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:
Apr. 28, 2015
Filed:
Dec. 21, 2009
Nozomu Ikuno, Tokyo, JP;
Motomu Koizumi, Tokyo, JP;
Nozomu Ikuno, Tokyo, JP;
Motomu Koizumi, Tokyo, JP;
Kurita Water Industries Ltd., Tokyo, JP;
Abstract
Ultrapure water of high purity having extremely low TOC concentration is produced by efficiently degrading urea in raw water by biological activated carbon treatment even when the raw water contains ammonium nitrogen. The ultrapure water production method, where raw water is treated in a primary pure water system, and then the resulting water is treated in a subsystem, contains a step of treating pretreated water with chlorine based oxidizer added by a biological treatment means installed upstream to the subsystem. Chlorine based oxidizer is added so that the chlorine based oxidizer concentration is 5 times or more than the ammonium nitrogen concentration of water treated in the biological treatment means in terms of Cl.