| 摘要 |
<p>PURPOSE:To simultaneously remove nitrogen and phosphorus by preparing two aeration tanks at the minimum and controlling supply of air so that an anaerobic stage and an aerobic stage are performed respectively at the prescribed ORP value in a first tank and also the whole stage is regulated to the prescribed ORP value in a second tank in activated sludge treatment by intermittent aeration. CONSTITUTION:An aeration tank 2 is constituted of a first tank 2a into which sewage is introduced and a second tank 2b from which sewage is discharged to a precipitation tank 3. ORP value of the respective tanks 2a, 2b is measured by ORP meters 6a, 6b. An aeration stage and an anaeration stage are controlled by a timer. In the meantime, the feed rate of air is controlled so that ORP value in an anaerobic stage is set to <=-50mv and ORP value in an aerobic stage is set to 0mv or above in the first tank 2a and also ORP value in the whole stage is set to 0mv or above in the second tank 2b.</p> |
