纳米零价铁对水溶液中钒离子的吸附性能

Adsorption of vanadium ion in solution on nano zero-valent irons

采用液相还原法制备纳米零价铁(nZVI),采用PXRD,SEM,TEM,BET(N2吸脱附)和XPS等表征材料性能,考察了纳米零价铁用量、初始钒(V)浓度和初始pH对纳米零价铁吸附钒(V)性能的影响,测定了纳米零价铁对钒(V)的吸附等温线和吸附动力学曲线.结果表明,制备的纳米零价铁具有典型的核-壳结构,粒径为10~30nm,BET比表面积为53m^2/g.纳米零价铁对钒(V)的吸附容量随纳米零价铁用量和初始pH增大而减小.25℃时的平衡吸附容量为227.8mg/g.Langmuir等温线方程可很好拟合纳米零价铁对钒(V)的吸附,纳米零价铁对钒(V)的吸附动力学曲线符合准二级动力学模型.

Nano zero-valent iron (nZVI)was synthesized by the liquid-phase reduction method, and characterized by powder X-ray diffraction (PXRD),scanning electron microscope (SEM), transmission electron microscope (TEM),the Brunauer-Emmett-Teller (BET)and X-ray photoelectron spectroscopy (XPS)method.The adsorption performance of vanadium (V)on nZVI was investigated by rationally adjusting the parameters,such as additive amount of nZVI,initial concentration of vanadium(V)and initial pH value. Additionally,the adsorption isotherms and kinetic curves of vanadium(V)on nZVI were measured.The results showed that nZVI exhibited a regular core-shell structure with an average particle size of 10-30nm and the BET surface area of 53m^2/g.Furthermore,the adsorption capacity of vanadium(V)decreased with the increase in initial pH value and nZVI amount added,respectively.The maximum vanadium(V)adsorption capacity reached 227.8mg/g at 25℃.The adsorption isotherms of vanadium(V) on nZVI fitted well with Langrnuir model,and the adsorption kinetics of vanadium(V)on nZVI could be well described by a pseudo-second-order kinetic model.The nZVI synthesized in this work will provide an useful insights into the comprehensive utilization of waste SCR denitration catalyst.