Rhone-poulenc Chimie

Rhodia Chimie

R. P. Fiber & Resin Intermediates

Louis Le Bris

Philippe Marion

Faouzi Joulak

G&eacute;rard Berrod

Georges Dovergne

Philippe Perrona

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.

Method for treating aqueous solutions comprising acids and nitrated compounds

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:

Process for the preparation of diacids from the washing waters of

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.

Treatment/removal of byproduct aqueous effluents comprising

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Lyons, France

Louis Le Bris