In recent years,the contribution of sewers to methane emissions is increasingly rec-ognized.This study investigates the methane emission processes from gravity sewers in two cities in Southern and Northern China.It finds that the average concentrations of dissolved and gaseous methane in the sewers of southern cities are 9.52 mg/L and 1 076 ppm,respectively,with a meth-ane emission factor of 5.19 g/(med).In northern cities,these values are 0.84 mg/L,2 075 ppm,and 4.08 g/(m·d),respectively.The study also analyzes the relationships between methane con-centrations and various water quality indicators,compares the methane concentrations and emission factors between China and other countries,estimates the total methane production from China's sewer network,and proposes directions for future research.
维普
万方数据