低浊矿坑废水混凝优化试验研究

Study on the treatment of low-turbidity pit wastewater by optimized coagulation

针对某煤矿废水处理站对低浊废水混凝处理效果不佳、混凝剂投加量大等问题,通过正交试验及单因素试验对混凝条件进行了优化。试验结果表明,最优混凝操作条件:以PAC为混凝剂,投加量为20 mg/L;原水p H为8;依次快速(250 r/min)搅拌30 s,中速(100 r/min)搅拌8 min,慢速(40 r/min)搅拌12 min;在快速搅拌之后投加PAM,投加量为0.5 mg/L,投加时间为30 s。在最优混凝条件下,低浊废水的SS去除率高达90%以上。

Aiming at the problems that the coagulation treatment effect of low-turbidity pit wastewater in a coal min-ing wastewater treatment plant is not good,the coagulant dosage is too high,etc.,the coagulation conditions have been optimized by orthogonal tests and single factor tests. The experimental results show that the optimal coagulation operation conditions are as follows：using PAC as coagulant,its dosage is 20 mg/L,raw water pH=8,stirring in turn, quick-speed stirring （250 r/min） for 30 s,medium-speed stirring （100 r/min） for 8 min,slow-speed stirring （40 r/min） for 12 min,and after quick stirring adding PAM dosage=0.5 mg/L for 30 s. Under the optimum coagulation condi-tions,the removing rate of SS of the low-turbidity wastewater is as high as 90%.