| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an active sludge treatment method by biological membrane separation for removing a negative effect accompanied by increase of the number of membrane filtration units due to a larger amount of sludge treatment and maintaining the sludge treatment of a desired amount. <P>SOLUTION: At least four membrane filtration units 5 are immersed and disposed with a desired interval from each other in series in an aeration tank 4. Filtration water suction amount of each membrane filtration unit 5 and air release amount for each membrane filtration unit 5 are made to successively increase from the upstream side toward the down stream side of the treatment direction. Thereby, solid material deposited to membrane surface of each membrane filtration unit 5 of the sludge recovery side can be reliably stripped from each membrane surface in accordance with the deposition amount of the solid material, at the same time, sludge concentration on the end part of the recovery side where the sludge concentration is highest is made high, thereby, waste treatment of the recovered sludge is facilitated and drying energy upon the waste treatment can be reduced. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
