微生物电解电池的构建及其性能研究
文献类型：学位论文
| 作者 | 郭坤 |
| 学位类别 | 硕士 |
| 答辩日期 | 2010-05-21 |
| 授予单位 | 中国科学院研究生院 |
| 导师 | 李浩然 ; 杜竹玮 |
| 关键词 | 微生物电解电池 生物制氢 微生物燃料电池 产电光合细菌 醋酸钠 |
| 其他题名 | Study on the construction and performance of microbial electrolysis cells |
| 学位专业 | 生物化工 |
| 中文摘要 | 微生物电解电池（MEC）是以微生物为催化剂，同时在一定外加电能辅助条件下将有机物转化为氢气的全新的生物制氢装置。本论文从厌氧消解污泥中富集和分离到了产电光合细菌，考察了其电化学活性和产电能力；在实验室原有微生物燃料电池（MFC）的基础上构建了H-型双室MEC，实现了利用MEC制氢气；设计了两种新构型MEC装置：上升流无膜MEC和套筒型无膜MEC，提高了MEC的产氢能力。 先后通过富集培养基的富集、分离培养基的分离和MFC的筛选，成功地从厌氧消解污泥中获得产电光合菌液。循环伏安法检测吸附在电极表面的菌膜具有良好的电化学活性。将产电光合细菌运用于短臂型空气阴极MFC，发现去掉质子交换膜和连续向阳极通氮气均可以提高电池的产电能力，在较低的底物浓度条件下电池的输出电压随底物浓度的增大呈线性增长。 H-型双室MEC在外加电压大于 0.2 V的条件下能够产生氢气，且生成的氢气纯度很高（>98%），但是由于阴阳极距离较远和膜所造成了跨膜pH梯度，电池内阻很大，产氢速率很低。上升流无膜MEC由于没有膜的存在避免了跨膜的pH梯度，产氢能力较H-型双室MEC有很大的提高，在1.0 V的外加电压条件下，产氢速率达1.58 L/(L·d)。套筒型无膜MEC将桶状阴极插入到阳极石墨颗粒中，大大降低了电池的内阻，产氢能力得到进一步提高，在1.0 V的外加电压条件下，产氢速率达2.33 L/(L·d)。 无膜MEC的结构虽然提高了氢气的产生速率，但却损失了氢气回收率和氢气纯度。无膜MEC容易受到阳极菌群的影响，如嗜氢产甲烷菌可转化氢气生成甲烷，而产电菌则能将氢气重新转化成质子和电子，从而降低了体系氢气回收率和能量回收率。上升流无膜MEC的7 d长期运行试验表明，阳极菌群对氢气的消耗会随着运行时间的增长而逐渐增大，因此，降低反应周期可以提高氢气回收率和氢气纯度。 |
| 英文摘要 | Microbial electrolysis cell (MEC) is a new device for biohydrogen production, which could directly convert biodegradable organic matters into hydrogen using microbes as the catalyst under assist of the external electric energy. In this paper, electrogenesis photosynthetic bacteria (EPSB) were enriched and isolated from the anaerobic digestion sludge, and its electrochemical activity and electricity generation ability were examined. A H-shape MEC system was established based on the former microbial fuel cell (MFC) in our lab to realize hydrogen production from MEC. Two novel single-chamber MECs, one was cathode-on-top and the other one was tube-type MEC, were developed to enhance the hydrogen production ability. EPSB was successfully obtained from anaerobic digestion sludge by the enrichment of the enrichment medium, the isolation of the isolation medium, and the screening of MFC, sequently. The cyclic voltammetry result showed that the microbes attached on the surface of the electrode had good electrochemical activities. Then the EPSB was used to the air-cathode single-chamber MFC. The electricity generation tests showed that continuously sparging the anode chamber with nitrogen and removal of the proton exchange membrane were both able to enhance electricity generation. When the MFC was operated under low substrate concentration, the output voltage increased linearly with the increase of the substrate concentration. The H-type two-chamber MEC was able to produce hydrogen with a high purity when the applied voltage was higher than 0.2 V, while the hydrogen production rate was pretty low because of the large internal resistance caused by the far electrode distance and the pH gradient across the membrane caused by the membrane. Without membrane, the up-flow single-chamber MEC avoided the pH gradient. As a result, the hydrogen production ability of up-flow MEC was much higher than that of the H-type MEC. When the applied voltage was 1.0 V, the hydrogen production rate was 1.58 L/(L·d). The tube-type MEC was constructed by inserting the cathode tube into the anode graphite granule, which lowered the electrode distance greatly. Consequently, the internal resistance dropped significantly. Hence the hydrogen production rate was further enhanced. The hydrogen production rate reached 2.33 L/(L·d) when the applied voltage was 1.0 V. The MEC without membrane was able to improve the hydrogen production rate. However, unavoidably the hydrogen recovery and hydrogen purity were suffered a loss. MECs without membranes were apt to be influenced by the anodic bacteria community. For instance, the hydrogenotrophic methanogens were able to convert the hydrogen into methane, and the exoelectrogens were able to transform the hydrogen back into protons and electrons. Accordingly, the hydrogen recovery and energy recovery of the MECs dropped. The results of the 7 d operating tests of the up-flow MEC showed that the hydrogen consumption by the anodic bacteria community increased gradually with the lasting of the operating time. Therefore, shortening the batch time was able to improve the hydrogen recovery and hydrogen purity. |
| 语种 | 中文 |
| 公开日期 | 2013-09-22 |
| 页码 | 66 |
| 源URL | [http://ir.ipe.ac.cn/handle/122111/1638]  |
| 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 | 郭坤. 微生物电解电池的构建及其性能研究[D]. 中国科学院研究生院. 2010. |
入库方式： OAI收割
来源：过程工程研究所
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