Abstract: This invention is directed a method for producing an ultra-high purity semiconductor gas such as ammonia gas. The method includes the steps of directing an ammonia fluid having a liquid phase moisture content that is less than about 500 parts per million through an evaporation means, to produce purified vapor phase ammonia, and directing the purified vapor phase ammonia through an adsorption means to remove impurities therein and produce ultra-high purity ammonia gas.

Abstract: This invention is directed a method for purifying an impure gas to produce an ultra-high purity gas comprising the steps of a) passing the impure liquefied gas through a first adsorption means to remove impurities from the liquid phase therein to produce a first purified fluid; b) passing the first purified fluid through an evaporation means to remove impurities therein to produce a second purified gas; and c) passing the second purified gas through a second adsorption means to remove impurities from the vapor phase therein to produce the ultra-high purity gas.

Abstract: In the purification of deicing fluid for recovery of glycol, initially solid particles are separated, then dissolved organic compounds and positive and negative ions are separated by an ion exchange in an ion exchanger, and finally water is separated by distillation.

Abstract: A waste liquid processing method comprising a solvent separation process for separating a chlorine-based organic solvent contained in a waste liquid; a first vaporization process that includes vaporization of the chlorine-based organic solvent remaining in the waste liquid after the solvent separation process; a collection process for collecting substances other than the chlorine-based organic solvent contained in the waste liquid after being vaporized in the first vaporization process; a second vaporization process for vaporizing the chlorine-based organic solvent remaining in the waste liquid after the first vaporization process and the collection process; a photo-oxidative decomposition process where photo-oxidation is used to decompose a chlorine-based organic gas generated in the first vaporization process and in the second vaporization process, and a post-treatment process for carrying out adsorption, absorption, and neutralization of a decomposition product gas generated in the photo-oxidative decompos

Abstract: Fluorinated emulsifier acids bound to an anion exchanger resin can be eluted using a mixture of water, a compound of the formula M—X, in which M is an alkali metal or an alkylammonium ion, and X is hydroxyl, fluoride or chloride, and at least one organic solvent which completely dissolves the other components. For work-up of the eluent, this is advantageously subjected to steam distillation until all volatile constituents have been essentially removed, and the emulsifier acid is liberated from the steam distillation residue using a sufficiently strong acid. This emulsifier acid can advantageously be distilled off and collected as the ammonium salt in aqueous ammonia solution.

Abstract: In microelectronics (semiconductor) processing, pitting and voiding of aluminum and aluminum alloys by deionized (DI) water is prevented. The present method and apparatus degasifies the DI water to remove the dissolved oxygen gas. The oxygen gas concentration of the DI water is thus reduced from the saturation levels typically present to vastly less than saturation. It has been found that oxygen gas serves as the oxidizing agent in an electro-chemical reaction that includes the aluminum metal as the anode. The degasified DI water can be used at high temperatures and for long exposure times to rinse wafers without problematic aluminum etching. The present method is applicable to any semiconductor wafer fabrication or integrated circuit assembly process that uses DI water in contact with aluminum metallization.

Abstract: This invention is directed a method for purifying an impure gas to produce an ultra-high purity gas comprising the steps of a) passing the impure liquefied gas through a first absorption means to remove impurities from the liquid phase therein to produce a first purified fluid; b) passing the first purified fluid through an evaporation means to remove impurities therein to produce a second purified gas; and c) passing the second purified gas through a second absorption means to remove purities from the vapor phase therein to produce the ultra-high purity gas.

Abstract: An apparatus for the purification of crude N,N′-diphenyl-p-phenylenediamine (DPPD) in which there is an extraction unit containing a liquid permeable container and an adsorption layer downstream of the container, a solvent evaporator downstream of the adsorption layer, a filter unit, a line for returning the filtrate to the solvent evaporator, and a condenser for returning solvent to the extraction unit.

Abstract: Apparatus and method for condensing moisture from an air stream. The apparatus is a heating, extracting and condensing system and method for efficiently recovering an ingredient from a raw material. The condenser is a housing having one or more fins or the like that are efficiently cooled by one or more thermoelectric coolers. A plurality of condensers can be arranged in series to improve efficiency.

Abstract: A method for removing corrosive contaminants from a polar extraction solvent comprises adding water to the solvent to provide a mixture. Then the mixture is contacted with a basic ion exchanger resin to remove the corrosive contaminants. The solvent is recovered and may be reused.

Abstract: A process for isolating trioxane from an aqueous mixture which includes trioxane, water and formaldehyde, including removing trioxane from the mixture by pervaporation, and subjecting the mixture enriched in trioxane (permeate) to rectification to give trioxane and an azeotropic mixture of trioxane, water and formaldehyde.

Abstract: A modular water treatment and purification system, suitable for home use, is connected to a water supply and contains a closed fluid treatment circuit extending to a water outlet. The closed fluid circuit flows through a plurality of replaceable water treatment modules each having a specific water treatment function, such as the removal of a particular material from the water by the use of filtration, carbon adsorption, ion exchange or the addition of a chemical to balance the desired water conditions. Preferably the circuit also includes traversing a radiation device, for example an ultra violet light, for the purpose of sanitizing the water.

Abstract: A process for regenerating a solvent from a waste extract after use in a remediation process includes monitoring the water content and the amount of organic contaminants in the extract. If the water content in the extract is above a predetermined threshold value, the extract is distilled to yield the solvent therefrom for reuse in the remediation process. If the water content is below the threshold value but the amount of organic contaminants is above a predetermined limit, the extract is also distilled to yield the solvent therefrom for reuse. If the water content and amount of organic contaminants are both below their respective predetermined parameters, the extract is filtered through a molecular sieve to yield the solvent therefrom. The yield solvent is then collected from the distillation and filtering processes, and the regenerated solvent is then reused in the remediation process.

Abstract: The invention pertains to a system and process for removing contaminants from an oil and gas well bore stream. The system comprises a vessel adapted to receive the stream from the well bore. The system also contains a centrifuge separator for breaking the emulsion of the stream, the centrifuge separator having an input for receiving the output stream from the vessel. A media filter member, which is adapted to receive the stream from the output of the centrifuge separator is also included with the system. The system further contains a carbon adsorption means, adapted to receive the output stream from the media filter, for adsorption of contaminants contained within the output stream. Also included is a level controller switch for measuring the level within the various tanks and generating a signal once a predetermined height is reached.

Abstract: A method of separating heteropoly compounds from mixtures of polyethers, polyesters and/or polyether esters, a protic component and heteropoly compounds, wherein the protic component is removed from the mixture and subsequently separating off the heteropoly compound as a separate phase. The polymer phase which remains is preferably brought into further contact with a solid adsorbent that is capable of adsorbing heteropoly compounds.

Abstract: The invention relates to separating different substances, more concretely, to a method and apparatus for filters, degassing, dehydrating and removing products of ageing in insulating and other petroleum oils. The technical result is that the aforesaid phases of processing oil or a mixture of oils are ensured with high efficiency for a single passage through an active component, and also the possibility of regenerating the adsorbents being used is ensured during the process of operation of the equipment, with simultaneous simplification of the construction and reduction of size and of power consumption. The apparatus 1 for filtering, degassing, dehydrating and removing products of ageing comprises at least one tank 2, in which are disposed cylindrical partitions 3, 4 filled with an adsorbent 5 and secured in the tank 2 by means of fixing elements 6. Partitions 3, 4 form channels for the passage of oil being processed.

Abstract: Ultrapure water containing less than 10 ppt total ions, other than hydrogen ion and hydroxide ion is produced by passing deionized water through a system comprising an ultrafiltration step, an oxidizing step where water is exposed to ultraviolet light and ion exchange step. The treated water is recirculated through the oxidizing step and the ion exchange step. Product water from the system can be recovered on a continuous basis so long as the ratio of volume of water circulated within the system to volume of water drawn from the system is at least 10 and preferably at least 20.

Abstract: A method for the removal and purification of substantially all of the fluoride ions contained in a solution containing greater than 10 parts per million (ppm) fluoride ion, a mixture of other anions, silicon in the form of a fluorosilicic acid, silicic acid, silicates, or silicon tetrafluoride, and optionally also containing complex metal fluorides, to produce an ultrapure hydrofluoric acid, comprising the steps of (a) adjusting the pH of the solution to an alkaline pH to hydrolyze the fluorosilicic acid and any complex metal fluorides; (b) removing the fluoride ions and other anions from the solution by passing the solution through an ion exchange resin, where the ion exchange resin is adapted to adsorb substantially all of the fluoride passed over the ion exchange resin; (c) displacing the fluoride ions and other anions bound to the ion exchange resin, thereby forming a mixture of anions in an effluent emanating from resin; (d) optionally concentrating the effluent at a high pH and then lowering the pH; and

Abstract: A halohydrocarbon solvent recovery process. The process in one embodiment included heating a gross mixture including solvent, fatty-acid impurities and water in a bath to vaporize at least a portion of the solvent and the impurities. A portion of the vapor is then condensed in a reflux condenser to form a condensate mixture. After drying and impurity adsorption, a solvent product of at least 99% purity may be recovered. In one embodiment, the gross mixture is obtained from steam stripping dry-cleaner filter cartridges.

Abstract: A method for complex procesing of sea-water comprises the successive steps of mechanical filtration, calcium separation on modified zeolite, magnesium separation on weak-acid cation exchanger and processing of the resulting softened sea-water, regeneration of the modified zeolite and regeneration of the weak-acid cation exchanger. During the step of processing of the softened sea-water, its desalination it carried out so as to produce fresh water and simulatneously produce secondary brine having a concentration of salts at least as high as 100 g/l whereby the modified zeolite is regenerated. A plant for implemention of the method of complex processing of sea-water comprises a filter, two sorption columns for calcium separation connected in parallel with each other, a sorption unit for magnesium separation, a softened sea-water processing unit and a mixed concentrate processing unit.

Abstract: An apparatus for removing dissolved hydrogen sulfide from water including an atomizing tank defining an open end. A manifold is positioned adjacent the open end. The manifold defines an inlet channel having a first inlet port and a second inlet port. The first inlet port is in communication with aerated water containing dissolved hydrogen sulfide. An atomizing nozzle is in communication with the second inlet port for atomizing the water to cause the dissolved hydrogen sulfide to react with oxygen in the air to form sulfate in the atomizing tank. At least one filtering tank is in communication with the atomizing tank for filtering the sulfate from the water. The method of the present invention includes the steps of: (a) aerating water containing dissolved hydrogen sulfide with air at a predetermined pressure; and (b) atomizing the water to cause the dissolved hydrogen sulfide to react with oxygen in the air to form sulfate.

Abstract: Acidic and salt impurities are removed from a condensed phase obtained from dimethyl carbonate synthesis by obtaining the condensed phase from the effluent of a reactor in which carbon monoxide, oxygen and methanol are reacted to form dimethyl carbonate, the condensed phase containing acid and salt impurities, and partially evaporating the condensed phase in an evaporator thereby preparing an evaporated stream substantially free of impurities and a residual bottom stream.

Abstract: Processes for deionization and demineralization of a fluid containing ions comprising:(a) Loading an amine or ammonia buffer onto a first weakly acidic cation exchange resin to occupy cation exchange sites and to form a first bed comprising a first amine-buffered resin;(b) Passing said fluid containing ions through said first bed comprising said first amine-buffered resin and exchanging cations of said fluid for amine cations of said first amine-buffered resin to form a first effluent comprising an anion-buffer salt complex;(c) Passing said anion-buffer salt complex through a first weakly basic anion exchange resin where an anion portion of said anion-buffer salt complex is split from said anion-buffer salt complex by adsorption of said anion portion onto said weakly basic anion exchange resin to form a second effluent comprising buffer in free hydrated base form;(d) Passing said buffer in free hydrated base form to a second weakly acidic cation exchange resin where said buffer loads onto said second weakly a

Abstract: Raw water is made acidic so that the pH is not more than 4.5 and heated in the presence of an oxidizing agent to decompose TOC components in the raw water, and then deionized, thereby producing ultrapure water having a greatly low concentration of organic matters.

Abstract: A multiple-stage process for the collection and treatment of biological waste, and for rendering the biological waste biologically inactive for the safe and economical environmentally non-contaminating disposal thereof. Moreover, also disclosed is an arrangement for the collection and treatment of biological waste utilizing the inventive process, and is especially adapted for the collection and treatment of biological waste which is generated during a surgical or medical procedure implemented on a patient or during an autopsy.

Abstract: A water treatment system and process separates contaminants from water by flotation, by forming a removable floating scum of impurities utilizing a bubbling process, by filtering out suspended solids, by stripping dissolved impurities from the water with air, by oxidizing organic compounds, by adsorbing organic compounds, and finally, by disinfecting. Utilization of the disclosed process and system will transform contaminated water into an environmentally suitable state.

Abstract: A hydrated aluminosilicate material is used as a filtration media for filtering, including the removal of dissolved oxygen, water received by a carbonation apparatus, the particular hydrated aluminosilicate material having been crystallized under ultraviolet light to produce pore sizes of 75.ANG. to 200.ANG. at ambient temperatures (20.degree. C.-35.degree. C.) and in a low relative humidity (5%-20%).

Abstract: A water and energy recovery process for an ice rink is disclosed. The process includes softening and carbon filtering water for use as flood water on an ice rink. The water is then demineralized by reverse osmosis to produce flood water having a specific conductance of about 2 to 30 micromhos/cm. The demineralized water is heated to 90.degree. F. and utilized in a resurfacer to flood the surface of the ice rink. The ice shavings removed from the surface of the ice by the resurface are deposited into a holding means and melted by utilizing recovered heat from the ice rink's refrigeration unit. The melted water from the holding means is used as a coolant in the ice rink's refrigeration unit. The steps of the process are then repeated, utilizing the warmed water from the refrigeration unit.

Abstract: The process relates to the treatment of aqueous solutions of polyhydric alcohols to remove heavy metal components, oils, organic contaminants and, optionally, water. The process is particularly well suited for use in the treatment of spent antifreeze/coolant from the cooling systems of internal combustion engines.

Abstract: The present invention provides a method for treating hexamine waste water. The method includes subjecting the waste water to conditions sufficient to remove volatile constituents, passing the waste water through a cation exchange resin capable of absorbing cations, and optionally either subjecting the waste water to a bacteria culture capable of consuming formaldehyde in the presence of an organic nutrient for the bacteria or subjecting the waste water to ultraviolet light in the presence of an oxidizing agent. The method may include both optional method steps, but must include at least one. The method also includes regenerating the cation exchange resin to remove the absorbed cations and reform the cation exchange resin. The present invention also provides an apparatus for treating hexamine waste water.

Abstract: A method for the separation and recovery of volatiles from a sludge containing about 1 to 80% by weight liquid solvents and 20 to 99% by weight solids, in which said sludge is fed with a reagent powder material in an amount effective to form a mixture having a high surface area to a distillation vessel, said mixture is heated to a temperature up to about 350.degree. C. while said mixture is advanced through the vessel for a time sufficient to distil a sufficient portion of the solvents to yield a solid residue powder, distilled solvents are condensed, and the solid residue powder recovered. The vessel preferably is a mechanical fluidized bed distillation vessel and said mixture is fluidized while being heated therein under a partial vacuum in a non-oxidizing atmosphere. The effective amount of reagent powder material includes about 5 to 70 wt % of the reagent powder material.

Abstract: The invention pertains to the removal of volatile organic compounds (VOC), generally speaking from industrial fluids, but with special emphasis on water. The dominant feature of the invention is to resort to physical processes such as stripping, absorption and flash evaporation. so that no environmentally undesirable by-products will be formed. Basically the process achieves in one single tower structure air stripping of the contaminated fluid (water) and subsequent removal of the contaminants from the spent stripping air by controlled and special contacting of the contaminated air with certain low volatility solvents in film tray contacting equipment, which can be used with special advantages to permit removal of the VOC from the spent air, as well as for the recovery of the VOC from the VOC-rich solvents.

Abstract: A multiple-stage process for the collection and treatment of biological waste, and for rendering the biological waste biologically inactive for the safe and economical environmentally non-contaminating disposal thereof. Moreover, also disclosed is an arrangement for the collection and treatment of biological waste utilizing the inventive process, and is especially adapted for the collection and treatment of biological waste which is generated during an embalming procedure implemented on a cadaver, such as a human cadaver.

Abstract: A method for preparing an ultrapure water, from which impurities including inorganic salts, organic substances, fine particles and microorganisms are removed, by treatment including an ion exchange treatment, which comprises using an ion exchange resin comprising a copolymer of a polyvinyl compound and a monovinyl aromatic compound which may contain a monovinyl aliphatic compound, as the matrix, at least in a mixed bed ion exchange treatment of the ion exchange treatment, said ion exchange resin used comprising at least a regenerated form ion exchange resin A eluting an organic compound of a molecular weight of less than 3,000 but substantially not eluting an organic compound of a molecular weight of not less than 3,000 when dipped in a hot water at 50.degree. C. for 7 days.

Abstract: An improved method and apparatus for purifying liquid in a square or rectangular tank involving ultra violet (UV) treatment, oxidation, flotation, filtration, effluent purging and disinfection is described. The liquid to be treated is fed into the mixing chamber of the apparatus in the presence of UV light and an oxident (ozone and/or hydrogen peroxide), and then discharged into the flotation chamber for gas stripping of volatile organic compounds (VOC) and flotation removal of floating substances. The subnatant in flotation chamber flows downward through multiple automatic backwash liquid phase granular activated carbon (GAC) filters for final polishing before being discharged as the liquid effluent or further disinfected. The flotation chamber is hooded for collection of gas stream which is moved by a gas mover and purified by a gas phase granular activated carbon (GAC) filter.

Abstract: Ground water which contains heavy metal ions and toxic volatile organic compounds is purified by passing an air stream through it to purge out the organic compounds, adsorbing the displaced organic compounds on a molecular sieve and destroying them using a strong oxidizing agent such as hydrogen peroxide. This procedure avoids having the heavy metal ions from the water collect on the molecular sieve which causes the destruction of the oxidizing agent.

Abstract: The process relates to the treatment of aqueous solutions of polyhydric alcohols to remove heavy metal components, oils, organic contaminants and, optionally, water. The process is particularly well suited for use in the treatment of spent antifreeze/coolant from the cooling systems of internal combustion engines.

Abstract: Thimerosal is removed from aqueous effluent streams from vaccine production to provide an invironmentally-acceptable effluent stream. The thimerosal first is converted to ionic form by chlorination, the resulting solution is dechlorinated to remove dissolved unreacted chlorine, and then the ionic mercury is removed by ion-exchange employing thiol groups.

Abstract: A process for the removal of water soluble organic compounds from produced water is provided. The process allows for the removal of water soluble organic compounds by passing the produced water through a column of adsorbing resin which is capable of removing the soluble organic compounds from the water and providing an environmentally acceptable effluent. The removal of polllutants from the produced water is monitored continuously by a fluorescence detector. The process further allows for the generation of the adsorbing resin by regenerating the resin with a solvent capable of eluting accumulated soluble organic compounds from the column followed by treatment of the resin with steam to remove residual eluting solvent. The process further allows for the treatment of the eluting solvent and soluble organic compound admixture in a manner to allow reuse of the solvent and to allow recovery of the soluble organic compound or to allow direct injection of the soluble organic compound admixture into the oil stream.

Abstract: A method has been discovered for recovering hydrocarbon contaminants from wastewater. The wastewater is contacted countercurrently with stripping gas. The stripping gas is passed over a bed of activated carbon to remove hydrocarbon contaminants. Periodically, the activated carbon bed is regenerated with steam. Steam condensate and hydrocarbon contaminants are passed to a petroleum desalter. Hydrocarbon contaminants are transferred to the petroleum.

Abstract: A process for the removal of water soluble organic compounds from produced water is provided. The process allows for the removal of water soluble organic compounds by passing the produced water through a column of adsorbing resin which is capable of removing the soluble organic compounds from the water and providing an environmentally acceptable effluent. The process further allows for the regeneration of the adsorbing resin by backwashing the resin with a solvent capable of eluting accumulated soluble organic compounds from the column. The process further allows for the treatment of the eluting solvent and soluble organic compound admixture in a manner to allow reuse of the solvent and to allow recovery of the soluble organic compounds or to allow direct injection of the soluble organic compound admixture into the oil stream. Thus, the invention provides a process for removal and recovery of water soluble organic compounds from produced water which creates no environmentally hazardous waste streams.

Abstract: A unitized system for the processing of well water that is contaminated with volatile substances, such as organic substances, at a site where the contaminated water exists. This system has the primary components thereof mounted on a skid/frame that can be transported to the site. In the preferred form, the contaminated water is first processed in a spray tower where it is countercurrently contacted with air to remove the volatile contaminants. This air-treated water then is passed through an activated carbon bed for further purification before being used. While the treated water is not considered safe for human consumption, it can be used for most other uses. The system is controlled to normally operate only upon water demand by the system being supplied. Since activated carbon can cause the gradual growth of bacteria, the system is provided with a system for the periodic back flushing of the carbon bed, with the wash water being discarded in a separate holding tank or to a local sewer.

Abstract: There is disclosed a method of removing amines from aqueous solutions thereof, in particular from waste waters obtained in cellulose processing. The aqueous amine solutions are contacted with a cation exchanger whose anchor groups consist of carboxyl groups, in order to charge the cation exchanger with the amines. The charged cation exchanger is treated with an aqueous solution of a weak acid having a pK.sub.a larger than 3.0 in order to elute the amines. The eluate is processed by way of distillation, wherein a portion of the weak acid is separated from the amines and reclaimed, if desired.The method according to the invention offers a simple and cheap way of disposing amine-containing waste waters.

Abstract: Provided is a process for the disinfection of raw water with chlorine dioxide and the removal of virtually all disinfection by-products. The process comprises contacting the water to be purified with a sufficient amount of gaseous chlorine dioxide to kill any microorganisms and thereby disinfect the water. The water is then stripped with air to remove ClO.sub.2 and any organic chemicals, with the resulting water then being contacted with a strong anion exchange resin to remove any by-products such as chlorite and chlorate ions formed in the disinfection process. The integrated process efficiently and effectively provides a water product which can contain essentially no chlorine dioxide, chlorite ions, chlorate ions or trihalomethanes, and which also is fully disinfected.

Abstract: A process is provided for the selective removal of thiocyanate ions from a vanadium-containing loaded scrubbing solution used for oxidative hydrogen sulfide scrubbing. The thiocyanate ions are removed by means of an ion exchanger making reuse of the scrubbing solution possible. In this process, the ion exchanger can be loaded until the inlet and outlet concentrations of the thiocyanate ions are substantially the same.

Abstract: A method and apparatus for removing contaminants in waters used for industrial cleaning. The method and apparatus begins with water which has been purified to level of approximately 18 megaohms resistivity with total inorganic dissolved solids to 1 part per trillion and total organic dissolved carbon contaminants in the range of approximately 100 parts per billion, and purifies it to a level of approximately 18 megaohms resistivity with total inorganic dissolved solids to 1 part per trillion and total organic dissolved carbon contaminants in the range of approximately 10 parts per billion. The method and apparatus includes means for inducing cavitation in the water and irradiating the water with ultraviolet radiation to thereby cause the oxidizable contaminants to be oxidized and therefore removed before the water is used for industrial cleaning.

Abstract: A method for varying the capacity for a specific chemical element of an ion exchanger used for cleaning a liquid from a loop includes varying the chemical status of the element in the liquid to be cleaned immediately upstream of the ion exchanger by adding given substances. The given substances added are removed immediately downstream of the ion exchanger. The chemical element may be antimony, the loop may be the primary loop of a pressurized water reactor plant and the liquid may be primary coolant.

Abstract: A process for the recovery of silicone oil and chlorobenzenes from a mixture containing silicone oil, chlorobenzenes, and polychlorinated biphenyls comprising:(a) introducing the mixture into a distillation zone at a temperature and a pressure which will cause the chlorobenzenes to flash overhead and the mixture of silicone oil and polychlorinated biphenyls to pass to the bottom of the zone; and(b) removing the bottoms from step (a), cooling same, and passing the bottoms through at least one bed of activated carbon, which is an adsorbent for polychlorinated biphenyls.

Abstract: The invention concerns a process for converting toxic liquid waste materials containing harmful amounts of biologically difficult to degrade toxic waste materials containing organic halogen compounds, and which also may contain organically bound oxygen, nitrogen and/or sulfur, into an innocuous hydrocarbon stream. These waste materials together with hydrogen are passed over a hydrogenating catalyst at 250.degree.-400.degree. C. and under increased pressure. The effluent of this hydrogenolysis is cooled and separated into a non-toxic liquid hydrocarbon stream, a hydrogen halogenide, ammonia, and/or a hydrogen sulfide containing stream and a gaseous stream of light hydrocarbons and hydrogen. The waste material which contains 0.5-60 weight % halogen and possibly contains up to 10% sulfur and/or small amounts of nitrogen-containing compounds is conditioned and this conditioned stream is passed, together with hydrogen under a prssure of 30-80 bar and with a LHSV of 0.5-2.5 H.sup.

Abstract: A process for treating a waste water containing uranium and fluorine comprises a neutralizing precipitation step wherein slaked lime is added to the waste water containing uranium and fluorine and precipitate thus formed in separated and removed, and an adsorption step wherein supernatant from the neutralizing precipitation step is contacted with a chelating resin which can selectively adsorb fluorine ions and another chelating resin which can selectively adsorb uranyl ions to thereby adsorb and remove the fluorine and uranyl ions remaining in the supernatant. Eluates of the ions adsorbed by the chelating resins and waste liquors for washing and regeneration of these resins are returned to the neutralizing precipitation step. Prior to the neutralizing precipitation step, a decarbonation step may be provided for decomposing carbonate ions, if they are contained in the waste water to be treated.