Method and device for removing nitrogen

Abstract

Provided is a method and an apparatus for removing nitrogen capable of simply obtaining liquid suitable for anaerobic ammonia oxidation and efficiently removing nitrogen component by means of anaerobic ammonia oxidation treatment.Raw water in a raw water tank 12 is distributed to a first delivery line 24 and a second delivery line 26 by a distribution tank 14 and is delivered. The raw water in the second delivery line 26 is directly delivered to a mixing tank 20 and the raw water in the first delivery line 24 is subjected to nitrification treatment in a nitrification tank 16 and, thereafter, is delivered to the mixing tank 20. In the nitrification tank 16, the nitrification treatment is performed by using a carrier which is heat-treated in predetermined heating conditions, and ammonia nitrogen in the raw water is principally converted into nitrite nitrogen. The nitrification treating liquid is mixed with the raw water of the second delivery line in the mixing tank 20 and the mixed liquid is delivered to an anaerobic ammonia oxidation apparatus 22 and is subjected to the anaerobic ammonia oxidation treatment.

Description

technical field [0001] The invention relates to a nitrogen removal method and device, in particular to a nitrogen removal method and device for removing ammoniacal nitrogen in raw water by using an anaerobic ammonium oxidation method. Background technique [0002] In the previous nitrification and denitrification methods, ammoniacal nitrogen in raw water was removed by this method, that is, under aerobic conditions, nitrifying bacteria were oxidized to nitric acid by nitrous acid, and then under anaerobic conditions, The nitric acid is converted into nitrogen gas by denitrification bacteria. [0003] However, this method has a disadvantage of increased operating costs since it is necessary to add a hydrogen donor such as methanol during the denitrification treatment. [0004] As a method for removing nitrogen without adding a hydrogen donor, a method called anaerobic ammonium oxidation (ANAMMOX) has been proposed. [0005] In this method, a solution prepared so that the di...

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Problems solved by technology

[0012] However, in JP-A-2001-170684, harmful substances such as herbicides are used as nitrite oxidizing bacteria inhibitors, so it is not a practical method

[0013] In addition, in Japanese Patent Laid-Open No. 2001-170684, since a cultivation device using a nitrite oxidizing bacteria inhibitor is required, there is a problem of enlarging the entire device or increasing the operating cost.

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