Effects of low temperature on coagulation kinetics and floc surface morphology using alum
Effects of low temperature on coagulation kinetics and floc surface morphology using alum
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DOI：
10.1016/j.desal.2007.12.033
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发表时间：
2009-02
期刊：
影响因子：
9.9
通讯作者：
F. Xiao;Ju-chang Huang;Bao-jie Zhang;Chong-wei Cui
中科院分区：
文献类型：
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作者：
F. Xiao;Ju-chang Huang;Bao-jie Zhang;Chong-wei Cui
研究了低温对混凝动力学和絮体表面形态的影响。结果表明，低温使混凝过程减慢，反映在聚集速率和速率常数的降低。混凝过程中的聚集常数符合Arrhenius定律。高岭石颗粒在水中聚集的活化能为18.7kJ/mol。此外，对絮体表面形态的研究表明，在低温下形成的絮体具有更不规则的结构，基于周长的分形维数，Dpf。当温度从22°C降档到2°C时，Dpf从1.19增加到1.33。絮凝体的形状因子伸长率E符合概率统计规律。在2000个絮体中，约75%的絮体的E值在1.2至2.0之间。
The effects of low temperature on coagulation kinetics and floc surface morphology were examined in this study. The results show that low temperature slowed down the coagulation process as reflected in the decrease in aggregation rate and rate constants. The aggregation constant in the coagulation process was found to follow the Arrhenius law. The activation energy of the aggregation of kaolinite particles in water was 18.7 kJ/mol. Furthermore, the study on the surface morphology of the flocs indicates that those flocs formed at low temperatures had a more irregular structure in terms of perimeter-based fractal dimension, Dpf. Dpfincreased from 1.19 to 1.33 as the temperature was downshifted from 22°C to 2°C. The examined shape factor of the flocs, elongation E, was found to follow the probability rule of statistics. Out of two thousand flocs, around 75% of them have an E value ranging from 1.2 to 2.0.