Abstract: An improved system of resins comprising a combination of a sulfate-specific strongly basic anion exchange resin and a heterogenous hybrid thermally regenerable salt sorbent (TRSS) resin is provided. The anion exchange resin contains triethylamine and/or tributylamine groups. The TRSS resin comprises a macroporous host copolymer and a crosslinked guest copolymer having, respectively, weak acid groups and weak base groups. The system is used to treat feed water containing dissolved ions, including sulfate ions, and is efficiently regenerated.

Abstract: Water that is produced during offshore hydrocarbon processing, such as hot produced water accompanying hydrocarbons taken from subsea reservoirs, or cold water resulting from heating LNG (liquified natural gas) to convert it to gas, is changed in temperature to be closer to that of the surrounding sea using apparatus of minimal cost. The apparatus includes a mixer tube (52) that lies totally submerged in the sea and a nozzle (54) that receives the produced water and that has a nozzle end (76) lying in a middle portion of the mixer tube. A location of the mixer tube middle portion at the nozzle end has an inside diameter (A) much larger than the nozzle end outside diameter (B) to induce the through flow of sea water from the surrounding sea through the mixer tube. The produced water is pumped to a high enough pressure to create turbulence in the mixer tube immediately downstream of the nozzle end to better mix the produced and sea waters.

Abstract: The method for removing silicon dioxide from a contaminant-removal media bed comprises adding a scrub solution containing an acidic solution of sodium fluoride to a media bed containing silicon dioxide. The scrub solution is allowed to remove the silicon dioxide before the scrub solution is removed from the bed.

Abstract: The present invention provides a process for enhancing the metal contaminant sorption capacity of mineral compounds within a groundwater-bearing formation by manipulating the pH and the surface acidity of the mineral compounds. The process is useful in removing metal contaminants from groundwater within a groundwater-bearing formation, providing a backstop treatment for groundwater after previous water treatment, and for protection of water sources, for example well-head protection.

Abstract: A method of treating water containing a nitrogen compound, and an apparatus of treating water containing a nitrogen compound at high speed without using a biologically unstable treatment causing eutrophication in lakes and swamps. The waste water is introduced into an adsorbing tank that is filled with a zeolite, only nitrogen components are adsorbed by the zeolite, a solution containing hypochlorous acid or hypobromous acid is introduced into the adsorbing tank, and the nitrogen adsorbed in the zeolite is decomposed by the hypochlorous acid or the hypobromous acid.

Abstract: Process for drying wet F32, which comprises placing a stream of the said F32 in continuous contact with a feed stock of a composition comprising a molecular sieve chosen from a 3A type sieve, at a temperature of between 5 and 78° C. and at a pressure of between 0.5 and 25 atm.

Abstract: A method for removing at least one of chromate and other oxy-metal ions from liquid solutions includes contacting the liquid solution with solid barium compounds as adsorbents so that the at least one of chromate and other oxy-metal ions in liquid solution are subject to an exchange reaction with the anion of solid barium compounds to produce products including at least one of solid barium chromate and oxy-metal barium compounds and are removed from the liquid solution by a liquid-solid separation operation. A method for stabilizing at least one of chromate and other oxy-metal ions that are present in liquid or sludge wastes includes mixing the liquid or sludge wastes with barium compounds in solid form, so that the at least one of chromate and oxy-metal ions are immobilized in a solidified body after curing of the mixture.

Abstract: Alkali metal ions are separated off from alkoxylates containing alkali metal ions by a process comprising: a) dilution of the alkali metal-containing alkoxylate with an inert solvent, b) treatment of the alkali metal-containing solution of the alkoxylate with a cationic exchanger in order to obtain a substantially alkali metal-free solution of the alkoxylate, and c) removal of the solvent from the substantially alkali metal-free solution of the alkoxylate in order to obtain a substantially alkali metal-free and substantially solvent-free alkoxylate.

Abstract: A process for separation and environmentally benign disposal of amine borane complexes includes adsorbing amine borane complex onto a solid support, treating the adsorbed amine borane complex with an oxidizing agent in situ on the adsorbent thereby forming decomposition products without the formation of hydrogen gas, and collecting the decomposition products for disposal thereof.

Abstract: A method for the extraction of hydrophobic constituents, such as benzene, toluene, xylene and/or chlorinated hydrocarbons, from an aqueous solution, involving the steps of contacting said solution with a porous, preferably dimensionally stable granular or powdery material, of which the pores have a size of from 0.1 to 50 &mgr;m and contain a hydrophobic substance with affinity for the hydrophobic constituents to be extracted, which granular or powdery material has a particle size of from 0.1 to 10 mm, and is wetted more readily by the hydrophobic substance immobilized in the pores than by the aqueous solution to be treated, and regenerating the product of step a), essentially without the granular or powdery material being freed from the hydrophobic substance, by removal of the hydrophobic constituents.

Abstract: Contaminated fluids are treated by adsorbing contaminant onto a sorbent to concentrate the contaminant and then oxidizing the contaminant via the Fenton and related reactions. Iron is attached to the sorbent or can be added in solution with an oxidant. Both systems, iron attached to the sorbent or iron in solution, can be used to oxidize contaminants on or near the surface of the sorbent. The process can be used to treat contaminated water in above-ground and below-ground treatment systems, as well as contaminated gases.

Abstract: A fluid treatment device for reducing the level of a chemical compound in a fluid. The device comprises: a fluid inlet; a fluid outlet; a flow-through fluid treatment zone having comprising: a radiation source, an adsorbent and a photocatalyst. The fluid treatment zone is reversibly operable between: (i) a first mode in which the fluid flows in a first direction and at least a portion of the chemical compound is adsorbed on the adsorbent; and (ii) a second mode in which the fluid flows in a second direction different from the first direction in which the absorbed chemical compound is exposed to radiation from the radiation resulting in photooxidation of the chemical compound.

Abstract: A process for removing phenols from an aqueous solution is provided, which comprises the steps of contacting a mixture comprising the solution and a metal oxide, forming a phenol metal oxide complex, and removing the complex from the mixture.

Abstract: A process for separation and environmentally benign disposal of amine borane complexes includes adsorbing amine borane complex onto a solid support, treating the adsorbed amine borane complex with an oxidizing agent in situ on the adsorbent thereby forming decomposition products without the formation of hydrogen gas, and collecting the decomposition products for disposal thereof.

Abstract: The present invention aims at inhibiting a lowering in the modification ratio of a modified cation-exchange resin, in which part of the sulfonic acid groups have been modified with a thiol-containing amine compound and which is employed as a catalyst for producing bisphenol, during preservation. In the present invention, a modified cation-exchange resin is packed together with water into a container while regulating the surface area of the container to 0.5 m2 or less per liter of the resin and then the container is sealed up so that the resin is preserved in a state of being soaked in water.

Abstract: A method of treating a nitrogen compound-containing water, and an apparatus of treating a nitrogen compound-containing water realize such a method and an apparatus of treating nitrogen in a waste water at a high speed without using an unstable biological treatment; the nitrogen being a substance causing eutrophication in lakes and swamps. The waste water containing nitrogen is introduced into an adsorbing tank that is filled with zeolite, only nitrogen components are adsorbed to the zeolite, a solution containing hypochlorous acid or hypobromous acid is introduced into the adsorbing tank, and the nitrogen adsorbed to the zeolite is decomposed by the hypochlorous acid or the hypobromous acid.

Abstract: A process for removing a solute from a fluid process stream containing said solute and containing a solvent. The process comprises (a) continuously contacting the process stream with a portion of a rotating mass of sorbent material at a temperature that allows sorption of the solute by the sorbent material to form a solute-adsorbed portion of sorbent material; (b) continuously rotating the mass of sorbent material; (c) raising the temperature of the solute-adsorbed and rotated portion of sorbent material by contacting said portion with an eluant stream having a temperature that allows release of the solute to form an eluted portion of sorbent material; (d) cooling the further rotated and eluted portion with a cooling stream to form a regenerated portion of sorbent material; simultaneously with steps ad collecting product stream containing solvent, and continuously repeating the above-named steps.

Abstract: Contaminated water is treated by adsorbing contaminant onto a sorbent to concentrate the contaminant and then oxidizing the contaminant via the Fenton and related reactions. Iron is attached to the sorbent or can be added in solution with an oxidant. Both systems, iron attached to the sorbent or iron in solution, can be used to oxidize contaminants on or near the surface of the sorbent. The process can be used to treat contaminated water in above-ground and below-ground treatment systems.

Abstract: A simulated moving bed separation system is provided, in which a fluid circulation flow path can be washed for a short time. This system is provided with a circulation flow path having two or more packed beds connected in series and endlessly to each other, with desorbing-charging inlet, extract draw-out port, feedstock introducing port and raffinate draw-out port arranged in this order in the direction of flow of a circulation liquid, which are allowed to intermittently shift in the direction while being kept in this order, and with packed bed-washing pipes, valves and pumps. A desorbing liquid is introduced through the desorbing liquid introducing port into the circulation flow path. An extract rich in a strongly adsorptive constituent to be separated is drawn out through the extract draw-out port.

Abstract: Isotope water molecules, e.g., HTO and T2O, are separated from contaminated water by conveying the contaminated water through a separation chamber containing a separation material formed of an inorganic substrate with hydration sites having multiple associated waters of hydration, whereby the waters of hydration are preferentially replaced by the isotope water molecules. The discharged water, which is lower in concentration of isotope water molecules due to the preferential replacement, can be conveyed through a second separation chamber containing additional separation material to remove additional isotope water molecules. Following saturation, the separation material is heated to separate the isotope water molecules. The relatively concentrated water driven off by heating is stored or otherwise disposed of, and the separation material is reused.

Abstract: A method is disclosed for treating a flushing solution from an ion exchanger used in electroplating operations by co-precipitating or selectively precipitating out metal hydroxides derived from metal ions from the structures being plated in the electroplating bath, metal ions from the electrodes use in the electroplating bath and metal ions from the plating metal used in the electroplating bath, and a pH raising agent having a cation with a valence of at least 2. After the metals are precipitated out of the flushing solution, the flushing solution is aerated with carbon dioxide to precipitate out the cation from the pH raising agent as a carbonate. The carbonate precipitate is removed from the flushing solution and the resulting solution consists essentially of water that may be recycled for use in the electroplating plant or safely discharged into the environment.

Abstract: The process for removing impurities from a liquid by contact with a solid adsorbent using parallel contact adsorbent beds such that when one bed is contacting the liquid the parallel bed is being regenerated by contact with heated inert gas, wherein during changeover of the beds inert gas is transferred from the regenerated bed to the spent bed during the period that liquid is being drained from the spent bed.

Abstract: A fiber-based medium and method for binding chlorine gas utilizes sphagnum, a fibrous wetlands plant that is commercially available in dried form as sphagnum moss and sphagnum peat moss. It has been discovered that sphagnum moss is capable of binding up to 10% of its dry weight in chlorine gas, making it significantly more effective than activated carbon as a binding medium for chlorine gas. Sphagnum, sphagnum moss, and sphagnum peat moss each possesses the ability to bind chlorine gas.

Abstract: A self-regenerating ion exchange water softener has a lower tank for a resin chamber and an upper tank for a regenerative salt chamber, with an opening positioned between them, and with a restrictive pressure-sensitive valve, sensitive to pressure of water in the resin chamber, having a restricted opening limiting flow of water upwardly into the regeneration chamber or downwardly into the resin chamber.

Abstract: A polluted fluid, such as exhaust gas from a refuse incinerator, containing at least one pollutant, such as volatile organic compounds (VOCs), SOx or NOx, is processed by passing the polluted fluid through an adsorbing layer containing a high-silica adsorbent capable of adsorbing both ozone and at least one pollutant to adsorb at least one pollutant on the adsorbent. Then, ozone is brought into contact with the adsorbing layer to oxidize and decompose the pollutant adsorbed on the adsorbent, while stopping the flow of the polluted fluid.

Abstract: A method of operating a milling bath wherein a metal workpiece to be milled is immersed in a milling bath containing a milling medium, the metal oxidizing owing to a chemical reaction between the metal and milling medium and being transformed into a soluble complex. The resultant mixture is subjected to a separation process which separates the excess milling medium from the complex, the recovered milling medium being used for the further operation of milling baths and the complex being subjected to a preparation process. A mixture of dissolved complexed metallic ions and milling medium is removed from the milling bath at a concentration of dissolved complexed metallic ions which is far below the saturation limit thereof. The separation process is a nanofiltration process in which the milling medium is separated from the mixture according to the principle of reverse osmosis, the residue simultaneously being concentrated with complexed metallic ions.

Abstract: A water treatment system including a pair of water treatment tanks, each tank defining a flow path extending from a tank inlet to a tank outlet and containing a water treatment material disposed along the flow path for removing sulfur or H2S from the water. A system controller controls the frequency of regeneration of an exhausted tank as well as the regeneration cycle. The system includes a regenerant reservoir containing 5.25% sodium hypochloride which is generally available as household bleach. During a regeneration cycle, the bleach is drawn through a restrictor preferably in the form of a capillary tube that forms part of a draw tube assembly.

Abstract: There is provided a process for removing hydrocarbons from hydrophilic solutions in which the adsorbent is regenerated in situ. A solution containing at least one hydrocarbon impurity is passed through a resin bed and the hydrocarbon is retained by the resin. The solution passes from the resin bed substantially reduced of hydrocarbons. The filtration bed containing the resin is regenerated in situ by passing a second liquid therethrough such that the hydrocarbon is removed in the second liquid stream and the resin is available for reuse.

Abstract: A method and apparatus for removing arsenic from water at point of entry or point of use particularly for residential application. The point of entry system comprises a first stage having a manganese greensand oxidizer to convert arsenite (As+3) present in the water to arsenate (As+5) and a second stage for passing the water through an anion exchange resin. Each stage includes a control head for automatic regeneration at a predetermined frequency. The manganese greensand is regenerated with a solution of potassium permanganate and the anion exchange resin is regenerated with a salt solution. An alternate embodiment for point of use application comprises a manganese greensand oxidizer cartridge to convert arsenite (As+3) to arsenate (As+5) followed by removal of the arsenate (As+5) with a reverse osmosis system.

Abstract: Anion exchange resins sorbed with perchlorate may be regenerated by a combination of chemical reduction of perchlorate to chloride using a reducing agent and an electrochemical reduction of the oxidized reducing agent. Transitional metals including Ti, Re, and V are preferred chemical reagents for the reduction of perchlorate to chloride. Complexing agents such as oxalate are used to prevent the precipitation of the oxidized Ti(IV) species, and ethyl alcohol may be added to accelerate the reduction kinetics of perchlorate. The regeneration may be performed by continuously recycling the regenerating solution through the resin bed and an electrochemical cell so that the secondary waste generation is minimized.

Abstract: An improved method for regenerating ion exchange resin in a treatment tank having a flow direction, which includes the steps of providing a supply of regenerant under pressure into the tank, and introducing the regenerant into the tank in an opposite flow direction to the treatment flow direction. In the preferred embodiment, the regenerant is a combination of CO2 which is mixed with water to form carbonic acid and citric acid. This mixture is then introduced into the treatment tank without storage.

Abstract: To adsorb, on solid adsorbent particles, constituents dissolved in liquid, or to desorb (extract), from solid desorbent particles, soluble constituents in liquid, in a container a packed bed formed from granular material is mixed with adsorbent particles or desorbent particles smaller than 200 &mgr;m, said bed moves downwards by virtue of gravity, said liquid is passed upwards through the bed by means of a pressure differential, the said dissolved constituents being adsorbed on the solid adsorbent particles or the said soluble constituents being extracted from the desorbent particles.

Abstract: A process is provided for removing CO2 and/or H2S from a gas mixture containing as impurities CO2 and/or H2S and at least one other impurity selected from the group consisting of a cyanide and ammonia. The process includes contacting at least a portion of the reflux stream from the overhead vapor from a stripping column of an acid gas removal solvent (i.e., alkanolamine) treatment plant with an anion exchange resin to remove corrosive impurities. The ion-exchanged reflux stream is then recycled to the top of the stripping column or into the bulk circulating acid gas removal solvent (i.e., alkanolamine) passing from the bottom of the stripping column.

Abstract: A method is disclosed for treating a flushing solution from an ion exchanger used in electroplating operations by co-precipitating or selectively precipitating out metal hydroxides derived from metal ions from the structures being plated in the electroplating bath, metal ions from the electrodes use in the electroplating bath and metal ions from the plating metal used in the electroplating bath, and a pH raising agent having a cation with a valence of at least 2. After the metals are precipitated out of the flushing solution, the flushing solution is aerated with carbon dioxide to precipitate out the cation from the pH raising agent as a carbonate. The carbonate precipitate is removed from the flushing solution and the resulting solution consists essentially of water that may be recycled for use in the electroplating plant or safely discharged into the environment.

Abstract: A method and apparatus for the treatment and remediation of a contaminated aquifer in the presence of an uncontaminated aquifer at a different hydraulic potential. The apparatus consists of a wellbore inserted through a first aquifer and into a second aquifer, an inner cylinder within the wellbore is supported and sealed to the wellbore to prevent communication between the two aquifers. Air injection is used to sparge the liquid having the higher static water level and, to airlift it to a height whereby it spills into the inner cylinder. The second treatment area provides treatment in the form of aeration or treatment with a material. Vapor stripped in sparging is vented to the atmosphere. Treated water is returned to the aquifer having the lower hydraulic potential.

Abstract: A process for the removal of ethers and/or PAH's from water, such as contaminated groundwater, is provided that proceeds by initially separating off solid constituents and then adsorbing ethers and polycyclic aromatic hydrocarbons to an adsorber resin, then, as needed, desorbing the adsorbed compounds with steam and regenerating the adsorber resin with an acid, to provide purification of highly polluted groundwater to such a substantial extent that the groundwater can be added to flowing surface waters without problem, and, if desired, used as cooling water or, after further biological purification, as drinking water.

Abstract: A procedure for reducing the patulin content in a fruit juice which includes presenting the juice to a resin material having in abundance micropores of less than 20 Å minimum pore width and at least a pore surface capable of retaining patulin by the forces of chemisorption. Preferably the resin has weak base functionality and is substantially devoid of mesopores and macropores. The resin preferably has a surface area of greater than 900 m2/g (BET) and the resin has been hypercross-linked whilst in the swollen state. Regeneration involves the conversion of the resin held patulin to a more easily flushed out derivative using ammonia or a volatile base, preferably generated in situ from a high pH solution.

Abstract: A process for the reclamation of spent aqueous alkanolamine solutions by contacting a spent aqueous alkanolamine solution with a strong base ion exchange resin for time sufficient to sorb from the aqueous alkanolamine solution at least a portion of the accumulated ions and after a high concentration of ions accumulate on the resin, regenerating the strong base ion exchange resin by: a) purging the resin with water or nitrogen, b) contacting the strong base ion exchange resin with a sodium chloride solution for a time sufficient to remove the ions, c) purging the resin to remove the sodium chloride solution, d) contacting the resin with an alkali metal hydroxide solution, preferably sodium hydroxide, for a time sufficient to convert the resin to a substantially hydroxide form; and e) purging the resin, wherein the ion sorption capacity of the resin is maintained at a substantially constant value.

Abstract: A cross-linked water-insoluble ion exchange resin comprised of polymerized monomers having a phenyl ring is disclosed. A contemplated resin contains (i) polymerized phenyl ring-containing monomers having a phosphonic acid ligand linked to the phenyl ring, (ii) about 2 to about 5 millimoles per gram (mmol/g) of phosphorus as phosphonic acid ligands, and (iii) a sufficient amount of a sulfonic acid ligand such that the ratio of mmol/g of phosphonic acid to mmol/g sulfonic acid is up to 3:1. A process for removing polyvalent metal cations from aqueous solution, and a process for removing iron(III) cations from acidic copper(II) cation-containing solutions that utilize the contemplated resin or other resins are disclosed.

Abstract: A process is disclosed for the recovery of gold and/or silver values from activated carbon, wherein they are adsorbed as cyanide complexes. The process uses an eluant containing sugar. The process allows the eluant to pass through fresh carbon twice, thereby reducing the volume of the gold-loaded eluant. This, in turn, reduces the size of the electrowinning or zinc precipitation circuits. The process also improves elution efficiency when barren electrowinning solution is recycled in the elution process.

Abstract: The hydrophilic organic contaminants and hydrogen peroxide present in semiconductor fabrication reclaims are removed by means of adsorption of a pyrolysate of a macroreticular sulphonated vinyl-aromatic polymer having a carbon content of at least 85% by weight and a carbon/hydrogen atomic ratio of from 1.5:1 to 20:1. In spite of their hydrophobic surface, the pyrolysates have a comparatively high adsorptivity for these contaminants and provide for distinctively higher removal rates than customary activated carbons.

Abstract: Conventional regenerative adsorptive methods for the purification of waters of organic constituents are limited in their application, when owing to a low content of organic water constituents the loading of the adsorbers is so low that the condensed water vapor desorbate no longer has a tendency to form two phases, or when the organic components are readily water-soluble and thus, following desorption with water vapor, can be separated only with difficulty out of the condensed desorbate. The process of the invention improves the tendency toward phase separation by cycling back the aqueous phase of the desorbate onto a loaded adsorber prior to its desorption in order to increase the loading and reduce, through additional supply of external heat, the required amount of water vapor for desorption. The present process is particularly useful for purification of industrial process waters or ground water.

Abstract: Heated iron oxide particles are combined with membrane filtration to remove contaminants from water. The use of the heated particles reduces fouling of the membrane typically encountered when membranes alone are used to remove contaminants from water. The heated particles of iron oxide are regenerable and can be reconditioned to revive their adsorption capacity. The heated particles can be added to the stream of contaminant containing water upstream of the membrane.

Abstract: An apparatus and method for separating oxides of heavy isotopes of hydrogen (deuterium oxide, oxides of tritium and mixed isotope oxides) from light water (H2O) which is contaminated with these heavy hydrogen isotopes such as that currently being discharged in cooling water from nuclear power plants. A central aspect of this invention includes a plurality or bundle of elongated hollow core fibers which are positioned within an elongated enclosed housing having a feed water inlet, an exit stream outlet, and a permeate outlet. At least a portion of the hollow core fibers are at least partially filled or packed with small beads which are comprised of a porous exchange resin carrying waters of hydration. Porosity is controlled by the degree of cross-linking and bead diameter of the exchange resin which is preferably combined with aluminum sulfate or ammonium hydride to form (RSO.sub.3).sub.3 Al or RSO.sub.3 NH.sub.4.

Abstract: In a process for the partial desalination of water, especially of drinking water, with a mixture of weakly acid cation exchangers and strongly basic anion exchangers, whereby the charged ion exchangers are regenerated by CO.sub.2 -containing water, if required, with the addition of CaCO.sub.3, CaCO.sub.3 /MgO, Ca(OH).sub.2 or the like. Simultaneous with the partial desalination, the organic carbon compounds present in the water are reduced, whereby the charged ion exchangers are intermittently regenerated with HCl, NaCl, NaOH, or a mixture of NaCl and NaOH.

Abstract: A process is disclosed for the removal of algae-associated odorant from fresh water by contacting such water with cyclodextrin and recovering the water so contacted.

Abstract: For the removal of trace quantities of iodine-containing contaminants from corrosive liquid feed streams, an adsorbent with distinct advantages over prior-art materials is provided. The treatment method involves the use of a metal phthalocyanine compound where the metal selected from the group consisting of silver, mercury, copper, lead, thallium, palladium, or mixtures thereof. Such metals are known to be reactive with the iodine-containing contaminants in the feed stream. Furthermore, the metal phthalocyanine is deposited on a carrier material selected from the group consisting of an activated carbon, a phenolic polymer, and an inorganic refractory metal oxide. Such adsorbent materials have proven substantially insoluble even in corrosive liquid feed streams associated with the invention. Reactivation and regeneration techniques, which are generally incompatible with prior-art adsorbent materials, are also disclosed.

Abstract: The invention relates to a process for removing and recovering mercury, an impurity, from a hydrocarbon feedstream. The process comprises separating the hydrocarbon feedstream into a gaseous portion and a liquid hydrocarbon portion and separately treating the gaseous and liquid portions by adsorption in separate purifier beds. The gas and liquid purifier beds are regenerated sequentially with a heated regenerant stream that following desorption and recovery of mercury is further purified in a secondary regenerable adsorption bed. The sequential regeneration of the two separate purifier beds and the secondary adsorbent bed significantly reduces the capital and operating cost for the process and serves to concentrate the mercury in the secondary adsorbent bed where it can be removed at a lower cost.

Abstract: An ion exchange separation, recovery and regeneration process for the control of iron is disclosed that can replace the conventional bleed stream process used in copper electrowinning. The disclosed process minimizes the loss of cobalt from the electrowinning circuit and can effect a lowering of the total iron concentration in the electrolyte circuit with an associated increase in current efficiency. The process captures the iron as iron(III) on an ion exchange medium containing a plurality of --CH(PO.sub.3 R.sub.2).sub.2 or --C(PO.sub.3 R.sub.2).sub.2 -- groups through which the divalvent metal ions pass. The iron(III) is then reduced with copper(I) to form iron(II) that is freed from the exchange medium, thereby permitting regeneration of the medium.

Abstract: A cation exchanger is loaded only with radioactive cations by repeatedly converting the non-bivalent, inactive cations into anionic complexes and flushing the complexes out of the cation exchanger. The cation exchanger, which may be integrated in a primary system of a nuclear power plant, is connected to a feed line for a complexing agent and to a discharge line through which the anionic complexes are flushed from the exchanger.