【作者】 张旭；

【导师】 许波连； 袭锴；

【作者基本信息】 南京大学 ， 化学工程（专业学位）， 2021， 硕士

【摘要】 随着当社会的进步与繁荣稳定、经济化的快速发展,水污染问题成为焦点。水体中存在大量有机物,造成的水体污染也日趋严重。将污染物吸附的处理技术应用到含有机物的生活污水与工艺废水的处理领域中,这具有很好的应用前景,其中,重要的是开发具有良好吸附性能和可循环重复利用的材料是实现水体中有机物去除的关键。1、考虑到Hummers法的效率高,安全性好,产品品质好等优点,本实验采用改进的Hummers化学氧化还原法进行氧化石墨烯的制备。成功制备了品质较好的氧化石墨烯与石墨烯材料,产量充足,用于表征及吸附测试。五种石墨烯基材料对两种染料的吸附实验表明,纯氧化石墨烯对亚甲基蓝染料存在吸附选择性,对其的吸附性能表现最好。结合扫描电镜图片我们分析主要是由于氧化石墨烯材料材料的比表面积较大,同时自身具有较多且规整的孔洞;自身带有丰富含氧官能团,与带有多个苯环的亚甲基蓝染料分子之间通过多种作用力结合。除此之外,我们发现溶液p H值的变化对石墨烯基材料的染料吸附效果也有比较重要的影响。酸性环境和碱性环境下,染料分子与石墨烯基材料表面活性含氧基团之间的静电作用力强弱程度不同,导致石墨烯基材料对带正、负电荷染料的吸附性能存在差异。2、应用实验室合成的结晶性较好的UIO-66,以简单易操作的的水热自组装法制备出了UIO-66/石墨烯复合水凝胶材料。通过扫描电镜图片,红外光谱图及TGA谱图,我们可以得知成功制备了含有大量水分的UIO-66/石墨烯水凝胶。首先对比了纯石墨烯水凝胶与UIO-66/石墨烯复合水凝胶材料对亚甲基蓝染液的吸附性能。除此之外,我们探索了UIO-66/石墨烯复合水凝胶用量、亚甲基蓝p H值、吸附反应的外界温度、吸附反应进行的时间、光照强度等吸附过程中的几种不同的外界环境影响因素对吸附效果的影响。实验结果表明UIO-66的加入提升了石墨烯水凝胶对亚甲基蓝的吸附效果。随着石墨烯复合水凝胶加入量的提升,染料的去除率也在提升,效率降低,合适的添加量为40-50mg;碱性条件下亚甲基蓝去除率更高,适宜用于碱性水体中的亚甲基蓝去除;亚甲基蓝吸附是一个吸热过程,UIO-66/石墨烯复合水凝胶对亚甲基蓝的吸附处理适宜在温度较高的夏天进行;吸附反应开始后,吸附容量增速很快,吸附速率快,UIO-66/石墨烯复合水凝胶对亚甲基蓝的吸附处理可以在较快的时间内结束,对整体的吸附效果影响不大。UIO-66/石墨烯复合水凝胶在有光照条件下对亚甲基蓝的去除效率高于无可见光的环境,初步表明复合材料具有一定的光催化降解效果。吸附过程结束以后,UIO-66石墨烯水凝胶材料能够以较完整地姿态在水中,并较容易被过滤脱离溶液体系,避免了纯UIO-66因体积微小且易分散的特点,直接应用于水处理难以回收,从而对环境造成二次污染。更多还原

【Abstract】 With the progress,prosperity and stability of the current society,and rapid economic development,the problem of water pollution has become the focus.There are a large amount of organic matter in the water body,and the pollution of the water body is becoming more and more serious.The application of the treatment technology of pollutant adsorption to the treatment of domestic sewage and process wastewater containing organic matter has a good application prospect.Among them,it is important to develop materials with good adsorption performance and recyclable and reusable materials to realize water bodies,which is the key to organic matter removal.1.Considering the high efficiency,safety,and product quality of the Hummers method,this experiment uses an improved Hummers chemical oxidation-reduction method to prepare graphene oxide.Successfully prepared good quality graphene oxide and graphene materials with sufficient yield for characterization and adsorption testing.The adsorption experiments of five graphene-based materials on two dyes show that pure graphene oxide has adsorption selectivity for methylene blue dye,and its adsorption performance is the best.Our analysis is mainly due to the large specific surface area of the graphene oxide material,and at the same time,it has more and regular pores;it has rich oxygen-containing functional groups,and it passes a variety of methylene blue dye molecules with multiple benzene rings.Combination of forces.In addition,we found that the change of p H value of the solution also has a more important influence on the dye adsorption effect of graphene-based materials.In an acidic environment and an alkaline environment,the electrostatic force between the dye molecules and the active oxygen-containing groups on the surface of the graphene-based material is different,resulting in a difference in the adsorption performance of the graphene-based material on the positively and negatively charged dyes.2.UIO-66 with good crystallinity synthesized in the laboratory was used to prepare UIO-66/graphene composite hydrogel material by a simple and easy-to-operate hydrothermal self-assembly method.Through scanning electron microscopy pictures,infrared spectroscopy and TGA spectra,we can know that UIO-66/graphene hydrogel containing a large amount of water has been successfully prepared.Firstly,the adsorption performance of pure graphene hydrogel and UIO-66/graphene composite hydrogel materials for the methylene blue dye solution was compared.In addition,we explored several different external environmental influences in the adsorption process,such as the amount of UIO-66/graphene composite hydrogel,the p H value of methylene blue,the external temperature of the adsorption reaction,the time of the adsorption reaction,and the light intensity.The influence of factors on the adsorption effect.The experimental results show that the addition of UIO-66 improves the adsorption effect of graphene hydrogel on methylene blue.With the increase in the amount of graphene composite hydrogel added,the removal rate of dye is also improved,and the efficiency is reduced.The appropriate amount of addition is40-50mg;the removal rate of methylene blue is higher under alkaline conditions,and it is suitable for alkaline water The removal of methylene blue;methylene blue adsorption is an endothermic process.The adsorption treatment of methylene blue by UIO-66/graphene composite hydrogel is suitable for summer when the temperature is higher than other day;after the adsorption reaction starts,the adsorption capacity increases rapidly,and the adsorption rate Fast,the adsorption treatment of methylene blue by UIO-66/graphene composite hydrogel can be completed in a relatively fast time,and it has little effect on the overall adsorption effect.The UIO-66/graphene composite hydrogel has a higher removal efficiency of methylene blue under light conditions than in an environment without visible light,which preliminarily shows that the composite material has a certain photocatalytic degradation effect.After the adsorption process is over,the UIO-66 graphene hydrogel material can be in the water in a more complete posture,and is easier to be filtered out of the solution system,avoiding the small size and easy dispersion of pure UIO-66,which can be directly applied Water treatment is difficult to recycle,causing secondary pollution to the environment.更多还原