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:
May. 18, 1993
Filed:
Jun. 19, 1991
Anthony J Giuffrida, North Andover, MA (US);
Gary C Ganzi, Lexington, MA (US);
Millipore Corporation, Bedford, MA (US);
Abstract
Purified ion exchange resin particles are provided in a bifunctional electrodeionization step having anion depletion compartments containing anion exchange resin particles which are purified and cation depletion compartments containing cation exchange resin particle which are purified as well as ion concentration compartments. The bifunctional electrodeionization step for purifying resin particles is conducted under conditions to disassociate water into hydrogen ions and hydroxyl ions. Purified water having a purity of at least 1 megohm-cm is introduced into the anion depletion compartment and cation depletion compartments and water for accepting ionic impurities is introduced into the ion concentration compartments. The purified water is produced in an initial purification step which also can be an electrodeionization step. The water effluent from the anion depletion compartments and cation depletion compartments is recycled either to an initial water purification step or to the inlets of the anion depletion compartments or cation depletion compartments. The anion depletion compartments include an anion permeable membrane and a bifunctional interface. The cation depletion compartments include a cation permeable membrane and the bifunctional interface.