乙二胺改性MIL-101的制备及其对土霉素吸附性能研究

发布时间：2018-02-02 08:29

本文关键词： 金属-有机框架 MIL-101 土霉素吸附废水处理　出处：《昆明理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：药物抗生素的大量生产和使用对环境造成严重的危害,如何高效去除废水中抗生素污染物成为目前人们研究的一个热点问题。金属-有机框架材料(Metal-Organic Frameworks,MOFs)作为一类先进多功能材料,具有高比表面积、可调节的孔尺寸和表面易于修饰等优良特性受到国内外研究者们广泛关注。本研究采用高度多孔性的MIL-101对土霉素进行吸附,发现虽然吸附速率很快,吸附量却没有达到预期效果。为进一步开发MIL-101对土霉素吸附潜力,我们采用乙二胺对其进行合成后修饰改性,改性后的MIL-101吸附土霉素效果较原始MIL-101材料具有十分显著的提高。本文首先以九水硝酸铬、对苯二甲酸为反应物,HF为矿化剂和水作为溶剂在高压反应釜中合成MIL-101材料。随后又以甲苯为溶剂通过回流反应对合成后的MIL-101进行乙二胺(ED)修饰,得到改性后的MIL-101材料(ED-MIL-101)。通过XRD、SEM、FT-IR、TGA和BET等手段对改性前、后的MIL-101材料进行表征,MIL-101的表征结果与文献报道一致,表明本研究中MIL-101产物成功合成。改性前后对比发现:嫁接后,材料ED-MIL-101比表面积和孔容变小,晶体结晶性能稍微变差,但框架结构依然保持完整。为测试两种材料对土霉素吸附效果,我们对其展开动力学研究,动力学结果表明:ED-MIL-101在同等条件下对土霉素吸附量是MIL-101的5倍,两种材料的吸附行为满足拟二级动力学模型;为探索土霉素吸附机理,我们对材料吸附行为进行等温线和热力学研究,结果表明:MIL-101和ED-MIL-101吸附土霉素能较好满足Langmuir模型,并且吸附反应为自发放热反应。pH实验研究表明:随pH增加,ED-MIL-101表面电荷由正变为负,溶液pH为4-10时对土霉素吸附效果较好,ED-MIL-101吸附土霉素存在电子效应。最后我们采用“HCl溶液+乙醇”的方法在超声条件下对吸附剂进行再生,发现ED-MIL-101在经历3轮吸附-脱附实验后仍然具有很高的吸附量。
[Abstract]:The mass production and use of drug antibiotics cause serious harm to the environment. How to efficiently remove antibiotic pollutants from wastewater has become a hot issue. Metal-Organic Frameworks is a metal-organic framework material. As a kind of advanced multifunctional materials, MOFs has high specific surface area. The excellent properties of adjustable pore size and easy surface modification have attracted wide attention of researchers at home and abroad. In this study, oxytetracycline was adsorbed by highly porous MIL-101. In order to further develop the potential of MIL-101 to adsorb oxytetracycline, ethylenediamine was used to modify the surface of oxytetracycline. The adsorption of oxytetracycline by modified MIL-101 was much better than that of MIL-101. Firstly, chromium nitrate nine hydrate and terephthalic acid were used as reactants. HF was used as mineralizer and water as solvent to synthesize MIL-101 material in autoclave, then MIL-101 was modified by ethylenediamine (EDN) with toluene as solvent through reflux reaction. The modified MIL-101 material ED-MIL-101 was obtained by means of XRDX SEMT-IRGA-TGA and BET. The results showed that the MIL-101 products were successfully synthesized in this study. The results of comparison before and after modification showed that: after grafting. The specific surface area and pore volume of the material ED-MIL-101 become smaller, the crystalline properties of the crystal become a little worse, but the structure of the frame remains intact, to test the adsorption effect of the two materials to oxytetracycline. The kinetic results show that the adsorption capacity of Otochlomycin at the same conditions is 5 times of that of MIL-101. The adsorption behavior of the two materials meets the pseudo-second-order kinetic model. In order to explore the adsorption mechanism of oxytetracycline, the adsorption behavior of materials was studied by isotherms and thermodynamics. The results showed that the adsorption of oxytetracycline by ED-MIL-101 and WMIL-101 could satisfy the Langmuir model. The adsorption reaction was spontaneous exothermic reaction. The experimental results showed that the surface charge of ED-MIL-101 changed from positive to negative with the increase of pH, and the adsorption effect of oxytetracycline was better when pH was 4-10. ED-MIL-101 adsorbed oxytetracycline has an electronic effect. Finally, we use the method of "HCl solution ethanol" to regenerate the adsorbent under ultrasonic condition. It is found that ED-MIL-101 still has a high adsorption capacity after three rounds of adsorption-desorption experiments.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X703;O647.3

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