麦羟硅钠石对水中Zn2+的吸附性能研究

以沉淀白炭黑、NaOH、Na2CO3和水为原料,制备了单一晶相麦羟硅钠石(magadiite),并用BET、X射线衍射、红外以及SEM对其进行表征,并考察了magadiite对Zn2+离子的吸附行为.结果表明:magadiite是一种比表面积为19.38m2/g的非孔型材料,在25℃、Zn2+初始浓度20mg/L、pH值为6、吸附平衡时间为60min时, magadiite的饱和吸附量为42.55mg/g. Magadiite对Zn2+的吸附动力学符合准二级动力学方程,吸附等温线符合Langmuir方程.结合BET、X射线衍射、红外、SEM分析推断magadiite对Zn2+的吸附是物理吸附和化学吸附共存,但以化学吸附为主.

Adsorption characteristics of Zn2+ onto magadiite

The magadiite as a single phase was prepared by a hydrothermal synthesis method in SiO2-NaOH-Na2CO3-H2O system and characterized by Brunauer-Emmett-Teller (BET) method, X-ray diffraction, FT-IR spectroscopy and scanning electron microscope and then the adsorption of Zn2+ onto magadiite from water was examined. The results showed that, magadiite was nonporous material that has surface areas of 19.38 square metres per gram. The best adsorption conditions at 25℃ were obtained: the initial concentration of Zn2+ was 20mg /L, pH = 6, the adsorption of magadiite reached equilibrium at 60min and the adsorption capacity of Zn2+ was 42.55mg/g. In addition, the adsorption kinetics of the magadiite was best described by pseudo-second-order kinetic equation and the adsorption isotherms of the magadiite were fitted with the Langmuir adsorption model. The chemical and physical adsorption processes (mainly chemical process) in metal ions adsorption occur concurrently.