【作者】 赵娟；

【导师】 李秀芬；

【作者基本信息】 江南大学 ， 环境工程， 2010， 硕士

【摘要】 近年来,由于在实现废弃物或废水无害化的同时可产生宝贵电能,微生物燃料电池(Microbial Fuel Cell, MFC)技术受到各界广泛关注。其中,沉积型MFC (Sediment MFC, SMFC)因其不需投加电子受体或供氧剂、成本低、无二次污染、可用于水体原位修复等特点,引起越来越多研究者的兴趣。本研究分别以葡萄糖、乙酸钠、蓝藻酸化液和蓝藻为产电底物,从电池性能、产电特性、阳极生物膜特性等方面综合考察了底物类型对SMFC运行特性的影响,并结合循环伏安法对其电子传递特征进行了深入分析,不仅可丰富和充实SMFC的理论内涵,也是对现有蓝藻资源化技术的很好补充,具有重要的学术价值和应用前景。主要研究内容和结果如下：(1)不同底物条件下SMFC启动和电池性能研究表明,电池功率密度与底物去除之间呈明显的正相关关系。以蓝藻酸化液为底物的SMFC体系,不仅最大功率密度最高,为63.24mW/m2, COD去除率及底物降解速率也最大,分别为72.6%和0.607kgCOD/(m3·d)。其次为乙酸钠和葡萄糖体系,最大功率密度和COD去除率分别为50.92mW/m2、42.14 mW/m2和72.0%、53.6%。蓝藻酸化液可作为SMFC的产电底物。(2)底物类型对SMFC体系产电特性的影响研究表明,底物类型通过影响微生物的代谢活性和阳极生物膜生长情况改变体系的活化阻力、传质阻力及阴阳极电势,最终影响体系的功率密度输出。蓝藻酸化液体系的阳极电势最低,为-427 mV,阴极电势最高,为164 mV,电池电势最大,为591 mV,表观内阻最小,为461 Q,故其输出功率密度也最大,达71.77 mW/m2。(3)底物类型对SMFC体系阳极生物膜特性的影响研究表明,葡萄糖为底物的SMFC体系胞外聚合物(Extracellular Polymeric Substances, EPS)总量最高,为19.28mg/gVS.由于细胞内源代谢,空白体系EPS总量次之,为17.44mg/gVS。蓝藻酸化液为底物造成的传质阻力较小,EPS总量为16.99mg/gVS,其阳极碳毡上生物量最大,生物膜中P含量为7.46μgP/g碳毡。蓝藻酸化液为底物时阳极生物膜的电化学活性最高,0V时为77 mA,微生物以杆菌为主。(4)基于底物类型的SMFC体系电子传递特征分析表明,以厌氧消化污泥为接种物的SMFC体系中,电子传递特征以生物膜机制为主。提高体系的电流密度输出可通过优化阳极生物膜的成膜能力实现。更多还原

【Abstract】 In recent year, microbial fuel cell (Microbial Fuel Cell, MFC), as an advanced technology utilizing waste biomass directly for power generation, has gained extensive attention. Sediment MFC (SMFC), a sort of membrane-less MFC, which can be applied to water remediation and cost less without addition of electron acceptor or oxygen-supplier and secondary pollution, appeals to more and more researchers. In this study, the effect of substrate type on the performance of SMFC in sequencing batch is investigated in terms of cell performance, behavior of power generation and character of bioflim on anode electrode, with glucose, sodium acetate, cyanobacteria acidogenic fermentation liquid and cyanobacteria as substrates, respectively. Furthermore, the characteristic of electron transfer in anode is analyzed combined with cyclic voltammetry (CV). This will enrich the theory connotation of SMFC and be a helpful complement to the recycling technology of cyanobacteria so that it is worthy of great academic value and application perspective. The major contents of research and results are as follows:(1) The variation of substrate degradation is positively correlated with the power density. Both the maximum power density (63.24 mW/m2) and the substrate degradation (72.6%, 0.607 kgCOD/m3·d) of SMFC with cyanobacteria acidogenic fermentation liquid as substrate are the highest, followed by the SMFCs with sodium acetate (50.92 mW/m2,72.0%,0.573 kgCOD/m3·d) and glucose (42.14 mW/m2,53.6%,0.427 kgCOD/m3-d). The results show that SMFC utilizing cyanobacteria acidogenic fermentation liquid for power generation is feasible.(2) The substrate type affects microorganism metabolism activities and the growth of biofilm on anode electrode and results in the variation of activation resistance, mass transfer resistance, cathode, anode potential and power output of SMFC eventually. SMFC using cyanobacteria acidogenic fermentation liquid as substrate shows the lowest anode potential (-427 mV), the highest cathode potential (164 mV), the highest cell potential (591 mV) and the lowest internal resistance (461Ω), therefore the power output (71.77 mW/m2) is the highest.(3) Total extracellular polymeric substances (EPS) of SMFC taken glucose as substrate is the highest (19.28 mg/gVS) and total EPS of control SMFC (17.44 mg/gVS) is second only to that of glucose system because of autophagocytosis. Cyanobacteria acidogenic fermentation liquid leads to lower mass transfer resistance and total EPS of SMFC with it as substrate is 16.99 mg/gVS. It’s demonstrated that effect of activitation resistance is greater than ohmic resistance in biofilm on anode electrode of SMFC because biomass of SMFC with acidogenic fermentation liquid is the largest (7.46μgP/g carbon felt) and internal resistance is also the lowest (461Ω). Besides, the electrochemical activity of biofilm on anode electrode of SMFC with acidogenic fermentation liquid is the strongest (0.077 A at 0 V) and bacilli occupy the dominant position of microbial community.(4) The analysis on the characteristic of electron transfer in anode of SMFC based on substrate type shows that electron is transferred to anode electrode by adsorbing to the surface of electrode and forming biofilm in SMFC. The current output of SMFC can be increased by optimizing the capability of biofilm forming on anode.更多还原