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. 29, 1997
Filed:
Dec. 13, 1995
Applicant:
Inventors:
Allen R Boyce, Portland, OR (US);
James S Yates, Vancouver, WA (US);
Assignee:
SEH America, Inc., Vancouver, WA (US);
Primary Examiner:
Int. Cl.
CPC ...
B01D / ;
U.S. Cl.
CPC ...
210652 ; 210641 ; 210651 ; 210654 ; 210638 ; 210912 ;
Abstract
An ultrapure water purification scheme that incorporates the use of certain RO filtration membranes that are especially susceptible to oxidative attack employs the combination reducing/metals scavenger/biocidal agent dithiocarbamate as a pretreatment additive to maintain a non-oxidizing environment, to bind contaminant metals to improve their removal from source water, and to reduce microbial content. In addition, the generation of oxidants by cavitation effects is avoided by a reduced pressure retentate recycle. Both measures prevent oxidative attack and fouling of the RO membranes.