【作者】 何伟华；

【导师】 冯玉杰； 刘甲申；

【作者基本信息】 哈尔滨工业大学 ， 环境工程， 2011， 硕士

【摘要】 电化学辅助的微生物厌氧体系（EMAS）能够以秸秆为生物质源材料,获取多种形式的产物（如H₂、CH₄等）,并且具有效率高、成本低、能量转化率高等优点。构建与驯化高效的以秸秆为底物的微生物燃料电池体系（MFC）是构建EMAS实现秸秆综合利用的必要步骤和关键技术之一。将秸秆粉碎后直接投加到微生物燃料电池体系中,利用两种不同构型的反应器,即碳刷阳极空气阴极瓶型反应器与碳刷阳极空气阴极立方体反应器,构建秸秆作为“燃料”的微生物燃料电池体系。实验中所用微生物燃料电池系统均使用50mM磷酸盐缓冲体系,以纤维素糖化菌群H C作为主要秸秆降解菌群,原位利用秸秆产电。以1g/L葡萄糖为底物时,瓶型反应器最大输出功率为651±10mW/m²,投加H C菌群与玉米秸秆粉末后,最大输出功率为599±15 mW/m²,稳定周期的秸秆平均降解率为31%;立方型反应器最大输出功率为769±3mW/m²,投加H C菌群与玉米秸秆粉末后受传质影响,反应器的电压波动较大,最大输出功率降低至444±36mW/m²。立方体秸秆平均降解率为17%。结果显示,在可溶性底物条件下,立方体性能较好,但由于传质影响,在利用秸秆固体方面,瓶型反应器优于立方型反应器。利用纤维素糖化菌群H C,微生物燃料电池系统外降解秸秆,过滤收集0¹4日秸秆降解液,构建秸秆降解液作为“燃料”的微生物燃料电池体系。在14天的降解过程中,降解液COD呈波动上升状态,在第12天COD峰值达到2022mg/L。整个降解期间出现了三个明显的降解速率较高的时间段,分别出现在第3、7和12天附近。将秸秆降解液作为底物接入到微生物燃料电池体系中,秸秆降解液的最大功率输出与葡萄糖为底物时相比略低,但12、13两天采集的秸秆降解液作为底物时的最大功率密度（ 820.5±31.6mW/m² ,851.1±13.5mW/m²）输出高于葡萄糖为底物时的最大功率密度（802.5±19.4 mW/m²）。电位分析结果显示,与葡萄糖为底物的反应器阳极电位相比,秸秆降解液的水解产物能使反应器的阳极电位保持在一个更低的水平,更有利于阳极微生物的生长与产电,但是由于降解液使得反应器阴极电位有所下降,导致秸秆降解液最大输出功率略低于葡萄糖。实验结果证实:利用秸秆降解液作为底物构建MFC体系是可行的,选取适当时间的秸秆降解液作为底物,可以获得优于葡萄糖对照的产电性能。启动放大的微生物燃料电池反应器为后续建立可应用于实际的EMAS体系利用秸秆及秸秆降解液为潜在资源创造条件。反应器的阳极采用碳刷,阴极采用空气阴极,容积250L。以生活污水为进水,经过450h的驯化,获得了0.14⁰.18A的稳定输出电流。在生活污水中掺杂40%秸秆降解液后,通过极化曲线的测定,反应欧姆内阻仅为2.5±0.2Ω,最大功率输出为58mW （0.93W/m³）。放大微生物燃料电池系统的成功设计启动,可以使基于MFC技术的秸秆综合利用研究更具有实际意义。更多还原

【Abstract】 Electrochemical microbial anaerobic system （EMAS） make it possible to take corn stalks as potential recourse, yeilding diversiform production such as CH₄ and H₂. What is more, the predominances, such as high efficiency, low utilized cost and high energy transform ratio, of EMAS are obvious. Building up and domesticating high efficiency microbial fuel cell （MFC） system was considered to be the necessary process and key technic in approching the EMAS and comprehensive utilization of corn stalks.Raw corn stalks were added directly into microbial fuel cell （MFC） system after crushed . In order to obtain higher maximum power density, different types of anode material and configurations of air cathode MFCs （carbon brush anode bottle reactor and carbon brush anode cubic reactor） were investigated in MFC system. Raw corn stalks could be degraded by cellulose bacteria community H C , and be consumed in single chamber、air cathode MFC with 50mM phosphate buffer system . In the carbon brush anode and air cathode bottle reactors, the maximum power density was 651±10mW/m² using glucose （1g/L） as substrate. After adding H C and raw corn stover into this systerm at the same time, the maximum power density of corn stover reduced to 599±15 mW/m². In the carbon brush anode and air cathode cubic reactors, the maximum power density of glucose （1 g/L） was 769±3 mW/m². When the corn stover was used as substance, the maximum power density obtained was 444±36 mW/m², although the voltage generation was not very stable due to the problem of matter transfer between anode and cathode. The result indicated that changing anode material and configurations of reactor could greatly enhance the maximum power density. When dissolvable organisms were used as substrate, the cubic reactor obtained higher max power density. However, the bottle reactor has advantages in comparison with cubic reactor using raw corn stalks as substrate , due to larger volume and better mass transfer condition.Raw corn stalks could be degraded by cellulose degradation beacteria community H C without MFC system. Degradation solution of corn stalks , after 1¹4 days of degradation by H C ,were investigate about their possiblity to be used as substrate in MFc system . During the period of degradation, the COD of corn stalks degradation solution were observed to increase fluctuantly. The peak of COD data （2022 mg/L） was observed in the 12th day of degradation. During the degradation, three distinct areas of high degradation rates, respectively, observed in the vicinity of 3, 7 and 12 days. Compared with glucose, the maximum power output , using degradation solution of corn stalks as substrate, were generally low. Howere, when the degradation solution of straw collected at 12th and 13th day were used as substrate, higher maximum power density （respectively 820.5±31.6 mW/m² and 851.1±13.5 mW/m²） were observed to obtain than glucose （802.5±19.4 mW/m²）. The electrode potential analyse indicated that the corn stalks degradation solution could keep the anode potential relatively lower than that of glucose, which were thought to be propitious to the grow and power generation of anode bacteria community. However, the cathode protential were observed to decrease, which was the main cause that result in the maximum power output of degradation solution of corn stalks generally lower than that of glucose. It was approved in the experiment that power generation from degradation solution of corn stalks is doable. Compared with glucose, higher power density output could be obtained, using degradation solution of corn stalks through a proper period of degradation.In order to creat condition for farther study of using raw corn stalks and degradation solution in EMAS system as a potential resource, a application oriented pilot MFC system （250L, brush anode and air cathode ） was designed and started up. By far ,domestic sewage was used as substrate. After 250h’s domestication, stable output current （0.14⁰.18A） was generated. Measured by polarization curves, after adding 40% corn stalks degradation solution into the system, the reaction ohmic resistance was only 2.5±0.2Ω, maximum power output was 58 mW （0.93W/m³）. Sucessful design and strat up of the pilot MFC system, make the utilization of raw stalks, basing on the technic of microbial fuel cell, more meaningful and closer to the practical application.更多还原