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:
Sep. 23, 2003
Filed:
Mar. 08, 2001
Applicant:
Inventor:
William Dean Robertson, Waterloo, CA;
Assignee:
Centre for Research in Earth and Space Technology, North York, CA;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C02F 3/04 ;
U.S. Cl.
CPC ...
C02F 3/04 ;
Abstract
Phosphate-contaminated water passes through a domestic sewage treatment system, in which oxidation of the ammonium progresses far enough to cause a lowering of the pH to 5 or less. The water is passed over sand grains coated with aluminum hydroxide (gibbsite). Enough Al ions enter solution, at the low pH, to cause all the phosphate-P to precipitate as aluminum phosphate, and nothing else precipitates other than the aluminum phosphate.