US 12,343,678 B2
Nitrogen recovery method, nitrogen recovery device, and product obtained by same
Akira Fujino, Tokyo (JP); Yuko Sasagawa, Tokyo (JP); and Junichi Morota, Shizuoka (JP)
Assigned to JFR CO., LTD., Tokyo (JP)
Appl. No. 17/642,368
Filed by JFR CO., LTD., Tokyo (JP)
PCT Filed Sep. 11, 2020, PCT No. PCT/JP2020/034429
§ 371(c)(1), (2) Date Mar. 11, 2022,
PCT Pub. No. WO2021/049603, PCT Pub. Date Mar. 18, 2021.
Claims priority of application No. 2019-166997 (JP), filed on Sep. 13, 2019.
Prior Publication US 2022/0323901 A1, Oct. 13, 2022
Int. Cl. C12N 1/20 (2006.01); B01D 53/58 (2006.01); B01D 53/84 (2006.01); C12M 1/00 (2006.01); C12M 1/12 (2006.01); C12M 1/34 (2006.01); C12N 11/14 (2006.01); C12P 3/00 (2006.01)
CPC B01D 53/58 (2013.01) [B01D 53/84 (2013.01); C12M 25/18 (2013.01); C12M 29/06 (2013.01); C12M 29/26 (2013.01); C12M 41/26 (2013.01); C12M 47/10 (2013.01); C12N 1/20 (2013.01); C12N 11/14 (2013.01); C12P 3/00 (2013.01)] 11 Claims
 
1. A nitrogen recovery method for recovering a nitrogen component contained in ammonia as an ammonia gas decomposition product by decomposing an ammonia component in an ammonia-containing gas using nitrifying bacteria, the method comprising:
supplying circulating water to a microorganism decomposition tank equipped with a nitrifying bacterium carrier supporting nitrifying bacteria to maintain the nitrifying bacterium carrier in a wet state;
allowing the ammonia-containing gas to pass through the nitrifying bacterium carrier in the wet state under an oxygen-containing atmosphere dissolving an ammonia component in the ammonia-containing gas in the circulating water, together with an ammonia gas decomposition product produced by the nitrifying bacteria, and continuing to decompose the ammonia-containing gas while accumulating the ammonia gas decomposition product in the circulating water; and
collecting all or a portion of the circulating water to recover the ammonia gas decomposition product, when a concentration of nitrate ion as an ammonia decomposition product in the circulating water is increased to 5000 mg/L or more and reaches a predetermined concentration,
wherein the nitrifying bacteria supported to be the nitrifying bacterium carrier comprise ammonia-oxidizing bacteria and nitrite-oxidizing bacteria.