| 摘要 |
PURPOSE:To filtrate treated water treated in an aeration tank with simple construction and at a low cost without needing a sedimentation tank. CONSTITUTION:A filter body 1 is formed in the shape of a bag by placing water passing sheets 2 one upon another with a water passable porous material 3 for maintaining a clearance inserted between them and sealing the periphery of the placed water passing sheets 2. The filter body 1 is arranged in an aeration tank 5 above an aerating part 8 and immersed in treated water. A suction pipe 4 for drawing out treated water with low suction force caused by head difference lower than in the aeration tank is led to the outside. Thereby the treated water is directly drawn out from the aeration tank 5 as highly treated water by head difference. Even if active sludge comes to be hard to precipitate due to bulking, etc., operation can be continued and a cake layer becomes fragile and its sticking on and coming off from the filter body are repeated to keep its thickness nearly constant. |
