摘要
目的考察三种晶型纳米二氧化锰对水中As(Ⅲ)和As(Ⅴ)的去除效果。方法采用静态吸附实验,分别采用Mn(Ac)2.4H2O和硫酸锰制备α-MnO2、β-MnO2和δ-MnO2,观察100 mg/L的α-MnO2、β-MnO2和δ-MnO2三种晶型纳米二氧化锰吸附剂对水中As(Ⅲ)和As(Ⅴ)的吸附效果,并进行吸附等温线拟合。采用高效液相氢化物发生原子荧光法测定水中As(Ⅲ)和As(Ⅴ)的含量,并研究最佳反应条件。结果最佳反应条件为pH=2,反应时间10 min,0.5 mg/L的As(Ⅲ)和As(Ⅴ)为初始浓度。对As(Ⅲ)和As(Ⅴ)的Langmuir最大吸附量,α-MnO2分别为103.1和106.4 mg/g,β-MnO2分别为50和49.8 mg/g,δ-MnO2分别为31.3和34.9 mg/g。α-MnO2对As(Ⅲ)和As(Ⅴ)的吸附平衡数据符合Langmuir和Freundlich吸附等温方程,β-MnO2和δ-MnO2对As(Ⅲ)和As(Ⅴ)的吸附平衡数据符合Langmuir等温方程式。结论三种晶型纳米二氧化锰均是去除含砷废水的有效材料。
Objective To investigate the efficiency of nano-MnO2 with three kinds of crystal structures for removing As（Ⅲ） and As（Ⅴ） from aqueous solutions. Methods By means of static adsorption experiments, α-MnG2, β-MnO2 and δ-MnO2 was prepared successfully by using manganese acetate tetrahydrate and manganous sulfate, respectively. The adsorption capability of As（Ⅲ） and As（V） from aqueous solutions on α-MnO2, β-MnO2 and δ-MnO2 with the concentration of 100 mg/L was investigated. A batch equilibrium data were tested using the isotherm equations. Determination of As（ Ⅲ ） and As（Ⅴ）in water by high performance liquid chromatography coupled with hydride generation-atomic fluorescence spectrometry. The optimal reaction conditions were studied. Results Under the optimum condition [pH =2, reacting 10 min, As （ Ⅲ ） and As （Ⅴ） initial concentration 0.5 mg/L], the saturated adsorption capacity of nano-MnO2 for As （Ⅲ） and As （Ⅴ） were calculated from the Langmuir-type isotherm equations, which were 103.1 and 106.4 mg/g for α-MnO2, 50 and 49.8 mg/g for β-MnO2, 31.3 and 34.9 mg/g for δ-MnO2. Equilibrium data for the adsorption of As （Ⅲ） and As （V） by α-MnO2 were obtained and correlated with Langmuir-type and Freundlich-type isotherm equations, equilibrium data for the adsorption of As（Ⅲ） and As（Ⅴ） by β- MnO2 and β-MnO2 were obtained and correlated with Langmuir-type isotherm equations. Conclusion Nano-MnO2 can be used as a sorbent for removal of As（Ⅲ） and As（Ⅴ） from aqueous solutions.
出处
《环境与健康杂志》
CAS
CSCD
北大核心
2012年第7期645-648,共4页
Journal of Environment and Health
