利用微生物电解池处理牛奶废水过程中产电菌落与产氢性能之间的关系

Exoelectrogens community analysis and hydrogen production in the microbial electrolysis cell using dairy wastewater

摘要:

【目的】 研究微生物电解池(Microbial electrolysis cell, MEC)利用复杂有机物作为底物的运行特性, 对其在废水处理中的应用有着重要的意义。【方法】 以模拟牛奶废水为基质, 通过构建MEC反应器来考察在不同外加电压条件下产电菌群的性能。【结果】 当外加电压升高到1.2 V时, 最大电流密度可达到261 A/m3, 产氢速率可达0.048 m3 H2/m3 d, 分别比外加电压为0.4 V的情形提高了467%和700%。外加电压为1.2 V时, 系统对COD和蛋白质去除率可分别达59%和74%, 其中COD去除较之0.4 V的情形提高了22.5%。PCR-DGGE的分子生物学分析结果表明, 阳极生物膜中以Geobacter sp.作为优势菌, 说明在利用大分子有机物作为基质时产电菌与非产电菌的协同作用更为明显。【结论】 MEC能够利用牛奶废水作为燃料, 在实现高效降解的同时以产氢的形式进行能量产出, 这为MEC的实际应用提供了研究思路。

Abstract:

[Objective] Hydrogen production and the exoelectrogen activity under complex substrate microbial electrolysis cell (MEC) are of great significance to its application in wastewater treatment. [Methods] The characteristics of exoelectrogens were investigated with the single-chamber MEC fed by the artificial dairy wastewater under different applied voltages in this study. [Results] The maximum current could reach up to 261 A/m3 and the volumetric H2 production rate reached to 0.048 m3 H2/m3 d with the applied voltage of 1.2 V, which was increased by 467% and 700% compared with the applied voltage of 0.4 V, respectively. The COD and protein removal could be achieved by 59% and 74%, respectively. The COD removal at 1.2 V was improved by 22.5% compared with that at 0.4 V. The PCR-DGGE community analysis demonstrated that Geobacter sp., one of well-know exeoelectrogens, existed in anode colonies as the dominant bacteria. There might be a synergies relationship between exoelectrogens and non-electrochemically active bacteria. [Conclusion] MEC can use dairy wastewater as fuel, achieve the purpose of efficient degradation and produce hydrogen gas at the same time, which provides research ideas for the practical application of MEC.