好氧颗粒污泥短程硝化过程一氧化二氮的生成机理

Application of aerobic granular sludge into high ammonium wastewater treatment through partial nitrification is promising due to its spatial structure and microorganism distribution. However, both of partial nitrification and polymeric substances for aerobic granular sludge can lead to emissions of N2O -- a persistent greenhouse gas. Nowadays, less of research was paid attention to the mechanisms of N2O generation and N2O emissions control in the process of aerobic granular sludge’s partial nitrification. And due to the high solubility of N2O, traditional off-gas analysis cannot quantify the N2O generation in liquid phase. To solve these problems, this project will adopt an online measurement methodology by using a novel sensitive N2O micro-sensor to analyze the process of aerobic granular sludge’s partial nitrification. This research will improve the N2O gas-liquid mass transfer modeling. With the consideration of molecular biological and N2O kinetics, the mechanisms of N2O generation in the process of partial nitrification will be discussed through the investigation of nitrogen balance, key microorganism species and their structure distribution in aerobic granular sludge system. Based on the obtained mechanisms, the key step of N2O emissions will be analyzed to establish an available method on the N2O emissions control in the process of actual wastewater treatment by means of aerobic granular sludge’s partial nitrification.

好氧颗粒污泥由于特殊的厌/好氧空间结构和微生物分布，可以通过实现短程硝化来解决高氨氮废水处理问题。但短程硝化和组成好氧颗粒污泥的多聚物结构都会导致N2O——一种具有持久性强温室效应气体的释放。目前，在好氧颗粒污泥短程硝化过程的N2O生成机理及释放控制方面的研究都比较欠缺，而且由于N2O易溶于液相，传统的只针对气相的分析方法，无法对N2O的生成过程进行准确定量。针对这些问题，本项目拟采用一种新型微电极检测技术，构建好氧颗粒污泥反应器并实现短程硝化；通过完善N2O的气液传质模型，结合微生物分子生物学和N2O生成释放动力学结果，考察好氧颗粒污泥脱氮过程的氮平衡变化，找出影响N2O生成的关键微生物种群及结构分布，从而探讨好氧颗粒污泥短程硝化过程N2O的生成机理；在此研究基础上，本项目将对N2O释放的关键时间和关键控制步骤进行分析，尝试建立起好氧颗粒污泥短程硝化处理实际废水过程中，N2O生成与释放的可行控制方法。

好氧颗粒污泥短程硝化和组成好氧颗粒污泥结构的微生物都会导致N2O 温室气体的释放。本项目针对好氧颗粒污泥短程硝化过程的N2O生成机理及释放控制方面的研究构建好氧颗粒污泥反应器实现短程硝化，并采用新型微电极探针检测技术完善N2O的气液传质模型。通过结合微生物分子生物学和N2O生成和释放动力学结果，考察好氧颗粒污泥脱氮过程的氮平衡变化，找出影响N2O生成的关键因素，并探讨好氧颗粒污泥短程硝化N2O的生成机理。在此基础上，本研究分析了N2O释放的关键时间和关键控制步骤，认为好氧颗粒污泥特殊的硝化细菌分布结构，可以减少N2O的生成，从而在此基础上尝试建立了好氧颗粒污泥短程硝化处理实际废水过程中，N2O生成与释放特性分析及可行的控制方法。本项目研究对进一步加深颗粒污泥生物脱氮过程的认识，更好地拓展好氧颗粒污泥的实际工程应用，均有重要的理论意义和实践意义。