| 摘要 |
<p>PURPOSE: To prevent the lowering of denitrifying activity caused by the outflow of a denitrifying catalyst in an apparatus performing denitrification using the denitrifying catalyst and to easily adapt the title method and apparatus to a sewage treatment plant due to a standard activated sludge method. CONSTITUTION: In a method and apparatus for removing nitrogen in water, a nitrate bacteria selective inhibitor 5 is injected into an aeration tank 4 to continuously perform nitrite type nitration stopping the oxidation of ammonia in a stage of nitrous acid by the control of an air sending amt. and, thereafter, a chemical denitrifying catalyst 20 is injected into a denitrifying tank 17 to bring about chemical denitrifying reaction to diffuse nitrogen gas. A dissolved oxygen meter 7, an ammonia measuring means 8 and a nitrous acid measuring means 9 are provided to the aeration tank 4 and the concn. ratio of ammonia nitrogen and nitrite nitrogen is calculated on the basis of measured data and an air sending amt. aiming at a nitration rate of 50% is determined with respect to the aeration tank 4.</p> |
