Abstract: A spacer element (1) is disclosed having an integral screen for use in filled cell electrodialysis. The spacer (1) has a continuous portion (2) impermeable to flow and a screen (3) which spans a centrally-located flow treatment region that contains active treatment material, such as ion exchange beads. The screen (3) may perform a structural function, allowing operation at elevated pressure, and may also define a minimum gap between adjacent membranes and enhance mixing along the flow path and at cell boundaries. The spacer element (1) may be configured to enhance hydraulic filling of the cells, and cell architecture is readily implemented in a wide range of useful flow path geometries utilizing the screen spacer element (1).

Abstract: An improved apparatus and operating method related thereto for deionizing water to produce substantially pure water using electric field and ion exchange materials are disclosed, including embodiments incorporating one or more of the novel features of brine and electrode streams flowing in a direction counter-current to the stream being deionized, a filling of the brine stream with stratified ion exchange materials, a stream mixing feature for mixing the stream being deionized, a gas removal feature for removal of gases, a spiral-wound embodiment of an electrodialysis device according to the invention, and a method for determining the preferred operating current for electrodialysis systems according to this invention.

Abstract: Methods of making basic aluminum halides, such as basic aluminum chlorides, are described, which includes the use of catalysts, such as nickel cations or cobalt cations.

Abstract: A treatment system passes feed water containing a contaminant such as perchlorate through a bed of strong base anion exchange resin that has been placed in a form (e.g., in sulfate form) to selectively capture the contaminant while passing other ions (e.g., nitrate) that may also be present in the water. The bed may include a carousel, and the exhausted upstream portion of the resin may efficiently be disposed of by incineration, or may be rotated out for regeneration.

Abstract: A water treatment system and method including a membrane-based boron removal unit includes a boron analyzer for detecting the concentration of boron in a treatment stream. The boron removal unit can be a reverse osmosis (RO) or electrodeionization (EDI) treatment unit. A controller responds to the detected boron concentration to control an operation of the RO or EDI units. In an EDI system, the controller may adjust current or voltage supplied to match current to changes in ionic load and maintain a portion of the dilute cell in a substantially regenerated state. In an RO system, the controller may control the high pressure side flow rate, the brine blowdown rate, the product water permeation rate, pH, or feed rate of chemicals in response to the detected boron concentration value.

Abstract: Apparatus and method are disclosed for introducing ion exchange or other particulates into compartments of an already-assembled electrodeionization or comparable stack by modulating a flow of slurry into the compartments with slugs of gas such as air. The air propels liquid through the cells, scavenging ponded liquid so that the particulates (which are retained, e.g., by a strainer or obstruction, in compartment of the apparatus) are deposited as well-packed beds to fill the compartments. Pressurized air filling protocols may deliver discrete slugs of slurry between bursts of air, and the direction of filling may be periodically reversed to diminish particle bed non-homogeneities or settling gradients that arise during transport. The slugs of air may be applied in the direction of slurry flow, in the reverse direction, or both. Different slurries may be transported in a sequence to form layered and packed beds of enhanced utility.

Abstract: The invention provides ion exchange and electrochemical methods and devices employing anion exchange polymers produced by substantially simultaneous quaternization and polymerization reactions. Anion selective polymers are produced in accordance with the invention by combining, an ethylenic tertiary amine monomer, an alkylating agent having a boiling point temperature of at least about 100° C., and a cross-linking agent in the presence of a polymerizing agent for a time and at a temperature sufficient to form the polymer. The alkylating agent and the cross-linking agent may be the same compound, a cross-linking alkylating agent. The polymers may be produced in the presence of solvents and/or in the presence of diluting monomers which are incorporated into the polymers.

Abstract: Water treatment systems or assemblies are normally tested after construction, at least for leaks, prior to shipping or storage. Pressure testing with a gas is hazardous, so testing with water is a standard method. After testing, the water is displaced from the system by draining or gas phase flushing. It is nearly impossible to remove all of the water from the system or assembly. This remaining water provides an environment for biological growth which contaminates the system or assembly over time. The purpose of this invention is to eliminate or minimize this biological contamination by adding a biocidal agent to the system or assembly before sealing it for shipment or storage.

Abstract: A method for pretreating waste water for use in reverse osmosis filtration is provided. Small amounts of chemicals are added to the waste water to promote formation of filterable particles from colloidal and dissolved solids. These particles are then removed via a closed-end, low pressure, high flowrate filtration system prior to reverse osmosis treatment.

Abstract: A method of cleaning a filter clogged with flocculating materials is provided. The method comprises determining the flocculated materials clogged on the filter and adding a dispersing agent to break up said flocculated materials to form dispersed precipitates. Then the dispersed precipitates are removed from the filter in a regular cleaning such as backflushing.

Abstract: An improved method of treating wastewater to remove ammonia and fluoride is provided. The method comprises the steps of chemical destruction of ammonia with an oxidizing agent, followed by treatment with calcium salts to precipitate insoluble calcium fluoride, and filtration to remove the precipitate.

Abstract: A system for removing fluoride from wastewater is provided. The system comprises a reaction tank for processing said wastewater by adding calcium salts, a filtration tank for removing the precipitated fluoride formed in the reaction tank, a single fluoride electrode disposed at the reaction tank for measuring a concentration of fluoride in the influent wastewater and providing an output signal, and a programmable controller for controlling addition of said calcium salts into said reaction tank. The programmable controller defines a setpoint of fluoride concentration in the reaction tank and automatically controls addition of calcium salts based on the setpoint and the output signal provided by the single fluoride electrode. A method of removing fluoride from wastewater is also provided.

Abstract: A method of removing arsenic and fluoride from aqueous solutions in the same process is provided. Specifically, the pH of the aqueous solution is adjusted to a pH in the range of about 5 to 8. A combination of calcium salts, and ferric or aluminum salts are added to form insoluble arsenic and fluoride bearing solids. The solids are then removed from the aqueous solution.

Abstract: A method of treating industrial wastewaters is provided. Specifically, the wastewater includes one or more organic contaminant materials and is pre-treated prior to filtering by the following steps The pH of the wastewater is adjusted to a pH in the range of about 2 to 6, and a combination of iron salts and peroxide are added to the wastewater and allowed to react for a period of at least about three minutes. Next, the pH of the wastewater is adjusted upwards to a value of at least 7 and precipitating or flocculating agents are added to form an insoluble contaminant bearing compound. The compound is then filtered from the wastewater thereby removing the contaminant materials from the wastewater. This invention is particularly suited for use with single pass flow-through filters, and most particularly suitable for high flow rate single pass flow-through filters.

Abstract: Water treatment systems or assemblies are normally tested after construction, at least for leaks, prior to shipping or storage. Pressure testing with a gas is hazardous, so testing with water is a standard method. After testing, the water is displaced from the system by draining or gas phase flushing. It is nearly impossible to remove all of the water from the system or assembly. This remaining water provides an environment for biological growth which contaminates the system or assembly over time. The purpose of this invention is to eliminate or minimize this biological contamination by adding a biocidal agent to the system or assembly before sealing it for shipment or storage.

Abstract: The invention provides ion exchange and electrochemical methods and devices employing anion exchange polymers produced by substantially simultaneous quaternization and polymerization reactions. Anion selective polymers are produced in accordance with the invention by combining, an ethylenic tertiary amine monomer, an alkylating agent having a boiling point temperature of at least about 100° C., and a cross-linking agent in the presence of a polymerizing agent for a time and at a temperature sufficient to form the polymer. The alkylating agent and the cross-linking agent may be the same compound, a cross-linking alkylating agent. The polymers may be produced in the presence of solvents and/or in the presence of diluting monomers which are incorporated into the polymers.

Abstract: Novel styrene sulfonate-based polymers and cation exchange membranes which are particularly suitable for use in electrodialysis of whey and improved methods for electrodialysis of whey are disclosed.

Abstract: Novel styrene sulfonate-based polymers and cation exchange membranes which are particularly suitable for use in electrodialysis of whey and improved methods for electrodialysis of whey are disclosed.

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.