活性污泥的表面特性与其沉降脱水性能的关系  

Surface properties of activated sludge and their effects on settlleability and dewaterability

作　　者：王红武[1] 李晓岩[2] 赵庆祥[1] 

机构地区：[1]华东理工大学环境工程系,上海200237 [2]香港大学土木工程系

出　　处：《清华大学学报（自然科学版）》2004年第6期766-769,共4页Journal of Tsinghua University(Science and Technology)

基　　金：香港研究资助局 ( RGC)项目 ( HKU710 0 /99E)

摘　　要：为改善活性污泥的沉降脱水性能 ,测定了实验室规模的反应器中培养的泥龄 5、 10、 2 0 d的污泥胞外聚合物(EPS)的总量和组成、絮体的粒径分布、 Zeta电位及其沉降和脱水性能。研究结果表明 :随着泥龄的延长 ,EPS的组成松散附着物 (L B)和紧密粘附物 (TB)两部分的质量比值(m L B/m TB)减小 ,小于 10 μm的微小絮体数量减少 ,Zeta电位值也减小。 EPS的总量对污泥的沉降脱水性能的影响很小 ,但其组成 (L B、 TB)有显著影响 ,m L B/m TB越大 ;污泥表面的 Zeta电位值越大 ,小粒径的污泥颗粒则越多 ,污泥的沉降脱水性能变差。因此 ,通过改变运行条件 ,减小 m L B/m TB和Zeta电位 。The extracellular polymeric substances (EPS) production, particle size distribution and Zeta potential of activated sludge were measured for different sludge ages in laboratory-scale reactors to study their effects on the settleability and dewaterability. The ratio of loosely bound EPS to tightly bound EPS and the amount of fine flocs (d<10 μm) decreased as the sludge retention time increased from 5 days to 20 days, while the Zeta potential of the sludge became less negtive. A higher sludge volume index, an indication of poorer settleability, and a longer modified capillary suction time, a reflection of poorer dewaterability, were associated with an increase of the number of smaller particles, a more negative Zeta potential and a larger mass ratio of loosely band to tighty bound EPS. No significant correlation was observed between sludge volume index or the suction time and the total amount of EPS.

关 键 词：活性污泥 沉降 脱水 

分 类 号：X703[环境科学与工程—环境工程]