三维电催化氧化法处理苯胺模拟废水的研究

发布时间：2018-04-22 14:13

本文选题：苯胺 + 三维电催化氧化法　；参考：《华东师范大学》2017年硕士论文

【摘要】：近年来水污染问题日趋严重,其中高浓度含氮有机污染物由于对微生物有很强的毒害性,常规水处理方法难以去除。三维电催化氧化法具有氧化降解能力强、处理效率高、无二次污染等特点,且可提高废水可生化性,非常适用于处理难降解废水。本文以苯胺这种典型含氮污染物为对象围绕三维电催化氧化苯胺开展以下几个方面的研究。(1)粒子电极对苯胺电催化降解效果的影响。活性炭三维电化学体系中最常用的粒子电极,采用浸渍法将.TiO2-SnO2负载于活性炭(GranularActivated Carbon,简称GAC)中得到一种具有催化活性的新型活性炭-载TiO2-Sn02活性炭(Ti02/SnO2-GAC,简称GTSO)。文章选取GAC和GTSO两种活性炭作为三维粒子电极,通过电镜扫描、能谱分析、红外分析、XRD粉末衍射分析以及孔径-比表面积分析等表征手段来对两种活性炭进行性能比较,分析发现在GTSO的表面以及孔道内都分布着晶型氧化钛,而且其比表面积比GAC减小了 390.61 m2·g-1,平均孔径减小了 0.27 nm,总孔容减小了 0.25 cm3·g-1。通过连续运行实验发现,两种活性炭都具有很强的吸附特性,每个批次实验进行了 2 h,实验进行到60批三维电催化氧化装置运行达到稳定。通过研究粒子电极作用效果发现,以GTSO作为粒子电极对苯胺的电化学降解去除率为85%,GAC作为粒子电极的去除率为61%,但是两者均远远高于不含粒子电极的二维电解体系中21%的去除率。由此,本文最终确定用GTSO作为三维粒子电极对苯胺废水进行降解实验,(2)三维电催化降解苯胺实验条件优化。通过单因素法来优化电场强度、电解质、pH、炭水比等影响因素,最终得到一组最优条件进行苯胺电解实验。实验结果表明,在实验条件为电场强度1.2V/cm、电解质Na2SO4为0.03mol/L、pH为7、炭水比为0.5,电解120 min条件下进行电解实验能够取到最佳效果,此时苯胺和COD去除率分别为84.5%和60.3%。(3)苯胺电化学降解途径分析。实验通过对体系中氮元素分析(氨氮、硝态氮、亚硝态氮)、羟基自由基含量的测定,以及通过UV-Vis分光光度法、GC-MS色谱分析等方法对电解出水的成分解析,从而最终确定苯胺的电化学氧化途径。实验结果表明,经过电解之后配水中氨氮含量由原先的0上升到27.70mg/L,硝态氮和亚硝态氮也分别由0上升到2.30 mg/L和0.15 mg/L,而总氮含量却由原先的126.10mg/L下降到50.30mg/L。这说明由于电解的作用确实使苯胺得到了有效降解。通过添加叔丁醇和乙醇等羟基自由基抑制剂来进行对比实验发现:当电解时间进行30min时,空白组苯胺去除率为40%左右,而加了叔丁醇的实验组苯胺去除率仅为20%。另外直接对体系中·OH的测定也发现,当电解120 min后,出水的吸光度为由原水的0上升到0.35。上述结果充分证明,经过电解作用之后,废水中产生了-OH这种强氧化性物质。通过对出水的UV-Vis扫描和GC-MS分析可知,由于电解作用使苯胺降解生成了醌类、酚类以及羧酸类物质,同时检测到有十一烷的产生。由此,本文推导出了苯胺的电化学降解路径,为后续对于苯胺的研究提供了一定的指导意义。
[Abstract]:In recent years, the problem of water pollution is becoming more and more serious, among which the high concentration of nitrogen containing organic pollutants is very toxic to microorganisms, and the conventional water treatment method is difficult to remove. The three dimensional electrocatalytic oxidation method has the characteristics of high oxidation degradation ability, high treatment efficiency, no two pollution and so on, and can improve the biodegradability of wastewater, which is very suitable for the treatment of difficult to drop. In this paper, the study on the three dimensional electrocatalytic oxidation of aniline is carried out in the following aspects. (1) the effect of the particle electrode on the electrocatalytic degradation of aniline. The most commonly used particle electrode in the three dimensional electrochemical system of activated carbon is loaded on the activated carbon (GranularAct) by impregnation method (.TiO2-SnO2) A new type of active carbon loaded TiO2-Sn02 active carbon (Ti02/SnO2-GAC, GTSO) with catalytic activity was obtained in ivated Carbon (GAC). In this paper, two kinds of activated carbons of GAC and GTSO were selected as three dimensional particle electrodes, and the characterization means, such as electron microscope scanning, energy spectrum analysis, infrared analysis, XRD powder diffraction analysis and pore specific surface area analysis, were used. To compare the performance of the two kinds of activated carbon, it is found that the crystalline titanium oxide is distributed in the surface and channel of GTSO, and the specific surface area is reduced by 390.61 m2. G-1. The average pore size decreases by 0.27 nm and the total pore volume decreases by 0.25 cm3. G-1.. The two kinds of activated carbons have strong adsorption properties. The experiment carried out 2 h for each batch, and the experiment carried out the 60 batch of three dimensional electrocatalytic oxidation device to achieve stability. By studying the effect of particle electrode, the removal rate of electrochemical degradation of aniline by GTSO as particle electrode was 85%, and the removal rate of GAC as particle electrode was 61%, but both were far higher than that of non particle electrodes. The removal rate of 21% in the two-dimensional electrolysis system was obtained. Thus, this paper finally determined that GTSO was used as a three-dimensional particle electrode to degrade aniline wastewater. (2) the optimization of the experimental conditions of aniline degradation by three-dimensional electrocatalysis was optimized. The factors such as electric field strength, electrolyte, pH, carbon water ratio and other factors were optimized by single factor method, and a group of optimal conditions were finally obtained for aniline. The experimental results show that the experimental conditions are electric field strength 1.2V/cm, electrolyte Na2SO4 0.03mol/L, pH 7, carbon water ratio 0.5, electrolysis 120 min electrolysis experiment can get the best effect. At this time, the removal rate of aniline and COD is 84.5% and 60.3%. (3) aniline electrochemical degradation pathway analysis. The experiment passed to the system. The analysis of nitrogen elements (ammonia nitrogen, nitrate nitrogen, nitrite state nitrogen), the determination of hydroxyl radical content, and the analysis of the composition of the electrolysis effluent by UV-Vis spectrophotometric method and GC-MS chromatography analysis, and finally determine the electrochemical oxidation pathway of aniline. The experimental results show that the ammonia nitrogen content in water is increased from 0 to 2 after electrolysis. 7.70mg/L, the nitrate nitrogen and nitrite nitrogen also increased from 0 to 2.30 mg/L and 0.15 mg/L respectively, while the total nitrogen content decreased from the original 126.10mg/L to 50.30mg/L., indicating that the effect of electrolysis did effectively degrade aniline. The comparison experiment with the addition of tert butyl alcohol and ethanol and other hydroxyl radical inhibitors was found to be used as an electrolysis. When the time was 30min, the removal rate of aniline was about 40% in the blank group, but the removal rate of aniline was only 20%. in the experimental group with the addition of TERT butanol in addition to the determination of OH in the system. When the electrolysis was 120 min, the absorbance of the effluent from 0 of the raw water to the 0.35. was fully proved. After electrolysis, the wastewater produced -OH By UV-Vis scanning and GC-MS analysis of the effluent, it is known that the degradation of aniline by electrolysis can produce quinones, phenols and carboxylic acids, and the production of eleven alkanes is detected at the same time. Therefore, the electrochemical degradation path of aniline is derived, which provides a certain reference for the follow-up study of aniline. Guide meaning.

【学位授予单位】：华东师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X703

【参考文献】