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:
The invention is a demineralization apparatus comprising an anode chamber disposed at one end of a vessel having an anode at the inside of the anode chamber. A cathode chamber is disposed at the other end of the vessel, having a cathode at the inside of the cathode chamber. At lease one diluting chamber and at least one concentrating chamber are located alternately between the anode chamber and the cathode chamber. The diluting chamber has an anion exchange membrane on the anode chamber side and a cation exchange membrane on the cathode chamber side. The diluting chamber has an inlet for water to be treated and an outlet for demineralized water. The concentrating chamber has an inlet for water and an outlet for ion-concentrated water. The diluting chamber contains a cloth comprising a mixture of strongly acidic cation exchange fibers, strongly basic anion exchange fibers and ionically inactive synthetic fibers. Preferably, the mixture contains from 20 to 70% by weight ionically inactive synthetic fibers.
Abstract:
Remediation of soil and groundwater using electropotential gradient induced migration of a target ion and immobilization and/or confinement of the target ion by a host receptor matrix (HRM). In addition to immobilizing and/or confining the target ion, the HRM can comprise a buffer or an ionizable species which releases an exchange ion during application of the electropotential gradient. The exchange ion, when less mobile than a (H.sup.+) ion or hydroxyl (OH.sup.-) ion, increases the efficiency of energy usage during decontamination. The exchange ion can also perform other tasks in the vicinity of the electrodes which improve the decontamination process. The host receptor matrix also can comprise a material which is water impermeable and which has a low surface energy, such as a layer of polytetrafluoroethylene film. When such a material is used, the host receptor matrix can comprise a receptacle in which there is a liquid and/or solid composition which immobilizes and/or contains the target ion.
Abstract:
The present invention is concerned with the separation of organic compounds in a mixture using their tendency of binding a weak acid by applying electrodialysis to a mixture of at least one of said organic compounds and said weak acid, while preferably an ionexchange resin is present in the electrodialysis cell.
Abstract:
The improved electrically regenerable demineralizing apparatus uses ion exchangers that are produced by radiation-initiated graft polymerization and that are packed in the demineralizing compartment of an electrodialyzer. The apparatus may use a mosaic ion exchanger that consists of alternately arranged cation- and anion-exchange groups. Alternately, the apparatus may have an immobilized amino acid packed in the demineralizing compartment of an electrodialyzer. The apparatus maintains consistent water quality for a prolonged time, is capable of treating from small to large volumes of water and yet is easy to service and manage.
Abstract:
Remediation of soil, concrete and groundwater using electropotential gradient induced migration of a target ion and immobilization and/or confinement of the target ion by a host receptor matrix (HRM). In addition to immobilizing and/or confining the target ion, the HRM can comprise a buffer or an ionizable species which releases an exchange ion during application of the electropotential gradient. The exchange ion, when less mobile than a (H.sup.+) ion or hydroxyl (OH.sup.-) ion, increases the efficiency of energy usage during decontamination. The exchange ion can also perform other tasks in the vicinity of the electrodes which improve the decontamination process. The host receptor matrix can comprise a material which is water impermeable and which has a low surface energy, such as a layer of polytetrafluoroethylene film. When such a material is used, the host receptor matrix can comprise a receptacle in which there is a liquid and/or solid composition. The liquid or solid composition can supply a predetermined ionic species to the bulk matrix and/or immobilize or isolate a target ion.
Abstract:
An apparatus for removing cations/anions from liquids including a container provided with an anode mounted centrally in the container, a cathode surrounding the anode and a layer of ion exchange material mounted between the cathode and anode, the cathode and a wall of the container form an outer space filled with water therebetween, the anode and cathode form a water-free inner space therebetween, the inner and outer spaces are connected with each other at opposite ends in order to generate a liquid circulation.
Abstract:
An electrodeionization apparatus is provided for removing ions from liquids. The apparatus is particularly well adapted for the removal of large, heavily hydrated, highly charged or weakly ionized molecules or complexes from feed water. Such removal is achieved by substituting, in at least one section of the apparatus, ion exchange membranes and/or resins having lower crosslinking and/or lower selectivity, for the ion exchange membranes commonly used in electrodeionization systems. Methods for reducing the electrical resistance across the membrane also are provided.
Abstract:
Purified ion exchange resin particles are provided in a bifunctional electrodeionization step having anion depletion compartments containing anion exchange resin particles which are purified and cation depletion compartments containing cation exchange resin particle which are purified as well as ion concentration compartments. The bifunctional electrodeionization step for purifying resin particles is conducted under conditions to disassociate water into hydrogen ions and hydroxyl ions. Purified water having a purity of at least 1 megohm-cm is introduced into the anion depletion compartment and cation depletion compartments and water for accepting ionic impurities is introduced into the ion concentration compartments. The purified water is produced in an initial purification step which also can be an electrodeionization step. The water effluent from the anion depletion compartments and cation depletion compartments is recycled either to an initial water purification step or to the inlets of the anion depletion compartments or cation depletion compartments. The anion depletion compartments include an anion permeable membrane and a bifunctional interface. The cation depletion compartments include a cation permeable membrane and the bifunctional interface.