淤泥絮凝沉降中清浑界面沉降速度数值模拟

基于DLVO胶体稳定理论和分形理论,通过对絮团中颗粒间相互作用的分析,提出了一种计算絮团极限粒径的方法,在此基础上,分析了絮团的受力情况,从微观的角度提出了一种非均匀沙絮凝形成的清浑界面的初始段沉降速度的计算方法.结合直线段、过渡段和压缩段清浑界面的沉降理论,计算了不加絮凝剂、添加50和100mg/L絮凝剂时清浑界面的沉降速度,利用取自黄河花园口的泥沙样品,进行清浑界面的沉降速度验证试验,试验结果和计算结果较为一致.研究成果对黄河等高浊度细颗粒含沙水流的治理与处理有一定的理论和实际应用价值.

Simulation for setting velocity of supernatant-sediment interface in sludge flocculation

A distributed model based on the limiting diameter for setting velocity of supernatant-sediment interface during sludge flocculation is presented.With DLVO and fractal theory,we proposed a new method to calculate the limiting diameter,in which the balance of hydrodynamic shear stress and inner force,including van der wanls attraction and double electrode layer repulsions,are used for explaining the stabilization of the limiting diameter.To simulate the settling velocity of interface,we put forward a method to calculate the accelerating section,after which the last three sections were simulated.The model proposed in this paper were verified using the data observed from the Huayuankou of Yellow River.A comparison between the calculated results and experimental data with the flocculant concentration series 50 and 100 mg/L were performed to verify our simulation technique,and they coincided well with each other.