纳米α-MnO_2去除水中各形态砷的最佳条件分析

Optimal conditions of nano α-MnO_2 arsenic removal

目的分析纳米二氧化锰α-MnO2吸附饮用水中三价砷(As(Ⅲ))、五价砷(As(Ⅴ))的影响因素。方法以高锰酸钾、硫酸锰、过硫酸铵等为主要原料,制得纳米α-MnO2,控制pH、温度、砷初始浓度和时间,采用静态吸附除砷实验,探讨除砷效果和能力。结果随着吸附时间延长,二氧化锰对砷的去除率缓慢上升,10min时即可达到吸附平衡;随着砷初始浓度的升高,吸附率呈降低的趋势;随着温度的升高,水中各形态砷的去除率随之升高;pH值越低,吸附率越高,去除砷的效果越好。结论吸附过程受pH、温度、砷初始浓度和时间的影响,在常温下,pH值小于7时吸附超过20min即可获得良好去除效果。

Objective To study the influential factors of adsorption of trivalent arsenic（As（Ⅲ））,pentavalent arsenic（As（V）） by nano-manganese dioxide α-MnO2 in the drinking water.Methods Potassium permanganate,manganese sulfate,ammonium persulfate were used as the main raw material to make nano alpha-MnO2;pH,temperature,initial concentration of arsenic and time were controled,and static adsorption arsenic removal experiments were adopted to investigate the effectiveness and capacity of arsenic removal.Results The removal efficiency of arsenic adsorpted by manganese dioxide rised slowly to reach equilibrium at 10min;with the arsenic initial concentration increasing,the adsorption rate was decreased;with the temperature increasing,the arsenic removal in the water increased concomitantly;the lower the pH value was,the higher the rate of adsorption for arsenic removal was.Conclusions The adsorption process is affected by pH,temperature,the initial concentration of arsenic,and time;with the pH value less than 7 at room temperature,the adsorption over 20min can be obtained a good removal effect.