微生物电解池新评价指标应用及放大式反应器产甲烷分析

发布时间：2018-03-21 03:11

本文选题：微生物电解池　切入点：活性炭催化剂　出处：《哈尔滨工业大学》2014年硕士论文　论文类型：学位论文

【摘要】：微生物电解池（Microbial electrolysis cell, MEC）是一种新型的且能兼顾氢气或甲烷回收的废水处理技术。MEC具有很好的应用前景，但在发展过程中存在诸多挑战，，如阴极材料的廉价化与高效化、评价体系有待完善以及连续流放大式MEC的运行效能有待进一步解析。面对上述挑战，本文考察了活性炭催化剂在微型MEC中的产氢效能，同时基于传统评价体系和新型的评价体系进行性能分析，探讨新型评价体系的可用性。本实验搭建了挡板式微生物电解池（baffled microbialelectrolysis cell, ABR-MEC），研究了ABR-MEC连续流运行效能，解析了甲烷可能的来源和阳极生物膜群落结构的动态变化。最后，本文探讨了ABR-MEC在连续流运行状态下的产甲烷效能与能量效益。本实验研究了活性炭-钢网阴极MEC（AC/SS-MEC）在不同外加电压下的产氢效能。基于传统的评价体系，AC/SS-MEC在1.4V下能够获得最高的最大电流密度和最大产氢速率，在1.0V和1.2V下能够获得最高的能量效率，并发现其产氢效率随外加电压的变大而升高。基于新型的评价体系，AC/SS-MEC在1.2V下能够获得最高的平均电流密度和最高的平均产氢速率，探明了产氢效率随外加电压的变大而升高的原因，并引入废水处理效率用以表征AC/SS-MEC的能量效率。本实验研究了ABR-MEC在不同水力停留时间（HRT）下的运行效能。当HRT从2天缩短至1天时，氢气日产量降低，甲烷日产量上升。随着HRT从1天继续缩短至0.5天，氢气日产量降低，甲烷日产量也有所下降。通过简化的电子平衡计算解析了ABR-MEC产甲烷的可能来源，发现在HRT为2天时，主要来源可能是嗜氢产甲烷菌。当HRT缩短至1天时，主要来源可能是嗜乙酸产甲烷菌。通过高通量测序技术解析了ABR-MEC阳极生物膜群落结构随HRT的缩短而产生的变化，发现随HRT从1天缩短至0.5天，产电微生物群落受到一定的抑制，影响了ABR-MEC的产电与产氢效率，降低了ABR-MEC的产甲烷效率。最后，本实验通过外加电压和底物浓度的调节，研究了ABR-MEC连续流产甲烷效能，结果表明，相比于提高底物浓度，提高外加电压有助于ABR-MEC产甲烷效能的迅速增强，但外加电压的变大却降低了ABR-MEC的能量效益。因此，当为连续流放大式MEC选择合适的外界条件时，应综合考虑其运行效能和能量效益。
[Abstract]:Microbial electrolysis cell (MECs) is a new wastewater treatment technology which can take hydrogen or methane recovery into account. MECs have a good prospect of application. However, there are many challenges in the development process, such as the cheap and high efficiency of cathode materials. The evaluation system needs to be improved and the operation efficiency of continuous flow amplified MEC needs to be further analyzed. In the face of the above challenges, the hydrogen production efficiency of activated carbon catalyst in miniature MEC was investigated. At the same time, based on the performance analysis of the traditional evaluation system and the new evaluation system, the usability of the new evaluation system is discussed. In this experiment, the baffle microorganism electrolytic cell microbialelectrolysis cell (ABR-MEC) is built, and the continuous flow operation efficiency of ABR-MEC is studied. The possible sources of methane and the dynamic changes of anode biofilm community structure were analyzed. Finally, the methanogenic efficiency and energy efficiency of ABR-MEC in continuous flow operation were discussed. The hydrogen production efficiency of AC / SS-MECs at different applied voltages was studied. The maximum current density and maximum hydrogen production rate were obtained at 1.4V based on the traditional evaluation system. The maximum energy efficiency can be obtained at 1.0V and 1.2V, and it is found that the hydrogen production efficiency increases with the increase of applied voltage. Based on the new evaluation system ACP-SS-MEC, the highest average current density and the highest average hydrogen production rate can be obtained at 1.2V. The reason for the increase of hydrogen production efficiency with the increase of applied voltage was found, and the efficiency of wastewater treatment was introduced to characterize the energy efficiency of AC/SS-MEC. The operation efficiency of ABR-MEC under different HRT (HRT) was studied. When HRT was shortened from 2 days to 1 day, the daily production of hydrogen decreased and the daily output of methane increased. With the further shortening of HRT from 1 day to 0. 5 days, the daily production of hydrogen decreased. The possible sources of ABR-MEC methanogenesis were analyzed by simplified electronic equilibrium calculations. It was found that when HRT was 2 days, the main source might be hydrophilic methanogenic bacteria. When HRT was shortened to 1 day, The changes of ABR-MEC anode biofilm community with the shortening of HRT were analyzed by high-throughput sequencing. It was found that the electrogen-producing microbial community was inhibited with the shortening of HRT from 1 day to 0.5 day. The electricity and hydrogen production efficiency of ABR-MEC was affected, and the methane production efficiency of ABR-MEC was decreased. Finally, the effect of ABR-MEC continuous abortion methane was studied by adjusting the applied voltage and substrate concentration. The results showed that compared with increasing the substrate concentration, increasing the applied voltage contributed to the rapid enhancement of the methanogenic efficiency of ABR-MEC. However, the increase of applied voltage reduces the energy efficiency of ABR-MEC. Therefore, when choosing suitable external conditions for continuous current amplifying MEC, the efficiency and energy efficiency should be considered comprehensively.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：X703;TM911.45

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