咪唑类离子液体键合硅胶的合成及其对2,4-二硝基酚的吸附性能研究

发布时间：2018-02-26 09:20

本文关键词： 吸附离子液体硅胶 2 4-二硝基酚　出处：《河南师范大学》2015年硕士论文　论文类型：学位论文

【摘要】：酚类化合物常见于一些工业排放的污水中,如金属铸造和造纸业等。这类化合物常具有毒性,低浓度即危害生物体,具有致癌和免疫抑制的作用,许多酚类化合物被列为危险污染物。因此,有效去除水体中酚类化合物是环境保护的必要工作。目前已有多种方法被用于此项研究,其中吸附法的成本低、方法简便且易于操作,是去除酚类化合物的有效方法。在此论文中,我们合成了两大类共六种咪唑类离子液体功能化硅胶,并作为吸附剂用于从水体中去除酚类化合物,系统研究了它们对2,4-二硝基酚的的吸附性能。本论文由五个章节组成。第一章,总结了酚类污染物的危害、离子液体的特性和分类及固定化离子液体的优点。综述了固定化离子液体在一些领域的应用及取得的成果,包括催化反应、表面改性、分离技术(包括固相萃取、液相色谱、气相色谱、毛细管电泳色谱和气体捕集)和电化学领域。第二章,使用共价键合的方法,将一系列咪唑类离子液体分别修饰于介孔硅胶表面,制成了六种离子液体键合硅胶新型材料。其中三种是分别将一种离子液体键合于硅胶表面,称为离子液体单功能化硅胶,另外三种是分别将两种离子液体共同键合于硅胶表面,称为离子液体双功能化硅胶。随后通过红外光谱、热重分析、N2吸脱附分析及元素分析四种表征方法对这六种材料的结构进行表征鉴定,分析结果表明目标材料被成功合成,保持了硅胶的骨架和多孔结构,并具有良好的热稳定性。在第三章和第四章中,首先,将几种酚类化合物作为吸附质研究了六种吸附剂对它们的吸附选择性,发现吸附剂均对2,4-二硝基酚有较高的吸附量,因此,选择以2,4-二硝基酚为吸附质,采用静态吸附和动态吸附方法研究了六种吸附剂对它的吸附性能。同时采用单因素实验优化了实验的不同变量,如吸附剂投放量、温度及p H,得到的最优条件分别为25 mg/50 m L、30°C及p H=4.0。六种吸附剂Silpr BIm Cl、Silpr NIm Cl、Silpr AIm Cl、Silpr DBIm Cl、Silpr DAIm Cl和Silpr BAIm Cl的最大吸附量分别为61.3 mg/g、67.0 mg/g、64.5 mg/g、83.1 mg/g、40.3 mg/g和49.2 mg/g。溶液中Cl-和NO3-阴离子的存在对吸附行为存在抑制作用,且阴离子浓度越大,抑制作用越显著。各吸附剂的吸附过程符合Langmuir等温吸附方程,Silpr BIm Cl对2,4-二硝基酚的吸附符合拟二级动力学模型。将几种吸附剂分别制成的固相萃取小柱对2,4-二硝基酚进行萃取,利用HCl溶液为洗脱剂,各萃取柱的最高洗脱率均在98%以上。用HCl溶液和蒸馏水淋洗萃取柱进行再生,重复利用十五次,其分离能力没有明显变化。第五章,得出结论,我们所合成的六种咪唑类离子液体键合硅胶材料对水溶液中的2,4-二硝基酚具有良好的分离富集能力。
[Abstract]:Phenolic compounds are common in industrial effluents, such as metal foundry and paper industry. They are toxic, harmful to organisms at low concentrations and have carcinogenic and immunosuppressive effects. Many phenolic compounds are classified as dangerous pollutants. Therefore, the effective removal of phenolic compounds in water is necessary for environmental protection. The method is simple and easy to operate and is an effective method to remove phenolic compounds. In this paper, we synthesized six kinds of imidazole ionic liquids functionalized silica gel and used as adsorbent to remove phenolic compounds from water. In this paper, the adsorption properties of 2 nitro 4-dinitrophenol were systematically studied. In the first chapter, the harm of phenolic pollutants was summarized. The properties and classification of ionic liquids and the advantages of immobilized ionic liquids are reviewed. The applications and achievements of immobilized ionic liquids in some fields are reviewed, including catalytic reactions, surface modification, separation techniques (including solid phase extraction, liquid chromatography, etc.). Gas chromatography, capillary electrophoresis chromatography and gas capture) and electrochemical fields. In chapter 2, a series of imidazole ionic liquids were modified on the surface of mesoporous silica gel by covalent bonding. Six new kinds of ionic liquid bonded silica gel materials have been made, three of which are to bond one kind of ionic liquid to the surface of silica gel, which is called ionic liquid monofunctional silica gel, and the other three are to bond two kinds of ionic liquids to the surface of silica gel respectively. The structure of the six materials was characterized by infrared spectroscopy, thermogravimetric analysis (TGA), N _ 2 adsorption and desorption analysis and elemental analysis. The results showed that the target material was successfully synthesized. In Chapter 3 and Chapter 4th, several phenolic compounds were used as adsorbents to study the adsorption selectivity of six kinds of adsorbents. It was found that the adsorbent had a high adsorption capacity for 2o 4-dinitrophenol, so the adsorbent was selected as the adsorbent. The static and dynamic adsorption methods were used to study the adsorption properties of six adsorbents, and the experimental variables, such as the amount of adsorbent, were optimized by single factor experiment. The optimum conditions of temperature and pH are 25 mg/50 mL ~ (-1) 30 掳C and 4.00.The maximum adsorption capacities of Cl ~-and no _ 3- are 61.3 mg / g / g ~ 67.0 mg / g ~ 64.5 mg / g ~ (83) mg / g ~ (-1) mg/g and 49.2 mg / g 路g ~ (-1), respectively. The maximum adsorption capacity of six kinds of adsorbents, Silpr BIm Clon, Silpr AIm Clnn, Silpr DBIm Clon, Silpr DAIm Cl and Silpr BAIm Cl, are 67.0 mg / g / g ~ (60) mg / g ~ (-1) mg / g ~ (-1) and 49.2 mg / g ~ (-1), respectively. There is inhibition of adsorption behavior, And the greater the concentration of anions, The inhibition effect was more obvious. The adsorption process of each adsorbent was in accordance with the Langmuir isotherm adsorption equation. The adsorption of 2o 4-dinitrophenol by Silpr BIm Cl was fitted to the pseudo-second-order kinetic model. The solid phase extraction column of several kinds of adsorbents was used to extract 2H 4-dinitrophenol, and the adsorption process of the adsorbents was in accordance with the Langmuir isothermal adsorption equation. When HCl solution was used as eluent, the highest elution rate of each extraction column was above 98%. The extraction column was regenerated by elution of HCl solution and distilled water for 15 times, and its separation ability did not change obviously. In chapter 5th, the conclusion was drawn that the extraction column was regenerated with HCl solution and distilled water for 15 times. The six imidazolium ionic liquid bonded silica gel materials have good separation and enrichment ability for 2o 4-dinitrophenol in aqueous solution.
【学位授予单位】：河南师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X703;TQ424.3

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