微生物电解池转化丁酸型发酵废水产氢机制及优化控制研究

In order to solve the low hydrogen yield problem which exist in the process of the hydrogen production by microbial electrolysis cell (MEC) from butyrate-type fermentation effluent, the highly effective butyrate-degrading electrogenesis microflora will be acquired by acclimation cultures. During the process of acclimation cultures, the microbial community structures of anode biofilms, functional gene expression and metabolic pathways will be investigated by transcriptomics sequencing analysis, the mechanism of butyrate degradation and anode microbial syntrophic interaction will be revealed. The batch test will be performed inorder to acquire the best kinetic parameter in the process of hydrogen production by MEC. At last, the kinetic model will be established for the hydrogen production by MEC from butyrate-type fermentation effluent. This research will be a one-stone two-bird paradigm, it not only enhanced the energy conversion efficiency but also resolve thoroughly the pollution from fermentation effluent. This research hopes to provide a theoretical basis and technical support for the hydrogen production by MEC from butyrate-type fermentation effluent.

针对MEC处理丁酸型发酵废水过程中丁酸难降解的问题，拟申请项目运用限制性底物驯化方法构建具有丁酸降解能力的MEC阳极产电微生物群落，并采用宏转录组学手段从阳极活性微生物群落组成、功能基因表达及物质代谢途径层面系统揭示功能微生物协同降解丁酸型发酵废水产电机制；通过批次试验获得MEC降解丁酸型发酵废水产氢过程关键性影响因素最佳阈值，提出不同影响条件下MEC处理废水的优化调控策略，确定MEC最佳运行参数，建立揭示MEC运行规律的动力学模型。本课题的实施将使MEC有效转化丁酸型发酵废水为清洁氢能，不仅有利于提高能源转化效率，而且彻底解决了发酵废水带来的次生污染问题，该研究对于构建稳定高效的MEC转化丁酸型废水制氢系统提供重要的理论依据和技术支撑。

氢能是理想的清洁能源载体，不仅热值高，且具有环保和可再生的特点，将秸秆氢发酵与微生物电解池（MEC）技术耦合可实现秸秆废弃物的两阶段梯级产氢。针对MEC处理丁酸型发酵废水过程中丁酸难降解的问题，课题组运用限制性底物驯化方法构建具有丁酸降解能力的MEC阳极产电微生物群落。重点考察了生物阳极驯化方式、底物浓度和外加电压对MEC产氢的影响，并采用Illumina MiSeq高通量测序技术研究了MEC生物阳极驯化方式对微生物群落结构的影响。研究表明：在外加电压下，采用丁酸驯化的MEC利用秸秆氢发酵废水获得产氢量的大幅提高。与采用发酵废水驯化的生物阳极相比，废水中丁酸降解率和COD去除率分别提高了35.1％和25％。秸秆通过两阶段梯级产氢后，与单独秸秆暗发酵产氢相比，氢产量提高了近5倍。高通量测序技术结果表明：与乙酸和发酵废水驯化的生物阳极相比，采用丁酸驯化的生物阳极具有更高的物种丰富度和微生物群落多样性。丁酸降解机理推断为：丁酸首先被丁酸氧化菌Syntrophomonas降解为乙酸，然后乙酸再被产电菌所利用，其中丁酸的氧化是影响MEC产氢的控速步骤。