IP Library Granted Patent US 7,655,455
Granted Patent B2
US 7,655,455 · App. 11/560,612 · Granted Feb 2, 2010

Method of producing a nitrification carrier containing ammonia-oxidizing bacteria for removing nitrogen

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Quick Facts
Patent No.
US 7,655,455
App. No.
11/560,612
Granted
Feb 2, 2010
Kind
B2
Abstract

Provided are a nitrite-type nitrification carrier and a method for producing the same and a method and an apparatus for removing nitrogen using the same, in which the quantity of organic matter to be added can be substantially reduced to reduce running cost. A method for producing a nitrite-type nitrification carrier in which ammonia-oxidizing bacteria for nitrifying ammonium to nitrite is preferentially accumulated comprises the steps of: entrapping and immobilizing any sludge selected from sediment from a lake, a river or the sea, soil from the surface of the earth, or activated sludge from a sewage-treatment plant into a monomer or a prepolymer for immobilizing microorganisms; and then subjecting the entrapped and immobilized sludge to heat treatment at 30 to 80° C.

Claims (9)

1. A method for producing a nitrification carrier in which ammonia-oxidizing bacteria for nitrifying ammonic nitrogen to nitrous nitrogen are preferentially accumulated, the method comprising:

entrapping and immobilizing a material containing ammonia-oxidizing bacteria selected from the group consisting of sediment from a lake, sediment from a river, sediment from a sea, soil from a surface of the earth, and activated sludge from a sewage-treatment plant by polymerizing a monomer or prepolymer in the presence of the material containing the ammonia-oxidizing bacteria while performing a heat treatment at a temperature of 50 to 70° C. during the polymerizing, thereby producing the nitrification carrier in which ammonia-oxidizing bacteria are preferentially accumulated.

2. A nitrification carrier produced by the method according to claim 1 .

3. A method for removing nitrogen, comprising the step of bringing the nitrification carrier according to claim 2 into contact with at least one of water and atmosphere containing ammonic nitrogen under aerobic conditions.

4. The method according to claim 3 , wherein the nitrification carrier is repeatedly subjected to reheat treatment at a temperature of 30 to 80° C. once per three to twelve months after production to maintain performance of the carrier.

5. The method according to claim 1 , wherein length of time of the heat treatment is at least one hour.

6. A nitrification carrier produced by the method according to claim 5 .

7. A method for removing nitrogen, comprising the step of bringing the nitrification carrier according to claim 6 into contact with at least one of water and atmosphere containing ammonic nitrogen under aerobic conditions.

8. The method according to claim 7 , wherein the nitrification carrier is repeatedly subjected to reheat treatment at a temperature of 30 to 80° C. once per three to twelve months after production to maintain performance of the carrier.

Assignments (2)
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 →