Abstract: A process using a regenerable inorganic media capable of removing contaminants by catalytic oxidation or reduction, as well as heavy metal adsorption, from well and surface water sources. The specific material is specially-treated gamma-type electrolytic manganese dioxide, the treatment involving comminuting to a 20-60 mesh size, complete neutralization and washing to remove fines, residual acidity and neutralization products. Certain taste, odor and staining water contaminants such as hydrogen sulfide, iron and manganese can be oxidized and filtered by the media with subsequent removal from the system by simply backwashing with water or water in combination with simple chemicals. Heavy metals are removed by a different adsorption mechanism on the same media followed by regeneration with a dilute acid. Pretreatment of the media with sodium hydrosulfite further allows the removal of residual chlorine.

Abstract: A water treatment system is provided including a service step, a regenerating step and a rinse step. The service step includes introducing water to be treated into the inlet, through a treatment medium and out the outlet to a service location. If a prolonged period of idleness is determined automatically, a rinse step is automatically provided by which an amount of water to be treated is introduced into the inlet, through the treatment medium and out of the outlet to drain.

Abstract: Terpenes are removed from essential oils by(a) contacting terpene-containing essential oils with a polar solid (adsorbent);(b) separating the loaded adsorbent from the liquid phase enriched with terpenes; and(c) subjecting the adsorbent loaded with essential oils to an extraction with compressed carbon dioxide.

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: A biological contactor (8) comprises a granular bed including a layer (17) based on activated carbon the material of which satisfies the following conditions:density between 0.18 and 0.32 g/cm.sup.3,carbon tetrachloride adsorbing power between 60% and 120% by weight,carbon tetrachloride retention less than 25% by weight of the carbon tetrachloride adsorbed mass,methylene blue: between 5 and 30 ml,particle size: between 0.5 and 1.5 mm effective size with a coefficient of uniformity less than 2.A washing cycle (21, 24) (air only; air plus water; water only) of the contactor is triggered (38) when a parameter (36, 37) representative of the population of algae in said layer reaches a predetermined set point threshold.

Abstract: The present invention relates to a mobile inorganic recycling process and apparatus. In the preferred embodiment, the invention includes two vehicles, a first of which is utilized to receive hazardous wastes and mix them with treating chemicals and a second of which is provided to fixate the hazardous wastes into end products which are usable by consumers. The fixating vehicle includes a sophisticated scrubber designed to render inoffensive the hazardous gases which are created as a result of the process carried out in the vehicles. The inventive system is useful in converting all hazardous inorganic wastes into end products which do not include any hazardous aspect.

Abstract: A method and composition are described for the prevention of the mushing or the disintegration of solid sodium chloride in an aqueous medium.

Abstract: An equilibrated percent solids waveform is established in a simulated moving bed process. A contraction phase of the waveform is monitored as it rotates through a circulation loop including a plurality of resin bed compartments. The contraction phase is followed by a desorbent phase. A slurry of resin is added to each compartment between the contraction and desorbent phases.

Abstract: A water softening system is provided including a service step, a regenerating step and a rinse step. The service step includes introducing relatively hard water into the inlet, through an ion exchange resin and out the outlet to a service location. The regenerating step includes introducing a brine solution into the inlet, through the resin and out the outlet to drain. Prior to the service step, an automatic rinse step is provided by which an amount of the relatively hard water is introduced into the inlet, through the softening medium and out of the outlet to drain.

Abstract: Gold in a very dilute water solution is carbon filtered to capture the gold by adsorption; the gold in the filter is then recovered from the carbon by means of a highly-efficient non-explosive low-alcohol water-based eluant including a strong base and an elevated level of sodium or potassium cyanide.

Abstract: Water or gas containing organic impurities is purified by contact with a poly(trialkylsilylpropyne), such as poly[1-(trimethylsilyl)-1-propyne], operating as a bulk absorbent. Regeneration of the absorbent can be by vacuum or a stream of air.

Abstract: Trialkyl arsines are removed from fluids, in particular gases, by contacting with a solid sorbent material containing at least one silver component (preferably nitrate and/or oxide and/or metal) and a support material (preferably alumina, fluorided alumina, silica, fluorided silica, titania or magnesium aluminate).

Abstract: Disclosed is a process for removing selenium from wastewater effluent. The processd includes the steps of;(i) contacting a selenide containing wastewater and a strong-base anion exchange resin to absorb selenide on the resin;(ii) eluting the ion exchange resin with an eluant which is effective for stripping selenide therefrom; and(iii) recovering elemental selenium from the selenide containing eluate resulting from step (ii). Also disclosed is a process for regenerating the ion exchange resin by treatment of the resin with an acidic chlorate solution.

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 removing cations of a first alkaline earth metal species from an aqueous solution with an ion exchanger material that is a cation exchanger or contains one and subsequently regenerating the loaded or exhausted ion exchanger material. A cation exchanger that has been loaded in advance with cations of a second alkaline earth metal species is used to remove the cations of the first alkaline earth metal species. The cation exchanger that is loaded or exhausted with the first species to be removed is regenerated by bringing the loaded or exhausted cation exchanger into contact with an aqueous suspension of a slightly soluble carbonate and/or hydroxide of the second alkaline earth metal species, either alone or in a mixture with an anion exchanger, and introducing a CO.sub.2 -containing gas into the suspension.

Abstract: A process for removing heavy metal cations and/or alkali metal cations from aqueous solutions with an ion exchanger material that comprises a cation exchanger loaded with alkaline earth metal ions, and subsequently regenerating the loaded or exhausted ion exchanger material. The loaded or spent cation exchanger either alone or in a mixture with an anion exchanger is regenerated by bringing it into contact with an aqueous suspension of a slightly soluble carbonate and/or hydroxide of an alkaline earth metal ion and/or a completely or partially calcined, natural carbonate and introducing a CO.sub.2 -containing gas into the suspension.

Abstract: The Takahax gas desulfurization method is rendered more energy-efficient and compact by providing separate scrubbing and regeneration loops operating from a common reservoir (31,33) and by using hyperbaric pressure in the oxygenating or regenerator vessel (59). The overall height of a plant of comparable capacity can be reduced from the 13 meters (about 40 feet) required by the prior art to 3.3 meters (10 feet) and can therefore be transported by truck. The preferred washing or scrubbing liquid is an alkaline solution using sodium 1,4 napthoquinone-2-sulfonate as the catalyst. By oxidation, elemental sulfur is made to precipitate and this is filtered out continuously in a filter (77). Regenerated washing liquid flows via a degassing vessel (69) into the common reservoir (27,31,33). In the degassing vessel, under relaxed pressure, degassing occurs, and the sulfur foam, along with the oxygen or air it contains, is returned via a pump (55) to the regenerator pressure vessel (59) or to the filter (77).

Abstract: Gas containing sulfide is washed in the washing vessel (13) with a washing liquid that normally comprises an alkaline solution having sodium 1,4-naphthoquinone-2-sulfonate as the catalyst. Contaminated liquid is subjected in a pressure vessel (59) to aeration under pressure with air or pure oxygen. By oxidation, elementary sulfur precipitates out and this is filtered out continuously in the filter (77). Regenerated washing liquid flows via a degassing vessel (69) into the storage container (27) and from there returns to the washing vessel (13). In the degassing vessel, under relaxed pressure, degassing occurs, and the sulfur foam along with the oxygen or air it contains is returned via the pump (55) to the presure vessel (59) or to the filter (77).

Abstract: Mercury is selectively removed to very low levels of concentration from fluid streams such as natural gas, cracked gas, hydrogen or naphtha by passage of the stream through an adsorbent bed containing particles of a zeolitic molecular sieve having pore diameters of at least 3.0 Angstroms and in which the zeolite crystallites forming the outer shell of the adsorbent particle to a depth of not greater than about 0.1 millimeter into the adsorbent particle, contain ionic or elemental silver. These adsorbent particles are utilized to particular advantage in a compound adsorbent bed containing a desiccant substantially free of silver through which a fluid stream containing both mercury vapor and water vapor is both dried and purified with respect to mercury by passage therethrough, coupled with periodic regeneration of both media using conventional purge desorption methods.

Abstract: An adsorption-desorption process for separation of a component from a feed mixture of components wherein at least two components of the feed mixture are adsorbed by an adsorbent material during the adsorption step of the adsorption-desorption process and the adsorbent material has a greater affinity for a first one of said adsorbed components than for a second one of the adsorbed components, the process comprising charging the feed mixture to an inlet end of a bed of the adsorbent material, passing the feed mixture through the bed under such conditions that the adsorbent material adsorbs said first and second components of the feed mixture, withdrawing an effluent from an outlet end of the bed, the effluent consisting essentially of feed mixture decreased in content of the materials adsorbed by the bed, after the adsorbent material is substantially saturated, desorbing the first and second components from the adsorbent material in at least two steps at substantially the same pressure but at different temperat

Abstract: Water contaminated with at least one volatile compound is treated by air stripping the volatile compound into the gas phase, then removing the volatile compound from the gas phase by contacting it with an aqueous mixture of biological solids and powdered adsorbent. The partially-purified water is further treated by a biophysical aerobic process which in turn produces the aqueous mixture of biological solids and powdered adsorbent used to remove the volatile compound from the gas phase. The aqueous mixture of biological solids and powdered adsorbent containing the volatile compound is thickened and the solids slurry treated by regeneration, preferrably wet air oxidation, to destroy the biological solids and volatile compound as well as regenerate the powdered adsorbent. The regenrated adsorbent may be returned to the biophysical aerobic treatment process.

Abstract: A process for hydrogenating a hydrocarbonaceous charge stock containing nitrogen, sulfur or halogen-based impurities which process comprises the steps of: (a) contacting the hydrocarbonaceous charge stock in the presence of hydrogen with a hydrogenation catalyst in a hydrogenation reaction zone to simultaneously increase the hydrogen content of the hydrocarbonaceous charge stock and to generate at least one water-soluble inorganic compound produced from the reaction of said nitrogen, sulfur or halogen-based impurities in said hydrocarbonaceous charge stock and the hydrogen; (b) contacting the reaction zone effluent containing hydrogenated hydrocarbonaceous compounds and at least one said water-soluble inorganic compound with a fresh aqueous scrubbing solution; (c) introducing a resulting admixture of the reaction zone effluent and the aqueous scrubbing solution into a separation zone to provide a hydrogenated hydrocarbonaceous stream and a spent aqueous scrubbing solution stream containing at least a portion

Abstract: A method and apparatus for a regenerating dynamic adsorber system which removes a contaminant from fluid. The system includes at least one adsorption bed having a contaminant removal capacity that is based substantially on the flow of the contaminated fluid through the bed. The system alternately cleanses the contaminated fluid by feeding the contaminated fluid from a first volume to the bed and issuing cleansed fluid to a second volume, and regenerates the bed by providing clean fluid from a third volume and issuing the fluid back to the third volume.

Abstract: Purified barium salts essentially devoid of strontium impurities, e.g., highly pure barium carbonate, are produced by liquid/liquid extracting an aqueous solution of impure barium values with an organic solvent medium which comprises at least one water-insoluble carboxylic acid, phosphonic acid monoester, or substituted 8-hydroxyquinoline extractant. The mixture of extraction is separated into a purified aqueous phase containing the desired barium salt values and an organic phase containing the impurity values sought to be removed.

Abstract: The improved method and apparatus treats the stack gases from a commercial bakery oven to remove and recover pollutants, specifically ethyl alcohol. The method includes the steps of cooling the stack gases and passing the cooled gases through a packed column to condense the water and ethyl alcohol and if the ethyl alcohol is to be recovered drying the ethyl alcohol by distillation and by absorption of the water therefrom by a molecular sieve. The apparatus includes blowers and controls to maintain the normal flow of gases from the oven so that the removal and recovery of the ethyl alcohol from the stack gases does not interfere or change the baking conditions of the oven. This may be accomplished by a system of dampers or by controlling the discharge rate of the blowers used.

Abstract: A process for purifying an alkali metal halide brine containing aluminum as an impurity which comprises adjusting the pH of the alkali metal halide brine to the range of from about 8.5 to about 9.5 and contacting the alkali metal halide brine with an ion exchange resin having a phosphonic acid group.Using the novel process of the present invention, high purity alkali metal halide brines may be produced for use in electrolytic membrane cells which have concentrations of aluminum reduced to a level which will not cause damage to a cation exchange membrane or affect the membranes ability to transport cations or water molecules.

Abstract: Chelating agents on which metals such as uranium have been adsorbed are brought into contact with an eluent of aqueous solution containing reducing agents and basic compounds, until the metals are eluted. The elution is effected with large speed without degradation of the chelating agents. Preferred chelating agents are rather stable under basic conditions but not under acidic conditions, for example, those having .dbd.NOH group in their molecules. The reducing agents and basic compounds in the eluent are, for example, sulfurous acid or salts thereof and sodium hydroxide, respectively.

Abstract: In the process for removing organic impurity constituents from aqueous media by adsorbing same on an organophilic molecular sieve adsorbent, followed by regeneration of the adsorbent by contact with an oxidant, such as hydrogen peroxide, whereby the organic adsorbate is converted to innocuous materials, principally CO.sub.2 and H.sub.2 O, the efficiency of the regeneration operation is found to be substantially improved by decreasing the pH of the regenerating medium and/or increasing the number of Bronsted acid sites in the molecular sieve adsorbent.

Abstract: A continuous and valveless sorber device is described which utilizes a novel rotating sorption bed which operates through at least three zones (sorption, desorption and cooling). The rotating sorption bed is contained within a plurality of manifolds and the sorption bed and the manifolds are sealed to one another via sealing means. Contaminated fluid is directed through the sorption zone of the rotating sorption bed where the contaminants are removed by sorbents. The bulk of the fluid which is then cleaned is available for use. A portion of the clean fluid (regeneration fluid) is used to cool the sorbent in the cooling zone of the rotating sorption bed. The warmed regeneration fluid is then heated by a regeneration heater and is subsequently directed into the desorption zone of the rotating sorption bed where the hot clean regeneration fluid is used to desorb and carry away the contaminants from the sorbent.

Abstract: Contaminated water is contacted with an agent which contains salts or cations of mono-, di-, or trivalent metals in a maximum amount of 50 masspercent and rock granules containing at least 25 masspercent zeolite, preferably clinoptilolite and/or mordenite. The amount of metal salts respectively cations present in the parent zeolitic rock can be increased according to necessity by ion-exchange, adsorption and/or impregnation, i.e. by combination of these processes following eventual dehydration. The agent obtained is homogenized. The exhausted bed can be regenerated biologically or with aqueous solution of a potassium salt.

Abstract: Described are processes for improving and maintaining the performance of particulate and othe types of water-treatment solids, especially particulate ion exchange resins, filter media, and adsorbents which have become fouled with organic contaminants, micro-organisms, and wasteproducts thereof.

Abstract: A water softening apparatus and method for reducing odor in, and improving the taste of, problem water, including a pair of treatment tanks and a control valve assembly for determining which tank is on-line, and which tank is off-line, and for controlling the regeneration of the off-line tank. An exhausted tank is taken off-line and partially regenerated by communicating a regeneration solution from a reservoir to the tank and passing the solution through a resin compartment after which the solution is discharged to drain. After a predetermined quantity of regeneration solution is passed through the tank, the resin compartment is slowly rinsed using treated water from the on-line tank. Prior to fully rinsing the off-line tank, the fluid flow is terminated leaving a diluted regeneration solution in the off-line tank thereby keeping the off-line tank in a "high solids" condition.

Abstract: Gold is selectively extracted from an aqueous solution by contacting the gold-containing solution, which may contain other metals, with a resin which is a diallylamine homopolymer or copolymer, and then separating the resin from the solution.

Abstract: An improved process for the recovery of precious metal values is disclosed. By this process precious metals in the form of anionic complexes are contacted with a weak-base anion exchange resin capable of complexing with the anionic complex. Such weak-base anion exchange resins contain weak-base functionalities derived from linear or cyclic polyaminoalkylene amines which have more than 1 amine moiety and at least 3 carbon atoms in a 1,X-alkylene moiety or moieties separating at least 1 amine moiety from a second amine moiety (i.e., X is an integer greater than 2).

Abstract: Regenerated adsorbent particles, such as activated carbon, are recovered from a wet oxidation-regenerated mixed liquor sludge from a wastewater treatment system by diluting and settling a blowdown slurry from the wet oxidation reactor to obtain a first aqueous phase containing primarily regenerated adsorbent particles and fine ash particles and a first solids phase containing primarily grit particles. The first aqueous phase is combined with a portion of the regenerated adsorbent particle slurry withdrawn from the upper portion of the wet oxidation reactor and, after treatment with a dispersing agent and then an anionic flocculating agent, the resulting mixture is settled to obtain a second aqueous phase containing primarily fine ash particles and a second solids phase containing primarily regenerated adsorbent particles.

Abstract: A process for the removal of hydrogenatable hydrocarbonaceous compounds from a hydrocarbonaceous stream which comprises the steps of: (a) contacting the hydrocarbonaceous stream with an adsorbent to remove at least a portion of the hydrogenatable hydrocarbonaceous compounds from the hydrocarbonaceous stream to provide a hydrocarbonaceous stream having a reduced concentration of hydrogenatable hydrocarbonaceous compounds; (b) contacting spent adsorbent which has accumulated the hydrogenatable hydrocarbonaceous compounds from the hydrocarbonaceous stream with an elution solvent to remove the hydrogenatable hydrocarbonaceous compounds from the spent adsorbent thereby regenerating the adsorbent; (c) recovering at least a portion of the elution solvent from a resulting admixture of elution solvent and hydrogenatable hydrocarbonaceous compounds recovered from step (b) in an elution solvent recovery zone; (d) contacting the hydrogenatable hydrocarbonaceous compounds which were recovered from step (c) in the presence

Abstract: A method for reducing chemical oxygen demand (COD) in water. The water is contacted by a first adsorptive material selected from the group consisting of porous ceramic, activated alumina, magnesia, silica or mixtures thereof; adding an oxygen source to the water stream; adsorbing soluble contaminants on a second adsorptive surface selected from the group consisting of Group VIIIB metals, Group IB metals or mixtures thereof; catalytically reacting soluble contaminants adsorbed on the second adsorptive material with the oxygen source to decompose the chemical contaminants; reacting the products of the decomposition of the chemical contaminants to yield insoluble precipitates which adhere to the second adsorptive surface; and adsorbing and reacting additional contaminants on the second adsorptive material and the insoluble material adhering thereto. The second adsorptive material is, preferably, platinum, palladium, irridium, rhodium or mixtures thereof.

Abstract: A combination of pollution control technologies are employed in the treatment of effluent from photographic processing. The technologies employed are evaporation, oxidation by photolysis and catalyzed ozone, condensation, treatment by activated carbon and electrolysis. The method includes the steps of filtering the liquid wastes, electrolytically treating the filtered liquid, evaporating the wastes to create steam and vapors, oxidizing the steam and vapors by photolysis and photolytic catalyzed ozone, and condensing the vapors and passing them through a column of activated carbon. The carbon is regenerated by oxidizing the carbon sites with ozone.

Abstract: A process is described for the substantially complete recovery of cyanide reagent and metal forming water soluble metal-cyanide complexes contained in mill effluents and waste waters. The process is comprised of a loading cycle wherein the metal-cyanide complexes are adsorbed onto a basic ion exchange resin and the free cyanide containing column effluent is returned to the mill. The metal ions, which are usually mostly copper, nickel and zinc, and the complexing cyanide are eluted in the subsequent regenerant cycle by an acid solution having controlled pH and controlled redox potential, the latter being measured against the saturated calomel electrode. The preferred oxidant to control the redox potential of the regenerant solution is hydrogen peroxide. The generated hydrogen cyanide is sparged with air, or removed by subatmospheric pressure from the regenerant solution, and dissolved in an alkaline scrubber solution for reuse. The metal ions are recovered from a bleed solution.

Abstract: Water contaminated with a trihalocarbon is passed through a first or second bed containing particles of an activated composite adsorbent comprising alumina and zeolite. The trihalocarbon is adsorbed onto the particles, thereby reducing trihalocarbon concentration in the water. The adsorbed trihalocarbon is reacted with air or steam at an elevated temperature in order to regenerate the adsorbent particles for reuse. Gaseous HCl produced in the reaction with air or steam may be adsorbed in a third bed containing adsorbent agglomerates.

Abstract: A device for removing hydrogen sulfide from well water having in situ activated carbon adsorbent regeneration. The device includes a tank with a water inlet, a water outlet and a steam outlet. The hydrogen sulfide adsorbent material is situated in the tank so that water entering through the water inlet must pass through the adsorbent material before exiting the water outlet. The tank also has a heating element which may be activated to boil water which is in communication with the adsorbent material. The water inlet, the water outlet, and steam outlet each have valves which are operated so that water may enter the tank and pass through the hydrogen sulfide adsorbent material and out the water outlet during water purification stage without any water going out the steam outlet.

Abstract: A process for removing and preventing iron contamination of water treatment solids which tend to become iron fouled which comprises cyclically treating said water treatment solids with an aqueous solution containing an effective amount of:(a) a reducing agent;(b) a chelating agent;with a pH of said treating solution having been adjusted to within a range of about 4-6.

Abstract: The specification discloses a method for the extraction of metal ions having a reduction potential of above about +0.3 from an aqueous solution. The method includes contacting the aqueous solution with a polymeric extractant having primary phosphinic acid groups, secondary phosphine oxide groups, or both phosphinic acid and phosphine oxide groups.

Abstract: Toxic or otherwise contaminating organic impurity constituents in aqueous media such as waste water streams from industrial processes or potable water supplies are removed and converted to harmless oxidation products by contacting such media with an organophilic molecular sieve whereby the organic species are concentrated as adsorbates, and thereafter contacting the adsorbate-loaded molecular sieve with an aqueous solution of a compound which has a standard oxidation potential of at least 0.25 volt in an amount and for a sufficient time to convert the organic materials to non-toxic products such as CO.sub.2.

Abstract: The present invention relates to a method for removing a silicic compound from the waste liquor of steel pickling. A filtering method using a filter fabric or biscuit plate is impractical as an industrial method because the filtering medium becomes clogged.The present invention is characterized by an adsorption method in which silicic compounds are adsorbed on adsorbent substrates in an optional part of an adsorption bed.The present invention is characterized in that the waste liquor is passed through the adsorption bed for a two-month period or longer without clogging occurring.

Abstract: A continuous process for separating components of a fluid mixture is disclosed which comprises forming a sorption zone and a desorption zone, said zones being separated by a boundary of a sorbent material which continuously moves back and forth between the zones, causing a fluid mixture to flow into the sorption zone wherein the conditions are such to promote sorption of one of the components of the mixture by the sorbent material, and creating conditions in the desorption zone such that the sorbed component will be desorbed when the sorbent material containing the sorbed component moves into the desorption zone.

Abstract: Disclosed is a continuous process for removing an organic compound from water including passing an influent of water and organic compound through a filter bed of hard, substantially non-porous, inorganic particles to separate the organic compound and form a water effluent of reduced organic amounts, washing the particles to remove the organic compound and form a concentrated organic effluent, and recycling washed particles to the filter bed. The continuous process includes washing at a washing rate sufficient to shear organic compounds from solid filter media particles.

Abstract: A process for separating Fe(III) from an aqueous solution of metallic salts containing at least Fe(III), comprising: (1) bringing said aqueous solution into contact with an organic extraction solvent containing, as an extractant, an organic phosphinic acid represented by the following general formula to thereby extract at least Fe(III) from the aqueous phase and transfer it into the organic phase; ##STR1## wherein R.sub.1 and R.sub.2 are alkyls, respectively, having carbon number in the range of 1 to 20; the sum of carbon numbers for R.sub.1 and R.sub.2 is in the range of 12 to 36; and R.sub.1 is the same as or different from R.sub.2, and (2) separating the resulting Fe(III) loaded organic phase from said aqueous phase.A process for separating Fe(III) from an organic extraction solvent loaded with at least Fe(III), comprising: (1) bringing said extraction solvent into contact with an aqueous solution of a mineral acid having a low concentration at pH 1.

Abstract: Process for the long-duration removal of polychlorinated biphenyls (PCB) from transformer-insulating liquids when substituting insulating liquids, particularly silicon oils, for PCB oils. The PCB contaminants can be removed continuously or substantially continuously from the transformer-insulating liquids using an adsorption resin, thus preventing PCB from accumulating in the transformer-insulating liquid. The insulating liquid is passed substantially continuously through the adsorption resin; adsorption resin, after enrichment with PCB oil, is washed with a solvent for PCB oils; and the washed resin is freed from residual solvent by rinsing it with a gas prior to reusing the thus regenerated resin to adsorb additional PCB oil.

Abstract: Novel anion exchange resin composites having hydrous chromium III oxide (Cr.sub.2 O.sub.3.nH.sub.2 O) incorporated therein are useful in removing a wide array of polyvalent metal cations from aqueous solution.