亲水性分子印迹聚合物用于水中硝基酚类污染物的选择性萃取及去除研究

发布时间：2018-06-12 09:25

本文选题：分子印迹聚合物 + 硝基酚类污染物　；参考：《华中科技大学》2013年硕士论文

【摘要】：分子印迹技术（Molecular Imprinting Technique，MIT），是基于抗原/抗体的基本原理而延伸的分子识别技术。分子印迹聚合物(Molecularly Imprinted Polymers，MIPs)是在模板分子存在的情况下，运用分子印迹技术通过功能单体与交联剂的共聚反应制得，去除模板分子后，分子印迹聚合物上可形成与模板分子在空间结构上相匹配的三维孔穴，可特异性地吸附模板分子及其结构类似物，因此也被称为“人工抗体”。本文采用沉淀聚合的方法，获得了对硝基酚类污染物具有特异性识别作用的亲水性分子印迹聚合物（MIPs），并实现水体中痕量硝基酚污染物的选择性萃取及去除。主要研究内容由以下两部分组成： 1.为了克服传统固相萃取所具有的缺点，本研究采用亲水性MIPs-固相微柱萃取技术对水样（东湖，长江，工业废水）中硝基酚类污染物进行萃取。固相微柱萃取技术不需要传统的萃取装置及蒸发等复杂操作流程，仅通过离心便可完成对样品的上样、淋洗和洗脱，具有操作简单、快速的优点。在最佳萃取条件下，亲水性MIPs-固相微萃取柱对硝基酚类化合物的萃取回收率达到87%-92.9%，且具有良好的净化效果。与常规的萃取吸附剂（活性炭、多壁碳纳米管、LC-C18等）相比，，亲水性MIPs显示出更高的萃取效率和更好的选择性识别性能。本研究建立亲水性MIPs-固相微柱萃取结合HPLC-UV法对实际水样中硝基酚类污染物进行检测，结果显示：该方法的线性范围为2-1000ng/mL（2,4-二硝基酚，2-硝基酚）、6-1000ng/mL（4-硝基酚），相关系数（R2）大于0.998，方法检测限为0.3-0.5ng/mL,日内RSDs值为4.0%-6.7%，日间（5日）RSDs值为5.9%-8.2%。 2.将亲水性MIPs作为吸附剂对地表水及工业废水中2,4-二硝基酚进行选择性去除研究。吸附动力学模型及吸附等温模型结果显示，亲水性MIPs对2,4-二硝基酚的最大吸附容量为138.9mg/g，同时，进一步研究了吸附过程中水样的流速、初始浓度、pH和腐殖酸含量对去除效果的影响。大体积上样时（上样体积高达1L），与活性炭、多壁碳纳米管、LC-C18等常规吸附柱及常规方法制备的MIPs相比，亲水性MIPs（100mg）具有最好的去除效率（92%），并可重复使用5次以上，具有较好的实际应用前景。
[Abstract]:Molecular imprinting technique is an extended molecular recognition technique based on the basic principle of antigen / antibody. Molecularly imprinted polymers (MIPs) were prepared by the copolymerization of functional monomers and crosslinkers in the presence of template molecules, and the template molecules were removed. Molecular imprinted polymers can form three-dimensional pores that match the spatial structure of template molecules, and can specifically adsorb template molecules and their structural analogues, so they are also called "artificial antibodies". In this paper, a hydrophilic molecularly imprinted polymer (MIPsN) with specific recognition effect on nitrophenols was obtained by precipitation polymerization, and the selective extraction and removal of trace nitrophenol pollutants in water were realized. The main research content consists of the following two parts: 1. In order to overcome the shortcomings of traditional solid phase extraction (SPE), the hydrophilic MIPs- solid phase microcolumn extraction (SPME) technique was used to extract nitrophenols from water samples (Donghu, Yangtze River, industrial wastewater). Solid-phase microcolumn extraction technology does not need the traditional extraction equipment and evaporation and other complex operation flow, only by centrifugation can be completed on the sample, elution and elution, has the advantages of simple operation, rapid operation. Under the optimum extraction conditions, the extraction recovery of hydrophilic MIPs- solid phase microextraction column was 87-92. 9%, and it had a good purification effect. Compared with conventional extraction adsorbents (activated carbon, multi-walled carbon nanotubes, LC-C18, etc.), hydrophilic MIPs show higher extraction efficiency and better selective recognition performance. A hydrophilic MIPssolid phase microcolumn extraction (SPME) method combined with HPLC-UV was established for the determination of nitrophenols in real water samples. The results showed that the linear range of the method was 2-1000ng / mL ~ (2) -dinitrophenol ~ (2-nitrophenol) = 6-1000ng / m ~ (-1) N ~ (-1) 路m ~ (-1) N ~ (4-nitrophenol) > 0.998, the detection limit was 0.3-0.5ng 路mL ~ (-1), the value of RSDs within day was 4.0-6.7, and the value of RSDs was 5.9- 8.22. Hydrophilic MIPs were used as adsorbents for selective removal of 2-trichloro-4-dinitrophenol from surface water and industrial wastewater. The results of adsorption kinetics model and adsorption isotherm model show that the maximum adsorption capacity of hydrophilic MIPs for 2o 4-dinitrophenol is 138.9 mg / g. At the same time, the flow rate of water sample during the adsorption process is further studied. Effects of initial concentration pH and humic acid content on removal efficiency. The hydrophilic MIPsn 100mgcompared with conventional adsorption columns such as activated carbon, multi-walled carbon nanotube LC-C18 and MIPs prepared by conventional methods, has the best removal efficiency and can be reused for more than 5 times. It has a good prospect of practical application.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：R123.1

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