Abstract: A method for removing and recovering ammonium and/or potassium and/or phosphate ions from wastewater is presented which comprises:permitting said wastewater to pass through at least one bed of ion-exchange resins capable of removing selectively those nutrient ionsregenerating those ion-exchange resins with a Na Cl solution or other suitable regenerant solutions so that said nutrient ions may be obtained in a much more concentrated formadding to said regeneration eluates (or, eventually, directly to wastewater) at least one Mg salt, in proper pH conditions so as to precipitate hydrous MgNH.sub.4 PO.sub.4 and/or MgKPO.sub.4, slightly soluble salts of great agronomic value.

Abstract: A method of processing naturally occurring kaolin clay wherein ion exchange resins are utilized to remove charged soluble impurities from the clay thereby eliminating the filtration step required in conventional clay beneficiation process. Further, by saturating the ion exchange resin utilized with a bleaching agent, ferric ions in the clay will be reduced to soluble ferrous ions and removed from the clay without the conventional acid leaching.

Abstract: A process for the partial desalination of water with a combination of weakly acid cation exchangers in free acid form and basic anion exchangers in hydrogen carbonate form, both present in aqueous suspensions, and subsequent regeneration of the charged ion exchanger material. The partial desalination is effected with a combination or mixture of a weakly acid cation exchanger material and a basic anion exchanger material. Depending on the combination or mixing ratio of the two exchangers, non-equivalent quantities of neutral salt cations and anions are removed from the water. The regeneration of both exchangers together is effected exclusively with the aid of CO.sub.2.

Abstract: A cooling arrangement particularly for cooling electrical devices having water cooled electric conductors with deionized cooling water in a closed cooling system which contains a parallel loop with a mixed bed filter in which an anion exchanger in OH form is provided which can be connected parallel with the mixed bed filter as well as in series with the mixed bed filter, permitting the cooling system to be run with the cooling water having an increased pH-value range which can be preferably 8 to 8.4.

Abstract: The invention relates to a cooling arrangement, particularly for cooling electrical devices with water-cooled electric conductors, with deionized cooling water (deionate) and a closed cooling system which contains a parallel loop with a mixed-bed filter. According to the invention, the mixed-bed filter is preceded by an alkalizing cation exchanger and an anion exchanger in OH-form, and the mixed-bed filter is provided with a bypass. With this arrangement, the cooling water can be run in a higher pH-value range which for generators may preferentially be about 8 to 8.4.

Abstract: A deionization method and apparatus comprising separate cation and anion removing sections 10a, 10b, the cation section having separate tanks 14, 16 and the anion section having separate tanks 24, 26. Respective cation and anion control valve assemblies 18, 28 control the fluid communication between various components of respective sections and control the regeneration cycle of exhausted cation and anion tanks, respectively. Each valve assembly includes independent water usage monitoring devices 118 which, upon sensing a predetermined quantity of water discharge by its respective valve assembly, effects regeneration of an associated tank. An exhausted cation tank is regenerated by feeding cation regeneration fluid by way of the cation control valve assembly into the exhausted cation tank in a counterflow direction for a predetermined time. Decationized water from the on-line cation tank is then passed through the exhausted cation tank in a counterflow direction to effect a counterflow rinse.

Abstract: Disclosed is an improved process for purifying waste water in which a waste water containing contaminants, including dispersed solids, water-immiscible organic materials, and metallic cations, is first introduced to a sedimentation zone to remove water-insoluble materials having a density higher than that of water, then to a flotation zone to separate as an upper layer water-insoluble and water-immiscible materials having densities lower than that of water. The waste water stream is then introduced to an adsorption zone, where activated carbon particles are added to adsorb remaining water-insoluble and water-immiscible materials, following which the solids are removed in a liquid-solids separation zone. The aqueous phase from the last zone is then passed through a cation exchange zone to remove cations.

Abstract: Process for treating wastewater, which includes measuring the pH of the wastewater, adjusting the pH to about 10-11; filtering the wastewater; and subjecting the wastewater to ion-exchange treatment; and certain filter media.

Abstract: Water of low solids content is purified by ion exchange treatment in separate beds with anion and cation exchange resins, the rate of flow of water through the last bed at least being fast. The beds are usually shallow and the flow rate through the last bed at least, and generally through all the beds, is at least 100 meters per hour. Apparatus suitable for use in such a process comprises a tower including supports for holding the beds one above the other and means for passing the water to be treated vertically through the tower.

Abstract: Process for producing fully desalted process water by the treatment of raw water with cation and anion exchangers in a separate multi-stage arrangement. The water which leaves the main cation exchanger stage or stages, has a residual sodium content of less than 0.5 mg Na/l before entering the anion exchange stage. Such water is fed through a strong acid cation exchanger stage, in which the exchanger material is present at a maximum of 50 percent as a suspended bed and the remainder as a solid bed. The exchanger material in the strong acid cation exchanger stage following the first strong acid cation exchanger stage, is present at a maximum of 25 percent as a suspended bed and the remainder as a solid bed.

Abstract: Ion exchange techniques are utilized to treat waste water flows, especially those from plating baths, by passing the waste water through a multi-level ion exchange resin bed, the bed thereafter being regenerated by a series of steps, including backwashing, passage of an acidic regeneration fluid through the bed, multi-stage rinsing of the bed, and passage of a caustic regeneration fluid through at least a portion of the bed. Acidic waste flows developed during regeneration steps are, when desired, further treated to recover cyanide values therefrom by heating same within a generally closed tank to drive off a hydrocyanic gas, which is then reacted with caustic within a circulation reactor having an inclined passageway in order to form and recover a cyanide salt liquor suitable for re-use in the plating bath.

Abstract: A process for treatment of a liquid stream, optionally comprising solids such as minerals, comprises passing at least two different treating reagents through contactors each comprising a drum with a rotor having axially spaced discs compartmentalizing the drum interior and carrying receptacles which rotate with the rotor and cause transfer of portions of one phase in the contactor to the other phase as the rotor turns. The liquid stream being treated is caused to flow along a path including, in succession, parts of each contactor so that the liquid stream is brought into contact with the reagents successively and in rotation.

Abstract: An ion exchange composition comprising an insoluble substrate of a synthetic resin having ion exchanging sites at least on its available surface; and a finely divided, insoluble material comprising synthetic resin particles of from about 0.1 to about 5 microns median diameter (with respect to volume) having, at least on their outer surfaces, ion exchanging sites which attract the ion exchanging sites of the substrate, irreversibly attached as a monolayer to the available surface of the substrate. The composition is used for removal and separatin of ions, and is especially useful in liquid ion exchange chromatography.

Abstract: Ion retardation resins particularly useful for desalting caustic solutions are prepared by employing ion exchange resins consisting essentially of a mixture of a reticular, insoluble, cross-linked styrene/divinylbenzene copolymer with an entrapped non-leachable polymer of acrylic acid contained therein and where the amount of carboxylic acid groups on the polyacrylic acid are in substantial excess over the amount needed to react with all the quaternary ammonium groups which are nuclear substituted on the styrene copolymer chains.

Abstract: Raw water is fed to a first column containing a weak acid cation exchange resin in hydrogen form where alkalinity causing ions and hardness causing ions to the extent of alkalinity are converted to carbonic acid. The carbonic acid, which hydrolyzes to dissolved carbon dioxide, is stripped from the water in a decarbonation unit by passing air countercurrent to the flow of water through the unit. The water is then fed to a second column containing a weak acid cation exchange resin in sodium form which removes residual hardness causing ions along with neutralization of any mineral acids or residual dissolved carbon dioxide. Both resins are substantially completely regenerated upon exhaustion to provide a process in which the maximum capacities of the resins are utilized, and the process is carried out with a minimum of monitoring and control.