IP Library Granted Patent US 7,144,508
Granted Patent B2
US 7,144,508 · App. 11/086,242 · Granted Dec 5, 2006

Method and apparatus of removing nitrogen

View Patent ↗
Loading inventors, assignments & file history…
Monitor This Case
Get email alerts when status or documents change.
Order Certified Copies
Most orders are placed with the USPTO same day — all within 24 business hours.
Order via The Patent Place →
Pre-filled with this patent's details
Quick Facts
Patent No.
US 7,144,508
App. No.
11/086,242
Granted
Dec 5, 2006
Kind
B2
Abstract

A method of removing nitrogen, in which the nitrogen is removed from wastewater containing a BOD component and ammonium nitrogen by anaerobic ammonium oxidation, comprising the steps of: distributing the wastewater into two portions which are a nitrification vessel and a denitrification vessel at a predetermined distribution ratio; mixing first treated water which is nitrified by ammonium oxidizing bacteria from ammonia to nitrite in the nitrification vessel, with second treated water which is denitrified by denitrification bacteria in the denitrification vessel; and feeding the mixed water to an anaerobic ammonium oxidation vessel to simultaneously denitrify ammonia and nitrite by ammonium oxidizing bacteria, thereby obtaining a third treated water treated in the anaerobic ammonium oxidation vessel, which is then fed back to the denitrification vessel for denitrification and BOD decomposition.

Claims (4)

1. A method of removing nitrogen, in which the nitrogen is removed from wastewater containing a BOD component and ammonium nitrogen by anaerobic ammonium oxidation, comprising the steps of:

distributing the wastewater into two portions which are a nitrification vessel and a denitrification vessel at a predetermined distribution ratio;

mixing first treated water which is nitrified by ammonium oxidizing bacteria from ammonia to nitrite in the nitrification vessel, with second treated water which is denitrified by denitrification bacteria in the denitrification vessel; and

feeding the mixed water to an anaerobic ammonium oxidation vessel to simultaneously denitrify ammonia and nitrite by ammonium oxidizing bacteria, thereby obtaining a third treated water treated in the anaerobic ammonium oxidation vessel, which is then fed back to the denitrification vessel for denitrification and BOD decomposition.

Assignments (3)
MERGER Recorded Mar 4, 2014
From: HITACHI PLANT TECHNOLOGIES, LTD.
To: HITACHI, LTD.
Reel/Frame 032384/0877 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Aug 16, 2007
From: HITACHI PLANT ENGINEERING & CONSTRUCTION CO., LTD.
To: HITACHI PLANT TECHNOLOGIES, LTD.
Reel/Frame 019714/0076 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Mar 23, 2005
From: ISAKA, KAZUICHI; SUMINO, TATSUO
To: HITACHI PLANT ENGINEERING & CONSTRUCTION CO., LTD.
Reel/Frame 016412/0859 →