聚酯纳米纤维负载铁酞菁催化降解抗生素的研究

发布时间：2019-03-02 10:16

【摘要】：随着社会的不断发展,水资源的污染问题也越来越受到人们的关注。其中工业中的废水是水污染的最大污染源,大部分的工业废水中都含有大量的有毒污染物,如氯代芳香族化合物、抗生素、共扼染料等。这些有机化合物若不经处理而排出将会对水体生物和人体产生非常严重的危害。对于传统的高级氧化技术而言,催化体系常常具有H_2O_2利用率低、对难降解的有机污染物催化活性差、催化剂难以重复使用等问题。因此,设计高效绿色的催化体系去除水中有机污染物具有非常重要的意义。金属酞菁(MPc)是一种与细胞色素P-450的活性中心金属卟啉类似的大环共轭大分子,具有类似生物酶的催化活性,催化过程主要是通过中心金属原子与底物进行配位而实现的。且通过负载在不同的载体上,实现不同的催化活性。聚酯纤维(PET)具有强度高,耐摩擦,尺寸稳定性好,且具有良好的耐弱酸及弱碱等化学性能。因此可以选取聚酯纤维作为金属酞菁的载体,制备负载型金属酞菁,研究催化体系的催化性能并探究其催化机理。本文通过静电纺丝将配体聚4-乙烯基吡啶(P4VP)与载体聚酯纤维进行混合纺丝,改变配体与载体的质量比,制备配体与载体质量比两种不同(分别为1:1及1:5)的纳米纤维,再通过回流的方式将金属铁酞菁(FePc)负载在纳米纤维上。通过场发射扫描电子显微镜(FE-SEM)对所制得的催化剂FePc-P4VP/PET的形貌进行表征以及通过紫外可见漫反射(Uv-vis)、傅里叶红外(ATR-FTIR)和X射线光电子能谱(XPS)等表征方法证明FePc是通过轴向配位的方式负载在载体上。对于利用质量比为1:1的载体与配体比制得的FePc-P4VP/PET采用磺胺喹恶啉(SQX)为目标底物,H_2O_2为氧化剂,发现催化剂对底物有很强的降解能力,还研究了温度、H_2O_2浓度以及pH等影响因素对催化性能的影响。并通过加入羟基自由基捕获剂IPA、EPR测试以及对氧化DMSO的底物进行GC-MS分析得出在此催化体系中,高价铁活性种占据主导地位。对于利用质量比为1:5的配体与载体比制得的FePc-P4VP/PET,采用磺胺甲恶唑(SMX)为目标底物,PMS为氧化剂,通过紫外光照,检测催化剂的活性。实验表明:催化剂在光照的情况下可以有效的活化PMS对底物磺胺甲恶唑进行降解,并研究了PMS浓度以及pH对催化体系的影响。通过加入IPA以及EPR测试检测出此催化系统中有大量的羟基自由基生成。表明该体系是由羟基自由基作为主导的降解过程。
[Abstract]:With the development of society, people pay more and more attention to the pollution of water resources. The industrial wastewater is the biggest pollution source of water pollution, most of the industrial wastewater contains a large number of toxic pollutants, such as chloro-aromatic compounds, antibiotics, conjugate dyes and so on. If these organic compounds are discharged without treatment, they will cause serious harm to aquatic organisms and human beings. As far as the traditional advanced oxidation technology is concerned, the catalytic system often has the problems of low utilization of H_2O_2, poor catalytic activity for refractory organic pollutants, and difficult reuse of catalysts. Therefore, it is very important to design an efficient and green catalytic system for the removal of organic pollutants in water. Metalphthalocyanine (MPc) is a macrocyclic conjugated macromolecule similar to the active center metalloporphyrin of cytochrome Px450 and has the catalytic activity similar to that of biological enzymes. The catalytic process is mainly achieved by the coordination of the central metal atoms with the substrate. And by loading on different carriers to achieve different catalytic activity. Polyester fiber (PET) has high strength, friction resistance, good dimensional stability, and good resistance to weak acid and weak alkali and other chemical properties. Therefore, polyester fiber can be selected as the carrier of metal phthalocyanine to prepare supported metal phthalocyanine. The catalytic performance of the catalytic system and its catalytic mechanism can be studied. In this paper, the ligand poly (4-vinylpyridine) (P4VP) was mixed with the carrier polyester fiber by electrospinning, and the mass ratio of the ligand to the carrier was changed. Two kinds of nano-fibers with different mass ratio (1:1 and 1:5) of ligand to carrier were prepared and then metal iron phthalocyanine (FePc) was loaded on the nanofibers by reflux method. The morphology of the catalyst FePc-P4VP/PET was characterized by field emission scanning electron microscopy (FE-SEM) and the UV-visible diffuse reflection (Uv-vis) was used to characterize the morphology of the catalyst. Fourier transform infrared (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS) methods show that FePc is supported on the carrier by axial coordination. For the FePc-P4VP/PET prepared from the carrier to ligand ratio of 1:1, sulfaquinoxaline (SQX) was used as the target substrate and H_2O_2 as the oxidant. It was found that the catalyst had a strong ability to degrade the substrate, and the temperature was also studied. The influence of H_2O_2 concentration and pH on the catalytic performance. The addition of hydroxyl radical trapping agent IPA,EPR and GC-MS analysis of the substrate of oxidized DMSO showed that the active species of high-valent iron were dominant in the catalytic system. Sulfamethoxazole (SMX) was used as the target substrate and PMS was used as the oxidant to determine the activity of the catalyst in the FePc-P4VP/PET, prepared by the ratio of the ligand to the carrier at a mass ratio of 1:5. The activity of the catalyst was determined by UV irradiation. The results showed that the catalyst could effectively activate PMS to degrade sulfamethoxazole under light condition, and the effects of PMS concentration and pH on the catalytic system were also studied. The formation of hydroxyl radical in the catalytic system was detected by adding IPA and EPR. The results show that the degradation process is dominated by hydroxyl radical.
【学位授予单位】：浙江理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X703

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