| 题名 | 微生物燃料电池中生物膜产电及用于过程监测的研究 |
| 作者 | 刘志丹 |
| 学位类别 | 博士 |
| 答辩日期 | 2008-06-04 |
| 授予单位 | 中国科学院过程工程研究所 |
| 授予地点 | 过程工程研究所 |
| 导师 | 苏志国 |
| 关键词 | 微生物燃料电池 生物膜 产电 厌氧消解 生物传感器 |
| 其他题名 | Study on biofilm catalyzed electricity generation and its application for process monitoring in Microbial fuel cells |
| 学位专业 | 生物化工 |
| 中文摘要 | 无介体微生物燃料电池(MFC)是一种新型的环境生物技术。本论文围绕无介体MFC，以不同的微生物为对象综合研究了微生物与电极之间电子传递机制，构建了五套不同特征的MFC装置，考察了微生物产电的关键影响因素，依据生物膜催化的概念发展了一种生物传感器，并成功地将其用于厌氧消解(AD)的过程监测。 利用模式微生物Rhodoferax ferrireducens 和Geobacter metallireducens考察了固态物质异化还原过程中的电子传递，培养基置换实验、细胞浓度定量分析和扫描电镜（SEM）观察等证实了生物膜形成是微生物与电极间电子传递的主要形式。去除培养基中氮磷元素使R. ferrireducens MFC产电量增加了60%，突出了生物膜存在的重要性。进一步以环境中混合菌为对象对微生物产电机制和微生物进化进行了探索，200余天运行使海泥MFC的输出功率提高了300多倍（100 mW/m2），库伦效率增加了25倍（59%），说明了体系极化损失的减小和高效生物膜的建立。另外，循环伏安跟踪分析表明多阳极污泥MFC在富集过程中电极表面生物膜的电化学变化与产电信号变化一致，这些结果证实了微生物产电过程不仅伴随着生物膜形成过程，而且也伴随着生物膜电化学成分的进化。 在生物膜催化产电的认识基础上，考察了MFC产电的影响因素。基质实验证实了富碳的乙酸钠和富含蛋白质的OECD合成废水诱导了两种不同电信号响应的MFC。微生物种类、接种浓度、培养方法均未对MFC产电有显著影响。与生物因素相比，物化因素（阴极反应剂、反应器构型、离子交换材料、外接电阻等）的变化更容易改变阴阳两极的过电位，从而影响MFC性能。设计的“阳极-膜-阴极-膜-阳极-膜-阴极”结构的MFC与改装前单电池相比，使输出电压和短路电流提高一倍，体系内阻减少了一半多（约100 Ω ），实际处理废水能力也提高了近一倍。 以生物膜作催化剂在H形双室MFC体系上进行了有机废水和糖类物质的直接转化产电实验。以6 g COD/L味精废水为燃料，MFC产电持续时间长达60余天，功率密度为17.7 mW/m2。废水的COD、NH4-N、SO42-去除率分别为83%、88%和84%。另外，味精废水诱导的MFC和城市生活废水诱导的MFC在都以味精废水为燃料时，前者的产电输出功率和废水处理效率较高，SEM图片也证实了前者的微生物菌群更丰富，这是由于味精废水成分较为复杂，处理过程需多种微生物的协同作用，这与基质实验结果一致。 进一步探索了电化学活性生物膜的功能化应用，构建了一种无介体MFC型夹套式生物传感器、优化后的参数为阴极流速7.28 mL/min，阳极流速7.74 mL/min，阴阳极电极液均为60 mM PBS缓冲液(含50 mM NaCl)，外电阻为200 Ω。6个月的厌氧发酵罐监测运行表明，生物膜传感器（Biofilm MFC）实现了异常外部环境的在线反馈，有效监测了人工模拟大分子的代谢过程。MFC电信号与其它在线信号（生物气流量、pH）、离线分析（COD值、气体成分、挥发性脂肪酸等）存在一定函数关系。低基质浓度时（<50 mg COD/L），pH变化和气体流量变化均不及电信号变化灵敏。作为参比的控制传感器（Control MFC）在初始2个月内未能出现针对外部环境的反应，3个月后，Biofilm MFC和Control MFC的产电变化随着基质浓度增加均呈现了特征性的Monod方程拟和，但Biofilm MFC变化更灵敏。在线信号的瞬间关联分析揭示Biofilm MFC可与pH或气体流量同时反映厌氧罐内瞬时的微生物代谢活力，但Control MFC不能，说明了Biofilm MFC电化学活性生物膜的重要性。利用MFC/pH/气体流量计@厌氧发酵罐组成的集成传感器成功地在线监测了马铃薯甚至城市固体垃圾的水解过程，这也充分说明了基于生物膜的传感器的稳定性和实用性。 |
| 英文摘要 | This thesis was focused on mediator-less microbial fuel cell (MFC), which is a novel environmental biotechnology. The mechanisms of extracelluar electron transfer between microorganisms and electrodes were investigated by employing different bacteria as inoculums. Five suits of MFCs with various configurations were established towards a better understanding of electricity generation. Crucial parameters were discussed with focuses on the substrate and the architecture of MFC. On top of these, a novel biosensor, based on biofilm-catalyzed mediator-less MFC, had been developed for on-line monitoring of anaerobic digestion. The electron transfer during solid-based dissimilatory reduction was investigated using Rhodoferax ferrireducens and Geobacter metallireducens as model microorganisms. Medium replacement operation, the quantitative analysis of microbial cells and SEM observation demonstrated the dominant role of biofilm in anodic electron transport. Coulombic yield was significantly improved by 60% through the removal of N and P elements in the medium, which also illustrated the important role of biofilm. Mixed culture collected from environment was introduced to further understand the electricity-producing process. Over 200 days operation, power density rose to 100 mW/m2 by 300 fold and coulombic efficiency was increased to 59 % by 25 fold, indicating the stepwise reduction of system limitations. In addition, the analysis of a multi-anode MFC via cyclic voltammogram (CV) scanning revealed that electricity production was found not only coupled with biofilm formation, but also accompanied with the evolution of electrochemical property of biofilm. Crucial factors of MFC were studied based on the understanding of biofilm-catalyzed electricity generation. Substrate study showed that two different kinds of MFCs were induced by using carbon-rich acetate and protein-rich OECD wastewater. Electricity production was not remarkably influenced by microbial species, inoculums concentration and cultivation approach. In comparison to biological factors, abiological factors could more easily affect the MFC performance by changing the cell overpotential. Electricity production was significantly affected by cathodic reactant, cell architecture, ion exchange material and external load. In particular, a stacked MFC, bridged internally through an extra cation exchange membrane, resulted in doubled voltage output, half reduced optimal external resistance and improved wastewater treatment efficiency. Biofilm based H type MFC was used to evaluate the feasibility of producing electricity from organic wastewater and sugars. MFC fed with 6 g COD/L monosodium glutamate wastewater (GMW), obtained a sustained electricity outputs for more than 60 days with a peak power density of 17.7 mW/m2. The removal efficiencies of COD, NH4-N and SO42- were 83%，88% and 84%, respectively. In addition, GMW induced MFC was proved to gain higher power output and treatment efficiency than domestic wastewater (DW) induced MFC, due to more complex microbial consortia present in GMW. This well supported the result of substrate study. The function of electrochemically active biofilm was further exploited and a novel wall-jet biosensor was developed based on the concept of mediator-less MFC. The optimal conditions were 7.28 mL/min cathodic flow rate, 7.74 mL/min anodic flow rate, 60 mM PBS buffer based electrolyte and 200 Ω external resistor. During 6 months operation of an anaerobic digester, biofilm MFC reflected real-time online information of digestion under different external onditions. Biofilm MFC was also applied to monitor the simulated metabolism of macromolecules. The online electrical signal was found to have the function relationships with other online signals i.e. biogas flow rate, pH or off-line analysis i.e. COD, gas content and Volatile fatty acids (VFAs). In addition, electrical signal had higher sensitivity than pH or gas flow rate when the bioreactor was fed with the substrate at lower concentration (<50 mg COD/L). On the contrary, control MFC was incapable of bringing the corresponding signal under different operational conditions in the initial period. Only after three months, the electricity outputs of both control MFC and biofilm MFC had Monod relations with substrate concentration, however biofilm MFC had higher sensitivity. The analysis of instant association between online signals revealed that biofilm MFC, other than control MFC, exhibited comparable process information with pH or gas flow rate, which reflected the biological activity of metabolism in anaerobic reactor. This result clearly confirmed the importance of electrochemically active biofilm. Besides these, an online integrated sensor system, based on robust MFC/pH probe/gas flow meter @anaerobic reactor, had been proposed for successful monitoring of hydrolysis of solid organics. |
| 语种 | 中文 |
| 公开日期 | 2013-09-13 |
| 页码 | 199 |
| 内容类型 | 学位论文 |
| 源URL | [http://ir.ipe.ac.cn/handle/122111/1255]  |
| 专题 | 过程工程研究所_研究所（批量导入） |
| 推荐引用方式 GB/T 7714 | 刘志丹. 微生物燃料电池中生物膜产电及用于过程监测的研究[D]. 过程工程研究所. 中国科学院过程工程研究所. 2008. |
| 个性服务 |
| 查看访问统计 |
| 相关权益政策 |
| 暂无数据 |
| 收藏/分享 |
除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。
修改评论