隐形的地下碳源:城市排水管道CH4排放

Potential carbon emission source underground: Fugitive methane emission in the urban sewers

城市排水管道内存在复杂的微生物活动和物理、化学反应,产生了不容忽视的CH无组织排放。综述了城市排水管道系统不同部位的CH排放研究现状,估算了2016年我国城市排水管网CH排放量为6.32 MteCO,为城市“隐形”CH排放的重要来源;总结了管道内CH排放的主要驱动因素是污水管道内的水力条件和污水特性;比较了已有排水管道CH排放计量模型;综述了排水管网CH排放控制策略,并对未来排水管道无组织CH排放的研究和减排措施进行了展望。

Urban sewers produce significant amount of fugitive methane emissions due to the complex microbial activities, physical and chemical reactions in it. This paper summaries different parts of the sewers networks. It is estimated that in 2016, the CHemission of the urban sewer networks was 6.32 MteCOin China, which has become an important and imperceptible source of urban CHemission. Meanwhile, the key factors of sewers methane emissions are analyzed including hydraulic conditions and sewage compositions, and the existing models and control measures for methane emissions are reviewed. Finally, future research of fugitive methane emission from sewers are suggested to benefit the reduction of greenhouse gas emissions from urban water systems.