Abstract: Electrochemical processes using solid gas-impervious membranes are disclosed for gas cleanup by (A) providing an electrochemical cell comprising first and second zones separated by a solid gas-impervious membrane comprising a mixed metal oxide material of a perovskite structure having electron conductivity and oxygen ion conductivity, (B) passing a gas containing N2O, NO, NO2, SO2, SO3, or a mixture thereof, in contact with the membrane in the first zone, and (C) passing a gas capable of reacting with oxygen in contact with the membrane in the second zone. More particularly, the mixed metal oxide material of a perovskite structure comprises a combination of elements selected from the group consisting of lanthanides, alkaline earth metals, Y, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, and Nb, oxides thereof, and mixtures of these metals and metal oxides. Advantageously a catalyst is present in the first zone.

Abstract: A process treats contaminated media and comprises detecting a non-uniform contaminated media property selected from electrical conductivity or electroosmotic permeability; and selectively applying an electric field to the contaminated media to effect the process in a selected area of the contaminated media.

Abstract: In a method of removing impurities, especially iodine and/or silica ions, from a salt solution to be used for electrolysis, the salt solution and zirconium hydroxide are brought into contact with each other under acidic conditions, and the zirconium hydroxide adsorbs the impurities. Thereafter, the zirconium hydroxide containing the adsorbed impurities is brought into contact with an aqueous solution at a higher pH value to desorb the impurities from the zirconium hydroxide, thereby enabling the zirconium hydroxide to be recycled.

Abstract: The present invention provides an electrochemical process for reducing metal contaminants in calcium carbonate by solubilizing the metal contaminate in an aqueous solution of calcium carbonate and then removing the solubilized metal contaminant by passing an electrical current through the aqueous calcium carbonate solution containing the solubilized metal contaminant. Calcium carbonate produced according to the process of this invention is particularly suitable for use as food or pharmaceutical additives. The calcium carbonate is also suitable for use in papermaking process as fillers, or coatings, or as additives in the production of plastics, paints and adhesive products. Other uses of high purity calcium carbonate include catalysts and catalyst supports, electrical/semiconductor applications, florescent lighting, and optical/laser applications.

Abstract: The invention concerns a method for decreasing the oxygen content of the atmosphere above photographic processing baths. The method comprises using a solid electrolyte which is a compound of bismuth, vanadium or another transition metal. The oxidation in air is thus minimized and the life of the bath is extended.

Abstract: A method of manufacturing an aqueous solution of biocompounds containing peptide as a major component and a hydroxyapatite containing minerals and being useful an inorganic or organic composite material from tissue in an electrolytic cell by performing the electrolysis of an aqueous solution of the tissue and by taking advantage of an electrode reaction using suitable electrodes. In this case, a DC current is passed between the electrodes in the aqueous solution, thereby dissolving and crystallizing the tissue components. After unreacted matters are removed, the resultant mixed solution is separated into solid matters and a liquid. The aqueous solution of biocompounds is obtained from the filtrate, and the hydroxyapatite is obtained from the recrystallized solid matters.

Abstract: The invention relates to a method and a device for regenerating exhausted tin-plating solutions which contain tin and copper ions, free complexing agent and complexing agent bound to the copper ions, as well as expended and unexpended reducing agent. By means of a suitable rinsing technique, the rinse water of the tin-plating process is concentrated to a 10 to 15 percent dilution of the process solution. The regenerating solution thus produced is fed to an electrolytic cell. The electrolytic cell comprises a cathode chamber, a middle chamber and an anode chamber. The cathode chamber is separated from the middle chamber by an anion-exchange membrane and the anode chamber is separated from the middle chamber by a cation-exchange membrane. The regenerating solution is initially provided in the cathode chamber. Here, the interfering copper component is cathodically deposited.

Abstract: Wastewater containing a surfactant and an oil content that has been emulsified by the action of the surfactant can be freed of the oil content by a method including feeding the wastewater into the anode compartment, for electrolysis, of a diaphragm electrolyzer having an anode and a cathode provided in the anode compartment and a cathode compartment, respectively, which are spaced apart by a porous diaphragm and which are supplied with a dc voltage between the anode and the cathode, passing part of the electrolyzed wastewater through the diaphragm so that it enters the cathode compartment, discharging the influent from the cathode compartment, discharging the remainder of the electrolyzed wastewater from the anode compartment and introducing the same into the intermediate portion of a gas-liquid separator, withdrawing part of the influent from the top of the gas-liquid separator and introducing the same into a layer packed with an adhering material, where it is brought into contact with the adhering material,

Abstract: Wastewater containing a surfactant and an oil content that has been emulsified by the action of the surfactant can be freed of the oil content by a method to including feeding the wastewater into the anode compartment, for electrolysis, of a diaphragm electrolyzer having an anode and a cathode provided in the anode compartment and a cathode compartment, respectively, which are spaced apart by a porous diaphragm and which are supplied with a dc voltage between said anode and cathode, passing part of the electrolyzed wastewater through the diaphragm so that it enters the cathode compartment, discharging the influent from the cathode compartment, discharging the remainder of said electrolyzed wastewater from the anode compartment and introducing the same into the intermediate portion of a gas-liquid separator, withdrawing part of the influent from the top of the gas-liquid separator and introducing the same into a layer packed with an adhering material, where it is brought into contact with the adhering material

Abstract: A method for electrochemically purifying solutions with a pH higher than 14 to reduce metal impurities to the level of traces. The method comprises processing the solutions in an electrolytic cell in which the cathode has a fibrous web produced from a mixture of fibres including at least one fraction consisting of electrically conductive fibres and a binder selected from fluoropolymers, said fibrous web being deposited on an electrically conductive porous support. Said cathode may also be combined with a diaphragm or a membrane. A cathode having a fibrous web produced from a mixture of carbon fibres, cellulose compounds, and a cationic polymer such as cationic starch is also disclosed.

Abstract: The invention is a method and apparatus using high cerium concentration in the anolyte of an electrochemical cell to oxidize organic materials. The method and apparatus further use an ultrasonic mixer to enhance the oxidation rate of the organic material in the electrochemical cell. A reaction vessel provides an advantage of independent reaction temperature control and electrochemical cell temperature control. A separate or independent reaction vessel may be used without an ultrasonic mixer to oxidize gaseous phase organic materials.

Abstract: The invention provides a method and processing system for removing both anionic and cationic technetium complexes from an aqueous solution by adjusting the pH of the solution to greater than approximately 2, and directing the solution into an integrated resin and electrochemical plating device. The integrated resin and plating device has a resin bed or resin membrane in which is disposed one or more cathodes, and one or more anodes. A potential generator produces at least a 1 volt potential between the cathodes and the anodes. As the solution passes through the resin, the technetium complexes are adsorbed onto it. When a sufficient concentration of technetium complexes is adsorbed, the plating process can atlernatively be driven to plate out the technetium onto the cathodes, or to collect various species in system anolytes/catholytes.

Abstract: A method and apparatus for electrolytically extracting lithium at high purity and high efficiency are disclosed, in which the apparatus 1 includes a partition 2 constituted mainly of a perovskite-type Li ion conducting solid electrolyte, a feed chamber formed on one side of the partition in which a crude liquid containing a lithium component and impurities is introduced so as to come into contact with the partition, a recovery chamber formed on the other side of the partition in which a liquid for recovery is introduced so as to come into contact with the partition, and a means for applying an electrical field to the partition in such a manner that the crude liquid side is positive and the recovery liquid side is negative. On applying an electrical field to the partition, the lithium component of the crude liquid selectively passes through the partition in the form of Li ions into the recovery side.

Abstract: The invention provides a composition for use in the recovery of precious metals, or the treatment and/or purification of water, the composition being selected from a catolytic solution having a pH greater than 7, an anolytic solution having a pH less than 7, and a near-neutral solution having a pH near 7, or a mixture of two or more of said solutions. The invention also relates to a process for the recovery of precious metals from precious metal-bearing ore using the above composition. Further, there is provided a process for making a composition, the process comprising activating water by subjecting it to a magnetic treatment; subjecting the water to electrolysis in a reactor; introducing additives to the activated water in the reactor to form a reaction mixture; subjecting the reaction mixture to photoelectrolysis and/or radioelectrolysis; and separating an anolyte and catholyte in the reactor.

Abstract: Electrolyte ionized water production device wherein voltage is produced or an electrical current is passed, between anode and cathode of an electrolytic cell to which various electrolytes and raw water are supplied after being mixed, and wherein various electrolytes are delivered to an electrolytic cell by use of quantitative pumps and raw water is delivered to said electrolytic cell by use of mechanisms including quantitative pumps or pressure reducing valves, and constant flow valves.

Abstract: A radioactive waste stream (12) is of high pH and contains a wide variety of different fission products and also organic materials which act as complexants. Technetium and/or ruthenium are removed by first electrolytically oxidising the organic materials at an anodically stable anode (26), and then electrolytically reducing the technetium and/or ruthenium at a porous fluid-permeable cathode (42). The cathode (42) might for example be of lead wool.

Abstract: Wastewater containing a surfactant and an oil content that has been emulsified by the action of the surfactant can be freed of the oil content by a method including feeding the wastewater into the anode compartment, for electrolysis, of a diaphragm electrolyzer having an anode and a cathode provided in the anode compartment and a cathode compartment, respectively, which are spaced apart by a porous diaphragm and which are supplied with a dc voltage between the anode and the cathode, passing part of the electrolyzed wastewater through the diaphragm so that it enters the cathode compartment, discharging the influent from the cathode compartment, discharging the remainder of the electrolyzed wastewater from the anode compartment and introducing the same into the intermediate portion of a gas-liquid separator, withdrawing part of the influent from the top of the gas-liquid separator and introducing the same into a layer packed with an adhering material, where it is brought into contact with the adhering material,

Abstract: An electrochemical leaching system for cleaning contaminated fines. The system has a waste vessel for receiving and holding a contaminated fines and lixiviant mixture. On a side of the waste vessel is an anolyte vessel holding an anolyte fluid. An anolyte barrier separates the waste and anolyte vessels. On an opposite side of the waste vessel is a catholyte vessel holding a catholyte fluid. A catholyte barrier separates the waste and catholyte vessels. A potential between an anode in the anolyte vessel and a cathode in the catholyte vessel ionizes the fines contaminants into anionic and cationic contaminants in the lixiviant. The anolyte and catholyte barriers allow the anionic and cationic contaminants, respectively, to flow from the lixiviant and into the anolyte and catholyte fluids in their respective vessels without allowing bulk transfer therebetween. The anionic and cationic contaminants are then removed from the anolyte and catholyte fluids. A cleaner lixiviant and fines exits the system.

Abstract: A process is described for preparing onium hydroxides from the respective onium salts and for purifying onium hydroxides in an electrochemical cell. In one example, the present invention relates to a process for preparing onium hydroxides from the corresponding onium salts which comprises the steps of: (A) providing a cell comprising an anode, a cathode and one or more unit cells assembled for operational positioning between the anode and the cathode, each unit cell comprising: (A-1) four compartments defined by, in sequence beginning at the anode, a bipolar membrane, a first divider and a second divider, said bipolar membrane having an anion selective side facing the anode and a cation selective side facing the cathode.

Abstract: Metal salts are removed from solution in an electrolyte by subjecting the solution to electrolysis in a cell having an anode that has an anion exchange membrane closely associated therewith which sequesters the anion of the salt. The cathode may also be provided with a closely associated cation exchange membrane that sequesters, at least partially, the cation of the salt. A metal salt solution can be regenerated by reversing the polarity of the electrodes and conducting an electrolysis using fresh electrolyte.

Abstract: A method for removing sulfur dioxide and nitrogen oxides from a gaseous stream using a magnesium-enhanced lime scrubbing slurry containing a ferrous chelate where oxidized ferrous chelate is regenerated by electrochemical treatment. The spent scrubbing solution containing ferric chelates is passed as a catholyte, at an acidic pH of 4.0-6.5 through a cathode compartment while an anolyte solution containing magnesium sulfate, at a pH of 1.5 to 6.5 is passed through an anode compartment, the compartments separated by a microporous separator. An electrical current is passed from the cathode compartment to the anode compartment and ferric chelates are regenerated to ferrous chelates.

Abstract: In one embodiment, the invention relates to a process for purifying solutions containing a hydroxide compound, including the steps of: (A) providing an electrochemical cell containing an anode, a cathode, a cation selective membrane and a bipolar membrane, the bipolar membrane having an anion selective side facing the anode and a cation selective side facing the cathode, wherein the cation selective membrane is positioned between the anode and the bipolar membrane, and the bipolar membrane is positioned between the cation selective membrane and the cathode, thereby defining a feed compartment between the cation selective membrane and the anode, a recovery compartment between the bipolar membrane and the cation selective membrane, and a water compartment between the bipolar membrane and the cathode; (B) charging a solution of an ionic compound at a first concentration to the water compartment, and water to the recovery compartment; (C) charging a solution containing the hydroxide compound at a second concentra

Abstract: A process for removing oxygen from a feed stream to obtain an oxygen-depleted product stream by applying the feed stream to at least one separator including a feed zone and a permeate zone separated by a solid electrolyte mixed conductor membrane, and driving a first portion of entrained oxygen in the feed stream from the feed zone to the permeate zone via the mixed conductor membrane by applying at least one of a purge stream and a negative pressure to the permeate zone to establish a lower partial pressure of oxygen in that zone. Oxygen-depleted retentate is withdrawn as a product stream. Preferably, at least one additional solid electrolyte ionic or mixed conductor membrane is also employed in feed series with the mixed conductor membrane.

Abstract: In one embodiment, the invention relates to a process for purifying solutions containing a hydroxide compound, including the steps of: (A) providing an electrochemical cell containing an anode, a cathode, a cation selective membrane and an anion selective membrane, wherein the cation selective membrane is positioned between the cathode and the anion selective membrane, and the anion selective membrane is positioned between the cation selective membrane and the anode, thereby defining a feed compartment between the cation selective membrane and the anion selective membrane, a recovery compartment between the cathode and the cation selective membrane, and a water compartment between the anion selective membrane and the anode; (B) charging a solution of an ionic compound at a first concentration to the water compartment, and water to the recovery compartment; (C) charging a solution of the hydroxide compound at a second concentration to the feed compartment; (D) passing a current through the cell to produce the

Abstract: An electrode, electrochemical cell, and electrochemical processes are disclosed. The electrode is a porous, multi-layered electrode which can have an element in flexible, strip form wound around a central, usually flat plate core, which core may serve as a current distributor. In any form, each layer can be represented by a very thin, highly flexible metal mesh. This can be a fine, as opposed to a coarse, mesh which has extremely thin strands and small voids. The electrode will have an active coating. For utilizing this electrode, the cell in one form will be a monopolar cell providing upward, parallel electrolyte flow through the porous, multi-layered electrode. A representative cell can have such electrode at least substantially filling an electrode chamber. The cells can be contained in a cell box that will provide the desired flow-through relationship for the electrolyte to the electrode.

Abstract: An electrolyte contains a tetravalent salt of titanium and a trivalent salt of cerium in a methanesulfonic acid solution. A reducing agent consisting of trivalent titanium and an oxidizing agent consisting of tetravalent cerium are provided in the same solution. An electrochemical cell is disclosed wherein the catholyte and anolyte utilize this electrolyte. The reduction of tetravalent titanium into trivalent titanium is accomplished by electrolysis in the presence of extraneous trivalent cerium ions. The oxidation of trivalent cerium into tetravalent cerium is accomplished by electrolysis in the presence of extraneous tetravalent titanium ions. Simultaneous reduction of tetravalent titanium into trivalent titanium and oxidation of trivalent cerium to tetravalent cerium by electrolysis is also disclosed. Reduction of organic compounds using trivalent titanium in the presence of trivalent cerium in methanesulfonic acid is disclosed.

Abstract: Process for the production of pure tungsten and/or molybdenum solutions from sources, such as alkaline decomposition solutions, which are contaminated with tantalum, niobium, titanium, aluminium, tin, arsenic, phosphorus and/or silicon, by application of a three stage purification process of pH reduction, anion exchange and membrane electrolysis.

Abstract: The invention relates to a method of producing pulp comprising a step of forming green liquor containing alkali metal sulfide and alkali metal carbonate. The method further comprises a step of electrochemically treating the green liquor to oxidize at least part of the sulfide therein.

Abstract: Electric parts including semiconductor substrates, glass substrates and the like are washed with various cleaning solutions. After the cleaning, said parts are cleaned with either anolyte or catholyte electrolytic ionized water (EIW) produced from deionized water.

Abstract: Sulphide-containing white liquor is treated in a continuously operating electrolytic cell having separate anode and cathode compartments separated by a partially permeable barrier. White liquor is introduced into the anode compartment of the cell, and an aqueous solution of alkali metal hydroxide is introduced into the cathode compartment of the cell so that sulphide is oxidized in the anode compartment, while at the same time alkali metal cations are transported through the barrier into the cathode compartment, where water reacts to form hydroxide ions. An electrolytic cell suited for implementing the method is also disclosed.

Abstract: An electrolytic process and apparatus is disclosed for oxidizing or reducing inorganic and organic species, especially in dilute aqueous solutions. The electrolytic reactor includes an anode and cathode in contact with a packed bed of particulate ion exchange material which establishes an infinite number of transfer sites in the electrolyte to significantly increase the mobility of the ionic species to be oxidized or reduced toward the anode or cathode, respectively. The ion exchange material is cationic for oxidation and anionic for reduction, or a combination of both for special circumstances. Preferably, the ion exchange material is treated to convert a portion of the transfer sites to semiconductor junctions which act as mini anodes, or cathodes, to significantly increase the capacity of the reactor to oxidize or reduce the species to be treated. Exemplary applications for the disclosed electrolytic process and apparatus are the conversion of halides to halous acids in dilute solutions.

Abstract: Effluent streams from photographic processes contain both silver and thiosulphate ions, and because of the formation of complex anions it is difficult to remove the silver. The silver may be removed using a cell (12) with a cathode (24) exposed to the effluent liquid, and an anode (25) separated from the liquid by a barrier (22) permeable at least to anions. Some silver sulphide is formed electrochemically at the cathode (24); at the anode (25) water is electrolysed and becomes acidic, so the complex anions migrating through the barrier (22) generate silver sulphide chemically. The resulting silver sulphide precipitate is separated from the liquid by a filter (14).

Abstract: Sulfuric acid used in the process of fabricating semiconductor devices, etc., can be recycled to reduce the amount of sulfuric acid to be discarded. A sulfuric acid effluent is fed to an anode chamber of a sulfuric acid-concentrating electrolyzer partitioned by at least one cation exchange membrane to concentrate sulfuric acid and generate oxidizing substances, so that the sulfuric acid can be used at the step of using sulfuric acid, and, when the concentration of impurities built up in the system exceeds a certain level, a part of sulfuric acid in the system is fed to a unit for refining sulfuric acid, where the sulfuric acid is refined and whence the refined sulfuric acid is fed back to the system. According to this recycling process, it is possible to obtain sulfuric acid having high oxidizing power with no addition of an oxidizing substance such as hydrogen peroxide thereto.

Abstract: The present invention relates to the method of treating the salt bath liquid. In the surface treatment of the steel material by the use of the high-temperature salt bath mainly comprising sodium hydroxide and sodium nitrate, the salt ingredients contained in the washings generated are separated to be recovered and the metal salts contained are separated in the form of the insoluble salts. The salts contained in the nitrate radical-containing liquid system are recovered as the free acids again, the alkalies being recovered, and the reagents contained in the overflow from the salt-washing tank being recovered. The anode chamber liquid generated in the recoverying operation of the reagents is returned to the washing tank again to increase the concentration of the salts. The anode chamber liquid is poured into the pickling tank to reduce the oxidizing soluble metal salts contained in the washings by iron within the pickling tank, whereby the oxidizing soluble metal salts are insolubilized.