ZVI介导的限氧活性污泥微生物群体行为及高效脱氮机制与调控策略

The low C/N ratio of wastewater have presented challenges to traditional nitrogen removal technologies. In our previous research, an upflow oxygen limited sludge reactor (UOLSR) was constructed, and the excellent efficiency of carbon and nitrogen removal synchronously from wastewater with low C/N ratio demonstrated that the developed UOLSR was a novel economical and efficient process with good application prospect. However, its sludge acclimation need a long time and nitrogen removal efficiency need to be further improved. Zero-valent iron (ZVI), as a new environment-friendly sewage treatment material, has shown an excellent bio-oxidation-reduction activity. Therefore, the project ‘Mediation mechanism and control strategy of zero-valent iron to the microbial social behavior in oxygen limited activated sludge process for enhancing nitrogen removal’ is proposed. The research focuses on: (1) analyzing mechanism of ZVI stimulating nitrogen removal efficiency of oxygen-limited activated sludge, (2) studying the start-up and regulation operation characteristics of the UOLSR with the intervention of ZVI, (3) clarifying the successional law of biological nitrogen removal functional bacteria (including ammonia-oxidizing bacteria, nitrite-oxidizing bacteria, anaerobic ammonia oxidation bacteria and denitrifiers) with different operation conditions intervened by ZVI, (4) revealing the population behavior of multiple nitrogen removal functional bacteria mediated by quorum sensing system with ZVI intervention, (5) identifying the mechanism of enhanced nitrogen removal intervened by ZVI in the UOLSR at molecular and biological processes level and exploring an effective regulation strategy. This research will provide theoretical basis and technical guidance for the theory development and the technology application of oxygen limited biological treatment technology.

针对低C/N比有机废水因碳源不足所导致的生物脱氮效果差、处理费用高等技术瓶颈，前期提出了以限氧活性污泥系统处理低C/N比有机废水的技术思想，并成功开发出以厌氧氨氧化为主要脱氮途径的升流式限氧活性污泥反应器（UOLSR）工艺，实现了在无外加碳源条件下的碳氮有效同步去除，展现了良好应用前景。为解决该工艺存在的污泥驯化期长、系统脱氮效率有待提高等关键技术问题，基于零价铁（ZVI）所具有的优良生物氧化还原活性，本申请项目拟在探讨ZVI刺激限氧活性污泥脱氮效能的有效性基础上，系统研究ZVI干预下的UOLSR启动和变参数运行特征，阐明ZVI胁迫下由群体感应信号分子介导的群落演替与顶极群落形成、功能菌群生长代谢变化以及彼此间的代谢平衡调节等群体行为，从分子和生物过程水平揭示ZVI对限氧活性污泥系统效能的强化机制，提出有效调控策略，为限氧废水处理理论的发展及技术进步和推广应用提供理论指导和技术支撑。

大量污水和废水的集中排放，是造成水体富营养化的主要原因，如何经济高效地实现废水的脱氮除磷，逐步改善水体环境，是我国生态文明和美丽中国建设的战略需求。针对低C/N比有机废水来源广、生物脱氮效果差、处理费用高等技术瓶颈，前期提出了以限氧活性污泥系统处理低C/N比有机废水的技术思想，并成功开发出以厌氧氨氧化为主要脱氮途径的升流式限氧活性污泥反应器（UOLSR）工艺，实现了在无外加碳源条件下的碳氮有效同步去除，展现了良好应用前景，但也存在污泥驯化期长、系统脱氮效率有待提高等关键技术问题。基于零价铁（ZVI）所具有的优良生物氧化还原活性，项目组通过对比实验系统研究了ZVI（形态和投加量）对AOB、NOB、ANAMMOX菌群和反硝化菌群结构及其活性的影响，明晰了各类功能菌群特征群体感应信号分子，阐明了ZVI强化限氧活性污泥脱氮效能的有效性与机理；研究了ZVI干预下的UOLSR启动和变参数运行特征，证实了ZVI可以显著提高UOLSR的脱氮除磷效能，总氮和总磷去除效能分别达到了90%和80%以上，阐明了ZVI胁迫下由群体感应介导的群落演替与顶极群落形成、功能菌群生长代谢变化以及彼此间的代谢平衡调节等群体行为，揭示ZVI促进限氧活性污泥系统启动进程及强化脱氮除磷效能的机制，提出了基于ZVI干预的限氧活性污泥系统快速启动和高效稳定运行调控策略。这些研究成果，为克服UOLSR污泥驯化期长，进一步提高系统脱氮除磷效率，提供了理论和方法指导，为限氧废水处理理论的发展及技术进步和推广应用提供理论指导和技术支撑。项目组还在限氧废水处理系统抗生素与抗性基因去除效能及机制、基于深度学习的限氧处理系统的生物脱氮过程分析与状态预测、低碳氮比有机废水生物脱氮处理工艺及调控技术等方面开展了拓展性探索研究，取得了更多创新性成果，促进了多学科交叉融合发展与环境生态工程技术进步。