搅拌速率和时间对强化混凝去除微污染水中镍(Ⅱ)及有机物的影响

Effect of stirring speed and time on removal of nickel(Ⅱ) and organic matter in micro-polluted water by enhanced coagulation

采用静态实验考察了投加高铁酸钾强化混凝的效果,通过控制不同的絮凝搅拌速率、絮凝时间及原水浊度来强化镍(Ⅱ)和有机物的去除。结果表明,絮凝搅拌速度和时间、原水浊度是影响镍(Ⅱ)和有机物的去除效果的重要因素。原水镍(Ⅱ)质量浓度为1 mg·L^(-1)、TOC为10 mg·L^(-1),在一级絮凝搅拌速率为200 r·min^(-1)、时间为2 min,二级絮凝搅拌速率为40 r·min^(-1)、时间为10 min,原水浊度为36.7 NTU时,出水剩余镍为0.018 mg·L^(-1),去除率达到98.2%,TOC去除率为58.8%,浊度去除率为73.8%。出水可满足《生活饮用水卫生标准》的要求。高铁酸钾强化混凝可作为给水厂应对镍污染的一种有效处理措施。

A static trial was performed to study the effect of enhanced coagulation though the addition of potassium ferrate,with flocculation stirring speed,flocculation time,and raw water turbidity controlled to strengthen the nickel（ Ⅱ） and organics removal. The results showed that flocculation stirring speed,flocculation time,and raw water turbidity were key influences on nickel（ Ⅱ） and organics removal efficiency. The first level of flocculation stirring speed was 200 r·min-1,flocculation time was 2 min; the second level of flocculation stirring speed was 40 r·min-1,flocculation time was 10 min; and raw water turbidity was 36. 7 NTU. The nickel concentration in the effluent was 0. 018 mg·L-1,and the removal rate of the nickel（ Ⅱ）,TOC,and turbidity were 98. 2%,58. 8%,and 73. 8%,respectively,when the nickel（ Ⅱ） and TOC concentrations were 1 mg·L-1and 10 mg·L-1,respectively,in the raw water. These levels satisfied the demand of the Hygienic Standard for Drinking Water. Potassium-ferrate-enhanced coagulation can be used as an effective treatment for nickel pollution in water supply plants.