细颗粒泥沙絮凝现象研究综述

概述了河口泥沙絮凝研究工作中有关絮凝机理、絮凝特性、影响河口细颗粒泥沙絮凝的若干因子。一般研究表明,泥沙颗粒越细,絮凝现象就越明显。絮团的沉降速度主要取决于絮团密度和絮团大小。水流一方面能加强细颗粒泥沙的相互碰撞,促进絮凝作用的发生,另一方面水流又具有剪切破坏作用,因此水流对细颗粒泥沙絮凝沉降的影响表现为在低流速时的促进絮凝作用和高流速时的阻滞絮凝作用。

Review on flocculation of fine suspended sediments

This paper reviews the research work on the mechanism of flocculation,the characteristics of flocculation and the factors infuencing the flocculation of fine sediments,such as turbulent steams,salinity,organic substances,etc.General research shows the finer the sediment particles are,the more obvious flocculation phenomenon will be.Floc velocity depends primarily on the density and size of floc.On one hand,the stream can strengthen the mutual collisions among fine sediment,which promotes the occurrence of flocculation.On the other hand,shear flow may destruct the sediment flocculation.Thus in terms of sediment flocculation,low-velocity stream may promote flocculation while high-velocity stream may block flocculation.