水合氧化锰混凝效能与机理

以高锰酸盐和硫代硫酸钠制备水合氧化锰(MnO),研究其电荷特性、界面特征及结构形貌,考察其混凝效能,并探讨其混凝机理.结果表明,MnO粒子在纯水体系中的pHPZC值为1.8,具有丰富的表面羟基,比表面积为131.59 m2/g,具有极强的吸附作用和化学吸附活性及易于发挥吸附架桥作用的结构形貌.MnO混凝效能良好,对沉淀后水浊度及TOC的去除率分别为77.94%和49.15%.MnO助滤效果显著,较低投量(4 mg.L-1)下,可使过滤后水浊度降至0.01NTU以下.其混凝除浊和除有机物的主要机制为吸附架桥及进而形成的网捕卷扫作用.

Coagulation Efficiency and Mechanism of Hydrated Manganese Dioxide

Hydrated manganese oxide (MnO) is prepared with potassium permanganate and sodium subsulfite. Interface performance, charge property and structure topography of MnO are investigated. Turbidity and organic matters removal efficiency by coagulation, and coagulation mechanism of MnO are approached. Results show that the zero charge point of the MnO particles is about 1.8 of pH value (pH_(PZC)) in pure water. MnO contains with rich hydroxyl with specific surface area of 131.59m~2·g~(-1). MnO shows extremely strong adsorption action and chemical adsorption activity, and structure topography for easy adsorption bridging action. MnO is provided with better turbidity and organic matters removal efficiency by coagulation. Turbidity and TOC removal rate of the settled water are 77.94% and 49.15% respectively. MnO is provided with remarkable filtration aid action. The filtered water turbidity can be decreased below 0.01NTU under lower MnO dosage of 4mg·L~(-1). The main mechanism of coagulation for turbidity and organic matters removal is the actions of adsorption bridging and enmeshment rolling sweeping.