a cross section of the separation layer in the thickness direction, is 0% to 60%.

The present invention relates to a fresh water generation method including: feeding raw water or pretreated water thereof as feed water into a semipermeable membrane module in a pressurized state using a booster pump, thereby separating the feed water into a concentrate and a permeate having a low concentration, in which a scale inhibitor having a reducing function is dosed intermittently or continuously upstream from the semipermeable membrane module, thereby inhibiting scale generation and maintaining an oxidation-reduction potential of at least either the feed water or the concentrate to a threshold value or lower.

The present invention relates to a fresh water generation method including: feeding raw water or pretreated water thereof as feed water into a semipermeable membrane module in a pressurized state using a booster pump, thereby separating the feed water into a concentrate and a permeate having a low concentration, in which a scale inhibitor having a reducing function is dosed intermittently or continuously upstream from the semipermeable membrane module, thereby inhibiting scale generation and maintaining an oxidation-reduction potential of at least either the feed water or the concentrate to a threshold value or lower.

An ion-permeable membrane is substantially free of holes and has excellent ion permeability, heat resistance, strength, and flexibility. A battery electrolyte membrane uses the ion-permeable membrane, and can form an electrode composite body. The polymer-ion-permeable membrane has an average radius of free volume of 0.32-0.50 nm.

An ion-permeable membrane is substantially free of holes and has excellent ion permeability, heat resistance, strength, and flexibility. A battery electrolyte membrane uses the ion-permeable membrane, and can form an electrode composite body. The polymer-ion-permeable membrane has an average radius of free volume of 0.32-0.50 nm.

The present invention relates to improved methods for the preparation of thin film composite membranes by interfacial polymerization, preferably (organic) solvent resistant thin film composite membranes. More in particular the method of the present invention allows for the preparation of thin film composite membranes wherein a thin film is deposited on a porous crosslinked support. Said method comprises the one step solidification, impregnation and crosslinking of the porous support through phase inversion by immersion of the cast membrane polymer film in an (aqueous) solvent comprising a polyfunctional monomers.

A method for making a composite polyamide membrane including a porous support and a thin film polyamide layer, wherein the method includes: (i) applying a polar solution comprising a polyfunctional amine monomer and a non-polar solution comprising a polyfunctional acyl halide monomer to a surface of a porous support and interfacially polymerizing the monomers to form a thin film polyamide layer; (ii) treating the thin film polyamide layer with a polyfunctional arene compound; and (iii) exposing the thin film polyamide layer to nitrous acid; wherein the polar and non-polar solutions further comprises at least one of the following: (A) at least one of the solutions further comprises a tri-hydrocarbyl phosphate compound represented by Formula (I): and (B) the non-polar solution further comprises an acid-containing monomer comprising a C.sub.2-C.sub.20 hydrocarbon moiety substituted with at least one carboxylic acid functional group or salt thereof and at least one amine-reactive functional group. ##STR00001##

A method for making a composite polyamide membrane including a porous support and a thin film polyamide layer, wherein the method includes: (i) applying a polar solution comprising a polyfunctional amine monomer and a non-polar solution comprising a polyfunctional acyl halide monomer to a surface of a porous support and interfacially polymerizing the monomers to form a thin film polyamide layer; (ii) treating the thin film polyamide layer with a polyfunctional arene compound; and (iii) exposing the thin film polyamide layer to nitrous acid; wherein the polar and non-polar solutions further comprises at least one of the following: (A) at least one of the solutions further comprises a tri-hydrocarbyl phosphate compound represented by Formula (I): and (B) the non-polar solution further comprises an acid-containing monomer comprising a C.sub.2-C.sub.20 hydrocarbon moiety substituted with at least one carboxylic acid functional group or salt thereof and at least one amine-reactive functional group. ##STR00001##

Embodiments provide a filter with a generally rectangular, non-cylindrical profile. The filter may have multiple pleat packs positioned between pleat covers that define regions and flow channels in a cavity of the filter body. The pleat covers have openings that allow a fluid to flow through the multiple pleat packs via parallel flows or series flows. End caps bonded to the body define flow passages for directing the fluid from an inlet to an outlet via the pleat packs for series or parallel filtration. The pleat packs may be made of the same or different materials and may be configured with the same or different heights based on flow requirements. A cage or a separator may be positioned between the pleat packs. The pleat packs may be made of a continuous pleated membrane with bridges defining a space between the pleat packs to accommodate the cage or separator.