微生物燃料电池中产电微生物的电诱导驯化

发布时间：2018-03-11 09:27

本文选题：产电微生物　切入点：直流电压　出处：《中国矿业大学》2015年硕士论文　论文类型：学位论文

【摘要】：微生物燃料电池(MFC)是利用微生物催化剂将其代谢能直接转化为电能的装置,在生物质能和环境保护领域展现了巨大的前景。本研究设计了间歇流和连续流两种MFC装置,阳极材料为碳棒,阴极材料使用碳纸。菌种来源为徐州某酒厂厌氧工艺剩余污泥,间歇流接种量约为300m L,连续流接种量约为1000m L。先在间歇流的条件下,施加不同直流电压对污泥进行电诱导驯化,使用乙酸钠为碳源,浓度为1000mg/L。培养7天后,进入产电阶段,从中选出产电效果最佳的外加直流电压值。然后在连续流的条件下,分别使用厌氧泥直接启动MFC,以及将厌氧泥用间歇流实验选出的最佳电压进行电诱导驯化后的在启动。在间歇流运行中,外加±1.5V直流电压的环境中,系统输出电压极其微弱,说明较高的外加电压刺激对产电微生物的生长有抑制作用。负电压培养各组产电效果远不如正电压驯化效果理想,说明与产电时电子传递方向相反的直流电诱导可能会阻碍产电时电子的转移,造成电压损失。而1.0V的直流电压是最佳电压,相比于0.5V的电刺激,电诱导效果更为明显,产电性能更加优越,这说明在微生物能够承受的低强度电压刺激范围内,电刺激强度越大,越有利于产电微生物的生长以及其细胞活性的提高。在连续流运行中,首先用最佳电压对厌氧泥进行电诱导驯化,这期间每天定时进行短暂产电测试约1.5h,发现产电菌每天产电能力在逐步上升,在第10天达到最大值1.82V,超过了电源的额定电压。这说明最佳电压的刺激下,产电菌的能力得到了提高。两种培养方式进行启动,直接启动的MFC的稳定值是241m V,启动用时25天,而1.0V直流电驯化的MFC的稳定值为258m V,比前者搞约7%,启动成功时间为17天,比前者减少了32%。产电稳定后,改变电阻值,得到相应的电压,作极化曲线和功率密度曲线,估算未加电培养和加电MFC的内阻分别为580.7Ω和636.7Ω,以及486.1Ω和557.8Ω。最大功率密度为20.92m W/m和24.452m W/m。分别考察不同有机物浓度和水力停留时间下,电诱导驯化对微生物产电性能的影响,发现较低的有机物浓度范围内,有机物浓度越大,电压输出越高。HRT小于4h时,MFC系统中较短的水利停时间更有利于产电菌的生长。本研究确认电诱导驯化微生物能够提高其产电性能,找出了电诱导驯化微生物的最适电压,并考察了电驯化后产电菌的有利的运行环境。为电诱导驯化后产电菌的实际应用提供了参考。
[Abstract]:Microbial fuel cell (MFCs) is a device that converts metabolizable energy directly into electric energy by using microbial catalyst, which shows great prospect in the field of biomass energy and environmental protection. Two kinds of MFC devices, intermittent flow and continuous flow, have been designed in this paper. The anodic material is carbon rod, and the cathode material is carbon paper. The source of bacteria is excess sludge of anaerobic process in Xuzhou distillery, the inoculation amount of intermittent flow is about 300ml, and the amount of continuous flow inoculation is about 1000mL.Firstly, under the condition of intermittent flow, The sludge was acclimated by electric induction with different DC voltages. Sodium acetate was used as carbon source and the concentration was 1000 mg / L. After 7 days of culture, the sludge was cultured for 7 days, and the best applied DC voltage was selected. Then under the condition of continuous flow, The MFC is started directly by anaerobic sludge, and the optimum voltage selected by intermittent flow experiment is used to acclimate the sludge. The output voltage of the system is very weak in the environment of 卤1.5 V DC voltage added to the intermittent flow. The results showed that high applied voltage stimulation could inhibit the growth of electric-producing microorganism, and the effect of negative voltage culture was not as good as that of positive voltage acclimation. The results show that direct current induction, which is opposite to the direction of electron transfer during generation, may hinder the transfer of electrons and cause voltage loss, and the DC voltage of 1.0 V is the best voltage, which is more obvious than that of 0.5 V electric stimulation. The higher the electric stimulation intensity, the more favorable the growth of the electroproducing microorganism and the higher the cell activity in the continuous current operation, the higher the electric stimulation intensity is, the better the electrical production performance is. At first, the anaerobic sludge was acclimated by electrical induction with the best voltage. During this period, a brief test of electricity production was carried out for about 1.5 hours every day, and it was found that the electricity production capacity of the electricity-producing bacteria was increasing step by step. On the 10th day, the maximum value of 1.82V was reached, which exceeded the rated voltage of the power supply. This indicated that the ability of the electric-producing bacteria was improved under the stimulation of the optimum voltage. The stable value of the directly started MFC was 241m V, and the start-up time was 25 days. The stable value of the 1.0V DC domesticated MFC is 258mV, which is about 7 times longer than the former, and the start-up success time is 17 days, which is 32 times less than the former. After the electricity is stabilized, the resistance value is changed, the corresponding voltage is obtained, the polarization curve and the power density curve are obtained. The internal resistance of uncharged and uncharged MFC were estimated to be 580.7 惟 and 636.7 惟, and 486.1 惟 and 557.8 惟, respectively. The maximum power density was 20.92m W / m and 24.452 W / m respectively. The effects of electrical induction and acclimation on the electrical properties of microorganisms were investigated under different organic concentrations and HRT, respectively. It was found that in the range of lower concentration of organic matter, the higher the concentration of organic matter, When the voltage output is higher. HRT is less than 4 h, the shorter water conservancy stop time in MFC system is more favorable to the growth of electroproducing bacteria. This study confirmed that the electroinduction acclimation microorganism can improve its electrical production performance, and found out the optimum voltage of electroinduction acclimated microorganism. The favorable operating environment of electro-producing bacteria after electric acclimation was also investigated, which provided a reference for the practical application of electro-producing bacteria after electric induction and acclimation.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM911.45

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