机械球磨制备Fe0/ZSM-5复合材料及其对Pb2+的去除研究

Pb^(2+) Removal from Water with a Ball Milled Fe^0/ZSM-5 Composite

利用机械球磨法将零价铁(Fe^0)颗粒负载到疏水性、高硅比的ZSM-5分子筛上,成功制备出Fe^0/ZSM-5复合材料,研究了此复合材料对水溶液中Pb^(2+)的去除性能。XRD结果表明,Fe^0/ZSM-5复合材料保持了ZSM-5分子筛的晶体结构,元素点映射表明零价铁颗粒均匀地负载在ZSM-5分子筛上。实验结果表明,在30℃,初始Pb^(2+)浓度为1~100mg·L^(-1),pH值为3.0,Fe^0/ZSM-5复合材料投加量为0.2 g·L^(-1),反应时间为60 min条件下,Pb^(2+)的最大去除率和最高吸附量分别为78.05%和102 mg·g^(-1)。研究发现在去除Pb^(2+)的过程中伴随着Fe^(2+)的释放以及pH值的升高,且反应过程中释放出Fe^(2+)会加速Fe^0表面的给电子过程,增加其表面活性位点,进而进一步提升对Pb^(2+)的还原去除。研究表明,反应过程符合一级反应动力学。

Pb2+removal from water was investigated using a Fe0/ZSM-5composite prepared by a mechanical milling method via grinding and spitting of hydrophobic and high silica ZSM-5zeolite.XRD results demonstrate that the structure of the composite maintains crystalline structure of ZSM-5zeolite.Elemental spot mapping indicates that Fe0can be homogeneously loaded on ZSM-5zeolite during mechanical milling.The highest Pb2+removal efficiency(78.05%)and adsorption capacity(102mgg1)are obtained for1~100mgL1Pb2+at pH3.0for60min.The results show that the Pb2+treatment process is accompanied by Fe2+release and pH increase.Furthermore,electrons from Fe0surface contribute to the rapid release of Fe2+and thereby increase the surface active sites,which enhance Pb2+reduction in solution.Kinetic results show that the reaction process can be fitted with pseudo-first order.