硅藻土强化混凝处理城市河道水的试验研究

Experimental study on diatomite enhanced coagulation for the treatment of urban river water

以聚合氯化铝(PAC)为絮凝剂,研究了硅藻土强化混凝处理城市河道水的效果,考察了硅藻土对PAC混凝去除水中浊度、有机物、磷的影响及对沉降性能的改善作用,并采用响应曲面法优化了水力条件。试验结果表明,硅藻土能强化PAC对水中污染物的混凝效果,浊度、DOC、TP去除率相较于未加硅藻土分别提高了12.8%、15.5%和10.7%。最优水力条件:快搅速度243 r/min,慢搅速度62 r/min。在此条件下,浊度、DOC、TP去除率均值分别为72.4%、66.9%、92.1%,与模型预测结果较为吻合。

Using polymeric aluminum chloride(PAC) as flocculent,the effects of diatomite enhanced coagulation on the treatment of urban river water have been studied systematically,and the influences of diatomite on PAC coagulation for the removal of turbidity,organic matter,and phosphorus from water,as well as the improving function of settling property investigated. The hydraulic condition has been optimized by Box-Behnken response surface method. The experimental results show that diatomite can enhance the coagulation effect of PAC on pollutants in water. Compared with the case without adding diatomite,the removing rates of turbidity,DOC and TP are increased by 12.8%,15.5%and 10.7%,respectively. The optimal hydraulic conditions are as follows:rapid stirring velocity is 243 r/min,and slow stirring velocity 62 r/min. Under these conditions,the average removing rates of turbidity,DOC and TP from urban river water are 72.4%,66.9% and 92.1%,respectively,which are comparatively consistent with the predicted results of the model.