无机悬浮颗粒的混凝特性和絮凝体形态学研究  

MECHANISM OF COAGULATION OF INORGANIC SUSPENDED PARTICLES AND THEIR MORPHOLOGICAL CHARACTERISTICS

作　　者：王广华[1] 金鹏康[2] 王晓昌[2] 

机构地区：[1]广州市市政工程设计研究院,广东广州510060 [2]西安建筑科技大学环境与市政工程学院,陕西西安710055

出　　处：《水处理技术》2006年第5期30-32,38,共4页Technology of Water Treatment

基　　金：国家自然科学基金项目(50278076);陕西省自然科学基金项目(2002E215)

摘　　要：研究了絮凝体的形成过程及其形态学特性。结果表明,无机悬浮颗粒体系的最佳混凝pH值在7～8之间,在低投药量时,压缩双电层和吸附电中和是主要的混凝机理,在高投药量条件下,则是卷扫絮凝起主导作用。絮凝体平均粒径和分形维数都随搅拌时间的延长而增大,并最终趋于稳定。在pH=7和以硫酸铝作为混凝剂的条件下,形成的絮凝体最大粒径为0.3mm,对应的分形维数在1.78左右。随着投药量的增大,絮凝体分形维数的变化较小,但絮凝体平均粒径显著增加;当投药量过高时,网扫絮凝作用下的絮体结构松散,抗剪切能力差,具有较小的平均粒径和分形维数。In this paper, the mechanism of coagulation of inorganic suspended particles and their morphological characteristics were studied by microscopic analysis. The results showed that the optimum coagulation pH of inorganic suspended particles was about 7～8, and absorption and charge neutralization was the dominant mechanism when the dosage was lower; and sweeping fiocculation was the dominant mechanism when the dosage was higher. It was found that the mean diameter and fractal dimension increased with agitation time, and finally reached a steady-state; with the coagulant of aluminium sulfate at pH 7, the maximum mean diameter was 0.30 mm, and the fractal dimension was about 1.78. The mean diameter increased with the increases of alum dosage, but the fractal dimension did not vary. However, extremely high dosage of aluminum resulted in an increase of fioc diameter but a decrease of the fractal dimension. The main reason is that the sweeping fiocs is too loose in their structure, and can not resist the shear force.

关 键 词：无机悬浮颗粒 絮凝体 形态学 分形维数 

分 类 号：TU991.22[建筑科学—市政工程]