| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain treated water of high water quality by separating a kind of activated sludges efficiently over a long period by a method in which a filter body having a filter cloth which allows substantially activated sludge particles to pass is immersed in an endless water passage, filtration is done by an activated sludge adhesion layer formed on the surface of the filter cloth, and the filtrate is taken out as treated water. SOLUTION: In the endless water passage of an oxidation ditch type activated sludge treatment apparatus, usually, several filter bodies 1 which are immersion- arranged in parallel are formed by a process in which nonwoven fabrics 4 as a filter cloth are installed on both sides of a plate-shaped support 2 through spacers 3 and fixed by an installation frame 5. Communication pipes 21 communicating with both plate sides in the thickness direction are installed in two places of the support 2, and filtrate take-out pipes 22 which are washing water introduction pipes communicating with the pipes 21 from the end surface side of the bottom part of the support 2 are installed in the pipes 21. To take out the filtrate, dynamic filter layers are formed on the surfaces of the nonwoven fabrics 4 of the filter body 1 under oxygen supply of a mechanical aerator to be done by level difference between the endless water passage and the treatment tank as driving force.</p> |
