| 摘要 |
PROBLEM TO BE SOLVED: To provide a membrane separation activated sludge treatment apparatus that can improve the quality of treated water and suppress operation power, and to provide a method of operating the apparatus.SOLUTION: A membrane separation activated sludge treatment apparatus 1 comprises: a first biological reaction tank 20 that has aeration means (22, 24) and in which water to be treated is treated with activated sludge; a second biological reaction tank 30 in which the water to be treated is treated under an oxygen-free condition; a membrane separation tank 40 that has a membrane separator 41 and aeration means (42, 44) and in which the treated water is treated under an aerobic condition; a first treated water passage 110, 140 that makes the treated water of the first biological reaction tank 20 flow into the membrane separation tank 40; a connecting passage 120 that connects the second biological reaction tank 30 and the first biological reaction tank 20 to each other; a second treated water passage 130, 140 that makes the treated water of the second biological reaction tank 30 flow into the membrane separation tank 40; and a return passage that returns the treated water of the membrane separation tank 40 to the second biological reaction tank 30. |
