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:
Dec. 26, 2000
Filed:
Sep. 19, 1991
Jerry A Partridge, Richland, WA (US);
Siemens Power Corporation, Richland, WA (US);
Abstract
A method for removing low levels of heavy metal from chemical/industrial waste streams containing interfering anions which typically form strong complexes with heavy metals such as uranium utilizes an ion exchange resin having amino-phosphonic functional groups which selectively capture the heavy metal from the chemical waste stream in an efficient manner such that the amount of heavy metal in the waste stream is reduced to sub-ppm levels. After capture, the resin is treated with a sequestering agent, such as a solution of ammonium fluoride or ammonium sulfate, which releases the heavy metal from the resin. The resin is then regenerated with a sodium solution and returned to service. Utilizing ion exchange and a resin containing amino-phosphonic functional groups allows removal of heavy metal to a level of less than or equal to 0.1 ppm which is a substantial reduction in view of the presence of significant quantities of complexing anions in the waste stream.