| 摘要 |
<p>PURPOSE:To adequately replenish nutrients of denitrifying bacteria by consituting this method so that a stage for admitting sewage over a anaerobic stage of the next period is set from the required time of an initial aeration stage in a batchwise sewage treatment. CONSTITUTION:The specified volume of the sewage, for example, about half the volume of the treated water to be withdrawn is supplied from a raw water vessel to a reaction chamber 1. The first anaerobic stirring stage 2, a spot stirring stage 3 and a first aeration stage 4 are successively executed for the prescribed period of time. The sewage inflow 5 of the second time is started after lapse of the prescribed time of the first aeration stage 4; for example, from the period of lapse of about 1 hour and 30 minutes to 40 minutes. The prescribed volume of the sewage is supplied for the prescribed time further from the start period of the second anaerobic stage 6; for example, for about 20 minutes. The second anaerobic stage 6 and the second aeration stage 7 are then executed respectively for the prescribed time. A settling stage 8 and a water draining stage 9 are executed after the end of the second aeration stage 7.</p> |
