Characterization of floc size, strength and structure under various coagulation mechanisms

被引:294
作者
Li, Tao
Zhu, Zhe
Wang, Dongsheng [1 ]
Yao, Chonghua
Tang, Hongxiao
机构
[1] Chinese Acad Sci, State Key Lab Environm Aquat Chem, Res Ctr Ecoenvironm Sci, Beijing 100085, Peoples R China
[2] E China Univ Sci & Technol, Resources & Environm Engn Inst, Shanghai 200237, Peoples R China
基金
中国国家自然科学基金;
关键词
floc; size; fractal dimension; strength; coagulation mechanism;
D O I
10.1016/j.powtec.2006.07.003
中图分类号
TQ [化学工业];
学科分类号
0817 ;
摘要
Flocs generated by various coagulation mechanisms exhibit different size, strength and structure. The properties and fractal dimensions of flocs formed under three common coagulation mechanisms, i.e. charge neutralization, sweep and bridging, were investigated at various hydraulic conditions. The results showed that the floc size decreased with the increasing average velocity gradient G and the stable floc size exponent T was of the following hierarchy: charge neutralization (0.6107)> sweep (0.5618) > bridging (0.3674). Furthermore, fractal dimensions of flocs were the highest when formed by sweep and the lowest when generated by bridging flocculation. The mass fractal dimensions measured by light scattering were between 2.0 and 3.0 and the floc strength was between 0.01 and 0.58 N m(-2). An intrinsic unity of the relationship among floc size, fractal dimensions, floc strength under the three coagulation mechanisms was demonstrated. (c) 2006 Elsevier B.V. All rights reserved.
引用
收藏
页码:104 / 110
页数:7
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