胞外聚合物对活性污泥沉降和絮凝性能的影响研究

胞外聚合物 (EPS)对污泥沉降和絮凝性能具有重要影响 ,它由松散附着 (LB)和紧密粘附 (TB)的两部分组成。笔者考察了不同运行方式和不同泥龄培养的污泥LB和TB的含量及其成分对污泥沉降和絮凝性能的影响 ,研究结果表明 :虽然LB只占总EPS的 0 .6 %～ 13.5 % ,但它对污泥的沉降和絮凝性能起着决定作用 ,LB含量越多 ,污泥的沉降和絮凝性能越差 ;而TB的影响很小。因此 ,选择合适的运行方式 ,延长污泥泥龄 ,可减少LB含量 ,有利于活性污泥工艺运行安全、稳定、高效。

Effect of Extra-cellular Polymeric Substances (EPS) on Bio-flocculation and Settlement of Activated Sludge

Extra cellular polymeric substances (EPS), composed of loosely bound (LB) and tightly bound (TB) parts, show important impact on the settlement and bio flocculation of sludge. The EPS production and the roles of EPS (LB) and EPS (TB) on the settlement and bio-flocculation of activated sludge in laboratory-scale reactors were studied on different aged sludge. A higher sludge volume index (SVI), an indication of poorer settlement, or a higher level of effluent turbidity, as an index of poorer bio flocculation, was associated with a larger amount of LB. However, no significant correlation between SVI or effluent turbidity and the total amount of TB was observed. Results indicate that it is the LB, rather the TB that governs the settlement and bio-flocculation of the activated sludge.