强化不同胞外电子途径的污水中异化铁还原磷回收机制研究

污水中磷的资源转化与回收是“城市污水再生与资源化”的重要组成部分，对于同步解决水体富营养化和磷资源危机两大全球性环境问题具有重要意义。蓝铁石广泛存在于污水处理的消化污泥中，可作为污水处理厂的“磷汇”，其合成与回收是环境领域近年来关注热点。厌氧微生物异化铁还原是蓝铁石合成的核心机制，而微生物电子转移是铁还原的关键科学问题。本研究尝试解析异化铁还原的磷回收过程电子转移驱动的物质迁移转化规律与微生物作用的成核机制，识别蓝铁石合成的关键功能微生物、功能基因和功能蛋白，揭示微生物代谢分子机制。基于厌氧微生物胞外呼吸基本原理，分别提出间接和直接电子传递途径下蓝铁石回收强化调控机制。识别促进间接电子传递的关键电子穿梭体，解析其对微生物代谢分子机制的正向与逆向反馈。考察微生物-矿物间以及微生物种间直接电子传递促进异化铁还原机制。基于上述成果建立污水蓝铁石强化回收的调控策略，指导蓝铁石回收工艺的优化运行。

Phosphorus transformation and recovery from wastewater is an important part of "urban sewage regeneration and recycling". It is of great significance to solve the two global environmental problems of eutrophication and phosphorus resource crisis simultaneously. Large amount of vivianite exists in digested sludge, which can serve as "phosphorus sink" of wastewater treatment plants (WWTPs). The potential of vivianite production in phosphorus recovery has been recognized recently. The dissimilated iron reduction (DIR) is the main mechanism for vivianite production, and microbial electron transfer is the key scientific problem of DIR. In this study, we attempt to analyze the elements migration and.transformation in DIR driven by electron transfer, identify the key functional microorganisms, functional genes and functional proteins, and reveal the microbial metabolic molecular mechanism for DIR and vivianite production. Based on the extracellular respiration mechanism of anaerobic microorganisms, the enhanced regulation mechanisms of vivianite recovery through indirect and direct electron transport pathways are expected to be proposed. We try to identify the key electrons shuttles which promote indirect electron transfer and analyze their positive and negative feedback to microbial metabolic molecular mechanism. We investigate the enhancement of DIR by direct electron transfer, including direct electron transfer between dissimilatory metal reduction bacteria (DMRB) and minerals, as well as between different microorganisms. Besides, we try to establish control strategies through different extracellular electron transfer pathway for vivianite recovery from wastewater, which is benefit to optimize operation of wastewater treatment process for phosphorus recovery.