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:
Mar. 02, 1999
Filed:
Nov. 04, 1997
Applicant:
Inventors:
Steven D Jons, Eden Prairie, MN (US);
Kenneth J Stutts, Midland, MI (US);
Michael S Ferritto, Midland, MI (US);
William E Mickols, Chanhassen, MN (US);
Assignee:
The Dow Chemical Company, Midland, MI (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B01D / ;
U.S. Cl.
CPC ...
21050038 ; 210654 ; 210490 ; 210506 ; 427341 ; 427244 ; 427245 ;
Abstract
Composite polyamide reverse osmosis membranes are treated with an aqueous chlorinating agent at a concentration of 200 to 10,000 ppm for a time sufficient to improve flux, lower salt passage and increase the stability to base. In a preferred embodiment the membrane is treated with heated water at temperature of 40.degree. C. to 100.degree. C. before being exposed to the chlorine treatment.