长江口粘性细颗粒泥沙絮凝试验研究

Experimental Study on Flocculation of Cohesive Fine Grain Sediment at Yangtze River Estuary

长江口航道淤积的主要成因是河流从上游带来的大量粘性细颗粒泥沙 ,在河口盐、淡水交汇处遇强电解质海水 ,产生絮凝形成絮团而加速沉降形成的 .用长江口粘性泥沙在不同盐度的人工海水中做了大量的试验 ,研究结果表明 ,影响絮凝的主要因素为含盐度、颗粒大小、含沙量、泥沙矿物成分、有机质含量等 。

The main factors causing sediment deposition on the waterway at the Yangtze River Estuary are the flocculation of large amounts of cohesive fine grain sediment from the upper reaches, induced by strong electrolyte seawater at the border of seawater and freshwater, and the quick settling of flocs. A number of experiments performed on cohesive sediment in artificial seawaters of different salinities show that the main factors affecting flocculation and floc size are salinity, grain size, sediment concentration, mineral characteristics of sediment, organic solid concentration of seawater, and so on. The results can be applied to the research of sediment movement at the Yangtze River Estuary.