【作者】 朱峰；

【导师】 陶冠红；

【作者基本信息】 苏州大学 ， 分析化学， 2011， 硕士

【摘要】 微生物燃料电池是指借助微生物的催化作用直接将燃料(如有机酸、糖类等)的化学能转换为电能的装置,它不仅可以直接将水中或者污泥中的有机物降解,而且同时可以将有机物在微生物代谢过程中产生的电子转化成电流,在处理废水的同时输出电能。微生物燃料电池具有能量转化效率高、操作条件温和、无需输入较大能量等优点,是一种可再生清洁能源。本论文构建了一种结构简单,操作方便的新型下流式空气阴极微生物燃料电池,使其达到在处理废水的同时又能产电的双重效果,较之传统的上流式微生物燃料电池,不仅装置简单,操作方便,而且产电更高;另外,本论文还开展了微生物脱氮电池的研究,利用微生物脱盐电池的原理去除废水中的氨氮,达到同时产能并脱氮的目的。论文的主要内容与结果如下:1、构建了一种新型的无膜空气阴极微生物燃料电池,废水直接加入到水平置于微生物燃料电池顶部的阴极板上,空气中的氧气能很好地被直接利用。实验结果表明,营养液的初始DO浓度对产电几乎没有任何影响,初始COD浓度与产电有着很好的饱和型关系;当进液COD为3500mg/L,流速为4.0mL/min的时候,下流式微生物燃料电池能产出37.4mW/m2的最大功率密度,并进一步研究了啤酒废水的产电情况。此种下流式微生物燃料电池无需在阴极区曝气,使得装置简单可靠,操作方便灵敏,且具有相对较高的电能输出,同时使用了价格便宜的平板石墨裸电极作为电极材料,因而易于放大,且有望实际应用。2、构建了一种新型的微生物脱氮电池,在处理废水和产能的同时去除废水中的氨氮。实验结果表明,微生物脱氮电池能够在脱氮的同时产生稳定的电流。在微生物脱氮电池的启动阶段,脱氮时间随着电压的升高而减小,当电压升高到450mV左右,脱氮时间缩减到46h,氨氮去除率达到95.15%,但是随着电压进一步的上升到550mV,脱氮时间并没有进一步的缩短,氨氮去除率略有上升,达到97.09%,电荷转移效率基本维持在100±5%左右的较高水平,剩余氨氮浓度约为5mg/L;阴极面积的增大能够缩短脱氮的时间,然而阴极液的pH值并没有对微生物脱氮电池的脱氮时间产生影响,因而表明本实验使用的装置对阴极液的pH值具有一定的抗冲击负荷能力。更多还原

【Abstract】 A microbial fuel cell (MFC) is a device that uses microorganisms to convert chemical energy (such as organic acids, sugars, etc.) from biodegradable substrates to electrical energy via microbial-catalyzed redox reactions. As a renewable clean energy, it has many advantages, such as high energy conversion efficiency, mild operating conditions, and more energy output and etc. Because it can not only degrade organic matters in wastewater or sludge but also transform the electrons generated from the degradation of organic compounds by microbial metabolism into electronic current, MFC can be used for the development of new energy sources while mitigating the increasingly serious environmental pollution.In this dissertation, a new type of down-flow air-cathode MFC was constructed to treat the wastewater while producing electricity. Compared to the conventional up-flow MFC, the developed system is not only of simple configuration and easy operation but also produce higher power. In addition, a study was also conducted on microbial denitrification cell for the treatment of ammonia containing wastewater. Electrical power was produced during the removal of NH4+-N from wastewater.The main contents and results obtained are as follows:In the first section, a novel membrane-less MFC with down-flow feeding was constructed to generate electricity. Wastewater was fed directly onto the cathode which was horizontally installed in the upper part of the MFC. Oxygen could be utilized readily from the air and thus air aeration was not required. The concentration of dissolved oxygen in the influent wastewater had little effect on the power generation. A saturation-type relationship was observed between the initial COD and the power generation. The influent flow rate could affect greatly the power density. Fed by the wastewater with a COD value of 3500 mg/L at a flow rate of 4.0 mL/min, the MFC could produce a maximum power density of 37.4 mW/m2, and its applicability was further evaluated by the treatment of brewery wastewater. The developed MFC could be scaled up readily due to its simple configuration, inexpensive non-catalyzd flat graphite electrodes, easy operation and relatively high power density.In the second section, we created a novel nitrogen removal technology using the microbial denitrification cell to treat wastewater and generate electricity while removing NH4+-N from wastewater. The results showed that microbial denitrification cell could produce steady electricity while remove NH4+-N. In the start-up phase, the denitrification time decreased with the increasing of cell voltage. When the voltage increased to about 450mV, the denitrificaiton time reduced to 46h and the NH4+-N removal rate was up to 95.15%. However, with the voltage further increasing to 550mV, there was little effect on denitrifcation time and the NH4+-N removal rate slightly rose to 97.09%. The charge transfer efficiency generally remained at a high level, approximately 100±5%, and the residual NH4+-N was about 5mg/L. Increasing the cathode area could shorten the denitrifcation time, yet the pH of the cathode solution had little effect on the removal time, which indicated that the developed system had a certain anti-shock load capacity.更多还原