AlCl_3对细颗粒泥沙絮凝沉降的影响  

Effects of AlCl_3 on Fine Sediment Flocculation and Settling

作　　者：陈洪松[1] 邵明安[1] 

机构地区：[1]中国科学院水利部水土保持研究所

出　　处：《水科学进展》2001年第4期445-449,共5页Advances in Water Science

基　　金：中国科学院知识创新工程项目 (KZCX2 -4 1 1 ) ;国家自然科学基金项目 ( 5 98790 2 6 )资助~~

摘　　要：铝类絮凝剂对细颗粒泥沙絮凝沉降有重要作用 ,常应用于浑水澄清、农业污水处理等研究中。在AlCl3 浓度为 0～ 1 7mmol/L ,泥沙浓度为 1 0g/L时 ,用吸管法研究了AlCl3 对细颗粒泥沙絮凝沉降的影响 ,结果表明 :在液面下同一深度 ,泥沙浓度随时间呈指数衰减 ;悬液经多次搅拌后再沉降 ,其沉速减缓 ;当AlCl3 浓度为 0 9～ 1 7mmol/L时 ,出现明显的清浑水交界面 ,交界面随时间等速下降 ,平均沉速为 4 75 6cm/min ,对应的絮团平均粒径为 0 0 31 5mm ;土娄土絮凝临界粒径为 0 0 2 7mm。Aluminum flocculants have an important role in the flocculation and settling of fine sediment, and are often used to clear muddy water and treat agricultural waste water. In this paper, sediment concentration of 10 g/L is prepared in 1000 mL cylinder which contained AlCl3 solutions with concentration ranging from 0 to 1.7 mmol/L. The relative sediment concentration at the depth of 20 cm below suspension surface is measured with a 20 mL pipette. The results show that the sediment concentration decreases exponentially with time at the same depth below suspension surface. Effects of electrolyte on fine sediment flocculation and set-fling become small and the mean velocity decreases obviously after the suspension is mixed completely for several times. At the given sediment concentration, the emergence of the interface between supernatant and sediment suspension depends on the electrolyte and its concentration. When AlCl3 concentration is higher than 0.9 mmol/L, the obvious interface will appear. At the same time, the interface settles uniformly with time, and the mean particle size is 0.0315 mm with the mean velocity of 4.756 cm/min. The critical particle size to flocculate is 0.027 mm.

关 键 词：细颗粒泥沙 絮凝 沉降 浑水澄清 三氯化铝 絮凝剂 农业污水处理 

分 类 号：TV142.1[水利工程—水力学及河流动力学] X710.31[环境科学与工程—环境工程]