pH和腐殖酸对水合二氧化锰去除水中铅的影响

Effect of pH and humic acid on removal of lead by hydrous manganese dioxide coagulation

以实验室配制模拟水为本底,考察了高锰酸钾还原法制备的水合二氧化锰对水中微量铅的混凝及强化混凝去除效能。探讨了水体pH值、腐殖酸对铅去除效果的影响以及水合二氧化锰去除水中重金属铅的机理。结果表明:水合二氧化锰对水中的微量铅具有显著的去除作用,1.5 mg.L-1的水合二氧化锰对实验室配水中铅的去除率达92%,作为助凝剂时,1 mg.L-1的水合二氧化锰可使铅的去除率达95%以上。中性和弱碱性条件下铅的去除率高于酸性条件,水中腐殖酸浓度升高使铅的去除率降低。水合二氧化锰够消除或减弱腐殖酸对铅的络合作用。

The removal efficiency of Pb（Ⅱ）from raw water with hydrous manganese dioxide produced by reduction of KMnO4 were studied by coagulation experiments.The effects of pH value and humic acid of raw water on removal of Pb（Ⅱ） were investigated and the possible mechanism were discussed.The results showed that the hydrous manganese dioxide had excellent effect of removing Pb（Ⅱ）from raw water.The removal efficiency of Pb（Ⅱ）reached 92% with 1.5 mg·L-1 hydrous manganese dioxide.The removal efficiency of Pb（Ⅱ）reached 95% with 1 mg·L-1 hydrated manganese dioxide as a coagulant aid.A better removal was achieved in neutral and basic condition than in acid condition.The removal efficiency of lead decreased while the humic acid concentration increased,and the negative effect of humic acid on lead removal could be reduced by hydrous manganese dioxide.