Abstract: In the process for treating contaminated mud or suspended earth, the mud or the suspended earth in concentrations of 3% to 25% dry matter is wet-oxidized by addition of pure oxygen or an oxygen-containing gas at a temperature of 120.degree. C. to 220.degree. C., under a pressure of 3 bar to 50 bar and at pH values <7. To accelerate the oxidation reaction, iron ions alone or in combination with quinones or quinone-forming substances are added to the mud or to the suspended earth.

Abstract: The present invention relates to a process for the disposal of waste or the conversion of hydrothermally labile chemical groups and compounds to species which are environmentally acceptable, or are amendable to further degradation by conventional disposal systems to produce environmentally acceptable products, which process comprises:(a) conveying an aqueous solution or slurry of the waste material into a reaction zone capable of withstanding the temperatures and pressures of hydrothermal decomposition;(b) reacting the waste material in the reaction zone with an aqueous composition comprising catalyst selected from silica or one or more alkali metal silicates, borates, phosphates, biphosphates, or trisubstituted-phosphates, or comprising as promoting reagent independently selected from one or more alkali metal nitrites, alkaline earth metal nitrites or combinations thereof at between 200.degree. C. and 500.degree. C. and at a pressure between 10 and 400 atmospheres for between about 0.

Abstract: Manganese(IV)-containing oxides are effective catalysts for oxidation of water-soluble cyanide over a wide pH range (0.5-12) and temperature (15.degree.-250.degree. C.). Oxygen is the preferred oxidizing agent at partial pressures between about 0.2 and 5 atmospheres (2.9-75 psi, 20-517 kPa). Electrolytically deposited MnO.sub.2 is one preferred form of the catalyst. Another preferred manganese(IV)-containing oxide is the group of cation-stabilized manganese(IV)-containing oxides illustrated by cryptomelane. Yet another preferred form of manganese(IV)-containing oxide is a group of crystalline manganese phosphate compositions having an extended network and an empirical composition on an anhydrous basis expressed by an empirical formula of:(A.sup.a+).sub.v (Mn.sup.b+)(M.sup.c+).sub.x P.sub.y O.sub.

Abstract: A process for treating wastewaters containing carbonaceous COD and at least one nitrogen-containing compound is disclosed comprising wet oxidizing the wastewater with an oxidizing agent at a temperature less than 373.degree. C. and a pressure sufficient to maintain a liquid water phase, to produce an oxidized wastewater containing a reduced concentration of COD. The nitrogen of the nitrogen-containing compound is substantially converted to ammonia, nitrate and nitrite. Sufficient inorganic nitrogen-containing compound is added to the oxidized wastewater to produce essentially equal concentrations of ammonia-nitrogen and nitrite-nitrogen plus nitrate-nitrogen. Mineral acid is added to the oxidized wastewater to produce a pH between 4 and 7, and optionally, a transition metal salt is added, to catalyze a thermal denitrification step. The wastewater is heated at temperatures between about 100.degree. C. and 300.degree. C. to decompose the nitrogen compounds, producing a purified wastewater.

Abstract: The present invention provides a catalyst used in wastewater treatment process wherein not only an organic compound not containing nitrogen, sulfur or halogen is decomposed, but also a nitrogen-containing compound, a sulfur-containing compound and an organic halogeno compound are effectively decomposed, thereby wastewater are treated with excellent efficiency for a long period of time. The invention also provides a production process for the catalyst and said wastewater treatment process. The first catalyst comprises: an oxide of iron as an A component; and at least one kind of element as a B component selected from a group consisting of cobalt, nickel, cerium, silver, gold, platinum, palladium, rhodium, ruthenium and iridium.

Abstract: An apparatus is provided for oxidizing an aqueous suspension of organic matter at elevated pressure. The apparatus has a reactor and an inlet for the aqueous suspension which is introduced to an upstream end of the reactor. A device for circulating the aqueous suspension through the reactor. An inlet for an oxygen containing gas introduced to the aqueous suspension. An outlet for removing treated aqueous suspension from a downstream end of the reactor and a static mixer vane arrangement for splitting, rearranging and combining the aqueous suspension as the circulating device circulates the aqueous suspension through the reactor. The improvement comprises withdrawing the treated aqueous suspension from the downstream end of the reactor and combining a major portion thereof with fresh incoming aqueous suspension. The circulating device returns the combined aqueous suspension to the reactor via the inlet for the aqueous suspension.

Abstract: A process is provided for destroying formic acid and/or formaldehyde in an aqueous, organic acid waste stream by contacting the stream with a supported precious metal catalyst and passing air or molecular oxygen gas through the solution to promote chemical oxidation. The invention is a safe, practical and cost-effective alternative to bio-system treatment of these compounds using microorganisms. The process of the invention may be practiced in either a batch or continuous mode and, in accordance with the invention, formic acid present in a stream at a level of 3800 ppm and formaldehyde present in an amount of 5800 ppm can be reduced respectively to levels of 200 ppm or less.

Abstract: An improved process and apparatus are disclosed for the supercritical water oxidation of organic waste materials which avoids or at least substantially reduces the corrosion and solids deposition problems associated with prior art techniques. According to this invention, externally heated supercritical water is fed to a platelet tube reactor to both protectively coat its inner surface and heat the waste stream to oxidation reaction conditions. Higher reaction temperatures can be used as compared to prior art processes, which significantly improves the reaction rate and permits smaller reactors to be used. The protective film of water on the reactor inner surface, coupled with the elimination of preheating of the waste material, substantially reduces solids deposition and corrosion.

Abstract: A process and apparatus for the supercritical water oxidation of organic waste materials which avoids or at least substantially reduces the corrosion and solids deposition problems associated with prior art techniques and which provides for efficient heating of the waste material to reaction conditions. Externally heated supercritical water is fed to a compound platelet tube reactor. The compound reactor includes a reaction zone and inner (smaller) and outer (larger) concentric platelet tubes supported concentrically within a shell. The water fed to the reactor both protectively coats surfaces of the inner and outer platelet tubes facing the reaction zone and heats the waste stream to oxidation reaction conditions. Higher reaction temperatures can be used as compared to prior art processes, which significantly improves the reaction rate and permits smaller reactors to be used.

Abstract: A process for water oxidation of combustible materials in which during at least a part of the oxidation corrosive material is present and makes contact with at least a portion of the apparatus over a contact area on the apparatus. At least a portion of the contact surface area comprises titanium dioxide coated onto a titanium metal substrate. Such ceramic composites have been found to be highly resistant to environments encountered in the process of supercritical water oxidation. Such environments typically contain greater than 50 mole percent water, together with oxygen, carbon dioxide, and a wide range of acids, bases, and salts. Pressures are typically about 27.5 to about 1000 bar while temperatures range as high as 700.degree. C. The ceramic composites are also resistant to degradation mechanisms caused by thermal stresses.

Abstract: A process for purifying a photographic waste solution is disclosed. The photographic waste solution is purified by successively performing: noncatalytic wet oxidation at a temperature of from 140.degree. C. up to 370.degree. C. under such a pressure as to hold said waste solution in a liquid phase while supplying an oxygen-containing gas thereto; solid-liquid separation of the solid matters and/or suspended matters thus formed; catalytic wet oxidation at a temperature of from 140.degree. C. up to 370.degree. C. under such a pressure as to hold said waste solution in a liquid phase while supplying an oxygen-containing gas thereto; and a biological treatment comprising a combination of an aerobic biological treatment with an anaerobic biological treatment.

Abstract: A process for hydrothermal oxidation of combustible materials in which, during at least a part of the oxidation, corrosive material is present and makes contact with at least a portion of the apparatus over a contact area on the apparatus. At least a portion of the contact surface area comprises iridium, iridium oxide, an iridium alloy, or a base metal overlaid with an iridium coating. Iridium has been found to be highly resistant to environments encountered in the process of hydrothermal oxidation. Such environments typically contain greater than 50 mole percent water, together with oxygen, carbon dioxide, and a wide range of acids, bases and salts. Pressures are typically about 27.5 to about 1000 bar while temperatures range as high as 800.degree. C.

Abstract: A method for treating an aqueous stream containing a water-soluble, inorganic sulfide compound wherein the stream is contacted with oxygen in a thermal, non-catalytic conversion zone to convert the inorganic sulfide compound to sulfate and thiosulfate. The aqueous effluent from the thermal, non-catalytic conversion zone is then contacted with oxygen and an oxidizing catalyst on a carbon support at catalytic oxidation conditions selected to provide a high conversion of the thiosulfate to sulfate which produces a substantially sulfide-free aqueous stream.

Abstract: A process for the oxidation of ammonium ions and organic carbon in wastewaters containing ammonium ions and organic carbon by means of nitric acid at from 100.degree. to 350.degree. C., wherein the molar ratio between organic carbon and ammonium nitrogen is adjusted to a value in the range from 0.3:1 to 4:1 by addition of organic carbon or ammonium nitrogen.

Abstract: The present invention relates to a process for the disposal of waste or the conversion of hydrothermally labile chemical groups and compounds to species which are environmentally acceptable, or are amendable to further degradation by conventional disposal systems to produce environmentally acceptable products, which process comprises:(a) conveying an aqueous solution or slurry of ordnance waste material into a reaction zone capable of withstanding the temperatures and pressures of hydrothermal decomposition;(b) reacting the waste material in the reaction zone with an aqueous composition comprising one or more alkali or alkaline earth metal silicates, borates, phosphates, biphosphates, or trisubstituted-phosphates, at between 200.degree. C. and 500.degree. C. and at a pressure between 10 and 400 atmospheres for between about 0.

Abstract: A process for treating waste water containing chlorinated organic substances, particularly waste water from production of epichlorohydrin which contains more than 10 mg of adsorbable organic halogen compounds (AOX) per liter, comprising charging the waste water at a pH of 10 to 14 (measured at room temperature) into a reactor and maintaining a temperature of at least 75.degree.C., a pressure of at least 1 bar (abs.), and a residence time of at least 0.5 hours in said reactor, thereby partially dechlorinating and/or dehydrochlorinating chlorinated organic compounds contained in the waste water, and thereafter subjecting the waste water to further dechlorination and/or dehydrochlorination treatment in the presence of a hydrogen-containing gas, a hydrogen-releasing compound and/or a catalytically active material; and optionally subjecting the waste water to a biological treatment with the use of microorganisms; and apparatus for carrying out the foregoing process.

Abstract: A method for treating polluted material such as industrial waste water or polluted water from other sources, sewage or sewage sludge, or other forms of sludge, to degrade oxidizable substances therein. The polluted material is subjected to a wet oxidation process in a tubular reactor so as to decompose and/or modify oxidizable substances therein and improve the filterability of any solids present in the material. The material may also be pretreated to facilitate the wet oxidation process. Solid polluted material is preferably in the form of an aqueous suspension when subjected to wet oxidation. The wet oxidation process is performed to such an extent that the decomposed and/or modified substances remaining after the oxidation step are substantially biodegradable. Heavy metals may also be removed subsequent to the wet oxidation process.

Abstract: Waste water chemical oxygen demand is reduced from a waste water by passing the water in the presence of an oxidizing agent through an adsorbent porous solid substrate, preferably zeolite A, zeolite X, zeolite Y, ZSM-5, erionite, or chabazite which has been partially ion exchanged with a water insoluble metal compound, copper (Cu), that cataytically facilitates oxidation of the offensive substances or the components in the waste water that increase its chemical oxygen demand, such as cyanide, sulfide, thiosulfate, sulfite, mercaptan, or disulfide. The preferred oxidizing agent is air. It is desired to develop a process for waste water treatment that is effective at reducing the concentration of the offensive substances in the waste water while minimizing the deposition of undesirable residues into the treated waste water.

Abstract: An organic or inorganic feed compound can be treated in two or more zones to progressively oxidize the compound. The first zone oxidizes the compound to an intermediate product which includes a first intermediate compound which is intermediate the feed compound and end product. The second zone further oxidizes the intermediate product to an end product or a second intermediate compound which is intermediate the first intermediate compound and an end product. One or both zones may operate catalytically and/or at supercritical conditions for water to oxidize the compounds.

Abstract: Disclosed is an apparatus and a process for high temperature water oxidation of combustibles in which during at least a part of the oxidation, corrosive material is present and makes contact with at least a portion of the apparatus over a contact area on the apparatus, wherein at least a portion of the contact surface area comprises a zirconia based ceramic, with the temperature of the oxidation process in excess of about 300.degree. C. and the pressure of the oxidation process is in excess of about 27.5 bar (400 psi).

Abstract: Disclosed is a method of substantially completely oxidizing material in an aqueous phase at supercritical temperatures and sub- or supercritical pressures by initiating the oxidation in the presence of small amounts of strong oxidizing agents that function to increase the initial reaction rate for the oxidation. The strong oxidizing agents suitable for use in the present invention comprise at least one selected from the group consisting of ozone (O.sub.3), hydrogen peroxide (H.sub.2 O.sub.2), salts containing persulfate (S.sub.2 O.sub.8.sup.2-), salts containing permanganate (MnO.sub.4.sup.-), nitric acid (HNO.sub.3), salts containing nitrate (NO.sub.3.sup.-), oxyacids of chlorine and their corresponding salts, hypochlorous acid (HOCl), salts containing hypochlorite (OCl.sup.-), chlorous acid (HOClO), salts containing chlorite (ClO.sub.2.sup.-), chloric acid (HOClO.sub.2), salts containing chlorate (ClO.sub.3.sup.), perchloric acid (HOClO.sub.3), and salts containing perchlorate (ClO.sub.4.sup.-).

Abstract: The present invention is directed to a method for recovering 2-chloropropionic acid so that this compound can be separated in a high-purity form. According to the method, crude 2-chloropropionic acid is heat-treated in the presence of a metal compound at a temperature in the range of 130.degree.-180.degree. C. where dichloro derivatives are contained as impurities or at a temperature not exceeding 160.degree. C. where no dichloro derivatives are contained. The metal compound is then removed at 160.degree. C. or lower. Final purification is thereafter conducted to obtain 2-chloropropionic acid as a high-purity product.

Abstract: A process is presented for the treatment of wastewater containing non-volatile pollutants and volatile chemically oxidizable organic and inorganic pollutants. The process combines efficient evaporation to concentrate the non-volatile compounds and a catalytic oxidation reaction to convert the volatilized organic and inorganic pollutants. A condensate product may be obtained by treating wastewater according to the inventive process that is of distilled water quality and substantially free of minerals and organics.

Abstract: A method for the purification of waste water by the use of a heat-exchanger type reaction vessel composed of a plurality of inner tubes and a shell defining jointly with the outer peripheries of the inner tubes a passage for the flow of a heat transfer medium, which method comprises passing said waste water through said inner tubes and, at the same time, feeding a molecular oxygen-containing gas to the flow of said waste water thereby establishing contact between said waste water and said feed gas and consequently effecting wet oxidation of the impurities present in said waste water.

Abstract: A method for the treatment of waste water, which comprises wet oxidizing said waste water with a molecular oxygen-containing gas of an amount 1.0 to 1.5 times the amount thereof theoretically necessary for decomposing at least one substance selected from the group consisting of organic substances and inorganic substances present in said waste water to nitrogen, carbon dioxide, and water at a temperature not exceeding 370.degree. C. under a pressure enough for said waste water to retain a liquid phase in the presence of a solid catalyst comprising of a first catalytic component formed of titanium dioxide, a second catalytic component formed of the oxide of an element of lanthanide series, and a third catalytic component containing at least one metal selected from the group consisting of manganese, iron, cobalt, nickel, tungsten, copper, silver, gold, platinum, palladium, rhodium, ruthenium, and iridium or a water-insoluble or sparingly water-soluble compound of said metal.

Abstract: The invention provides processes for treating waste water comprising subjecting waste water to liquid phase oxidation without catalyst, liquid phase oxidation with catalyst and anaerobic digestion and/or aerobic treatment.

Abstract: A method for treating polluted material such as industrial waste water or polluted water from other sources, sewage or sewage sludge or other forms of sludge, or polluted soil, to degrade oxidizable substances therein, comprising subjecting the polluted material to a wet oxidation process in a reactor so as to decompose and/or modify oxidizable substances therein and optionally improve the filterability of solids when present in the material; the material may optionally be pretreated so as to facilitate the wet oxidation process. Solid polluted material is preferably in the form of a liquid suspension, such as an aqueous suspension, when subjected to wet oxidation. The wet oxidation process is performed to such an extent, optionally with subsequent substantial removal of heavy metals, that the decomposed and/or modified substances remaining after the wet oxidation and the optional removal of heavy metals are substantially biodegradable.

Abstract: This invention provides a method for the detoxification of aqueous solutions of organic compounds utilizing a liquid-phase oxidant such as hydrogen peroxide (aq) or ozone (aq). The aqueous solutions of organic compounds and the liquid-phase oxidant are mixed, then compressed and heated to bring the mixture into a supercritical phase. The oxidation reaction proceeds in the supercritical phase.

Abstract: A process comprising removing alkyl-substituted aromatic compounds, alkyl compounds, or cycloalkyl compounds from an aromatic stream containing these compounds by contacting the aromatic stream with molecular oxygen in the presence of a zeolite.

Abstract: The present invention relates to an improved process for the wet oxidation of water soluble organic pollutants or of an aqueous suspension of organic pollutants. In the contacting of an oxidizing gas and a polluted aqueous phase, the improvement comprises forming a fine mist of the polluted aqueous phase in the presence of the oxidizing gas, thereby increasing the interfacial area between the gas and the polluted aqueous phase. Then the formed mist is introduced into a heated reaction chamber under pressure, thereby enhancing the rate of the destructive oxidation of the organic pollutant by the increase in mass transfer between the gaseous phase and the aqueous mist, the reaction temperature being selected to favor rapid destruction of the pollutant without the formation of stable intermediate reaction products. After destruction of the pollutants, the reaction mixture is allowed to flash off at a pressure lower than the reaction pressure.

Abstract: Efficient treatment of waste water is accomplished by subjecting the waste water to wet oxidation under continued supply of an oxygen containing gas at a temperature of not more than 370.degree. C. under a pressure enough for the waste water to retain the liquid phase thereof intact, in the presence of a catalyst containing a composite oxide of at least two metals selected from the group consisting of Ti, Si, and Zr and at least one metal selected from the group consisting of Mn, Fe, Co, Ni, W, Cu, Ce, Ag, Pt, Pd, Rh, Ru, and Ir or a compound of the one metal mentioned above.

Abstract: Waste water containing at least two kinds of components among suspended solids, ammonia and chemically oxidizable substances is treated in a liquid phase oxidation in the presence of a catalyst supported by a carrier of honeycomb construction.

Abstract: A process for oxidizing an aqueous suspension of organic matter at elevated temperature and pressure includes exposing the organic matter to an oxygen-containing gas in a reactor for a period sufficient to reduce chemical oxygen demand of the organic matter to a predetermined desired level. An aqueous suspension of organic matter and bubbles of oxygen containing gas is split, rearranged and combined by an arrangement of vanes within the reactor core.

Abstract: Thiosalts contained in waste streams are oxidized to sulfate ions in the presence of sulfur-bound copper. Air oxidation of the waste stream is effected in a slurry of the copper compound, which may be CuS, Cu.sub.2 S or chalcopyrite, and continuous long term operation is possible without loss of catalytic activity and without catalyst degradation.

Abstract: A process for the decontamination of an effluent loaded with organic substances, which effluent has, where appropriate after the addition of a redox system, a redox potential of 300-600 mv measured at a platinum electrode versus a silver/silver chloride electrode, comprising oxidizing the effluent with oxygen or an oxygen-containing gas at a pH of 1 to 4, a temperature of 50.degree. to 200.degree. C. and a pressure of 1 to 60 bar in the presence of a redox catalyst and a co-catalyst comprising coal, lignite or peat which has been pretreated with alkali.

Abstract: This invention relates to a process by which waste water containing ammonia or chemically oxidizable substances (hereinafter referred to as "COD components"), suspended solids, etc. in addition to ammonia is subjected to wet oxidation in the presence of a catalyst to convert these pollutants to nitrogen, carbon dioxide, water and the like and to thereby render the waste water harmless.According to this invention, the ammonia contained in the waste water includes ammonium compounds which liberate ammonium ions when dissociated in water. The COD components include phenol, cyanides, thiocyanates, oils, thiosulfuric acid, sulfurous acid, sulfides, nitrous acid, etc.

Abstract: The purity of organically polluted waters is improved by contacting with a zinc titanate catalyst under oxidizing conditions. In one embodiment, an aqueous stream containing oxidizable organic pollutants is subjected to oxidizing conditions in the presence of a metal promoted zinc titanate catalyst to improve the purity of the aqueous product. In a second embodiment, an aqueous stream containing oxidizable organic pollutants is subjected to oxidizing conditions in the presence of a metal promoted zinc titanate catalyst to convert the water to a potable aqueous product.