Abstract: A process and system for reducing the concentration of odorous contaminants, primarily hydrogen sulfide, in the vapor spaces of sewage handling and treatment systems, primarily the vapor spaces of sewage trunk lines, by injecting a fine spray, mist or fog of a dilute solution of hydrogen peroxide and a base selected from a group consisting of sodium hydroxide, potassium hydroxide, ammonium hydroxide and sodium carbonate to mix intimately with the vapor flow. The peroxide and base solutions may be pre-mixed and diluted with water and injected through atomizing nozzles utilizing compressed air as an atomizing fluid. The system may also provide for separate storage of the peroxide and base solutions, mixing of the peroxide and base solutions with dilution water with in-line mixing devices and direct injection with or without compressed air atomization into the vapor space.

Abstract: A process for treating precious metal tailing slurries with Caro's acid, in which the Caro's acid is accompanied by reduced amounts of Caro's acid mist, is disclosed. The hot Caro's acid-containing mixture, formed by reaction of concentrated sulfuric acid and hydrogen peroxide, is quenched with water to reduce or eliminate the Caro's acid mist. The resulting cooled and diluted mixture is introduced into a precious metal tailings slurry to reduce the amount of cyanide values in the slurry.

Abstract: A process for reducing or eliminating Caro's acid mist, created when producing a hot mixture containing Caro's acid by reaction of sulfuric acid and hydrogen peroxide, is carried out by quenching the hot Caro's acid mixture with water to both cool and dilute the Caro's acid.

Abstract: A process for treating effluents, such as precious metal tailings, having a pH of at least 9 and containing cyanide is described in which Caro's acid is added to the effluent having a pH of at least 9 and commencing the reaction of the cyanide with Caro's acid at 0.degree. C. to 80.degree. C. in the absence of an added alkali; adding sufficient Caro's acid within a mole ratio of Caro's acid to cyanide of 0.3/1 to 3/1 to reduce the pH of the effluent to below 9, continuing the reaction between Caro's acid and the cyanide to reduce the amount of cyanide remaining in the effluent and to recover an environmentally compatible effluent reduced in amounts of cyanide.

Abstract: A process is provided for detoxifying an aqueous solution containing weak acid-dissociable cyanide metal complexes. The process comprises incorporating hydrogen peroxide and at least 1 mole of citric acid per mole of complexed metal ion and maintaining the pH of the solution between 8 and 12.

Abstract: Fats and proteins in wastewater are commonly concentrated in a dissolved air flotation cell as a sludge ("skimmings") which has a very high water content, even after centrifuging or the like. A process is provided to reduce the water content of the sludge thereby reducing the cost of disposal of the sludge.

Abstract: A process is provided for purifying finely divided minerals contacting organic material sufficiently to make the minerals useful for coating a filling paper or for use as catalysts, catalyst supports or the like. The process comprises concomitantly contacting an aqueous slurry of the mineral with a peroxygen and a gas containing ozone at a pH from 5 to 12. Preferably, the peroxygen is incorporated into the slurry prior to contacting the slurry with a gas containing ozone. Optionally, the slurry may be pretreated with a chelating agent or subsequently bleached with a reducing agent.

Abstract: A process for removing hydrogen sulfide from saturated steam is described whereby the steam and hydrogen sulfide entrained therein are contacted under conditions of turbulent flow with hydrogen peroxide. The effectiveness of the process is improved by simultaneously contacting the steam with a basic reagent such as sodium hydroxide.

Abstract: Polymeric foam compositions, useful as insulating material are obtained from the reaction of polymaleic anhydride with a hydroxyl-containing compound like ethylene glycol or its derivatives, in the presence of an organic isocyanate. Hydroxyl-containing compounds suitable for reaction with polymaleic anhydride include C.sub.2 -C.sub.10 diols, C.sub.3 -C.sub.6 trilos, C.sub.4 -C.sub.5 tetraols and their derivatives.

Abstract: A method for controlling the concentration of dissolved thiosulfate byproduct which forms in a wet desulfurization process, by introducing a peroxygen chemical into its recirculating aqueous absorption medium. A peroxygen chemical such as aqueous hydrogen peroxide is introduced into the recirculating aqueous alkaline absorption medium, preferably after its regeneration, in an amount sufficient to maintain the concentration of thiosulfate byproduct below a saturation concentration. The method is applicable to cyclic wet desulfurization processes, used to recover elemental sulfur from H.sub.2 S-containing gas streams, in which the absorption medium contains a regenerable oxidizing agent and is subject to thiosulfate byproduct buildup.