高岭土絮凝体粒径变化实验研究

Experimental study on change of particle size of kaolin flocs

通过室内试验,利用ADV测量流速,计算紊动剪切率G代表紊动强度,配合使用现场激光粒度分析仪(LISST100X)和OBS 3+研究在不改变絮凝环境条件下,不同紊动强度和盐度及悬沙浓度对高岭土絮凝体粒径变化的影响。研究结果表明:在絮凝过程中,存在促进絮团增大的紊动强度临界峰值和饱和盐度,但在不同盐度和悬沙浓度下,紊动强度峰值大小有明显差异。低悬沙浓度时,实验中的饱和絮凝盐度为1 ppt,且随着浓度的增大而增大;紊动剪切率G的临界值在23. 09～34. 72 s^(-1)之间。

The experiments investigated the effect of salinities,turbulent shear rates and suspended sediment concentrations on the particle size of kaolin flocs using the in-situ laser particle size analyzer (LISST100X) and OBS 3+ without changing the flocculation environment. ADV was used to measure the flow velocity,and the turbulent shear rate G was calculated as the turbulence intensity. The results indicate that for kaolin flocs,there are critical peaks of turbulence shear rates and saturation salinity in the process of flocculation,but there are significant differences in the peak values of turbulence shear rates at different salinities and suspended sediment concentrations . Under low suspended sediment concentration,the saturated floccular salinity in the experiment is 1 ppt,and increases with the suspended sediment concentrations; the critical value of the turbulent shear rate G is between 23.09 and 34.72 s -1 .