| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an activated sludge method by which the cleaning performance in an aeration tank can be increased at a low cost and the amount of excess sludge can be suppressed. SOLUTION: In the activated sludge method by aerating a mixture liquid of raw water and activated sludge to 20 to 60 m<3> air per one day per 1 m<3> of the raw water in an aeration tank 5, sending the aerated mixture liquid to a settling tank 6 and returning a part of the activated sludge separated in the settling tank 6 to the aeration tank 5 while the rest of the sludge is removed and discarded, the amount of the activated sludge removed and discarded from the settling tank 6 is controlled and decreased to keep the MLSS(mixed liquor suspended solid) in the aeration tank 5 to >=15,000 ppm.</p> |
