| 摘要 |
PROBLEM TO BE SOLVED: To provide a flocculation sedimentation active sludge treatment system capable of more improving the flocculation properties of active sludge, and a method for operating the same.SOLUTION: Provided is a flocculation sedimentation active sludge treatment system comprising: an aeration tank 1 having active sludge and subjecting the raw water to be introduced to biological treatment; an inorganic addition tank 2 in which an inorganic flocculant is added to treatment water from the aeration tank 1; a sedimentation tank 4 in which the treatment water added with the inorganic flocculant in the organic addition tank 2 is introduced, and sludge is subjected to precipitation separation; a return line L1 in which a part of the sludge precipitation-separated at the sedimentation tank 4 is returned to the aeration tank 1; a first polymer coagulant addition part 5 adding a first polymer coagulant to the treatment water from the physical reaction part at the downstream than the physical reaction part and at the upstream than the inorganic addition tank 2 or in the inorganic addition tank 2; and a second polymer coagulant addition part 6 in which a second polymer coagulant is added to the treatment water added with an inorganic flocculant at least at the downstream than the inorganic addition tank 2. |
