农村污水非点源污染人工湿地处理系统甲烷排放控制研究

Agricultural non-point pollution was the first largest pollution source in China from 2009. Constructed wetland which is to key role on polluiton control for non-point source pollution in China, is the main technology of pollution degradation for agricultural non-point source pollution in China. But some important control mechanism on methane emission from constructed wetland ought to be urgently probed into and conducted to the engineering application. This research, Firstly, will establish the constructed wetland after hydraulics optimization for agricultural non-point source sewage pollution in laboratory. Secondly, the methane emission rules and mechanism from constructed wetland for agricultural non-point source sewage pollution will be researched by gaining net information of methane emission from established constructed wetland. Thirdly, the methane transportation pathway emission pathway will be simulated in order to control the methane emission. With the comprehensive research approaches such as the combination between laboratory analysis and field sample, the combination between field test and indoor simulation, methane emission control mechanism and influence factors on constructed wetland for agricultural non-point source sewage pollution will be deeply researched, in order to develop the methane control technologies for engineering applications. This research can effectively conduct the system efficiency of constructed wetland for agricultural non-point source pollution in China, and support the science foundation on methane emission for constructed wetland. This research also can provide the basic data on saving energy and carbon reduce in Chinese sewage treatment system.

中国农业非点源污染已成为第一大污染源，而人工湿地系统作为有效解决农村非点源污染的技术手段，将在我国农业非点源污染控制起重要作用，但同时，人工湿地产生甲烷温室气体的排放控制机理还急需进一步研究以指导工程应用。本研究在实验室先构建水力学最优化的人工湿地拟解决农村非点源污水污染，然后研究农村非点源污水人工湿地处理系统中CH4温室气体的排放规律及机理，收集CH4 净贡献有价值信息。对甲烷在人工湿地中的输送进行模拟研究为后续甲烷排放控制奠定基础。并采用野外采样与实验室分析相结合、现场试验与室内模拟试验相结合的方法，系统研究农村非点源污水人工湿地处理系统中甲烷排放控制和影响机理，并探索和应用CH4排放控制技术。本研究旨在指引我国农村污水非点源污染的人工湿地处理系统效能，为人工湿地温室气体排放控制提供科学依据，并为我国污水处理系统的节能和碳减排提供基础数据。

中国农业非点源污染已成为第一大污染源，而人工湿地系统作为有效解决农村非点源污染的技术手段，其甲烷排放控制还急需进一步研究以指导工程应用。本课题采用野外采样与实验室分析相结合、现场试验与室内模拟试验相结合的方法，探索了农村非点源污水人工湿地处理系统中甲烷排放的控制。在成都市郫县园田村和安龙村监测了农村污水非点源污染人工湿地处理系统所产生的甲烷排放通量，发现农村非点源污水人工湿地处理系统是甲烷的排放源，排放通量具有较大变化。基于illumina MiSeq 2 × 300 bp 高通量测序平台，从产甲烷菌的分子生态学特征探索了农村污水非点源污染人工湿地处理系统的甲烷产生机理，发现甲烷微菌目（Methanomicrobiales）、甲烷杆菌目（Methanobacteriales）和甲烷八叠球菌目（Methanosarcinales）为主要的产甲烷微生物机制。利用示踪法和计算流体技术（CFD）完成了农业非点源污水处理系统的垂直流人工湿地的水力学优化设计，最终的优化方案为增加进水口个数和出水池全部池底增加有穿孔口的布水管。利用二相流（水气二相）模拟了甲烷在人工湿地介质中的传递模拟，发现人工湿地介质对甲烷的传输具有一定的影响。在满足水环境治理的基础上，发现利用水位控制、微孔曝气（间歇曝气和自动曝气方式）、添加氧化还原电位（Eh）调节剂，可以有效地对农业非点源污水垂直流人工湿地处理系统甲烷排放进行控制。不仅可以指引我国农村污水非点源污染的人工湿地处理系统效能，而且这些控制方式可以最大程度地控制人工湿地甲烷的排放，可为我国人工湿地污水处理系统在全球气候变化中的贡献和碳减排提供一定的参考。