【作者】 李靖；

【导师】 赵庆良；

【作者基本信息】 哈尔滨工业大学 ， 环境科学与工程， 2010， 硕士

【摘要】 随着全球经济的高速发展,在全世界范围内,社会发展与资源环境的矛盾日趋尖锐,能源危机和环境污染已成为制约人类生存和发展的两大重要难题。研发新的废水处理工艺从有机废水中回收有价能源已经成为环境工程领域的一个重要研究方向,是实现废水处理能源化与可持续发展的重要途径之一。微生物燃料电池(Microbe fuel cell,MFC)技术是一项兼顾从有机物中回收电能和废水处理的可持续性技术。该技术发展至今,就目前存在的各种形式MFC而言,由于产电过程需要贵重金属催化、加载阴阳极隔离膜、产电量偏小、MFC反应器结构不适合实际污水处理等多方面原因,导致该项技术成本过高并与实际应用仍有一段距离。针对MFC的现有问题,在考虑有效能源回收、成本降低、实际应用为目标的基础上,设计研究了更加适用于有机废水处理的无膜生物阴极MFC反应器构型,并分析了反应器的产电特性及污染负荷去处能力。主要开展了三部分的研究,分别为:挡板式MFC和无挡板式MFC产电性能及污染物去除能力研究、无挡板式MFC产电性能及污水净化效果条件优化、无挡板式MFC与A/O工艺处理实际生活污水的差异,论文取得了以下研究成果:使用厌氧污泥能够成功启动两种反应器,但与挡板式MFC相比,无挡板式MFC能在较短的时间内启动(150h)。在运行稳定后,外电阻Rex=500?时,挡板式MFC和无挡板式MFC反应器电压峰值分别为0.21V和0.42V。通过极化曲线测定可知,无挡板式MFC与挡板式MFC的内阻分别为79.4Ω和178.6Ω,最大功率密度分别为8.4W/m3、0.83W/m3,库仑效率分别为9.4%和6.3%。表明,由于挡板式反应器加长了阴阳极电极之间的距离,增大了电池内阻,虽然防止了阴极氧的扩散,但同时也增大了有机物转化为甲烷的比例,从而导致挡板式反应器功率密度、库仑效率偏低。挡板式和无挡板式反应器COD去除率分别为93.2%和90.7%,表明两种MFC都能够实现产电与有机物的同步降解。利用生活污水进行了无挡板式MFC产电性能及污水净化条件优化试验。研究结果表明,MFC的功率密度随有机底物浓度的变化具有饱和效应,在一定范围内电池的平均功率密度随有机底物浓度的增高而增高,在COD为120mg/L时功率密度增长到达平台期。通过减小水力停留时间,从而提高单位时间内的有机物绝对供给量,可以提高电池的输出功率,但当水力停留时间低于12h,出水水质无法达标。阴极溶解氧量的提高对增高电池功率输出和有机物去处是有利的,但当曝气量达到300mL/min时,电池电压为0.43V达到峰值,继续增加曝气量,电池电压则开始出现下降趋势。废水的缓冲能力对电池的功率输出有重要影响,但对污染物去除影响不明显。无挡板式MFC与传统A/O工艺连续处理实际生活污水对比实验表明,无挡板式MFC在水力停留时间为12h,30分钟间隔曝气(300mL/min)条件下,连续流处理生活污水,最大电压达0.42V(Rex=500Ω),最大功率密度为7.6W/m3,内阻为71Ω,出水浊度也较A/O法更低。最大COD去除率可达92.4%、氨氮去除率94.6%,而A/O的最大COD去除率和氨氮去除率为82.1%和67.7%。无挡板式MFC实际上可以看成是废水处理中A/O工艺反应器在结构和功能上的改型,更适合废水处理的实际应用,具有重要的应用推广价值。更多还原

【Abstract】 World-wide depletion of energy reservers and environmental contamination are inspiring the search for renewable and environment-friendly technologies to recover useful energy and materials from organic wastes. This has been particularly emphasised as a significant approach so as to make the wastewater treatment more sustainable and economical in the field of environmental engineering.This study systematically investigated the feature and corresponding mechanisms of two-chambered MFC, including the basic characteristics of power generation, the effects of MFC power generation performance and optimization of wastewater treatment effects, differences between MFC and A/O. Some findings have been made as follows:Using anaerobic sludge can successfully start the two reactors, but compared with the flapper MFC, non-flapper MFC can start within in a short time (150 h). When external resistance Rex = 500?, the two MFC’s peak voltage were 0.21V and 0.42V. MFC’s internal resistance were 79.4? and 178.6Ω, maximum power density was 8.4 W/m3, 0.83W/m3, coulomb efficiency was 9.4% and 6.3%. Shows that due to flapper MFC lengthened the distance between the anode and cathode electrodes, battery internal resistance increases, while preventing the spread of the oxygen, but it also increases the proportion of organic matter into methane, leading to baffle reactor low coulombic efficiency. Two MFC’s COD removal rates were 93.2% and 90.7%, showed that the two MFC can achieve power generation and synchronization of organic matter degradation.MFC power generation performance and optimization of wastewater treatment test. The results show that, MFC power density with the organic substrate concentration in a saturation effect. In a certain range of the average power density of batteries with higher concentrations of organic substrate and increase in COD was 120mg/L when the power density increased to reach plateau. By reducing the hydraulic retention time, thereby enhancing the unit of time the absolute supply of organic matter can increase the output power of the battery, but when the hydraulic retention time is less than 12 hours, water quality can not be complianced. Cathode to increase the amount of dissolved oxygen increased power output and the battery is beneficial organic place, but when the aeration reached 300mL/min, the battery voltage is 0.43V, continued to increase aeration, the battery voltage is then began to decline. Buffering capacity of the wastewater of the power output has an important influence, but no significant effect on contaminant removal.MFC with traditional A/O process treating domestic wastewater continuously experiment shows that MFC in HRT 12h, 30 min interval aeration (300mL/min) conditions, the continuous flow treatment of domestic sewage can receive maximum voltage of 0.42V (Rex = 500Ω), the maximum power density of 7.6 W/m3, resistance to 71Ωturbidity. Maximum COD removal rate reached 92.4% and 94.6% and ammonia removal rate were 82.1% and 67.7%. Non-flapper MFC actually can be regarded as A/O process reactor in structure and function, and is more suitable for application of wastewater treatment and has important value in applications.更多还原