• 关键词：氟离子  纳米γ-Al₂O₃  吸附  动力学  热力学

• 基金项目：国家自然科学基金(No. 51178212);辽宁省自然科学基金(No.201102082)

• 刘雪岩
• 辽宁大学化学院, 沈阳 110036

• 姜鑫
• 辽宁大学化学院, 沈阳 110036

• 逯义
• 辽宁省地质矿产研究院, 沈阳 110032

• 杨丽君
• 辽宁大学化学院, 沈阳 110036

• 李莹
• 辽宁大学化学院, 沈阳 110036

• 张蕾
• 辽宁大学化学院, 沈阳 110036

• 摘要：研究了纳米γ-Al₂O₃吸附剂对氟离子的吸附行为,考查了吸附平衡时间、温度、溶液的pH等对吸附过程的影响.结果表明,在室温下,纳米γ-Al₂O₃对氟离子的吸附在3 min基本达到平衡;在pH 3~9 范围内,吸附率达95%以上;吸附过程符合准二级反应动力学模型,其反应的表观活化能(E_a)为10.99 kJ·mol^-1;颗粒内扩散过程是吸附的主要控制步骤,而颗粒外扩散过程对吸附也有影响;吸附过程符合Langmuir、D-R等温模型,常温下,纳米γ-Al₂O₃对氟离子的平均吸附能为11.15 kJ·mol^-1.吸附反应的ΔG^θ< 0,ΔH^θ> 0,说明该吸附过程是自发的吸热反应.共存阴离子HCO₃^-和PO₄^3-、阳离子Cu²⁺对氟离子的吸附影响较大.纳米γ-Al₂O₃在动态和静态吸附实验中的除氟效果相近.

• Abstract：The adsorption behavior of fluorine ions on nano γ-Al₂O₃ was investigated. The influences of contact time, temperature, pH and other parameters on the adsorption efficiency of fluoride were explored. The results showed that equilibrium was reached within 3.0 min at indoor temperature. The adsorption efficiency could reach over 95% at pH 3~9. The kinetic experimental data was well fitted with the second-order kinetic model. The apparent activation energy was calculated to be 10.99 kJ·mol^-1. The intraparticle diffusion was the main control step of the rate, while the overall process was also influenced by boundary layer diffusion. The sorption data could be well interpreted by the Langmuir and Dubinin–Radushkevich sorption isotherm. The mean energy of adsorption was 11.15 kJ·mol^-1 at room temperature. The thermodynamic parameters for adsorption reaction: ΔH^θ>0 and ΔG^θ<0, indicated that the adsorption process was a spontaneous and endothermic reaction. The co-existed ions such as HCO₃^-, PO₄^3- and Cu²⁺ had larger effects on adsorption of fluorine ions. Removal efficiency of nano-γ-Al₂O₃ obtained by dynamic adsorption was close to that obtained through static adsorption.

• Key words：fluorine  nano-γ-Al₂O₃  removal  kinetics  thermodynamics

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