煤质腐植酸的制备及其结构研究

发布时间：2018-04-26 12:50

本文选题：腐植酸 + 氧化法　；参考：《安徽工业大学》2017年硕士论文

【摘要】：腐植酸是一种具有胶体性质和多维空间结构的高分子有机物,主要具有以下性质:1)酸性;2)络合性;3)离子交换性4)吸附性;5)生理活性,因此腐植酸被广泛应用在农业、工业、医疗等领域。通常采用碱溶酸析法从褐煤中提取腐植酸。为了提高腐植酸的产率,本文使用双氧水作氧化剂,通过磁力加热搅拌、超声波降解、CuO催化等工艺技术来提高腐植酸产率,并利用傅里叶红外光谱分析(FT-IR)、X射线光电子能谱分析(XPS)、Ba(OH)2和(CH3COO)2Ca阳离子交换法等手段分析表征腐植酸结构,得到以下主要结论:(1)碱溶酸析法提取的原生腐植酸产率为43.7%;H_2O_2直接氧化的产率为55.4%;H_2O_2-超声得到的产率为52.3%;H_2O_2-CuO得到的最优产率为57.5%。由于H_2O_2-超声氧化性较强,易使腐植酸氧化为CO_x、NO_x和水。因此采用H_2O_2-CuO氧化方案制备腐植酸最好;(2)制备提取的原生黄、棕、黑腐植酸的FT-IR表明其含有的相同C-H、O-C=O、C-C、O-C含碳官能团结构;通过XPS对三种腐植酸中C、N、S、P等官能团进行表征,表明黑腐植酸无C=O结构,棕、黄腐植酸有C=O和C-H、O-C=O、C-O、C-C结构,且各个官能团相对含量也各不相同;黄腐酸中没有发现吡咯(N-5)和吡啶(N-6)官能团结构,黑腐酸中无氮的Sp3杂化结构;黄腐酸中没有检测到含硫结构,棕、黑腐植酸不存在硫醇(吩)型;三种腐植酸都没有检测到含磷结构。(3)通过比较三种氧化方法前后的羧基、酚羟基的含量,发现超声氧化处理后的腐植酸的羧基含量增加,酚羟基含量减少。黄腐酸中羧基含量由5.22增加到6.67;棕腐酸5.19增到7.46;黑腐植酸由3.49变为4.63 mmol/g。
[Abstract]:Humic acid is a kind of macromolecular organic compounds with colloidal properties and multi-dimensional space structure, mainly having the following properties: 1) acid 2) complexing property 4) ion exchangeability (5) physiological activity. Therefore, humic acid is widely used in agriculture and industry. Medical and other fields Humic acid is usually extracted from lignite by alkali-soluble acid analysis. In order to improve the yield of humic acid, hydrogen peroxide was used as oxidant to improve the yield of humic acid by magnetic heating and stirring and ultrasonic degradation of CuO. The structure of humic acid was characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The main conclusions are as follows: (1) the yield of primary humic acid extracted by alkali-soluble acid analysis method is 43.7%. The yield of direct oxidation of H _ 2O _ 2 is 55.4%. The optimum yield of H _ 2O _ 2-CuO is 57.5%. Because of the strong oxidation of H2O2- ultrasonic, humic acid can be oxidized into COxCOXNOX and water easily. Therefore, the FT-IR of the extracted primary yellow, brown and black humic acids, which were prepared by H_2O_2-CuO oxidation method, showed the same structure of C-HHO-Con C-CnOC-C functional groups, and characterized the functional groups such as C _ (N) N _ (N) Schion _ (P) in three kinds of humic acids by XPS, and the results were as follows: (1) in the three humic acids, the original yellow, brown and black humic acids were prepared by FT-IR. The results showed that black humic acid had no CnO structure, brown and yellow humic acid had Cno and C-HHO-CnOOOOC-C structures, and the relative contents of each functional group were different, pyrrolidine N-5) and pyridine-N-6) functional groups were not found in fulvic acid, and the nitrogen-free Sp3 hybrid structure was found in black humic acid. No sulfur-containing structure was detected in fulvic acid, and no thiol type was found in brown and black humic acid, and no phosphorus-containing structure was detected in any of the three kinds of humic acids. The contents of carboxyl and phenolic hydroxyl groups before and after the three oxidation methods were compared. It was found that the carboxyl content of humic acid increased and the phenolic hydroxyl content decreased after ultrasonic oxidation. Carboxyl content in fulvic acid increased from 5.22 to 6.67, brown rot acid increased from 5.19 to 7.46, and black humic acid changed from 3.49 to 4.63 mmol / g.
【学位授予单位】：安徽工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O636.9

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