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.
Patent No.:
Date of Patent:
Jul. 19, 1988
Filed:
Jan. 30, 1987
Applicant:
Inventors:
Alfred Henz, Reinach, CH;
Heinz Pfenninger, Lupsingen, CH;
Assignee:
Ciba-Geigy Corporation, Ardsley, NY (US);
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
B01D / ; C02F / ;
U.S. Cl.
CPC ...
210639 ; 210654 ; 210655 ; 210917 ;
Abstract
There is disclosed a process for purifying/decolorizing dyeing wastewaters that have been adjusted in a pretreatment step to a pH in the range from 4 to 9 by addition of acid or alkali by means of a membrane separation process. The concentrate obtained after the first step is further decolorized and deionized in the second step. The permeate of the second step is recycled to the pretreatment step, while the permeate of the first step and the concentrated wastewater obtained after the second step are disposed of in conventional manner.