Abstract: The present invention relates to a bio-electrochemical system (BES) and a method of in-situ production and removal of H2O2 using such a bio-electrochemical system (BES). Further, the invention relates to a method for in-situ control of H 2O2 content in an aqueous system of advanced oxidation processes (AOPs) involving in-situ generation of hydroxyl radical (OH) by using such a bio-electrochemical system (BES) and to a method for treatment of wastewater and water disinfection. The bio-electrochemical system (BES) according to the invention comprises: an aqueous cathode compartment comprising a first cathode and a second cathode, an aqueous anode compartment comprising an anode at least partly covered in biofilm, wherein the first cathode is connected to a first circuit and the second cathode is connected to a second circuit, wherein the first and the second circuit are connected to the system by an external switch.

Abstract: The invention relates to a method for producing an ammonium peroxydisulfate or alkali metal peroxydisulfate, to an undivided electrolytic cell which is composed of individual components, and to an electrolytic device composed of a plurality of said electrolytic cells.

Abstract: A sulfuric acid electrolyte is produced efficiently as a functional solution and persulfuric acid produced by electrolysis is supplied efficiently to a use side while suppressing self-decomposition thereof.

Abstract: Provided are an electrolyzing unit (electrolyzing device 1) that electrolyzes a sulfuric acid solution having a sulfuric acid concentration of 75 to 96% by weight to generate peroxosulfuric acid, a gas-liquid separation unit (gas-liquid separation tank 10) that subjects the sulfuric acid solution thus electrolyzed to gas-liquid separation, a circulation line 11 that causes a portion of the sulfuric acid solution subjected to gas-liquid separation in the gas-liquid separation unit to circulate between it and the electrolyzing unit, a supply line 20 that supplies a portion of the sulfuric acid solution subjected to gas-liquid separation in the gas-liquid separation unit to an application side (single-wafer cleaning device 100), and a heating unit 22 that is provided in the supply line 20 and heats the sulfuric acid solution to 120 to 190° C.

Abstract: A wear of an electrode is prevented as much as possible, thereby efficiently electrolyzing a sulfuric acid solution and the like. An electrolysis method includes: passing an electrolytic solution through an electrolysis cell including at least a pair of an anode and a cathode; and supplying the electrodes with an electric power, so as to electrolyze the electrolytic solution, wherein a viscosity of the electrolytic solution is set in a range in response to a current density upon the electric power supply to carry out the electrolysis. The viscosity of a sulfuric acid solution as the electrolytic solution is equal to or less than 10 cP when the current density is equal to or less than 50 A/dm2, the viscosity of the sulfuric acid solution is equal to or less than 8 cP when the current density is from more than 50 to 75 A/dm2, and the viscosity of the sulfuric acid solution is equal to or less than 6 cP when the current density is from more than 75 to 100 A/dm2.

Abstract: A cleaning system includes: a sulfuric acid electrolytic portion configured to electrolyze a sulfuric acid solution to generate an oxidizing substance in an anode chamber, a concentrated sulfuric acid supply portion configured to supply a concentrated sulfuric acid solution to the anode chamber, and a cleaning treatment portion configured to carry out cleaning treatment of an object to be cleaned using an oxidizing solution comprising the oxidizing substance. The sulfuric acid electrolytic portion has an anode, a cathode, a diaphragm which is provided between the anode and the cathode, the anode chamber which is demarcated between the anode and the diaphragm and a cathode chamber which is demarcated between the cathode and the diaphragm.

Abstract: An apparatus for electrolyzing sulfuric acid, the apparatus comprising an electrolytic cell comprising a cathode chamber having a cathode and an anode chamber having an anode, the cathode chamber and the anode chamber being separated by a diaphragm, a sulfuric acid tank configured to store the sulfuric acid, a supply pipe connecting the sulfuric acid tank to an inlet port of the anode chamber, a connection pipe connecting an outlet port of the cathode chamber to the inlet port of the anode chamber, a first supply pump provided on the supply pipe and configured to supply the sulfuric acid from the sulfuric acid tank to the cathode chamber through the supply pipe, and a drain pipe connected to an outlet port of the anode chamber and configured to supply to a solution tank a solution containing an oxidizing agent generated by electrolysis in the anode chamber.

Abstract: Sulfuric acid electrolysis process wherein; a temperature of electrolyte containing sulfuric acid to be supplied to an anode compartment and a cathode compartment is controlled to 30 degree Celsius or more; a flow rate F1 (L/min.) of the electrolyte containing sulfuric acid to be supplied to said anode compartment is controlled to 1.5 times or more (F1/Fa?1.5) a flow rate Fa (L/min.) of gas formed on an anode side as calculated from Equation (1) shown below and a flow rate F2(L/min.) of said electrolyte containing sulfuric acid to be supplied to said cathode compartment is controlled to 1.5 times or more (F2/Fc?1.5) a flow rate Fe (L/min.) of gas formed on a cathode side as calculated from Equation (2) shown below. Fa=(I×S×R×T)/(4×Faraday constant)??Equation (1) Fe=(I×S×R×T)/(2×Faraday constant)??Equation (2) I: Electrolytic current (A) S: Time: 60 second (Fixed) R: Gas constant (0.082 1·atm/K/mol) K: Absolute temperature (273.

Abstract: The cleaning method by electrolytic sulfuric acid and the manufacturing method of semiconductor device comprising: the process in which the first sulfuric acid solution is supplied from outside to the sulfuric acid electrolytic cell to form the first electrolytic sulfuric acid containing oxidizing agent in the sulfuric acid electrolytic cell; the process in which the second sulfuric acid solution, which is higher in concentration than said the first sulfuric acid solution previously supplied, is supplied from outside to said sulfuric acid electrolytic cell; said the second sulfuric acid solution and the first electrolytic sulfuric acid are mixed in said sulfuric acid electrolytic cell; and electrolysis is performed to form the cleaning solution comprising the second electrolytic sulfuric acid containing sulfuric acid and oxidation agent in said sulfuric acid electrolytic cell and the process in which cleaning treatment is performed for the cleaning object with said cleaning solution.

Abstract: Methods and systems for generating sulfuric acid are disclosed. In some embodiments, the method includes combusting a sulfur-containing material with a gas including oxygen to produce a first stream of sulfur dioxide, mixing water with the first stream of sulfur dioxide to produce a mixed stream, using an energy, electrolytically converting the mixed stream of sulfur dioxide and water into sulfuric acid and hydrogen, generating a source of energy from the hydrogen, and providing the source of energy as at least a portion of the energy for electrolytically converting the first stream of sulfur dioxide and water into sulfuric acid and hydrogen. In some embodiments, the system includes a first chamber for combusting a sulfur-containing material to produce a first stream of sulfur dioxide, an electrolytic cell for converting the first stream into sulfuric acid and hydrogen, and a fuel cell for generating an energy source from the hydrogen.

Abstract: The method of making a composite particle for an electrode in accordance with the present invention comprises a granulating step of integrating a conductive auxiliary agent and a binder adapted to bind the conductive auxiliary agent and an electrode active material together with a particle made of the electrode active material while in close contact with each other in an inert gas atmosphere so as to form a composite particle for an electrode containing the electrode active material, conductive auxiliary agent, and binder. When the composite particle obtained by this method is used as a constituent of an electrode, an electrode having an excellent electrode characteristic and an electrochemical device having excellent electrochemical characteristics can be formed easily and reliably.

Abstract: A process for the electrochemical production of peroxo-disulfuric acid and peroxo-disulfates is provided. In the process, an anode having a partially pre-polarized electrode which has been provided with a doped diamond layer is used.

Abstract: The invention relates to a process for the production of a peroxodisulfate, such as ammonium-, sodium- and potassium peroxodisulfate by anodic oxidation of an electrolyte containing a sulfate and/or hydrogen sulfate. The disadvantages of the conventional platinum anodes used for this hitherto can be avoided by using as the anode a diamond film mounted on a conductive carrier and made conductive by doping with a tri- or pentavalent element and by not adding a promoter to the anolyte.

Abstract: An electrolytic production of sodium persulfate in a decreased number of steps with low unit power cost is described. Sodium persulfate is caused to crystallize by the reaction between an anode product and sodium hydroxide. The resulting sodium persulfate slurry is separated into a mother liquor and sodium persulfate crystals which are recovered and dried to obtain product sodium persulfate. In the process of the invention, ammonia liberated in the reaction-type crystallization of sodium persulfate is recovered into a cathode product, which is then neutralized by sodium hydroxide and/or ammonia. The neutralized solution is combined with sodium sulfate recovered from the mother liquor after recovering the sodium persulfate crystals and reused as a part of the starting material for an anolyte feed solution.

Abstract: A process for the simultaneous preparation of sodium peroxodisulfate and sodium dithionite in an electrolysis cell divided into two by a cation exchanger membrane, wherein sodium dithionite is produced at the cathode and sodium peroxodisulfate is produced at the anode.

Abstract: A process for forming a polyimide composite electro-deposited film, which excels in durability of ink repelling function, wear resistance or mold-releasing property, has the following steps. An electrically conductive film is formed on at lest one side of a resin substrate. The polyimide composite electro-deposited film is formed on the electrically conductive film, while allowing co-deposition of at least one type of eutectic fine particles selected from the group consisting of water-repellant fine particles, wear-resistant fine particles and mold-releasing fine particles. This process can be used in the production of a nozzle plate having a discharge nozzle, by employing the water-repellant fine particles as the eutectic fine particles. When a metallic substrate is used, the polyimide composite electro-deposited film may be directly formed on one or both surfaces of such a metallic substrate.

Abstract: There are disclosed (1) a process for producing ammonium persulfate which comprises electrolyzing, as the starting raw material for an anode, an aqueous solution containing ammonium sulfate wherein ammonium ions are present in an amount of at least one equivalent based on sulfate ions; (2) a process for producing sodium persulfate which comprises the step (A) of electrolyzing an aqueous solution containing ammonium sulfate at an anode, the step (B) of producing sodium persulfate, the step (C) of crystallizing and separating the sodium persulfate and the step (D) of recycling the liquid produced at a cathode together with ammonia for use as the starting raw material for an anode in the step (A); and (3) a process for producing potassium persulfate which comprises the step (A′) of electrolyzing an aqueous solution containing ammonium sulfate at an anode; and the step (B′) of producing potassium persulfate.

Abstract: There is disclosed a process for producing sodium persulfate which comprises the step (1) of electrolyzing, at an anode, a solution containing ammonium sulfate, and the step (2) of producing sodium persulfate from the resultant liquid produced at the anode and sodium hydroxide and, as desired, the step of removing sodium sulfate, and further as desired, the step (3) of performing crystallization on the reaction liquid as produced in the step (2). According to the above process, it is made possible to efficiently produce sodium persulfate having a markedly high purity substantially free from nitrogen components at a high yield at a high current efficiency in electrolysis.

Abstract: Articles of copper and brass can be uniformly pickled in a solution utilizing peroxosulfate as the active agent when the concentration of additives in the form of organic sulfur compounds, inorganic sulfur compounds, organic sulfur-free nitrogen compounds, and inorganic sulfur-free nitrogen compounds are increased to increase the current yield, when the speed of the solution of less noble metals than copper is inhibited and when an organic complex former is added to the pickle.

Abstract: The invention concerns the combined production of sodium peroxide disulphate and soda lye from sodium sulphate. According to the invention, electrolysis is carried out in at least one two-chamber electrolysis cell with cathode and anode chambers separated by a cation-exchanger membrane. The electrolysis temperature is set at between 30 and 70.degree. C., a sodium sulphate solution which is at least 75% saturated at this temperature is introduced into the anode chamber, the sodium ion concentrations are maintained in the range of between 4.5 and 6.0 mol/l and soda lye is extracted from the cathode chamber.

Abstract: Chlorine dioxide is produced by reaction of chlorate ions, usually provided by sodium chlorate, with a persulfate in an aqueous acid reaction medium containing sulfuric acid. By-product sodium sulfate, sulfuric acid feedstock or mixture may be electrolyzed to form the persulfate for the reaction.

Abstract: An electrolytic cell and process for the cogeneration of a peroxy acid and salts thereof in an anolyte compartment of the cell and hydrogen peroxide at a desired ratio of an alkali metal hydroxide to hydrogen peroxide in the catholyte compartment of the cell. An ammonium compound is present as a reactant in the catholyte compartment. Ammonia is recycled from the catholyte compartment of the cell to the anolyte compartment of the cell or removed as a product.