钛基修饰二氧化铅电极联合电芬顿降解有机物研究

发布时间：2018-05-02 06:43

本文选题：二氧化铅 + 电芬顿　；参考：《苏州科技学院》2015年硕士论文

【摘要】：为了处理难生物降解有机污染物,制备了形稳性阳极(DSA)与介孔碳/PTFE气体扩散阴极。探索了阴阳极协同作用处理有机污染物的可行性,研究结果如下:(1)制备了聚乙二醇(PEG)改性Ti/Sb-SnO2/PEG-PbO2电极,分别用线性伏安扫描(LSV)、扫描电镜(SEM)、X射线衍射(XRD)、计时电流、电极加速寿命等方法对电极性能进行了表征,并以邻甲酚为目标污染物,考察了PEG改性PbO2电极的电催化氧化性能。研究结果表明,掺杂PEG后,电极的电催化活性以及稳定性均得到提高,PEG最佳掺杂量为9g/L。在此条件下制备的PbO2电极,其析氧电位为2.48V,强化电极寿命为114h,是未修饰电极的3.35倍。利用该电极降解邻甲酚模拟废水,邻甲酚去除率随着其初始浓度增加而下降,当初始邻甲酚浓度为100mg/L、溶液初始pH=10、电流密度为10 mA/cm2时,1.5h邻甲酚去除率为100%。邻甲酚的降解反应是·OH参与的间接氧化反应,且遵循一级动力学规律。(2)利用介孔碳CMK-3与聚四氟乙烯(PTFE)制备了CMK-3/PTFE气体扩散电极。作为反应体系的阴极,利用电芬顿反应电催化降解邻甲基苯酚,溶液中的溶解O2在阴极表面发生还原反应生成H2O2,同时探究了不同实验因素对电极电催化活性的影响。实验结果表明,当CMK-3与PTFE的质量比为1:1时,对应的电极催化活性最高。当控制Na2SO4支持电解质浓度为0.1mol/L、初始pH=3、初始电流密度为9mA/cm2、外界曝气量为1.5L/min时,通电150min后,溶液中H2O2的含量达到122mg/L。(3)以自制Ti/Sb-SnO2/PEG-PbO2作为阳极,CMK-3/PTFE气体扩散电极作为阴极,组建了阴阳极协同催化体系来降解有机污染物,考察了不同的实验条件对于邻甲基苯酚的去除效果。实验结果表明,电流密度、邻甲基苯酚初始浓度、初始pH、支持电解质浓度均对最终降解效果有一定影响。当初始电流密度为9mA/cm2,在中性条件下,支持电解质Na2SO4浓度为0.1mol/L,反应120min后,邻甲基苯酚去除率可以达到100%。
[Abstract]:In order to deal with difficult biodegradable organic pollutants, stable anode DSAs and mesoporous carbon / PTFE gas diffusion cathodes were prepared. The feasibility of the synergistic action of cathode and anode in the treatment of organic pollutants was explored. The results are as follows: (1) Polyethylene glycol (PEG) modified Ti/Sb-SnO2/PEG-PbO2 electrode was prepared. The modified electrode was characterized by linear voltammetry, X-ray diffraction and chronoelectric current, respectively. The electrocatalytic oxidation of PEG modified PbO2 electrode was investigated with o-cresol as the target pollutant. The results show that the electrocatalytic activity and stability of the electrode can be improved by doping PEG with the optimum doping amount of 9g / L. Under these conditions, the oxygen evolution potential of the PbO2 electrode is 2.48 V, and the life of the enhanced electrode is 114 h, 3.35 times of that of the unmodified electrode. The removal rate of o-cresol decreased with the increase of the initial concentration of o-cresol. When the initial concentration of o-cresol was 100mg / L, the initial pH value of solution was 10 mg / L, and the current density was 10 mA/cm2, the removal rate of o-cresol was 100g 路L ~ (-1). The degradation of o-cresol is an indirect oxidation reaction in which OH is involved, and follows the first-order kinetics. The CMK-3/PTFE gas diffusion electrode was prepared by using mesoporous carbon CMK-3 and PTFE. As the cathode of the reaction system, the electrocatalytic degradation of o-methylphenol was carried out by electrocatalytic Fenton reaction. The dissolved O2 in the solution reduced to H _ 2O _ 2 on the cathode surface to form H _ 2O _ 2. At the same time, the effects of different experimental factors on the electrocatalytic activity of the electrode were investigated. The experimental results show that the corresponding electrode has the highest catalytic activity when the mass ratio of CMK-3 to PTFE is 1:1. When the supporting electrolyte concentration of Na2SO4 is 0.1 mol / L, the initial pH is 3, the initial current density is 9 Ma / cm ~ 2, and the external aeration is 1.5L/min, the content of H2O2 in the solution reaches 122 mg / L 路L ~ (-3) after the 150min is electrified. The self-made Ti/Sb-SnO2/PEG-PbO2 is used as the cathode of the anode CMK-3 / PTFE gas diffusion electrode. The co-catalytic system of cathode and cathode was set up to degrade organic pollutants, and the removal efficiency of o-methylphenol was investigated under different experimental conditions. The results showed that the current density, initial concentration of o-methylphenol, initial pH and the concentration of supporting electrolyte had certain influence on the final degradation effect. When the initial current density is 9 Ma / cm ~ 2 and the concentration of supporting electrolyte Na2SO4 is 0.1 mol / L under neutral conditions, the removal rate of o-methylphenol can reach 100% after the reaction of 120min.
【学位授予单位】：苏州科技学院
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：O646.54;X703

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