脉冲电解法处理刚果红废水的降解及其机理研究

发布时间：2018-12-19 18:28

【摘要】：染料废水具有高色度、强毒性、危害大、难降解等特点,对环境造成了严重的影响,如何能高效快速地降解染料废水,一直是环境保护的热点话题。而脉冲电催化氧化技术因其能耗低、操作简单、无二次污染等优势,在处理难降解有机废水领域引起了广泛关注。本文采用脉冲电催化氧化法处理刚果红染料废水,针对其降解过程的影响因素、降解产物及降解机理等方面做系统的研究。本文通过单因素法研究电解过程中各因素对刚果红脱色效果的影响,实验表明刚果红脱色率随初始浓度和pH值的升高而减小,随电解质浓度、脉冲电压峰值、频率和占空比的升高而增大。综合单因素实验结果,通过响应面分析得出,脉冲电压峰值对脱色率影响最大,NaCl浓度和初始pH值之间交互作用最强。通过验证TOC去除率和脱色率之间关系时得出,随着脉冲电压峰值或刚果红初始浓度变化,刚果红TOC去除率与脱色率的变化趋势始终保持一致,但TOC去除率比脱色率低。通过比较不同电压峰值下处理单位TOC时系统的能耗,得出脉冲电压峰值为15V时,系统能耗性价比最高。本文还通过离子色谱和LC-MS分析降解产物,得出刚果红的降解途径为:刚果红→萘酚→萘醌、酮类→小分子羧酸→CO2和H2O,但只有小部分刚果红被完全降解,故TOC去除率较低。然后通过高效液相色谱法检测到电解过程中有羟基自由基产生,并在羟基自由基和氯离子分别单独作用的情况下,比较脱色效果,得出脉冲电催化氧化过程中,电解机理以氯离子的间接氧化作用为主。
[Abstract]:Dye wastewater has the characteristics of high chromaticity, strong toxicity, great harm, difficult to degrade, and has a serious impact on the environment. How to degrade dye wastewater efficiently and quickly has always been a hot topic in environmental protection. Because of its advantages of low energy consumption, simple operation and no secondary pollution, pulse electrocatalytic oxidation has attracted wide attention in the field of treatment of refractory organic wastewater. In this paper, Congo red dye wastewater was treated by pulse electrocatalytic oxidation. The factors affecting the degradation process, degradation products and degradation mechanism were systematically studied. In this paper, the effect of various factors on decolorization of Congo red was studied by single factor method. The experimental results show that the decolorization rate of Congo red decreases with the increase of initial concentration and pH value, and with the concentration of electrolyte, the peak value of pulse voltage. The increase in frequency and duty cycle increases. Based on the single-factor experimental results, the response surface analysis shows that the peak pulse voltage has the greatest influence on the decolorization rate, and the interaction between the NaCl concentration and the initial pH value is the strongest. By verifying the relationship between TOC removal rate and decolorization rate, it is concluded that with the change of peak pulse voltage or initial concentration of Congo red, the change trend of TOC removal rate and decolorization rate of Congo red remains consistent, but the removal rate of TOC is lower than that of decolorization. By comparing the energy consumption of the system with unit TOC at different peak voltages, it is concluded that when the peak value of pulse voltage is 15 V, the system energy consumption performance ratio is the highest. The degradation pathways of Congo red were obtained by ion chromatography and LC-MS analysis. The degradation pathways of Congo red were as follows: Naphthol naphthoquinone, ketones, carboxylic acid CO2 and H _ 2O, but only a small part of Congo red was completely degraded. Therefore, the removal rate of TOC is low. Then the hydroxyl radical was detected by high performance liquid chromatography, and the decolorization effect was compared under the condition that hydroxyl radical and chlorine ion acted separately, and the pulse electrocatalytic oxidation process was obtained. The main mechanism of electrolysis is the indirect oxidation of chloride ions.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X791

【相似文献】