Abstract: The invention concerns a method for treating an aqueous solution derived from sluicing of crude mononitrated or dinitrated aromatic compounds obtained by nitration of the corresponding aromatic compounds, consisting in: (a) contacting said aqueous solution with said aromatic compound thereby obtaining an aqueous phase and an organic phase; (b) recycling said organic phase in the nitration process; (c) distilling said aqueous phase; (d) recycling the resulting concentrated acid solution in the nitration process; (e) recycling or eliminating the recuperated water after distillation.

Abstract: The present invention relates to a process for the preparation of diacids or mixtures of diacids from aqueous solutions derived from the washing of cyclohexane oxidation products. More specifically, the present invention provides a process for the preparation of aliphatic diacids from washing waters derived from a process for the oxidation of cyclohexane and containing peroxides, the process of the invention comprising successively:(a) at least partially deperoxidizing said washing waters by subjecting them to catalytic hydrogenation at a temperature of between about 0.degree. C. and about 100.degree. C., in the presence of at least one platinum group metal;(b) oxidizing with nitric acid the products contained in the washing waters after deperoxidation.

Abstract: Objectionable byproduct aqueous effluents containing contaminating amounts of hydroxynitroaromatic compounds, in particular those aqueous effluents produced during the synthesis of nitroaromatic compounds, e.g., dinitrotoluenes, via reaction of an aromatic compound with nitric acid in the presence of sulfuric acid, are efficiently, facilely and economically treated/removed by (a) intimately contacting a mixture of at least one nitroaromatic compound and at least one hydroxynitroaromatic compound with an aqueous wash medium containing a neutralizing agent, (b) separating the resulting admixture into an organic phase and an aqueous phase, (c) recycling a fraction of the separated aqueous phase to the aqueous wash medium to thus constitute a portion thereof, and (d) periodically draining a fraction of the wash medium, whether to destruction thereof or to waste.

Abstract: Objectionable byproduct aqueous effluents containing contaminating amounts of hydroxynitroaromatic compounds, in particular those aqueous effluents produced during the synthesis of nitroaromatic compounds, e.g., dinitrotoluenes, via reaction of an aromatic compound with nitric acid in the presence of sulfuric acid, are efficiently, facilely and economically treated/removed by (a) intimately contacting a mixture of at least one nitroaromatic compound and at least one hydroxynitroaromatic compound with an aqueous wash medium containing a neutralizing agent, (b) separating the resulting admixture into an organic phase and an aqueous phase, (c) recycling a fraction of the separated aqueous phase to the aqueous wash medium to thus constitute a portion thereof, and (d) periodically draining a fraction of the wash medium, whether to destruction thereof or to waste.