亚氧化钛阴极用于微生物电解去除酸性红B的效能研究

发布时间：2018-01-18 15:49

本文关键词：亚氧化钛阴极用于微生物电解去除酸性红B的效能研究　出处：《哈尔滨工业大学》2015年硕士论文　论文类型：学位论文

【摘要】：偶氮染料作为品种或数量上最大的一类合成染料,被广泛应用于纺织、印染、塑料、皮革和食品等行业,但偶氮染料废水色度大、COD高、毒性强、有机成分复杂,处理不当会对公众健康和自然水体环境带来严重危害。目前针对偶氮染料废水的传统处理工艺基本分为物理法、化学法、生物法及多种工艺的耦合,但众多的处理手段也有其固有的弊端,即高效率和低成本难以兼顾的问题。本研究以典型的偶氮染料酸性红B为目标污染物,基于微生物电解的原理,采用双室微生物电解反应装置(MEC),研究其阴极对于酸性红B的还原去除效果,以实现经济、高效处理酸性红B废水的目的。在实验上设置了碳布、亚氧化钛阴极MEC,研究不同阴极材料强化酸性红B还原脱色的效果。实验完成了碳布、亚氧化钛阴极MEC反应器的启动及对酸性红B的还原去除效能的对比分析。利用单室MFC成功驯化生物阳极后将其转移至MEC体系中,启动过程中阳极微生物适应状况良好,阳极电位基本稳定于-450m V,阴极电位基本于-950m V。在对酸性红B还原脱色的考察中,两种阴极MEC体系均符合一级反应动力学特征,其中亚氧化钛阴极的反应速率常数为0.339h-1,碳布为0.179 h-1,亚氧化钛阴极仅需7h就可以达到91.95%脱色率,而碳布阴极则需要至少12h才能达到类似的处理效果,说明亚氧化钛阴极能够明显加快反应的动力学过程。此外对亚氧化钛阴极MEC还原酸性红B的产物和降解路径进行了分析,结果证明酸性红B分子中的偶氮键接受阴极的电子和质子而发生断裂,从而生成了产物1-萘胺-4-磺酸基和2-氨基-1-萘酚-4-磺酸基。实验对碳布、亚氧化钛阴极MEC进行了循环伏安和电化学交流阻抗测试,结果表明酸性红B可以在碳布、亚氧化钛阴极上发生还原反应,亚氧化钛的电荷转移内阻和扩散内阻分别为10Ω、12Ω,远小于碳布的588Ω、3411Ω,说明亚氧化钛相较于碳布更有利于电子的转移和物质的扩散,这归功于以大孔和介孔分配为主的三维多孔结构,该结构有利于物质在其表面的传输迁移,并可为酸性红B的还原提供较多的活性位点,有利于实现反应的快速进行。课题还探究了亚氧化钛阴极MEC关键运行参数对酸性红B还原及系统性能的影响。结果表明酸性红B在外加电压为0.5V、阴极p H为7.0,浓度在400mg/L以下时,均能保证较短的处理时间、较高的库伦效率和较低的反应能耗,实现了经济、高效处理酸性红B废水的目的。最后对亚氧化钛阴极的电化学稳定性进行了分析研究。结果表明在酸性或含有氯离子的腐蚀性溶液中,亚氧化钛电极的腐蚀电流密度随着电解液溶度的增大增加得极为缓慢,说明了亚氧化钛材料较强的抗腐蚀能力,适合于在电化学体系中的长期运行。
[Abstract]:Azo dyes are widely used in textile, printing, dyeing, plastics, leather and food industries as the largest synthetic dyes of variety or quantity. However, azo dye wastewater has high chromaticity and high toxicity. The organic composition is complex, the improper treatment will bring serious harm to the public health and the natural water body environment. At present, the traditional treatment process for azo dye wastewater is basically divided into physical method and chemical method. The coupling of biological process and various processes, but many treatment methods also have their inherent disadvantages, that is, high efficiency and low cost difficult to take into account. This study takes the typical azo dye acid red B as the target pollutant. Based on the principle of microbial electrolysis, the reduction and removal effect of the cathode for acid red B was studied by using a two-chamber microbial electrolysis reaction device, in order to realize economy. The purpose of high efficiency treatment of acid red B wastewater. Carbon cloth and titanium oxide cathode MECs were set up in the experiment to study the effect of different cathode materials to enhance the reduction and decolorization of acid red B. The start-up of the titanium oxide cathode MEC reactor and the comparative analysis of the reduction and removal efficiency of acid red B. the biological anode was successfully acclimated by single chamber MFC and transferred to the MEC system. The anodic potential was stable at -450 MV and the cathodic potential was about -950 MV during the start-up. In the investigation of acid red B reduction decolorization. The reaction rate constants of titanium oxide cathode and carbon cloth were 0.339h-1 and 0.179h-1, respectively. The decolorization rate of titanium oxide cathode can reach 91.95% in only 7 hours, while that of carbon cloth cathode is at least 12 hours. The kinetic process of the reaction was obviously accelerated by titanium oxide cathode, and the product and degradation path of acid red B reduction by MEC were analyzed. The results show that the azo bond in the acid red B molecule is broken by electrons and protons of the cathode. The products of 1-naphthylamine-4-sulfonic group and 2-amino-1-naphthol -4-sulfonic group were obtained. Cyclic voltammetry and electrochemical impedance measurements of carbon cloth and titanium oxide cathode MEC were carried out. The results show that acid red B can be reduced on carbon cloth and titanium oxide cathode. The charge transfer resistance and diffusion resistance of titanium oxide are 10 惟 ~ 12 惟, which is much smaller than that of carbon cloth (588 惟). 3411 惟, which indicates that titanium oxide is more favorable to electron transfer and material diffusion than carbon cloth, which is due to the three-dimensional porous structure, which is dominated by large and mesoporous distribution. This structure is beneficial to the transport and migration of substances on its surface and can provide more active sites for the reduction of acid red B. The effect of the key operation parameters of MEC on the reduction of acid red B and the performance of the system is also investigated. The results show that the applied voltage of acid red B is 0.5 V. When the cathode pH is 7.0 and the concentration is below 400 mg / L, the treatment time is shorter, the Coulomb efficiency is higher and the energy consumption is lower. The purpose of high efficiency treatment of acid red B wastewater. Finally, the electrochemical stability of titanium oxide cathode was studied. The results showed that in acidic or corrosive solution containing chloride ion. The corrosion current density of titanium oxide electrode increases very slowly with the increase of electrolyte solubility, which indicates that titanium oxide material has strong corrosion resistance and is suitable for long-term operation in electrochemical system.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X788

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