| 摘要 |
<p>PURPOSE:To control filamentous bulking of activated sludge without doing harm to bacteria except filamentous bacteria contained in activated sludge and to human and other animals by adding an anionic surfactant or a nonionic surfactant to an activated sludge treatment system. CONSTITUTION:In an activated sludge treatment method, drainage is mixed with activated sludge and aerated in an aeration tank. Sludge is separated in a solid-liquid separation tank and separated liquid is discharged as treated water. On one side, a part of separated sludge is returned to the aeration tank as return sludge and the residue is discharged as excess sludge. There may be cases where filamentous bacteria such as Sphaerotilus proliferate in activated sludge and filamentous bulking is generated. Drainage is treated by adding an anionic surfactant or a nonionic surfactant to the activated sludge treatment system to prevent such filamentous bulking. Thereby bulking is controlled by phenomena where filamentous bacteria in activated sludge are shrunk in a sheathlike body or fall from the sheathlike body and are made lytic.</p> |
