基于植物管理的人工湿地N2O减排机理研究

人工湿地是高效的废水生态处理系统，但其脱氮过程是氧化亚氮（N2O）重要释放源。由于N2O是重要温室气体，人工湿地N2O减排近年来备受关注。现有人工湿地N2O减排措施成本高或存在二次污染风险，植物刈割管理是否成为新的有效减排途径目前还不清楚。本项目以养殖废水人工湿地处理系统为对象，利用静态箱和静态平衡法，研究植物刈割下人工湿地N2O产生、扩散和释放规律，探明植物刈割对人工湿地N2O减排效应；采用原位监测结合室内培养，借助微电极技术，揭示植物刈割下影响N2O排放关键环境因子；通过分子生物学方法，明确参与N2O产生过程关键微生物，探讨N2O产生关键微生物对植物刈割响应变化特征；在此基础，通过统计学方法，进一步揭示植物刈割下人工湿地N2O排放、环境因子和关键功能微生物耦合关系。开展本研究有助于深入认识人工湿地N2O排放与植物刈割管理内在关系，进而为人工湿地N2O减排和湿地可持续运行管理供科学依据。

Constructed wetland is an efficient ecological wastewater treatment system, but its denitrification process is an important release source of nitrous oxide (N2O). Because N2O is an important greenhouse gas, N2O emissions from constructed wetlands has attracted much attention in recent years. The existing N2O emission reduction measures of constructed wetlands have high costs or secondary pollution risks. It is not clear whether the management of plant harvesting is a new and effective way to reduce N2O emissions. This project takes constructed wetlands treating swine wastewater as the object, using the static box and the static balance method to study the law of N2O generation, diffusion and release in the constructed wetland under plant harvesting, and explores the potential of plant harvesting on N2O emission reduction in the constructed wetland. In situ monitoring, lab culture, and microelectrode technology are used to reveal the key environmental factors affecting N2O emission. By means of molecular biology, the key microorganisms involved in the N2O generation process are identified, and the response characteristics of the key microorganisms involved in N2O generation to plant harvesting are discussed. On this basis, the coupling relationship among N2O emission, environmental factors and key functional microorganisms in constructed wetland under plant harvesting management will be further revealed by statistical methods. This study is helpful to deeply understand the internal relationship between N2O emission and plant harvesting management in constructed wetlands, so as to provide scientific basis for N2O emission reduction and sustainable operation management of constructed wetlands.