| 摘要 |
<p>PURPOSE:To improve the quality of purified waste water and the effect of coagulating sludge, by continuously adding macromolecular flocculant to mixed sludge for treatment in an aerating cell over a long time. CONSTITUTION:Macromolecular flocculant is added to mixed sludge for treatment in an aerating cell having a high ratio of removing a substrate. Said macromolecular flocculant is preferably one which has a high coagulation effect without being substantially accumulated in the sludge or lowering the activity of removing the substrate, such as a cationic macromolecular flocculant. Said cationic macromolecular flocculant may be, for instance, polyethylene imine, an acylated water-soluble polyethylene imine compound represented by the formula >NOCR (R is a 3-21C straight-chain alkyl or allyl group), an innoxious flocculant Fullonack based on chitosan collected from the crusts of crabs, etc. It is added to the mixed sludge at a ratio below about 5ppm, preferably about 3-0.01ppm.</p> |
