镁铝双氢氧化物和镁铝双氢氧化物负载型高岭土对水体中Cr(Ⅵ)的吸附性能研究

Research on Mg-Al LDHs and Kaolin Supported Mg-Al LDHs for Efficient Removal of Cr(Ⅵ)from Aqueous Solution

采用水热法合成了Mg-Al LDHs和Mg-Al LDHs负载型高岭土微纳米层状结构吸附剂,利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)对样品进行表征.考察了样品对水体中Cr(Ⅵ)的吸附效果,并进一步探讨其吸附等温和动力学过程.实验结果显示:Mg-Al LDHs高岭土负载前后的吸附动力学和吸附等温曲线分别符合准二级速率方程和Langmuir等温方程,饱和吸附量分别为34.36 mg/g和11.46 mg/g.

The layered structure Mg-Al LDHs and kaolin supported Mg-Al LDHs were prepared by the hydrothermal method using urea as precipitant.The micro/nano-structures were characterized by X-ray diffraction（XRD）and scanning electron microscope（SEM）. Mg- Al LDHs and kaolin supported Mg- Al LDHs were used as adsorbents for removal of Cr（VI）from aqueous solution,and further investigated the adsorption isotherm and kinetics process.The adsorption isotherm and kinetics of Mg-Al LDHs and kaolin supported Mg-Al LDHs can be described by the Langmuir isotherm and the pseudo-second-order kinetics.The maximum adsorption capacity was about 34.36 mg/g and 11.46 mg/g,respectively.