| 摘要 |
PROBLEM TO BE SOLVED: To lower the cost of aeration in a nitrifying step and the cost of addition of a carbon source in a denitrifying step by suppressing the degradation of COD components in the nitrifying step and stably carrying out nitrite forming nitrification when raw water containing ammoniacal nitrogen and COD components is subjected to a nitrification-denitrification treatment. SOLUTION: In a nitrification-denitrification treatment method, a nitrite forming nitrification reaction is carried out in raw water in the presence of ammonia oxidizing bacteria while keeping dissolved oxygen in the raw water at a low concentration, COD degrading bacteria are controlled by blocking due to the concentration of accumulated nitrous nitrogen, and after nitrification, nitrous nitrogen formed in the nitrifying step is denitrified by the action of denitrifying bacteria with residual COD components as electron donors.
|
