EDTA-Fe插层水滑石UV-Fenton降解偶氮胭脂红B的研究

发布时间：2018-05-28 19:30

本文选题：EDTA-Fe插层水滑石 + 偶氮胭脂红B　；参考：《湘潭大学》2016年硕士论文

【摘要】：为了解决目前异相光-Fenton反应体系中反应pH值较低,以及传统单因素实验方法存在的耗时长、成本高且过程复杂的问题,本论文制备了负载有含铁络合物的异相光-Fenton反应催化剂,并运用响应曲面法(RSM)对偶氮胭脂红B的异相光-Fenton降解过程进行了研究,还针对反应体系中可能存在的活性物种进行了检测,推测其反应机理。取得了以下一些研究成果：(1)通过离子交换法成功制备了EDTA-Fe插层水滑石(EDTA-Fe-LDH)异相光-Fenton催化材料。X射线衍射分析(XRD)、傅立叶变换红外光谱(FTIR)等结果表明[FeEDTA]-顺利插入锌铝水滑石(ZnAl-LDH)的层间；经紫外可见漫反射(UV-Vis)图谱分析表明EDTA-Fe-LDH对整个紫外光区域都具有明显的吸收性能；氮吸附-脱附等温线、扫描电镜(SEM)则显示经离子交换法制备的EDTA-Fe-LDH相较于ZnAl-LDH具有更大的比表面积和孔体积。而通过对偶氮胭脂红B的光-Fenton降解实验得出EDTA-Fe-LDH在紫外光辐射下具有较高的催化活性和稳定性。(2)采用Box-Behnken设计(BBD)对异相光-Fenton反应体系的实验条件进行优化,结果显示当pH值为6.54、偶氮胭脂红B的浓度为100 mg/L、过氧化氢的浓度为11.5 mM时具有最佳的反应效果,在此条件下偶氮胭脂红B的实际脱色率和TOC去除率分别为97.27%和90.36%,与BBD设计的预测结果相符。(3)通过实验证实在异相光-Fenton反应体系中有三种活性物质产生：羟基自由基(·OH)、超氧自由基(·O2-)和单线态氧(1O2),并对其产生机理绘制了相应的示意图。此外,还通过UV-Vis扫描图谱及GC-MS等表征手段对偶氮胭脂红B的降解途径进行了分析,发现偶氮胭脂红B分子首先分解为如1-亚硝基-2,4-二甲氨基苯等的具有苯环结构的中间产物,接着随着反应的不断进行,这些中间产物的苯环结构被打开,生成了丁酸等小分子物质,最后彻底矿化为C02和H20。
[Abstract]:In order to solve the problems of low pH value in the heterogeneous photo-Fenton reaction system and the problems of long time consuming, high cost and complicated process in the traditional single-factor experimental method, a heterogeneous light-Fenton reaction catalyst loaded with iron complex was prepared in this paper. The heterogeneous photo-Fenton degradation process of azo carmine B was studied by using response surface method (RSM). The possible active species in the reaction system were detected and the reaction mechanism was speculated. The following research results have been obtained: (1) EDTA-Fe intercalated hydrotalcite EDTA-Fe-LDH has been successfully prepared by ion exchange method. The results of X-ray diffraction analysis and Fourier transform infrared spectroscopy (FTIR) show that [FeEDTA]-successfully inserted into the interlayer of zinc aluminum hydrotalcite ZnAl-LDH; The UV-Vis-UV spectra showed that EDTA-Fe-LDH had obvious absorptivity to the whole ultraviolet region, and nitrogen adsorption-desorption isotherm, the absorption isotherm of nitrogen adsorption and desorption isotherm, Scanning electron microscopy (SEM) showed that EDTA-Fe-LDH prepared by ion exchange method had larger specific surface area and pore volume than ZnAl-LDH. However, the photo-Fenton degradation experiment of azocarmine B showed that EDTA-Fe-LDH had high catalytic activity and stability under ultraviolet radiation. The Box-Behnken design was used to optimize the experimental conditions of heterogeneous light-Fenton reaction system. The results showed that when pH was 6.54, the concentration of azo carmine B was 100 mg / L, and the concentration of hydrogen peroxide was 11.5 mm, the optimum reaction effect was obtained. Under these conditions, the actual decolorization rate and TOC removal rate of azo carmine B were 97.27% and 90.36%, respectively, which were consistent with the predicted results of BBD design. Base (OHH), superoxide free radical (O _ 2-O _ 2) and singlet oxygen ~ (1) O _ (2) O _ (2), and the corresponding schematic diagram of its production mechanism is given. In addition, the degradation pathway of azocarmine B was analyzed by means of UV-Vis scanning spectrum and GC-MS characterization. It was found that azo carmine B molecules were first decomposed into intermediate products with benzene ring structure, such as 1-nitroso -2o 4- dimethylaminobenzene, etc. As the reaction proceeded, the benzene ring structure of these intermediates was opened to form small molecules, such as butyric acid, which were mineralized to CO2 and H20.
【学位授予单位】：湘潭大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：X788

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