厌氧废水处理系统中外源非匀强电场对电活性微生物的定向富集机理

厌氧生物处理系统具有低能耗、可产能等优点，被越来越广泛地用于废水处理中。然而在厌氧系统中由于电子受体缺乏，微生物间常通过互营实现复杂污染物降解。近年来发现，种间直接电子传递互营过程扮演越来越重要的角色，该过程可简单通过外加电场进行调控。电活性微生物是厌氧废水处理系统中直接电子传递互营的核心，而其富集和生长过程可能受到外加电场的调控。目前培养电活性微生物的体系均采用匀强电场，难以在同一体系中确认电场强度对混菌电活性生物膜的影响。本研究提出在非均匀的阶梯式渐变电场中重点考察电活性生物膜的形成过程、空间群落分布，揭示模式电活性微生物对外加电场响应的分子机理，从种水平阐明电活性微生物在非匀强电场中的竞争机制。建立电活性活细菌电泳方法，解析直接电子传递互营微生物在非匀强电场中的行为。该研究将部分揭示厌氧废水处理系统中微生物电化学调控的基本原理，为强化种间直接电子传递的厌氧废水处理新技术提供理论基础。

Anaerobic technologies are widely used in wastewater treatment due to its low energy consumption and energy production. However, the lack of electron acceptor at anaerobic condition leads to the syntrophy of different microorganisms to degrade complex pollutants. In recent years, it is found that direct interspecies electron transfer (DIET) plays an important role on syntrophy, and this process can be controlled by external electric field. Electroactive bacteria is the key of DIET, and its acclimation and growth may be regulated by the external electric field. Nowadays, all the researches used uniform electric field to grow exoelectrogens, so it is hard to tell the effect of electric field intensity on mixed electroactive biofilm. Here we propose to apply a gradual decreased Non-uniform electric field to investigate the biofilm formation and spacial community distribution. We will discuss the response mechanism of different exoelectrogens to the electric field on the basis of molecular biology analysis. The competition mechanisms of different species in this field will be also discussed. We will construct novel electrophoresis method for living bacteria to analyze the behavior of electroactive bacteria in electric field. These researches will partly reveal the basic mechanism of bioelectrochemical control in anaerobic system, providing a theoretical basis for the enhanced DIET technologies in anaerobic wastewater treatment systems.