多孔碳基材料的功能化制备及其吸附去除水中典型污染物的性能研究

发布时间：2018-05-28 21:44

本文选题：多孔碳材料 + 吸附　；参考：《江苏大学》2017年硕士论文

【摘要】：多孔碳材料拥有高的比表面积、丰富的孔隙结构、强的耐腐蚀性等特点,其作为吸附材料被广泛应用于水污染处理领域。然而,多孔碳材料在应用的过程中依然有很多局限性,如制备成本高、吸附容量低和吸附平衡时间长等,无法完全满足实际应用的需求。目前,新型多孔碳材料的开发与改性已成为研究热点。为了应对复杂的水污染问题,本课题结合了多孔碳材料的内在优势和氮掺杂、酸化和热解等改性方法,制备出了具有良好形貌和吸附性能优异的新型多孔碳材料。利用多种表征手段对得到的多孔碳的结构和形貌进行分析,并研究了多孔碳材料对水体中不同类型污染物的吸附性能与机理。具体研究结果如下:(1)以SBA-15为模板材料,制备了一系列具有不同理化性质的氮掺杂介孔碳材料(MCN),并以亚甲基蓝的吸附容量为导向,优化MCN的合成。通过表征分析可得:改变前驱体的比例可以控制MCN的含氮量;其比表面积随煅烧温度增加呈现先变大后变小的趋势,且最大可达667 m2g-1。并通过静态吸附实验研究了吸附体系的条件对吸附过程的影响,以及建立相关的模型进一步探讨吸附机理。(2)以农业废弃物花生壳为原料、氯化锌为化学活化剂,并利用浓硝酸后改性处理,制备了一种新型活性炭材料(OAC)。表征结果显示:该材料的比表面积为1807 m2 g-1。由于具有广谱吸附性能,该活性炭材料对不同类型的污染物(如碱性蓝41、刚果红、苯酚、铬(VI)和铅(II)等)都显示出了大的吸附容量,说明OAC对多种不同的污染物都具有良好的吸附性能。(3)以柚子皮为原料,结合水热碳化与高温热解的方法制备了一种新型的碳气凝胶(PCA)。PCA显示出大的孔隙率、较低的密度和较好的疏水性能。考察了其对多种油与有机溶剂的吸附容量,结果显示,该气凝胶可以吸附它自身质量23~48倍的有机溶剂污染物。并对其再生方式与重复利用性能进行了考察,经过多次循环再生实验后,OAC依然显示出了较高的吸附容量,说明该材料在油污处理领域拥有良好的应用前景。(4)以廉价、可再生的竹子为原料制备了纳米纤维素,再将氧化石墨烯和纳米纤维素混合溶液,采用乙二胺诱导凝胶与高温热解反应制得一种具有低密度、疏水和多孔的还原氧化石墨烯/纳米纤维素混合碳气凝胶(rGO/NFC)。对比传统的碳基吸附材料,rGO/NFC对油与有机溶剂呈现出了高的吸附容量(自身质量的42-102倍)和快的吸附速率。乙醇吸附-燃烧循环再生实验显示该材料具有优异的再生和可重复利用性。
[Abstract]:Porous carbon materials with high specific surface area, rich pore structure, strong corrosion resistance and other characteristics, as adsorption materials are widely used in the field of water pollution treatment. However, there are still many limitations in the application of porous carbon materials, such as high preparation cost, low adsorption capacity and long adsorption equilibrium time, which can not fully meet the needs of practical applications. At present, the development and modification of new porous carbon materials has become a research hotspot. In order to deal with the complex water pollution problem, a new porous carbon material with good morphology and excellent adsorption performance was prepared by combining the internal advantages of porous carbon materials with nitrogen doping, acidizing and pyrolysis methods. The structure and morphology of porous carbon were analyzed by various characterization methods, and the adsorption properties and mechanism of porous carbon materials for different pollutants in water were studied. The specific results are as follows: (1) A series of N-doped mesoporous carbon materials with different physicochemical properties were prepared by using SBA-15 as template material. The synthesis of MCN was optimized based on the adsorption capacity of methylene blue. The results showed that the nitrogen content of MCN could be controlled by changing the ratio of precursor, and the specific surface area of MCN increased firstly and then decreased with the increase of calcination temperature, and the maximum was 667m2g-1. The influence of adsorption conditions on the adsorption process was studied by static adsorption experiments, and the related models were established to further explore the adsorption mechanism of peanut shell as raw material, zinc chloride as chemical activator, agricultural waste peanut shell as raw material, zinc chloride as chemical activator, and agricultural waste peanut shell as raw material and zinc chloride as chemical activator. A new activated carbon material was prepared by the treatment of concentrated nitric acid. The results showed that the specific surface area of the material was 1807 m ~ (2) g ~ (-1). Because of its wide spectrum adsorption properties, the activated carbon material showed large adsorption capacity for different types of pollutants (such as basic blue 41, Congo red, phenol, chromium Vi and lead II). It shows that OAC has good adsorption performance for many different pollutants. (3) A new carbon aerogel PCA-PCA-PCA-PCA-PCA-PCA3 was prepared by hydrothermal carbonization and pyrolysis with grapefruit peel as raw material. Lower density and better hydrophobicity. The adsorption capacity of various oils and organic solvents was investigated. The results showed that the aerogel could adsorb the organic solvent pollutants of 2348 times of its own mass. After repeated recycling experiments, the OAC still showed high adsorption capacity, indicating that the material has a good application prospect in oil pollution treatment field. Nanocellulose was prepared from renewable bamboo, and then the mixture of graphene oxide and nanocellulose was prepared by ethylenediamine induced gel reaction with high temperature pyrolysis to produce a low density. Hydrophobic and porous redox graphene / nanocellulose carbon aerogels rGOP / NFC. Compared with the traditional carbon-based adsorption material rGOR / NFC, the adsorption capacity of oil and organic solvents is high (42-102 times of their own mass) and the adsorption rate is fast. The experimental results of ethanol adsorption and combustion cycle regeneration show that the material has excellent regeneration and reusability.
【学位授予单位】：江苏大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X703;O647.3

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