Abstract: A method and apparatus is disclosed for oxidation of aqueous mixtures of organic material, including toxic material in the presence of inorganic materials, by reaction of said material with water and oxygen at supercritical conditions. Oxygen and the aqueous mixture are separately pressurized to greater than about 218 atmospheres, combined to form a reaction mixture and then directed through a tubular reactor having a substantially constant internal diameter. The velocity of the reaction mixture is sufficient to prevent settling of a substantial portion of solids initially present in the reaction mixture and of solids which form during passage through the reactor. The mixture is heated to temperature above about 374° C. in the tubular reactor. A substantial portion of the organic material in the reaction mixture is oxidized in the tubular reactor to thereby form an effluent mixture.

Abstract: A method and apparatus for recovering wash water from effluent generated by a pulp and paper mill. The method includes filtering at least a portion of the effluent to form a filtrate stream and an organic solids feed stream. The organic solids feed stream is exposed to a temperature and a pressure which are supercritical for water to cause a substantial portion of the organic component to oxidize and form a product stream that, when cooled, includes a gaseous component, an inorganic solids component, and a liquid wash water component. The wash water component is separated from the gaseous and inorganic solids components, thereby recovering wash water.