复合材料MnO_(2)/MCM-41对放射性废水中Sr^(2+)的去除

Removal of Sr^(2+)from radioactive wastewater by the composite MnO_(2)/MCM-41

采用一锅法制备MnO_(2)/MCM-41复合材料,探究其对放射性废水中Sr^(2+)的去除。通过SEM、BET、FT-IR对复合材料进行了表征。探究MnO_(2)和MCM-41的质量比、pH、吸附时间、竞争离子效应等参数对其吸附性能的影响。结果表明,复合材料能迅速吸附水中Sr^(2+),并在120 min达到吸附平衡,最大吸附容量为85.46 mg/g。MnO_(2)和MCM-41的质量比为4∶1时复合材料具有最高的吸附容量,在pH为4~9范围内复合材料具有较高的吸附性能,此外复合材料在Na^(+)、K^(+)、Mg^(2+)、Ca^(2+)存在的情况下依然保持良好的吸附容量,抑制吸附能力遵循Na^(+)<K^(+)<Mg^(2+)<Ca^(2+)的排序。吸附动力学分析伪二级模型比伪一级模型更能拟合吸附数据,说明化学吸附在吸附过程中占主导地位。所制备的MnO_(2)/MCM-41新型复合材料用于去除放射性废水中的Sr^(2+)具有吸附迅速、吸附容量大、选择性强、能够大规模制备等优点,这使得其有望在含Sr^(2+)放射性废水处理领域发挥重要作用。

MnO_(2)/MCM-41 composite was prepared by one-pot method to investigate its removal of Sr^(2+)from radioactive wastewater.The prepared composite were characterized by SEM,BET,FT-IR.The effects of parameters such as mass ratio,pH,adsorption time and competing ion effect of MnO_(2) and MCM-41 on the adsorption test were investigated.The results showed that the composite adsorbent could rapidly adsorb Sr^(2+)in water and reached the adsorption equilibrium in 120 min with the maximum adsorption capacity of 85.46 mg/g.The composite adsorbent had the highest adsorption capacity when the mass ratio of MnO_(2) and MCM-41 was 4∶1,and the composite adsorbent had high adsorption performance in the range of pH 4-9.In addition,the composite adsorbent maintained good adsorption capacity in the presence of Na^(+),K^(+),Mg^(2+)and Ca^(2+),and the inhibited adsorption capacity followed the order of Na^(+)<K^(+)<Mg^(2+)<Ca^(2+).The adsorption kinetic data analysis of the pseudo-secondary model fit the adsorption data better than the pseudo-first-order model,indicating that chemisorption dominated the adsorption process.The novel MnO_(2)/MCM-41 composite prepared for the removal of Sr^(2+)from radioactive wastewater had the advantages of rapid adsorption,high adsorption capacity,selectivity,and the ability to be prepared on a large scale,which made it promising to play an important role in the field of Sr^(2+)containing radioactive wastewater removal.