| 摘要 |
<p>PROBLEM TO BE SOLVED: To treat activated sludge stably by membrane separation by controlling the increase speed of an activated sludge concentration by constituting a retention area for retaining sludge by installing a partition plate in the upper side part of an aeration tank in which a membrane separator is immersed. SOLUTION: A retention area 4 for retaining sludge by installing a partition plate 3 is constituted in the upper side part of an aeration tank 2 in which a membrane separator 1 is immersed. Namely, low partition plates 3, 3 are installed close to the opposite side walls 14, 14 of the aeration tank 2, and the retention area 4 is constituted to retain sludge between the side wall 14 and the partition plate 3. In attention to a part of a slow rotary flow speed (sludge retention), especially the upper side of the aeration tank 1, by forming the retention area 4 positively in this place, and by holding part of sludge in a state of so-called scum (floated sludge), sludge can be stored in the aeration tank 2 without increasing the total volume so that the increase in the activated sludge concentration of a rotary flow part can be controlled.</p> |
