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:
Nov. 01, 1994
Filed:
Apr. 01, 1993
Applicant:
Inventor:
Oscar W Weber, Reading, PA (US);
Assignee:
Crompton & Knowles Corporation, Stamford, CT (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C02F / ;
U.S. Cl.
CPC ...
210719 ; 210725 ; 210727 ; 210728 ; 210735 ; 210736 ; 210917 ;
Abstract
A highly colored dye wastewater is treated by a sequence of steps to obtain a color reduction of 90 percent or more. The method requires acidifying the wastewater and adding a cationic flocculant. A reducing agent is then, optionally, added to further reduce the color value of the wastewater and produce an oxidation-reduction potential of at least -200 and, generally, about -400 to -800. The reducing agent is, preferably, either a hydrosulfite or both a bisulfite and an alkali metal borohydride.