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石墨烯吸附剂对抗生素的去除作用研究

时间:2019-07-12 23:07来源:毕业论文
四环素在石墨烯水凝胶材料上的吸附过程是一个由快到慢的物理吸附过程,四环素在石墨烯水凝胶上的吸附容量随着吸附剂质量增加而减小,阴阳离子强度因素对四环素吸附性能的影响

摘要:近年来抗生素的滥用导致了一系列的环境问题,人们开始越来越关注环境中的抗生素残留去除问题。吸附法是一种有效的去除环境中抗生素残留的方法,其关键问题在于吸附材料,新型碳纳米材料——石墨烯作为一种新型吸附剂,具有丰富的孔隙结构、高比表面积、良好的热稳定性及结构可控等独特优点,对于液相中的有机污染具有优良的吸附性能,作为一种潜在的可以高效地去除环境中抗生素的吸附材料,引起了国内外学者的广泛关注。本文旨在系统研究石墨烯水凝胶对抗生素的吸附性能(以四环素为代表),并研究各类环境因素对于石墨烯吸附抗生素的影响。37007
    石墨烯水凝胶吸附四环素的动力学实验结果表明其在1~10d为快速吸附过程,20d后达到吸附平衡时间。分别采用拟一级、拟二级和颗粒内扩散模型来进行拟合评价实验结果,发现石墨烯水凝胶吸附四环素的动力学符合拟二级动力学模型,由颗粒内扩散和外部扩散共同控制其吸附速率。37007
    通过对石墨烯水凝胶吸附等温线研究,采用Langmuir 和Freundlich方程进行模型拟合,从数据的相关性系数R2分析结果表明Langmuir模型的拟合效果比Freundlich模型的拟合效果要好(R2:0.980>0.905),通过Langmuir模型所计算出的最大吸附容量qm为858.15mg/g。D-R 方程模型发现吸附平均自由能Ea值0.225kJ/mol(<8kJ/mol),表明石墨烯水凝胶对四环素的吸附是以物理吸附为主的过程。
总之,四环素在石墨烯水凝胶材料上的吸附过程是一个由快到慢的物理吸附过程,四环素在石墨烯水凝胶上的吸附容量随着吸附剂质量增加而减小,阴阳离子强度因素对四环素吸附性能的影响较大,可能归结于其间络合作用。
源¥自%六:维;论-文'网=www.lwfree.cn

毕业论文关键词:抗生素,石墨烯,水凝胶,吸附,离子强度。
Abstract:In recent years, the overuse of antibiotics has led to a series of environmental problems, and it is an increasing concern for antibiotic residues in the environment. Adsorption is an effective method for removing antibiotic residues in the environment. The key problem of adsorption is the adsorbent material. A new carbon nanomaterial - graphene as a novel adsorbent, has many unique advantages, such as the abundant pore structure, high surface area, good thermal stability, structural controllability. Graphene has relatively good adsorption properties for the organic pollutants in aqueous solutions as a potential adsorbent, which can be 
efficiently removed antibiotics in the environment and is causing widespread concern in the domestic and foreign scholars. This article aims to systematically study the adsorption properties of antibiotics onto graphene (such as tetracycline), and study the effects of various environmental factors for antibiotics adsorption onto graphene.
The result of the adsorption kinetics of tetracycline onto graphene hydrogel was shown that the rapid adsorption process was in 1 ~ 10d, and the equilibrium time of tetracycline adsorption was after 20d. For further analysis of the adsorption kinetics of tetracycline on graphene hydrogel, pseudo first order, pseudo-second-and intra-particle diffusion model were used to fit the experimental results of the evaluation. Eventually we discovered that adsorption kinetics of tetracycline onto graphene hydrogel followed pseudo second-order kinetic model. Intra-particle diffusion and external diffusion jointly controlled adsorption rate.
By studying the equilibrium adsorption isotherm of tetracycline onto graphene hydrogel, experimental adsorption data were fitted using Langmuir and Freundlich equation. From comparing the correlation coefficient R2, the fitting results shown that Langmuir model was better fitted with the experiment data than Freundlich model (R2:0.980>0.905). The maximum adsorption capacity qm calculated by Langmuir model was 858.15mg/g. Results of D-R equation shown that adsorption average value free energy Ea is 0.225kJ/mol (<8kJ/mol), and the result indicated that the adsorption of tetracycline onto graphene hydrogel is based physical adsorption process. 石墨烯吸附剂对抗生素的去除作用研究:http://www.lwfree.cn/cailiao/20190712/35662.html
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