The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
Sep. 10, 1996

Filed:

Jan. 03, 1995
Applicant:
Inventors:

Faouzi Joulak, Chesnay, FR;

Louis Le Bris, Lyons, FR;

Philippe Marion, Villeurbanne, FR;

Assignee:

Rhone-Poulenc Chimie, Courbevoie Cedex, FR;

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C02F / ; C02F / ;
U.S. Cl.
CPC ...
210712 ; 210724 ; 210909 ; 568932 ; 568934 ;
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.


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