| 摘要 |
<p>PROBLEM TO BE SOLVED: To nitrate waste water containing ammonia nitrogen in high concn. at a high speed by charging a fiber carrier formed by twisting a large number of fibers and specifying the concn. of dissolved oxygen of the nitration tank to perform biological nitration. SOLUTION: In the case of the treatment of highly conc. ammonia nitrogen containing no BOD(biochemical oxygen demand), since treated water 4 and a fiber carrier 3 are separated by a screen 2 by using the fiber carrier 3, the fiber carrier 3 is held in a nitration tank 1 to be prevented from flowing out along with treated water 4. The nitration tank 1 is operated in such a state that MLDO (dissolved oxygen concn.) is set to 6mg/l or more. By the succession of this operation, the fiber carrier 3 becomes a nitration carrier suitable for environment high in the concn. of ammonia nitrogen. Therefore, waste water containing ammonia nitrogen in high concn. of 80mg/l or more can be nitrated at a high speed.</p> |
