Abstract: It is an object of the present invention to produce a cooking liquor containing polysulfide sulfur at a high concentration from white liquor in a pulp production process with a high selectivity at a low electric power with very little production of thiosulfate ions as by-product. The present invention provides a method for producing polysulfides, which comprises introducing a solution containing sulfide ions into an anode compartment of an electrolytic cell comprising the anode compartment provided with a porous anode, a cathode compartment provided with a cathode and a diaphragm partitioning the anode compartment and the cathode compartment, for electrolytic oxidation to obtain polysulfide ions, wherein at least the surface of said anode is made of nickel, and the porous anode has a physically continuous three-dimensional network structure.

Abstract: An electrolytic cell capable of controlling the pH and the ORP independently to each other, comprising an electrolytic chamber (113) to which subject water to be electrolyzed are supplied, membranes (115, 115) provided on the both side walls of the electrolytic chamber, a pair of electrode plates (116, 117) respectively provided inside the electrolyzed chamber and outside the electrolytic chamber sandwiching the membrane therebetween, and wherein the electrode plate (116) is provided outside the electrolytic chamber in contact with the membrane (115) or leaving a slight space.

Abstract: Treating water for dermatoses in domestic animals mainly composed of acidic water obtained by electrolysis, which acidic water is highly effective in treatment of a dermatosis in a domestic animal when applied or sprayed to domestic animals several times at an initial stage of the dermatosis.

Abstract: Acid water containing hypochlorous acid is produced by an anode chamber of an electrolytic chamber, and alkali water is produced by a cathode chamber. The acid water is reserved in a reservoir tank and is returned into the anode chamber by actuating a return pump. The acid water returned into the anode chamber is subjected to further electrolysis, and fed in the cathode chamber through a first water supply line, an interconnection means and a second water supply line, so as to sterilize the interiors of the first water supply line, the interconnection and the second water supply line.

Abstract: A method for pickling products in a metal alloy containing iron, and products in titanium and alloys thereof, in the absence of nitric acid as an oxidizing agent, and for the recovery of the exhausted solutions, characterized in that the recovery of the exhausted solutions deriving from pickling comprises the following steps: sending of the pickling solution, both as catholyte and as anolyte, in an electro-chemical cell optionally of the membrane type to separate the Fe2+ (or Ti2+) ions to be disposed of, from the Fe3+ (or of the Ti3+ and Ti4+) ions to be recovered, obtained by reduction at the cathode of the Fe3+ ions which are in the catholyte to Fe2+ (or of the Ti3+ and Ti4+ ions to Ti2+) and of oxidation at the anode Fe2+ (or Ti2+) ions which are in the anolyte to Fe3+ (to Ti3+ and Ti4+); treating the catholytic solution coming out of the cell and enriched in Fe2+ (or Ti2+) ions as to allow the separation in two phases, a

Abstract: In one embodiment, the present invention relates to a process for recovering an onium compound from waste solutions or synthetic solutions containing the onium compound and impurities including the steps: contacting the waste solution or synthetic solution with a metal ion scavenger to remove metal ion impurities, wherein the metal ion scavenger comprises at least one of a chelating compound, a nanoporous material, and a magnetically assisted (MACS) material; charging the waste solution or synthetic solution to an electrochemical cell containing at least two compartments, a cathode, an anode and a divider and passing a current through the cell whereby the onium compound is regenerated or produced; and recovering the onium compound from the cell.

Abstract: Stainless steel pickling process in which a pickling solution containing HF and Fe3+ ions as essential components is used, and wherein the oxidation to Fe3+ of the Fe2+ formed during the process in order to maintain the Fe3+ concentration to the predetermined value, is electrolytically carried out by submitting the pickling solution as it is to an oxidation process in an electrolytic cell equipped with anode made of inalterable materials chosen among graphite, granular coal, lead and with cathodes made of stainless steel, graphite or other unalterable materials, said cell working with an applied tension between 1 and 8 V and with an anodic current density between 0.4 and 15 A/dm2.

Abstract: Electrochemical incineration of p-benzoquinone was evaluated as a model for the mineralization of carbon in toxic aromatic compounds. A Ti or Pt anode was coated with a film of the oxides of Ti, Ru, Sn and Sb. This quaternary metal oxide film was stable; elemental analysis of the electrolyzed solution indicated the concentration of these metal ions to be 3 &mgr;g/L or less. The anode showed good reactivity for the electrochemical incineration of benzoquinone. The use of a dissolved salt matrix as the so-called “supporting electrolyte” was eliminated in favor of a solid-state electrolyte sandwiched between the anode and cathode.

Abstract: A method of water electrolysis for producing acidic water and alkaline water is disclosed, which is effective in preventing the dissolution of electrode material in the acidic water, etc. attributable to a reverse current flowing in a power supply cutoff state and also in preventing electrode deactivation caused by the electrode material dissolution. This enables the electrolytic cell to be operated stably over a long period of time to yield high-purity acidic and alkaline waters. An electrolytic cell 1 partitioned into an anode chamber and a cathode chamber with a cation-exchange membrane 2 as a solid electrolyte is used to electrolytically produce acidic water and alkaline water. A voltage of 1.2 V or higher and/or a current of 20 mA/dm.sup.2 or higher is applied between the anode 7 and the cathode 8 when the electrolytic cell is in a power supply cutoff state.

Abstract: A process for adjusting the pH of an aqueous flowable fluid includes an electrochemical mechanism for adjusting the pH of an aqueous flowable fluid and a mechanism for then electrochemically stabilizing the adjusted pH of the fluid. A device for performing the process is also included. The device includes an inlet and a channel in fluid communication with the inlet. The channel has the appearance and properties of a U-shaped connected vessel. The U-shaped connected vessel includes an inlet accumulating passage in fluid communication with an active zone between two spaced electrodes wherein the active zone has a small volume relative to the passage for accelerating fluid flow from the passage through the active zone complying with the physics of connected vessels.

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 process for the production of a hydroxide solution and a sulfate by the electrolysis of a waste aqueous mixture of oxidizable sulfur impurities in the anode compartment of at least one electrolytic cell while producing a hydroxide solution in the cathode compartment of the cell. The process is particularly applicable to the treatment of spent caustic solutions obtained by scrubbing a hydrocarbon process stream contaminated with oxidizable sulfur impurities. The electrolytic cell used in the electrolysis process of the invention can use either a porous membrane or a cationic permselective membrane to separate the anode and cathode compartments of the electrolysis cell.

Abstract: A recirculation system for electrochemically activated antimicrobial solutions returns antimicrobial solution which has been depleted of active antimicrobial species to a electrolytic cell for regeneration of the active species. Organic load, which frequently contaminates items to be sterilized or disinfected, such as medical instruments, rapidly depletes the active antimicrobial species in a conventional treatment system, reducing the effectiveness of microbial decontamination by electrochemically activated solutions. By recirculating the antimicrobial through the electrolytic cell, the concentration of active species is maintained at a level at which efficient sterilization is achieved.

Abstract: The invention concerns a method consisting: in passing the sea water through an electrically conductive catalyst (10), arranged in the cathode section of an electrolytic cell (1), comprising a cathode section (3) and an anode section (4) provided with, the former, with at least one cathode (11a, . . . ) and, the latter, with at least one anode (18) and separated by a wall (2) permeable only to the cations and in circulating, in the anode section (4), a conductive aqueous solution of a particular anolyte; in providing an electric voltage between the cathode and the anode of the cell (1) while maintaining the contents of the cathode and the anode sections at specific potentials, so as to produce, in the cathode section, consumption of oxygen dissolved in the treated water and in decomposing, in the anode section, an appropriate amount of solution for ensuring the electroneutrality of the treated water.

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: The present invention provides a sterilizing apparatus and a sterilizing method for medical instruments enabling easy sterilization of medical instruments in a short time.There are provided an electrolyzation device which produces acidic electrolytic water as a sterilization liquid by electrolyzing electrolytic water stored in an electrolytic cell, a sterilization bath for storing medical instruments to be sterilized by the acidic electrolytic water, and a circulation device which circulates the acidic electrolytic water between the electrolytic cell and sterilization bath thereby to sterilize the medical instruments.

Abstract: A method and a reactor for electrochemical conversion of a material (21) being insoluble in a fluid into a material being soluble in the fluid, which method comprises that a flow of the fluid is passed to a reaction zone which comprises an internal circuit consisting of: one or more working electrodes (12), one or more counter-electrodes (13), and one or more ion-selective electrolytes (11), and which internal circuit is applied with an electrical voltage difference sufficient for the electrochemical processes; and use thereof for removal of soot particles from flue gasses and removal of oil in waste water.

Abstract: A liquid mixture is efficiently separated using a separating membrane against which the liquid is sprayed, the membrane being intermittently heated to increase separation without subjecting the liquid mixture to high heat. The method is suited to flammable, toxic and temperature sensitive liquid mixtures.

Abstract: Disclosed herein is electrolyzed functional water produced by the process comprising a step of feeding water containing electrolytes to a first electrolytic cell equipped with an anode, a cathode and an ion-permeable membrane between them to electrolyze it, and a step of electrolyzing the electrolyzed water obtained from the cathodic side of the first electrolytic cell on the anodic side of a second electrolytic cell equipped with an anode, a cathode and an ion-permeable membrane between them. Production processes and production apparatus of the electrolyzed functional water are also disclosed.

Abstract: An electrolytic ionic water generating apparatus that produces electrolytic ionic water having a desired pH value and a semiconductor manufacturing apparatus that uses the electrolytic ionic water. The invention includes an electrolytic tank with an anode chamber and a cathode chamber, an introducing conduit or line to introduce electrolytic solution, and a discharge conduit or line to supply the generated electrolytic ionic water to other apparatuses such as a semiconductor washing machine and a semiconductor polishing machine. To control the pH value of the electrolyzed ionic water, pH meters and pH controllers are disposed on the introducing or discharge conduit. The pH meters detect the pH values of the electrolyzed ionic water and provide the detected result to the pH controllers. The pH controllers control the pH values of the supplied ionic water by controlling and changing the temperature of the solution.

Abstract: In one embodiment, the present invention relates to a process for recovering an onium hydroxide from a solution containing an onium compound, including contacting the solution with a cation exchange material so that at least a portion of onium cations from the onium compound are adsorbed by the cation exchange material; contacting an acid with the cation exchange material to elute an onium salt; charging the onium salt to an electrochemical cell containing at least three compartments, a cathode, an anode, and in order from the anode to the cathode, a bipolar membrane and a cation selective membrane, and passing a current through the cell whereby the onium hydroxide is regenerated; and recovering the onium hydroxide from the cell.

Abstract: A method of electrolytically producing acid water using an electrolytic cell partitioned by a cation-exchange membrane into an anode chamber and a cathode chamber. Chloride ion which generates hypochlorous acid by anodic oxidation is supplied to the cathode chamber without directly supplying chloride ion to the anode chamber. Part of the chloride ion permeates from the cathode chamber into the anode chamber through the cation-exchange membrane. The chloride ion which permeates through the cation-exchange membrane is present at the surface of an anode closely adhering to the cation-exchange membrane in the anode chamber or only in the vicinity of the anode, and is efficiently anodically oxidized to form hypochlorite ion. Also disclosed is an electrolytic cell for carrying out the method of electrolytically producing acid water.

Abstract: An electrically regeneratable electrochemical cell (30) for capacitive deionization and electrochemical purification and regeneration of electrodes includes two end plates (31, 32), one at each end of the cell (30). Two end electrodes (35, 36) are arranged one at each end of the cell (30), adjacent to the end plates (31, 32). An insulator layer (33) is interposed between each end plate (31, 32) and the adjacent end electrode (35, 36). Each end electrode (35, 36) includes a single sheet (44) of conductive material having a high specific surface area and sorption capacity. In one embodiment, the sheet (44) of conductive material is formed of carbon aerogel composite. The cell (30) further includes a plurality of generally identical double-sided intermediate electrodes (37-43) that are equidistally separated from each other, between the two end electrodes (35, 36).

Abstract: Electrochemically regenerated RuO.sub.4 (or corresponding oxides of Os, Ir, Rh) is used in the decomposition of matter, especially matter containing organic material. The method has particular advantage in dealing with compounds containing chlorine and, in a development, provides for the removal of heteroatoms N, Cl P, As, S, avoiding contamination with unoxidised organics and/or Ru (or Os, Ir, Rh as the case may be).

Abstract: In one embodiment, the present invention relates to a process for recovering an organic hydroxide from waste solutions containing the organic hydroxide and impurities including the steps: contacting the waste solution with a metal ion scavenger to remove metal ion impurities; charging the waste solution to an electrochemical cell containing at least two compartments, a cathode, an anode and a divider and passing a current through the cell whereby the organic hydroxide is regenerated; and recovering the organic hydroxide from the cell.

Abstract: Chlorine ion-containing water supplied from one of water discharge pipelines of an electrolysis vessel of an apparatus for continuously forming electrolyzed water is caused to flow backwardly to one of electrode chambers and a water supply branch pipe thereof, passed through a water supply branch pipe of the other of the electrode chambers and/or a water supply pipeline at the upstream thereof and discharged through the other of the electrode chambers and from the other of the water discharge pipe lines. In this state, water in the electrolysis vessel is electrolyzed while operating the electrode of the electrode chamber in which water is caused to flow backwardly as an anode, and the electrolysis vessel and water channels at the upstream thereof are cleaned and sterilized by electrolyzed cleaning water in which hypochlorous acid is formed.

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: There is disclosed a method and apparatus for generating a sterilizing solution through the electrolytic treatment of an aqueous salt solution. An aqueous salt solution is passed, under pressure, into the working chamber of an electrolytic cell, which cell is divided into a working chamber and an auxiliary chamber by a permeable membrane. The solution is filtered through the membrane, and collected from an output of the auxiliary chamber. Gases, such as chlorine, liberated in the working chamber during electrolysis, are dissolved in a water supply, and this water supply is partially or fully mixed with the output of the auxiliary chamber so as to generate a sterilizing solution. The method and apparatus disclosed serves to generate a sterilizing solution with less expenditure of energy and raw materials than in the prior art.

Abstract: A main feature of the present invention is to provide water for medical treatment that can eliminate superoxide anion radicals that trigger various disease. Raw water including at least sodium, potassium, magnesium, and calcium ions is supplied to an eloectrolytic water treatment apparatus comprising a cathode chamber and an anode chamber. A current within the range of 0.16 mA/cm.sup.2 .about.3.2 mA/cm.sup.2 is applied per each pair electrodes and one diaphragm for 0.5 seconds .about.5 seconds across a cathode electrode and an anode electrode to electrolyze the raw water. By this method, water for medical treatment is produced that has an oxidation-reduction potential value within the range of -150 mV.about.0 mV measured against a platinum electrode. The water for medical treatment can remove from the blood of a patient the SAR that causes various disease.

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: An electrochemical cell with a Co(III) mediator and neutral pH anolyte provides efficient destruction of organic and mixed wastes. The organic waste is concentrated in the anolyte reservoir, where the cobalt mediator oxidizes the organics and insoluble radioactive species and is regenerated at the anode until all organics are converted to carbon dioxide and destroyed. The neutral electrolyte is non-corrosive, and thus extends the lifetime of the cell and its components.

Abstract: An electrochemical cell with a Co(III) mediator and nitric acid electrolyte provides efficient destruction of organic and mixed wastes. The organic waste is concentrated in the anolyte reservoir, where the mediator oxidizes the organics and insoluble transuranic compounds and is regenerated at the anode until the organics are converted to CO.sub.2. The nitric acid is an excellent oxidant that facilitates the destruction of the organic components. The anode is not readily attacked by the nitric acid solution, thus the cell can be used for extended continual operation without electrode replacement.

Abstract: A method of fabricating a semiconductor wafers, which can prevent metal contamination when alkali etching is used. A semiconductor ingot is cut into wafers. The peripheral portion of the sliced wafers is chamfered. The chamfered wafers are then planarized by lapping. The planarized wafers are alkali etched. The alkali etched wafers are subjected to acid washing by using diluted mixed acid solution. The surface of the acid-washed wafers are then polished. The polished wafers are washed again.

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: 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: The invention provides a method and apparatus for producing an electrolytic water whereby one electrolytic water used in compliance with its intended use is transformed into a water more effectively used and the by-product electrolytic water, previously disposed as virtually useless, is transformed into a water which can be effectively used by use of at least two electrolyzer in series. At least one of an outlet for a primary anodic electrolytic water in a primary electrolyzer and an outlet for a primary cathodic electrolytic water in a primary electrolyzer is connected to an inlet of a secondary electrolyzer through a first switching valve and a second switching valve. The anodic electrolytic water only, the primary cathodic electrolytic water only, or mixture of the primary anodic and primary cathodic electrolytic water is fed to the secondary electrolyzer to be electrolyzed again.

Abstract: A method and apparatus for carrying out an electrolytic process produces clean gases, such as oxygen and hydrogen. For this purpose, a porous diaphragm is arranged between the cathode and the anode of an electrolyzer, and a liquid electrolyte is fixed in the pores of the cathode and anode. A first gas chamber adjoins the cathode, while a second gas chamber adjoins the anode, and an educt chamber is separated from the first gas chamber by a membrane. An aqueous, non-corrosive solution of salts of inorganic and organic acids or mixtures of water with organic additives is used as an educt, which, compared with the electrolyte, has a higher partial water vapor pressure.

Abstract: A method for preventing scale from precipitating and an apparatus for producing deionized water are disclosed. The acidic water produced by electrolysis in the electrolysis unit (30) is introduced into a concentrating compartment (19) in the continuous deionization unit (10). The pH of the concentrated water in the concentrating compartment decreases, thereby preventing scale from precipitating.

Abstract: A small portable electrolytic cell has an enclosed electrode in a compartment and an exposed electrode open to an electrolyte into which the cell is immersed. The cell is operable when immersed in aqueous liquid containing a chloride salt to generate chlorine or other oxidant when said exposed electrode is an anode, or to increase the pH of said liquid when said exposed electrode is a cathode.

Abstract: An inexpensive, safe method for sterilizing an apparatus for the preparation of a recording material, which obviates troubles affecting a coated surface of the recording material caused by bacteria and fungi, does not cause changes in photographic performance (sensitivity, fog, graininess and sharpness), can prevent the appearance of "resistant cells", and can comply with environmental problems, said method comprising sterilizing a surface of the apparatus being in contact with a coating composition for the recording material by use of a strongly acidic solution having a redox potential of 1,000 mV or more which is obtained by electrolysis of water.

Abstract: The method for producing electrolyzed water includes the step of applying a voltage to electrodes disposed in an electrolytic cell containing therein pure water including electrolyte therein. A strength of an electric field generated by applying a voltage to the electrodes is controlled to be variable by means of various techniques. The method makes it possible to produce electrolyzed water with a smaller amount of energy than prior methods.

Abstract: An acid water obtain by electrolysis is used for wash disinfection inside as artificial dialyzer, thereby completely eliminating the bacteria, fungi, viruses, and other deposits inside the dialyzer.

Abstract: The invention provides a method for producing electrolytic alkaline water and electrolytic acid water of enhanced effectiveness. According to the method of the invention, vitamin C is added to the cathodic electrolytic water produced by primary electrolysis, in a weight percentage of 0.005%.about.0.05%, and the primary cathodic electrolytic water with the vitamin C added is electrolyzed a second time. Thereby, a secondary cathodic electrolytic water is obtained in which the dissolved oxygen concentration and the oxidation reduction potential are remarkably lowered. Vitamin C is added to the anodic electrolytic water produced by the primary electrolysis in a weight percentage of more than 0.005%, and the primary anodic electrolytic water with the vitamin C added is secondarily electrolyzed. A secondary anodic electrolytic water is thereby obtained which contains a high dissolved oxygen concentration and a low oxidation reduction potential.

Abstract: An improvement is proposed in the cleaning treatment of semiconductor silicon wafers in which the conventional step of cleaning with an aqueous solution of an acid is replaced with a cleaning treatment with a temporarily acidic pure water which is produced electrolytically by the application of a DC voltage between an anode and a cathode bonded to the surfaces of a hydrogen-ion exchange membrane so that the acidic cleaning treatment can be performed under mild conditions so as to eliminate the troubles unavoidable in the conventional process. The apparatus used therefor comprises a rectangular vessel partitioned into a central anode compartment, in which the wafers are held in a vertical disposition within an upflow of pure water, and a pair of cathode compartments on both sides of the anode compartment by partitioning with a pair of hydrogen-ion exchange membranes, on both sides of which an anode plate and a cathode plate are bonded.

Abstract: An improvement is proposed in the cleaning treatment of semiconductor silicon wafers in which the conventional step of cleaning with an aqueous solution of an alkali is replaced with a cleaning treatment with a temporarily alkaline pure water which is produced electrolytically by the application of a DC voltage between a cathode and an anode bonded to the surfaces of a hydrogen-ion exchange membrane so that the alkaline cleaning treatment can be performed under mild conditions so as to eliminate the troubles due to formation of COPs unavoidable in the conventional process. In addition, the pure water rinse following the alkali cleaning of the wafers before transfer to the succeeding acidic cleaning step can be omitted to greatly contribute to the improvement of productivity.

Abstract: A high-purity water producing equipment comprises a primary purification treatment system, a primary deionized water tank, a secondary purification treatment system for producing high-purity water from a primary deionized water, a circulatory system pipe for returning the produced high-purity water to a primary deionized water tank and a branch water feed system branched off from the circulatory system for feeding the high-purity water to a use point. An electrolytic unit for producing the anolyte EIW (electrolytic ionized water) to be catholyte EIW from the electrolysis of the high-purity water is provided as a bypass midway along the circulatory system. The anolyte EIW is added to the circulatory pipe downstream of the branching point toward the use point, when cleaning of units is necessary.

Abstract: Improvements on the electrolytic reactor and process of U.S. Pat. No. 5,419,816 and copending U.S. application Ser. No. 08/400,950, filed Mar. 9, 1995, now U.S. Pat. No. 5,609,742, are disclosed for the controlled oxidation and reduction of inorganic and organic species in dilute aqueous solutions. More specifically, other physical forms and additives for the modified ion exchange material can be used in the packed bed electrolytic reactor, including powdered ion exchange materials and solid membranes containing the modified ion exchange materials. Direct contact with only one electrode, the anode for oxidation, and the cathode for reduction, is required for the modified ion exchange resin, instead of with both electrodes. Superior performance is also demonstrated for bipolar operation of the electrolytic reactor in comparison to monopolar operation. Preferably, the polarity of the electrodes is reversed every 1 to 60 minutes.

Abstract: An apparatus and method for soil remediation replaces specific ions in the soil electrochemically, using a DC voltage source and special multicompartment anodes and cathodes, each comprising an inner compartment containing electrolyte and a submerged electrode, a salt bridge connecting the electrolyte to an outer compartment containing a specific solution with replacement ions for soil remediation, and a membrane holding in the replacement solution. The membrane is put into contact with the soil, allowing electrical contact and ion migration while keeping the solution inside the anode or cathode. The multicompartment structure prevents the hydroxide and hydronium ion emplacement that causes acid and base fronts to form.

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.