【作者】 张鹏；

【导师】 左薇；

【作者基本信息】 哈尔滨工业大学 ， 环境科学与工程， 2021， 硕士

【摘要】 我国染料行业目前发展迅速,废水处理的难度逐渐增加,巨量染料废水的妥善处理成为该行业发展的瓶颈。本课题研究结合了传统吸附法和光催化降解染料废水的处理技术的优缺点,设计了膜吸附和光催化再生的耦合体系,膜吸附体系,利用CCTP复合膜上的功能性基团针对刚果红进行选择性的高效吸附。光催化体系,利用负载CCT材料良好的光催化性能,实现膜表面吸附刚果红的降解去除,光催化膜得以环保再生并继续循环使用。通过两个体系的耦合,实现了有机染料刚果红的高效吸附和降解去除、光催化剂的回收及环保再生,对于染料废水的处理具有重要意义。通过多种表征方法分析复合材料的物理化学性质,并调控合适的组分比例使膜材料达到最佳的吸附性能和光催化再生性能。在复合膜对刚果红吸附效能的研究中发现,CCT复合材料的添加量0.2 g及Cu₂（OH）₂CO₃和g-C₃N₄/TiO₂的比例为1:1时,复合材料具有最佳的吸附性能,在100 min时20 mg CCTP-2复合膜对50m L初始浓度为40 mg/L的刚果红降解率>80%,160 min时降解率>90%。复合膜在pH值为5时对刚果红表现出最佳的吸附效能。对CCTP复合膜吸附特性的研究发现拟二级动力学更加适用于复合膜对于刚果红的吸附行为,Freundlich方程更加贴合吸附等温线拟合结果,吸附过程主要为物理吸附和化学吸附相结合,并且发现复合膜对于阴离子染料具有吸附特异性。通过红外光谱分析官能团变化、XPS分析元素形态和化学键变化,得出复合膜对刚果红的吸附机理主要是静电吸附作用和配位作用的结合。在复合膜的光催化再生效能研究中发现,当复合膜中的Cu₂（OH）₂CO₃和g-C₃N₄/TiO₂的比例为1:1,复合膜同时具备良好的吸附和光催化再生能力。随着CCTP复合膜中CCT材料添加量的增加,复合膜再生后的吸附效果越佳,同时具备更高的光催化效率,最佳的CCT材料添加量为0.2 g。随着循环次数的增加,光催化再生后的复合膜吸附能力在逐渐降低,但循环五次后复合膜的去除率仍可以在4 h内达到45%。复合膜的光催化再生机理是:光生电子和溶解氧反应产生·O₂^-,光生空穴在价带之间发生迁移,方向为从TiO₂至g-C₃N₄,超氧自由基和g-C₃N₄的价带表面的较多光生空穴均可以将刚果红氧化为小分子物质。为了更贴近实际应用,进行了吸附过滤及光催化再生实验,主要探究了复合膜吸附过滤刚果红前后的膜通量和膜阻力等参数变化。研究发现复合膜的吸附过滤性能良好,能够有效截留刚果红,并能够通过光催化再生进行多次循环吸附,再生方法环保,吸附具有选择性和高效性,具有一定的应用前景。基于上述研究,本课题构建的膜吸附耦合光催化再生体系能够实现有机染料刚果红的高效去除,复合膜具有良好的光催化再生性能及循环吸附效能。即同时实现了污染物质去除和材料的高效再生及重复利用,性能优良。更多还原

【Abstract】 The dye industry in our country is currently developing rapidly,and the difficulty of wastewater treatment is gradually increasing.The proper treatment of huge amounts of dye wastewater has become a bottleneck for the development of the industry.This subject research combines the advantages and disadvantages of traditional adsorption method and photocatalytic degradation of dye wastewater treatment technology,and designs a coupling system of membrane adsorption and photocatalytic regeneration.The membrane adsorption system uses the functional groups on the CCTP composite membrane to select Congo red.Highly effective adsorption.The photocatalytic system uses the good photocatalytic performance of the loaded CCT material to achieve the degradation and removal of the Congo red adsorbed on the surface of the film,and the photocatalytic film can be environmentally regenerated and continue to be recycled.Through the coupling of the two systems,the efficient adsorption and degradation removal of the organic dye Congo red,the recovery of the photocatalyst and the environmental protection regeneration are realized,which is of great significance for the treatment of dye wastewater.Analyze the physical and chemical properties of the composite material through a variety of characterization methods,and adjust the appropriate component ratio to achieve the best adsorption performance and photocatalytic regeneration performance of the membrane material.In the study of the adsorption efficiency of the composite membrane on Congo red,it was found that the composite material has the best adsorption performance when the addition amount of CCT composite material is 0.2 g and the ratio of Cu₂（OH）₂CO₃ and g-C₃N₄/TiO₂ is 1:1.At 100 min,the degradation rate of 20 mg CCTP-2 composite membrane to 50 m L of Congo red with an initial concentration of 40mg/L was>80%,and at 160 min,the degradation rate was>90%.The composite membrane showed the best adsorption efficiency for Congo red at pH 5.The study on the adsorption characteristics of CCTP composite membranes found that the pseudo-second-order kinetics is more suitable for the adsorption behavior of composite membranes on Congo red.The Freundlich equation fits the adsorption isotherm better.The adsorption process is mainly a combination of physical adsorption and chemical adsorption.And found that the composite membrane has adsorption specificity for anionic dyes.Through infrared spectroscopy analysis of functional group changes,XPS analysis of element morphology and chemical bond changes,it is concluded that the adsorption mechanism of the composite film on Congo red is mainly a combination of electrostatic adsorption and coordination.In the study of the photocatalytic regeneration efficiency of the composite membrane,it is found that when the ratio of Cu₂（OH）₂CO₃ and g-C₃N₄/TiO₂ in the composite membrane is 1:1,the composite membrane has both good adsorption and photocatalytic regeneration capabilities.As the amount of CCT material added to the CCTP composite membrane increases,the adsorption effect of the composite membrane after regeneration is better,and it has a higher photocatalytic efficiency.The optimal amount of CCT material added is 0.2 g.With the increase of the number of cycles,the adsorption capacity of the composite membrane after photocatalytic regeneration is gradually reduced,but the removal rate of the composite membrane can still reach 45%within 4 h after five cycles.The photocatalytic regeneration mechanism of the composite film is:O₂^-is generated by the reaction of photogenerated electrons and dissolved oxygen,and the photogenerated holes migrate between the valence bands in the direction from TiO₂ to g-C₃N₄,superoxide radicals and g-C₃N₄ valence More photo-generated holes on the surface of the belt can oxidize Congo red into small molecules.In order to be closer to practical applications,adsorption filtration and photocatalytic regeneration experiments were carried out,mainly to explore the changes in parameters such as membrane flux and membrane resistance before and after the composite membrane adsorbed and filtered Congo red.The study found that the composite membrane has good adsorption and filtration performance,can effectively trap Congo red,and can be repeatedly adsorbed through photocatalytic regeneration.The regeneration method is environmentally friendly,and the adsorption is selective and efficient,and has certain application prospects.Based on the above research,the membrane adsorption coupled photocatalytic regeneration system constructed in this topic can achieve the efficient removal of the organic dye Congo red,and the composite membrane has good photocatalytic regeneration performance and cyclic adsorption efficiency.That is,the removal of pollutants and the efficient regeneration and reuse of materials are realized at the same time,and the performance is excellent.更多还原