| 摘要 |
PROBLEM TO BE SOLVED: To enable a process in which stable, high load nitrogen is removed stably and efficiently by a method in which calcium in drainage is alkali- aggregated, the drainage is brought into contact with air to strip off ammonia, ammonia in exhaust gas is collected by absorption liquid to be subjected biological nitration denitrification. SOLUTION: Alkali is added into drainage which was introduced into an ammonia aggregation tank 1 by an injector to adjust pH to a prescribed value, calcium aggregation, and aggregated calcium is discharged outside a system through a discharge route 14. Aggregation treatment liquid is sent to an ammonia stripping tank 2, alkali is added to adjust pH, and air is supplied for stripping. Exhaust gas is sent to an absorption tower 3 to collect ammonia by absorption liquid. The liquid is subjected to biological nitration denitrification by a nitration denitrification apparatus 4. In this constitution, the amount of alkali can be reduced, and stable, efficient, high load nitration denitrification can be done without using active carbon. |
