酚类化合物厌氧互营降解转化机制及调控研究

Coal gasification wastewater contains high concentration of phenolic compounds, which will seriously inhibit the activity of hydrolytic-acidifying bacteria and lead to the poor efficiency of anaerobic biological treatment of coal gasification wastewater. In recent years, it has been found that the syntrophic bacteria, whose trophic niches are between hydrolytic-acidifying bacteria and methanogens, not only have the characteristic of tolerance to toxic stress, but also can directly degrade phenolic compounds. This offers the possibility to solve the problem of low hydrolysis rate of phenolic compounds under stress conditions. However, the mechanism of degradation of phenolic compounds by the syntrophic bacteria under stress and the synergistic mechanism with methanogens are not clear..This project uses ammonia stress to enrich the syntrophic phenolic-degrading bacteria, examines the influence of environmental factors on the enrichment of the syntrophic phenolic-degrading bacteria, clarifies the enrichment mechanism of the syntrophic phenolic-degrading bacteria, and explores the mechanism of phenolic degradation by the syntrophic bacteria. Futhermore, this project investigates the interspecies electron transfer and gene transfer of syntrophic phenolic-degrading bacteria and methanogens, and reveals their synergistic mechanisms. Finally, the anaerobic digestion system is built for the enrichment of syntrophic phenolic-degrading bacteria and the principle of process control and ideas are put forward. The research results of this project will provide the theoretical basis and technical support for the development of novel anaerobic process treating coal gasification wastewater.

煤制气废水含有高浓度酚类化合物，会严重抑制水解酸化菌的活性，进而导致废水厌氧生物处理效率低。近年来研究发现，处于水解酸化菌和产甲烷菌营养生态位之间的互营菌，不但具有耐受毒性胁迫的特征，而且可以直接降解酚类化合物，这为解决胁迫条件下酚类化合物水解酸化效率低的问题提供了可能。然而，互营菌在胁迫条件下降解酚类化合物的机理及其与产甲烷菌的协同作用机制尚不清楚。.本项目采用氨胁迫富集互营酚类降解菌，考察环境因素对互营酚类降解菌富集的影响，阐明互营酚类降解菌的富集机理；探索互营菌降解酚类化合物的代谢途径及种内电子传递，明确互营菌降解酚类化合物的机制；研究互营酚类降解菌和产甲烷菌的种间电子传递和基因转移，揭示其协同作用机制；构建富集互营酚类降解菌的厌氧消化系统，提出工艺调控的原理和思路。该项目的研究成果将为煤制气废水新型厌氧处理工艺的研发提供理论依据和技术支撑。

煤化工废水含有酚类化合物等多种有毒难降解有机物，会严重抑制厌氧微生物代谢活性，导致废水厌氧处理效能低下。本项目完成了厌氧反应器中互营酚类降解菌的富集，基于污泥粒径视角阐明了污泥絮体中酚类降解菌和产甲烷菌之间的协作与污泥粒径尺寸之间的联系，指出小粒径污泥在苯酚厌氧互营协作中发挥重要作用。本项目提出了Fe3O4@ZVI、Fe3O4@H2和GAC@H2的新方法用于强化酚类化合物的厌氧消化，建立了基于互营乙酸氧化-嗜氢产甲烷路径的酚类化合物厌氧消化系统，分析了苯酚厌氧互营代谢途径及微生物种间电子传递过程，从分子水平和基因水平解析了苯酚厌氧系统中的电子传递过程和嗜氢产甲烷过程。通过功能菌群、功能蛋白和功能基因的相关性分析可知，GAC表面上构建的优势嗜氢产甲烷路径以及互营细菌和嗜氢产甲烷细菌形成的种间直接电子传递机制，是苯酚厌氧产甲烷效率提高的主要原因。本项目为有毒难降解有机物厌氧处理提供了新的路径，研究成果已应用于煤化工实际废水厌氧处理，完成了实验室研究并取得了突出的有毒难降解有机污染物去除效果。