低底物浓度条件下细胞聚合物驱动好氧颗粒污泥后反硝化脱氮除磷作用机制与过程控制

As a novel and promising wastewater treatment process, aerobic granular sludge technology has been widely evaluated. However, the quick start-up and stable operation of aerobic granular sludge reactor, especially for the treatment of low-strength municipal wastewater, is still the key problem that restricts its engineering application. . In this proposed research, start-up process of aerobic granular sludge for the treatment of low-strength municipal wastewater, simultaneous nitrogen and phosphorus removal mechanism, as well as the process control of aerobic granular reactor through post-denitrification driven by microbial polymers for the treatment of low-strength municipal wastewater are to be studied systematically. When the supply of exogenous sources is sufficient, the microbial polymers are accumulated. Subsequently, they are used as electron donors for nitrogen and phosphorus removal when the supply of exogenous sources is no longer sufficient. There are three main contents for the proposed research. The first is to explore the action mechanism of extracellular polymeric substances (EPS) in aerobic granulation process. Microbial community analysis is also to be performed to reveal the composition and dynamics of the microbial consortium in aerobic granulation process. The second is to explore the internal storage mechanisms and electron flows from the external substrate occurring in aerobic granule sludge. The metabolic pathways and action mechanisms of microbial polymers on biological nitrogen and phosphorus removal are also to be explored using experimental and modeling approaches. The third is to explore the reaction kinetics of simultaneous nitrogen and phosphorus removal occurring in aerobic granule sludge, and to optimize the reaction process of simultaneous nitrogen and phosphorus removal through post-denitrification with microbial polymers.. It is to be expected that the outcome of proposed research can provide a theory foundation and a new way for the biological nitrogen and phosphorus removal process of low-strength municipal wastewater.

好氧颗粒污泥是目前处理城市污水最有前景的工艺之一，但快速启动与稳定维持仍是制约其推广应用的关键问题。本课题将微生物在外碳源丰富-贫乏运行模式下产生的细胞聚合物积累/分解的代谢行为应用到颗粒污泥的同步脱氮除磷过程，利用颗粒污泥微生物在外碳源丰富时大量合成的细胞聚合物作为后续外碳源贫乏期脱氮除磷的电子供体用于反硝化脱氮和除磷，实现“内聚物驱动后反硝化脱氮除磷”。具体内容包括：探寻低底物浓度条件下快速启动好氧颗粒污泥反应器的方法和条件，探明EPS在颗粒污泥形成过程中的作用机制；获得细胞聚合物驱动后反硝化脱氮除磷的优化控制条件，探寻此过程的微生物种群动态演替规律；揭示细胞聚合物能量代谢过程与脱氮除磷行为间的关联关系，建立定量表达的脱氮除磷预测模型。课题的研究结果将能更好地解决我国低浓度城市污水脱氮除磷过程碳源缺乏、运行费用高、运行不稳定等问题，为城市污水处理工艺革新提供理论依据和方法参考。

好氧颗粒污泥因其良好的沉降性能和高效的生物活性等优点在废水生物处理领域广受关注，但快速启动与稳定运行仍是制约其推广应用的关键问题。本课题通过调控SBR反应器的周期时间和周期循环次数，同时结合不同的强化造粒手段，探明了低底物浓度条件下快速启动好氧颗粒污泥反应器的方法，结果表明，采用不同颗粒化促进手段，在14-50d内均能够实现好氧污泥的完全颗粒化。同时分析了好氧污泥颗粒化过程中EPS的组分变化及其作用机理，颗粒污泥中总EPS和溶解性EPS含量均高于普通活性污泥，而且不同的调控手段，对EPS中蛋白质和多糖产生的促进程度不一，这与宏观颗粒污泥形成时间的快慢具有相关性。构建了厌氧/限氧曝气的颗粒污泥脱氮除磷系统，优化了碳源浓度、曝气强度、pH值等控制条件，研究了基于PHA内碳源驱动的同步硝化/反硝化除磷过程的控制条件及作用机制，探明了好氧颗粒污泥脱氮除磷过程DO、ORP和pH值等控制参数的变化规律及其特征指示作用，这有利于低碳源条件下脱氮除磷过程的稳定维持。在此基础上，对实际城市污水中所赋存的典型PFCs持久性有机污染物对好氧颗粒污泥反应器长期运行稳定性、微生物群落变化和除污性能的影响进行了探索性研究。研究结果为好氧颗粒污泥技术的推广应用及城市污水处理厂的节能降耗提供了科学依据和技术参考。. 对照项目研究计划，课题组较好完成项目研究内容，达到预期研究目标，已发表学术论文5篇，其中SCI论文3篇；授权国家发明专利4项，培养硕士研究生3名。