粉煤灰制备混凝剂及其对黄河水的处理效果

以粉煤灰和铁泥为原料、加入一定量NaCl作助溶剂室温下制备粉煤灰混凝剂,考察酸灰比与酸浓度对Fe3+、Al3+溶出率及混凝剂对黄河水处理效果的影响。结果表明,Fe3+、Al3+的最佳溶出条件为酸灰比3 mL/g、HCl浓度4 mol/L,此时Fe3+溶出率为28.1%,浓度为11.81 g/L;Al3+溶出率为5.2%,浓度为1.86 g/L。粉煤灰混凝剂对黄河水的处理效果在投加量2.38 mL/L、沉降时间30 min、pH 6.2～7.5时最佳,对浊度、SS和CODMn平均去除率分别为89.7%、83.6%和62.3%,优于传统市售混凝剂PAC和FC,Fe3+、Al3+同时存在有利于各自优势的发挥从而提高混凝效果。

Preparation of coagulant from fly ash and its application in Yellow River water treatment

Coagulant was prepared with fly ash and iron mud, adding a certain amount of NaCl as cosolvent at room temperature. Effect of ratio of HCl to fly ash and HCl concentration on Fe³⁺ and Al³⁺ dissolution rate and coagulation performance on Yellow River water were investigated. The result showed that the optimal dissolution conditions of Fe³⁺ and Al³⁺ were HCl to fly ash ratio of 3 mL/g and HCl concentration of 4 mol/L. At the same time, Fe³⁺ concentration was 11.81 g/L with dissolution rate of 28.1%. Al³⁺ concentration was 1.86 g/L with dissolution rate of 5.2%. Furthermore, the optimal coagulation effect to Yellow River water was attained at dosage of 2.38 mL/L, sedimentation time of 30 min, pH 6.2~7.5, and the removal efficiency of turbidity, SS and COD_Mn could reach about 89.7%, 83.6% and 62.3%, respectively, so the water treatment effect of coagulant here is better than that of PAC and FC from market. AS co-exist of Fe³⁺ and Al³⁺ can better play their respective advantages, the coagulation effect can be enhanced.