氧化铈-二氧化硅介孔材料制备及对铜离子的吸附性能

采用共沉淀法和沉淀浸渍法制备了纳米氧化铈-二氧化硅（CeO₂-SiO₂）介孔材料吸附剂,主要考察了其对水中铜离子（Cu²⁺）的吸附行为。通过X射线衍射（XRD）、扫描电镜（SEM）和氮吸附（BET）等手段对合成的介孔材料进行了性能表征,并通过静态吸附实验分析了溶液pH、溶液初始金属离子质量浓度、吸附剂用量、吸附时间等条件对介孔材料吸附Cu²⁺性能的影响。结果表明：共沉淀法制备的纳米CeO₂-SiO₂介孔材料对Cu²⁺的去除效果较沉淀浸渍法要好;当溶液pH=7.0时CeO₂-SiO₂介孔材料对Cu²⁺的吸附效果最好,20 min时基本达到吸附平衡;溶液初始Cu²⁺浓度增大Cu²⁺去除率降低,Cu²⁺累计吸附量增大;随着吸附剂用量增加Cu²⁺去除率增大,当CeO₂-SiO₂吸附剂用量为0.15 g/L时对Cu²⁺的去除率趋于稳定;CeO₂-SiO₂吸附剂对不同金属离子吸附性能由大到小的顺序为Cu²⁺、Fe²⁺、Mn²⁺,该吸附过程均符合准二级动力学模型。

Preparation of CeO2-SiO2 mesoporous material and its adsorption property for copper ions

The CeO₂-SiO₂ mesoporous material adsorbent was prepared by co-precipitaion method and precipitation impregnation method.Adsorption behavior of CeO₂-SiO₂ for Cu ²⁺ ions in water was studied.The prepared material were characterized by XRD,SEM and BET etc.,and the effect of the conditions,such as pH of solution, initial concentration of metal ion in solution,adsorbent amount and adsorption time,on the adsorption property of CeO₂-SiO₂ was analyzed by static adsorption experiment.The results showed that the removal effect of CeO₂-SiO₂ mesoporous material prepared by co-precipitaion method for Cu²⁺ was better than precipitation impregnation method.The best adsorption efficiency of CeO₂-SiO₂ mesoporous material for Cu²⁺ was obtained at pH=7.0 and then the adsorption equilibrium was almost reached at 20 min.With the increasing of the initial concentration of Cu²⁺ in solution, the removal rate of Cu²⁺ decreased and the cumulative adsorption quantity of Cu²⁺ increased.The removal rate of Cu²⁺increased with the increasing of the adsorbent amount,and the removal rate of Cu²⁺ tended to be stable when the amount of CeO₂-SiO₂ adsorbent was 0.15 g/L.The adsorption property of CeO₂-SiO₂ adsorption for different metal ions was acording from big to small as follows：Cu²⁺,Fe²⁺ and Mn²⁺,which met the quasi second-order kinetic model.