Abstract: The present invention provides anion exchange membranes, processes for producing same and uses thereof. The anion exchange membranes according to embodiments of the present invention achieve a desirable combination of low resistance, high permselectivity and low degree of dimensional swelling. Anion exchange membranes according to embodiments of the present invention are also cost effective.

Abstract: The present invention provides anion exchange membranes, processes for producing same and uses thereof. The anion exchange membranes according to embodiments of the present invention achieve a desirable combination of low resistance, high permselectivity and low degree of dimensional swelling. Anion exchange membranes according to embodiments of the present invention are also cost effective.

Abstract: There is provided a membrane module comprising a membrane package comprising at least two membrane sleeves, wherein the membrane package is configured to allow essentially free flow of a first stream inside the sleeves and essentially free flow of a second stream between each two adjacent sleeves, and a frame, configured to support the membrane package, such that part of each of four surfaces of the membrane package is affixed to predetermined areas in the frame, forming a module having separate spaces configured to facilitate separate flows of the first stream and the second stream through the membrane package. The invention further provides a multi-modular stack, comprising at least two membrane modules and at least one membrane, wherein the first stream is fully enclosed inside each module and the second stream flows through all the modules.

Abstract: There is provided herein a membrane or film comprising one or more aromatic ionomers covalently crosslinked through aryl-aryl (—Ar—Ar—), aryl-ether-aryl (—Ar—O—Ar—), aryl-sulfide-aryl (—Ar—S—Ar—), aryl-sulfone-aryl bonds, or any combination thereof, wherein said one or more aromatic ionomers further comprises at least one electron withdrawing group adapted to improve oxidant resistance of said membrane or film.

Abstract: The present invention provides anion exchange membranes, processes for producing same and uses thereof. The anion exchange membranes according to embodiments of the present invention achieve a desirable combination of low resistance, high permselectivity and low degree of dimensional swelling. Anion exchange membranes according to embodiments of the present invention are also cost effective.

Abstract: There is provided herein a membrane or film comprising one or more aromatic ionomers covalently crosslinked through aryl-aryl (—Ar—Ar—), aryl-ether-aryl (—Ar—O—Ar—), aryl-sulfide-aryl (—Ar—S—Ar—), aryl-sulfone-aryl bonds, or any combination thereof, wherein said one or more aromatic ionomers further comprises at least one electron withdrawing group adapted to improve oxidant resistance of said membrane or film.

Abstract: There are provided herein selective membranes, such as composite membranes, and/or films and processes for their preparation. The membranes and/or films have a given morphology which may be stabilized, for example against swelling and chemical degradation, by covalent crosslinking and optionally, in addition, by hydrophobization. There is provided a membrane and/or film and a process for the preparation thereof, the membrane and/or film include an ionomer and/or polyelectrolyte crosslinked through aryl-aryl (—Ar—Ar—), aryl-ether-aryl (—Ar—O—Ar—) and/or aryl-sulfide-aryl (—Ar—S—Ar—) bonds.

Abstract: There are provided herein selective membranes, such as composite membranes, and/or films and processes for their preparation. The membranes and/or films have a given morphology which may be stabilized, for example against swelling and chemical degradation, by covalent crosslinking and optionally, in addition, by hydrophobization. There is provided a membrane and/or film and a process for the preparation thereof, the membrane and/or film include an ionomer and/or polyelectrolyte crosslinked through aryl-aryl (—Ar-Ar-), aryl-ether-aryl (—Ar—O—Ar—) and/or aryl-sulfide-aryl (—Ar—S—Ar—) bonds.

Abstract: There is provided herein a membrane package comprising a plurality of membranes, wherein said membrane package is adapted to facilitate a feed stream flow having a process stream flow wherein said hydrodynamic resistance of said feed stream flow is substantially the same as said hydrodynamic resistance of said process stream flow.

Abstract: Process for producing ion exchange membranes. A matrix material that comprises a polymeric component chosen from the group consisting of monomeric and oligomeric polymer precursors and cross-linkable polymers is provided. Ion cation or anion exchange particles, or proton or hydroxyl or ion conducting particles, or cation or anion exchange polymers, or proton or hydroxyl or ion conducting polymers are introduced in the matrix. The particles are mixed or the polymer is dissolved with the matrix. The resulting mixture is formed into membrane configuration. The particles or the domains of the polymer formed by polymer-matrix phase separation upon solvent evaporation or cooling, are ordered by an electric field.

Abstract: An evaporation device for increasing evaporation from a surface of a body of liquid, comprises at least one evaporation element having at least one evaporation surface wettable by the liquid and at least partially exposable to wind when wetted, so as to allow evaporation of the liquid from the evaporation surfaces whereby the total evaporation area of the surface of the body of liquid is increased.

Abstract: Process for producing ion exchange membranes. A matrix material that comprises a polymeric component chosen from the group consisting of monomeric and oligomeric polymer precursors and cross-linkable polymers is provided. Ion cation or anion exchange particles, or proton or hydroxyl or ion conducting particles, or cation or anion exchange polymers, or proton or hydroxyl or ion conducting polymers are introduced in the matrix. The particles are mixed or the polymer is dissolved with the matrix. The resulting mixture is formed into membrane configuration. The particles or the domains of the polymer formed by polymer-matrix phase separation upon solvent evaporation or cooling, are ordered by an electric field.

Abstract: An evaporation device for increasing evaporation from a surface of a body of liquid, comprises at least one evaporation element having at least one evaporation surface wettable by the liquid and at least partially exposable to wind when wetted, so as to allow evaporation of the liquid from the evaporation surfaces whereby the total evaporation area of the surface of the body of liquid is increased.

Abstract: The invention provides a polymeric netting for use as an ion-conducting ser in an electrodialysis stack having charged groups incorporated in a in polymeric coating applied thereto, imparting to the spacer an average ion exchange capacity of at least 0.25 meq/gr.

Abstract: The invention concerns heterogeneous ion exchange membranes used in electrodialysis which have anti-polarization and anti-fouling properties.The heterogeneous membranes of the invention comprise, in addition to ion-exchange particles embedded in the matrix, a layer of at least one hydrophilic cross-linked polymer bearing fixed electric charges. Alternatively, the heterogeneous membranes of the invention have a matrix which is itself made of at least one hydrophilic cross-linked polymer.

Abstract: A supported, mechanically stable bipolar membrane for electrodialysis having a cation-exchange layer on one side and an anion-exchange layer on the other side of a single sheet of woven fabric. The cation exchange layer is heterogeneous, the anion exchange layer is homogeneous and the two are interlocked. A process of making such bipolar membranes is described. The bipolar membrane may be fabricated into electrodialysis cells in which two membranes are joined along their edges.

Abstract: Water softening by a combination of electrodialysis and calcium carbonate precipitation. The hard feed water or alternatively recycled soft water is rendered alkaline and is then subjected to a treatment by which precipitation of calcium carbonate is induced. One way of bringing about such precipitation consists in passing the alkaline water across a cake of calcium carbonate crystals having a size not exceeding 100 microns, deposited on a filter and being in an at least fifty fold excess over the amount of calcium carbonate to be precipitated.

Abstract: Process for softening hard water by precipitation of calcium carbonate. The hard water is rendered alkaline, e.g. by the addition of sodium hydroxide, and is then contacted with a large excess of calcium carbonate crystals whose size does not exceed 100 microns, whereby precipitation occurs within a short contact time of the order of 2-60 seconds. Upon separation of soft water from calcium carbonate the bulk of the latter is recirculated and excessive amounts are removed.

Abstract: There are provided integrated modules for use in electrodialysis devices, which modules comprise a plurality of unit cells each of which consists of a cation specific membrane, a spacer and an anion specific membrane, said membranes being sealed along the edges of the cell, a spacer being provided between consecutive cells serving for sealing along the edges, an outlet being provided for the brine, outlets of individual cells being arranged as common outlet, a plurality of unit cells being confined in a frame which is provided with an outlet for said cells, each frame being provided with sealing means towards the next such frame. There are also provided electrodialysis stacks comprising a plurality of such modules.

Abstract: The invention provides a method for the performance of selective electrodialytic separation of a first group of charged ions from a solution containing other charged ions having the same sign and optionally the same valence as said first group comprising applying a current to an electrodialysis unit comprising at least one thin, dense, non-porous charged electrodialysis membrane made of water-insoluble hydrophobic polymeric material, containing covalently bound ionizable groups, wherein said membrane separates at least one diluting compartment from at least one concentrating compartment in said unit and wherein said membrane is in the form of a polymeric matrix optionally supported on a porous support and having a preselected dielectric constant and composition adapted to induce selective ion disassociation of said first group of charged ions whereby there is achieved a substantial ion migration of said selected ion group and its preferential transference across said membrane at a fraction larger than its rel