中文摘要：

采用4个平行的序批式反应器（SBR），研究了进水Ca^2＋浓度对活性污泥絮体表面特性和结构稳定性的影响，并由此来确定Ca^2＋在生物絮凝中的作用。结果表明：随着进水Ca^2＋浓度的增加，污泥中的Ca含量逐渐增大。进水中Ca^2＋的加入，增大了污泥絮体的粒径和密度，进而改善了污泥的沉降性能；Ca^2＋的加入，使可供结合的蛋白质数量最高增至近1倍，污泥表面疏水性也相应增强；污泥絮凝性能的改善，主要和可供Ca^2＋结合的蛋白质含量增加有关，而非多糖；EDTA通过络合污泥絮体中的Ca^2＋，破坏了由Ca^2＋架桥形成的污泥絮体结构，这说明Ca^2＋可通过和胞外聚合物（extracellular polymeric substances，EPS）中的负电官能团架桥来促进污泥絮体的形成并维持絮体结构的稳定性。

英文摘要：

The effects of calcium ions on the floe surface properties and structural stability were investigated in four parallel sequencing batch reactors, and then the role of calcium ions in bioflocculation was determined.The results show that the calcium concentration in the sludge increases with increasing calcium ions concentration in the influent. The improvements in settling properties due to increased floc size and floc density are associated with the increase in calcium ions in tile feed. The increase in relative hydrophobicity is well correlated to the bound protein content in addition to the increase in calcium ions. The calcium ions appear to bind mainly protein not polysaccharide. EDTA can remove the calcium ions from the floc matrix and therefore break floc structures linked by salt bridging. The results suggest that calcium ions aid in flocculation by bridging negative sites on exocellular biopolymers and maintain the structural stability.