基于Zeta电位的硅藻土复配剂强化混凝研究

采用硅藻土与传统无机絮凝剂复配处理模拟生活污水,考察硅藻土复配剂强化混凝过程中絮体Zeta电位的变化,以及浊度和COD的去除情况,研究絮体Zeta电位与强化混凝效果的关系。实验结果表明,絮体的Zeta电位与复配剂的强化混凝效果密切相关,可用于反映硅藻土复配剂的混凝处理效果。研究发现,氯化铝复配剂强化混凝时絮体Zeta电位在加药后迅速上升,25min后趋于稳定;絮体Zeta电位在pH值等于7时接近等电点,此时浊度与COD去除率最高,分别达到99.05%和45.77%;用硅藻土复配剂强化混凝时Zeta电位的控制值为-9.0～0mV之间,不同无机絮凝剂与硅藻土复配混凝时获得较好混凝效果的Zeta电位控制值略有差异。

Enhanced Coagulation by Diatomite Blends Based on Zeta Potential

Variety of floc Zeta potential,turbidity and COD removal rates while treating synthetic domestic sewage by using compounds of diatomite and traditional inorganic coagulants were investigated. Relation between Zeta potential and enhanced coagulation efficiency was studied. Results showed that the enhanced coagulation efficiency was closely related to floc Zeta potential and floc Zeta potential could reflect enhanced coagulation efficiency. It was found that the floc Zeta potential first raised rapidly,then tended to be steady 25min after adding AlCl3 blend. When pH was 7,Zeta potential got close to isoelectric point,turbidity and COD removal rates reached the best,being 99.05% and 45.77% respectively. Control value of coagulation Zeta potential was-9.0～0mV for diatomite blends. The control value of floc Zeta potential with best coagulation efficiency had a little difference for different blends.