CaCl_2对细颗粒泥沙静水絮凝沉降的影响

细颗粒泥沙的絮凝或分散对土壤渗透性、土壤可蚀性有重要作用 ,是水土保持研究的重要内容。在 Ca Cl2 浓度为 0～ 1.0 mmol/L ,泥沙浓度为 10 g/L时 ,用吸管法研究了 Ca Cl2 对细颗粒泥沙絮凝沉降的影响。结果表明 :泥沙沉降分 2个阶段 ,分选沉降段和絮凝沉降段 ;在絮凝沉降段 ,Ca Cl2 浓度越大 ,絮凝沉降越快。但较高浓度时 ,细颗粒泥沙平均沉速反而随 Ca Cl2浓度增大而逐渐减小 ;泥沙浓度随时间呈指数衰减 ;细颗粒泥沙絮凝临界粒径为 0 .0 3mm。

Fine sediment flocculation and deflocculation play an important role in soil penetrability and soil erodibility, and are one of the primary contents of soil and water conservation. Sediment concentration of 10 g/L is prepared in CaCl 2 solutions with the concentrations ranging from 0 to 1.0 mmol/L. Sediment laden water is sampled with a 20ml pipette, and then relative sediment concentrations are determined thereafter. The results showed that there are two stages during sediment settling in still water, i.e...