(1. 河南理工大學(xué) 化學(xué)化工學(xué)院，焦作 454003；
2. 武漢科技大學(xué) 國(guó)家環(huán)境保護(hù)礦冶資源利用與污染控制重點(diǎn)實(shí)驗(yàn)室，武漢 430081；
3. 河南理工大學(xué) 煤炭安全生產(chǎn)與清潔高效利用省部共建協(xié)同創(chuàng)新中心，焦作 454000)
摘 要: 用螯合樹脂D751吸附酸性溶液中的釩(Ⅳ)離子，考察溶液pH、釩初始濃度、溫度及雜質(zhì)離子濃度對(duì)吸附效果的影響，并分析了吸附等溫線及動(dòng)力學(xué)和熱力學(xué)過程，探討吸附機(jī)理。結(jié)果表明：D751樹脂對(duì)酸性溶液中的釩(Ⅳ)離子有較強(qiáng)的吸附能力(最大吸附量為78 mg/g)，釩吸附率保持在80%以上，同時(shí)鐵吸附率保持在20%以下，表明D751樹脂適合用于酸性釩(Ⅳ)溶液的釩鐵分離。酸性溶液中D751樹脂吸附釩是自發(fā)吸熱過程，熵增為驅(qū)動(dòng)力。朗繆爾等溫模型能很好地?cái)M合實(shí)驗(yàn)數(shù)據(jù)，表明D751樹脂吸附釩是單分子層吸附。D751樹脂吸附釩的過程受內(nèi)擴(kuò)散與液膜擴(kuò)散協(xié)同控制。根據(jù)吸附前后D751樹脂紅外光譜變化推測(cè)其吸附機(jī)制為：樹脂表面雙羧基官能團(tuán)與溶液中釩酰基陽離子形成穩(wěn)固的配位鍵，釩離子成功地被吸附在樹脂上。
關(guān)鍵字: 離子交換；螯合樹脂；吸附；釩(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
