Abstract: This invention relates to a catalyst for use in water treatment and to a method for the water treatment by the use of the catalyst. The catalyst comprises a first catalyst component e.g. the oxide of titanium, silicon, aluminum and zirconium, and a second catalyst component e.g. manganese, iron, cobalt, nickel, cerium, tungsten, copper, silver, gold, platinum, palladium, rhodium, ruthenium, and iridium or a sparingly water-soluble compound of the metal.

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: A catalyst for the purification of a gas containing ozone or a component of offensive odor is composed of (A) a composite oxide comprising (a) titanium and (b) at least one element selected from the group consisting of Si, Zr, and P and (B) at least one element selected from the group consisting of Mn, Fe, Co, Ni, Ag, Pt, Pd, and Rh.

Abstract: A method for purifying an exhaust gas containing catalyst poison(s) by subjecting the gas to a catalytic treatment which comprises previously passing the gas through a layer packed with a highly activated alumina to remove the catalyst poison(s); and an apparatus for purifying exhaust gas containing catalyst poison(s) by subjecting the gas to a catalytic treatment, wherein a layer packed with a highly activated alumina for removal of the catalyst poison(s) and a layer packed with an oxidation catalyst for removal of harmful substances in the gas are separately arranged.

Abstract: A method of disposing of organic chlorine compounds by burning them in contact with a catalyst of composite oxides selected from titanium-silicon composite oxides, titanium-zirconium composite oxides, and titanium-silicon-zirconium composite oxides, whereby the resulting hydrogen chloride (HCl) is adsorbed by a basic absorbent.

Abstract: A process for producing aromatic or heterocyclic nitriles, which comprises reacting an alkyl-substituted aromatic hydrocarbon or an alkyl-substituted heterocyclic compound with ammonia and oxygen in the presence of a catalyst composition comprising (a) at least one composite oxide selected from the group consisting of a binary composite oxide comprising titanium and silicon, a binary composite oxide comprising titanium and zirconium and a ternary composite oxide comprising titanium, silicon and zirconium, and (b) an oxide of at least one metal selected from the group consisting of vanadium, molybdenum, tungsten, chromium, antimony, bismuth, phosphorus, niobium, iron, nickel, cobalt, manganese and copper.

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: A method for the disposal of waste gas, which method comprises (a) heating the incoming waste gas containing hydrocarbons, carbon monoxide, and other inflammable organic compounds with the gas obtained by removing heat from the outlet gas of the catalytic-oxidation reactor, (b) further heating the resultant hot waste gas with part of the outlet gas of the catalytic-oxidation reactor, (c) subjecting the heated waste gas to complete oxidation in the catalytic-oxidation reactor thereby rendering the waste gas no longer noxious, (d) diverting part of the outlet gas of the catalytic-oxidation reactor to be used for heating the aforementioned heated waste gas, (e) causing at least part of the outlet gas of the reactor which has been used for heating the waste gas to mingle with the remainder of the outlet gas of the reactor, (f) causing the remainder of the outlet gas of the reactor which has been used for heating the waste gas to mingle with the aforementioned heated waste gas, and (g) subjecting to heat recovery