Abstract: A method for removing biodegradable compounds selected from the group comprising: phenolics, free and fixed ammonia compounds, thiosulfates, cyanides, thiocyanates, sulfides and the like from a feed wastewater. The method comprises the steps of treating the feed wastewater by adding soda ash thereto; and further treating the wastewater by means of an activated sludge treatment in a sludge reactor to reduce the level of biodegradable compounds in the wastewater.A method for removing biodegradable compounds selected from the group comprising phenolics, free and fixed ammonia compounds, thiosulfates, cyanides, thiocyanates, sulfides and mixtures thereof from a feed wastewater comprising the steps of: treating the feed wastewater with an inorganic carbon source; and further treating the wastewater by means of a single-stage activated sludge treatment in a sludge reactor to reduce the level of said biodegradable compounds in the wastewater.

Abstract: A crude naphthoquinone produced by an oxidation of naphthalene is purified by a reduced pressure distillation of a crude 1,4-naphthoquinone having an acid content of less than 5 equivalent % calculated as monobasic acid and the crude naphthoquinone is preferably treated by an oxidation of oxidizable impurities.

Abstract: Concentrated acetic acid of 95 to 100 weight percent concentration containing both ionic and coordinate bromine can be successfully purified to a bromine content of less than 3 ppm by the sequential steps of catalytic hydrogenation, contacting the resulting acetic acid with alkali metal hydroxide, carbonate or bicarbonate, and then distilling acetic acid from the alkali metal.

Abstract: In order to prevent corrosion of the apparatus in extraction and extractive distillation processes where N-substituted morpholine is employed as the selective solvent an additive is added to the solvent which additive consists of (a) phosphoric acid, (b) a salt thereof, (c) a vanadium compound, (d) a molybdenum compound or (e) a mixture of two or more of these compounds, the addition being effected in an amount of about 0.005 to 0.02% by weight of the morpholine solvent.

Abstract: Copper is processed via solutions of copper salts, both cupric and cuprous, in acidified aqueous solutions containing organic nitriles. Methods of producting solutions of cuprous salts include reduction of cupric salts and oxidation of copper and copper sulphides. Solutions of cuprous salts are thermally or electrochemically disproportionated to produce copper and solutions of cupric salts.

Abstract: Recovery of the chemical components of a cellulosic organic solvent regenerating solution containing a dialkylacylamide, water, nitrous and nitric acid. The process comprises neutralizing the solution to form the metal salts of nitrous and nitric acid, distilling the neutralized solution to remove and recover the water and dialkylacylamide solvent and pyrolyzing the metal salts in the presence of oxygen to remove and recover nitrogen dioxide gas. The process results in substantially total recovery of the process chemicals.

Abstract: Formic acid is removed from acetic acid substantially free of halide impurities but containing small amounts of formic acid by contacting the acid with a compound of hexavalent chromium and recovering the purified acid from the resulting mixture by distillation, ion-exchange, or the like. In a preferred embodiment, the acid to be purified is distilled in the presence of a solution of the hexavalent chromium compound, the purified acid being obtained as the overhead product while the bottoms stream contains the reduced chromium compound. With the preferred chromium trioxide as treating agent, this compound can be recovered for re-use by adding a strong mineral acid to the bottoms stream from the distillation, electrolytically oxidizing the chromium compound contained therein, and separating chromium trioxide from the strong mineral acid solution.

Abstract: A process is provided for producing ultra-pure propionic acid, i.e., acid containing less than 20 parts by weight of iodine per billion parts by weight of acid, wherein crude acid containing water and iodine contaminants is distilled in a single distillation zone and no waste streams requiring treatment or disposal are obtained.

Abstract: A recovery method by means of which an antimony compound is separated from polyester still bottoms. If desired, the method can be employed so as to recover in usable form, the antimony compound, and the monomers polymerized to produce the polyester.

Abstract: A crude alcohol-containing mixture comprising a saturated aliphatic alcohol of not more than three carbon atoms and associated impurities is processed in a three-tower distillation system to permit recovery of the desired alcohol product in highly concentrated and purified form. In the first tower the crude feed is subjected to extractive distillation with water to remove substantially all the impurities overhead. An aqueous bottoms stream from the first tower containing 5 to 10 wt.% alcohol and only minor amount of impurities is fed to the second tower where the alcohol product is concentrated and recovered. Overhead and intermediate purge streams containing low boiling and hgh boiling impurities are removed from the second tower and are fed to the third tower along with the overhead from the first tower. Stripped aqueous effluent is withdrawn from the bottom of the second tower and is recycled in part to the first tower.

Abstract: A process for treating an aqueous solution containing organic compounds and having a high chemical oxygen demand (COD) by distilling the aqueous solution at a pH not lower than 9, and recovering the water of low chemical oxygen demand (COD) from said aqueous solution. The aqueous solution containing the organic compounds to be treated is derived from the reaction mixture of the oxidation system of methyl-substituted aromatic compound in the liquid phase with molecular oxygen or a molecular oxygen-containing gas, in the presence of a heavy metal catalyst but in the substantial absence of a lower aliphatic acid solvent, to form the corresponding aromatic acid.

Abstract: An improvement in the process for removing vinyl chloride from a water-polyvinyl chloride slurry, which contains unreacted vinyl chloride, by steam distillation is disclosed. In many instances, steam distillation of the slurry results in an increase in the number of gels or fish eyes. The improvement comprises conducting the steam distillation in the presence of a minor, but effective, amount of an alkali metal sulfite or carbonate. The improved process results in a polyvinyl chloride having no substantial increase in, or a reduced amount of, gels or fish eyes, while still having good heat stability and porosity properties.

Abstract: Methods of reducing aqueous solutions of cupric sulfate to cuprous solutions by using organic nitrile compositions are disclosed. The particular nitrile used is acetonitrile and the reductant is sulphur dioxide. The method has application commercially to leaching ores containing oxidised copper to obtain cuprous ion solutions. Such solutions can be treated by electrochemical or thermal disproportionation methods to obtain very pure copper.

Abstract: Method of preparing cuprous sulfate and bisulfate solutions from materials containing copper and impurities by a leaching process are disclosed. The leaching composition contains sulfuric acid, cupric ions, water and an organic nitrile. The leaching composition may be used with copper sulfide ores in particulate form. The cuprous solutions resulting from the leaching can be treated by disproportionation methods to recover pure copper.

Abstract: A method of inhibiting the thermopolymerization of isoprene or butadiene in the process of isolation thereof by extractive distillation from a mixture of hydrocarbons obtained in dehydrogenation of isopentane and butane. The method of inhibiting includes, prior to the introduction of said mixture of hydrocarbons and a polar extractant into an extractive distillation metal apparatus, treating the surface of the apparatus with a 1-25% aqueous solution of passivators, viz. nitrites, sulphites or phosphates of alkali metals at a temperature of 20.degree.-100.degree.C. The mixture of hydrocarbons and the polar extractant with an inhibitor of isoprene or butadiene thermopolymerization introduced into the polar extractant are then fed into said apparatus in an amount of 0.01-1% of the extractant weight. The present method makes it possible to reduce markedly the formation of isoprene and butadiene and, hence, to prevent the plugging of the extractive distillation apparatuses with the aforementioned thermopolymers.

Abstract: A process for producing 2-methyl-3-buten-2-ol by reacting isoprene with a hydrohalide and then with an aqueous base and then distilling the aqueous mixture in the presence of excess base to maintain the reaction mixture during distillation at a pH of at least 4.