| 摘要 |
In a batch type activated sludge method, to efficiently perform a treatment by improving sedimentation properties of the sludge. In a biological treatment device provided with a first biological treatment tank and a second biological treatment tank, said biological treatment tanks being disposed in two stages in series, a batch type operation is performed by repeating the following steps (1) to (6): (1) introducing organic waste water into the first biological treatment tank; (2) stopping the introduction, aerating the inside of the first biological treatment tank, and converting organic matters into dispersed bacteria through a biological treatment by bacteria; (3) stopping the aeration and introducing first biologically treated water containing the dispersed bacteria into the second biological treatment tank; (4) stopping the introduction, aerating the inside of the second biological treatment tank, and allowing animalcules to prey the dispersed bacteria; (5) stopping the aeration and sedimenting sludge in the second biological treatment tank; and (6) discharging the supernatant. |
