(1. 河南理工大学 化学化工学院，焦作 454003；
2. 武汉科技大学 国家环境保护矿冶资源利用与污染控制重点实验室，武汉 430081；
3. 河南理工大学 煤炭安全生产与清洁高效利用省部共建协同创新中心，焦作 454000)
摘 要: 用螯合树脂D751吸附酸性溶液中的钒(Ⅳ)离子，考察溶液pH、钒初始浓度、温度及杂质离子浓度对吸附效果的影响，并分析了吸附等温线及动力学和热力学过程，探讨吸附机理。结果表明：D751树脂对酸性溶液中的钒(Ⅳ)离子有较强的吸附能力(最大吸附量为78 mg/g)，钒吸附率保持在80%以上，同时铁吸附率保持在20%以下，表明D751树脂适合用于酸性钒(Ⅳ)溶液的钒铁分离。酸性溶液中D751树脂吸附钒是自发吸热过程，熵增为驱动力。朗缪尔等温模型能很好地拟合实验数据，表明D751树脂吸附钒是单分子层吸附。D751树脂吸附钒的过程受内扩散与液膜扩散协同控制。根据吸附前后D751树脂红外光谱变化推测其吸附机制为：树脂表面双羧基官能团与溶液中钒酰基阳离子形成稳固的配位键，钒离子成功地被吸附在树脂上。
关键字: 离子交换；螯合树脂；吸附；钒(Ⅳ)；配位
（1. School of Chemistry and Chemical Engineering, Henan University of Technology, Jiaozuo 454003, China;
2. State Environmental Protection Key Laboratory of Mineral Metallurgical Resources Utilization and Pollution Control, Wuhan University of Science and Technology, Wuhan 430081, China;
3. Collaborative Innovation Center for Safe Production and Clean and Efficient Utilization of Coal, Henan University of Technology, Jiaozuo 454000, China）
Abstract:The chelating resin D751 was investigated to dislodge vanadium(Ⅳ) ion in acid solution, the effects of pH, initial concentration of vanadium in solution, temperature and concentration of impurity ions on the adsorption degree were discussed, the adsorption isotherm and kinetic process were analyzed, for which the adsorption mechanism was inspected gradually. The results show that D751 resin reveals a relatively sterling adsorption capacity for vanadium ion (Ⅳ) in strong acidic solution(the saturated adsorption capacity is 78 mg/g), in the presence of ferrous ion, the vanadium adsorption rate is still more than 80% (simultaneously the ferrous ion adsorption rate keeps a low level of ＜20%), which indicates that D751 resin can be suitably used for the separation of vanadium and iron in acidic system. The adsorption of vanadium in acidic solution by D751 resin is a spontaneous endothermic process, driven by entropy increase. Langmuir isothermal model can appropriately fit the experimental data, indicating the adsorption of vanadium in acidic solution by D751 resin is a monolayer adsorption. The process of vanadium adsorption by D751 resin is controlled by internal diffusion and liquid film diffusion. The infrared spectrum varies after adsorption, which can be inferred that the principle of the adsorption process is that the double carboxyl functional groups on the resin surface form a stable coordination bond with the vanadyl cations in the solution, and the vanadium ions are successfully adsorbed on the resin.
Key words: ion exchange; chelating resin; adsorption; vanadium(Ⅳ); coordination
