α-FeOOH对靛蓝胭脂红的吸附性能

Adsorption properties of indigo carmine by α-FeOOH

采用水热法合成纳米针铁矿α-Fe OOH,利用XRD、SEM对产物物相和形貌进行表征,研究了α-Fe OOH对靛蓝胭脂红的吸附性能,并进行动力学和等温吸附模型分析。结果表明,α-Fe OOH对靛蓝胭脂红具有良好的吸附性能,25℃时最大吸附量为40.31 mg·g-1。用Langmuir、Freundlich、D-R和Tempkind等4种等温吸附模型对实验数据进行拟合,Langmuir方程对实验数据拟合效果最好,D-R方程和Tempkin方程结果显示吸附是物理吸附。吸附过程符合准一级动力学方程,内扩散模型和Boyd模型结果显示膜扩散为吸附过程的主要速控步骤。

Nano-goethite, α-FeOOH, was prepared using the hydrothermal method, and characterized by scanning electron microscopy and X-ray diffraction. The adsorption of indigo carmine by α-FeOOH, the adsorp- tion isotherm model and kinetics were further researched. The experimental results revealed that α-FeOOH is sui- ted for indigo carmine adsorption, with a maximum adsorption capacity of 40.31 mg · g-1 at 25℃. The adsorp- tion isothermal data were fitted with the Langmuir, Freundlich, D-R, and Tempkin equations. The adsorption processes follow a Langmuir model, and can be described using a pseudo-first-order kinetic equation. While studies using the D-R and Tempkin equations revealed that adsorption processes are mediated by a physical ad- sorption mechanism, investigations using the intra-particle diffusion and Boyd models indicated that the processes are dominated by membrane diffusion.