不同混凝剂对流溪河水源水中藻类去除的对比

对夏秋季节广州流溪河下游含藻水源水进行了混凝沉淀试验处理,研究了硫酸铝、聚合氯化铝、聚合氯化铝铁、聚合硫酸铁等不同混凝剂及其投加量对藻类和浊度的去除效果,考察了pH值、温度对不同混凝剂去浊率和除藻率的影响,并用zeta电位及显微拍照分析方法,分别对混凝剂的静电中和能力与絮凝体的形态结构进行了初步的研究表征.结果表明,对于pH值为6～8、水温≥15℃、藻类和浊度分别为1.14×107～4.10×107个/L和27～38NTU的水源水,硫酸铝的混凝效果最好,当其投加量为3.0mg/L时,其除藻率和去浊率可分别达到80%和89%,其他混凝剂混凝效果的优劣顺序依次为:聚合氯化铝铁、聚合硫酸铝、聚合硫酸铁;而对冬季的低温水源水,采用聚合硫酸铝或聚合氯化铝铁时,除藻和去浊效果较好.

Removal algae with different coagulants from micro-polluted water in Liuxi River

Removal of algae and turbidity from raw water of Liuxi River was studied by using aluminum sulfate (AS), poly aluminum ferric chloride (PFAC), poly aluminum sulfate (PAS), poly ferric sulfate (PFS) in summer and autumn. The effect of different coagulants, dosages of coagulants, pH and temperature of raw water on coagulative efficiency were investigated. The charge neutrality capability of coagulants, structure and morphological of floc were characterized by zeta potential meter and micrograph. The coagulation efficiency of AS was the best when pH ranged from 6~8, water temperature was higher than 15℃, algae and turbidity were 1.14×107~4.10×107cells/L and 27~38NTU respctively. The removal rates of algae and turbidity can even reach 80% and 89% respctively when the AS dosage was 3mg/L. The coagulative efficiency of other coagulations were PFAC＞PAS＞PFS. Further more, the coagulative performance of PAS and PFAC were better than others when the temperature of raw water was low in winter.