基于排放源的中国城市垃圾填埋场甲烷排放研究

利用全国垃圾填埋场的点源数据，基于实际调研和实验室分析建立中国不同区域、不同规模、不同填埋时间的排放因子矩阵，采用IPCC推荐的一级降解动力学（FOD）方法自下而上地核算了中国2107个垃圾填埋场在2007年的甲烷（CH₄）排放量。针对不同区域和类型的填埋场，分别就城市垃圾组分、可降解有机碳、CH₄修正因子、CH₄氧化系数、填埋场CH₄收集率等进行了深入研究。结果显示，中国2007年填埋场CH₄排放量为118.61万t，与《中华人民共和国气候变化第二次国家信息通报》2005年填埋场排放量（220万t）差异较大，其主要原因是城市垃圾填埋场统计数据的差异，例如填埋场个数及垃圾填埋量。中国绝大部分填埋场CH₄年排放量在700 t以下，超过1000 t的有279个，超过1万t的仅10个。江苏省的CH₄排放量最高，达到9.87万t；西藏的排放量最小，仅为0.21万t。东部江苏、广东、浙江等省的整体排放量较高，西部地区西藏、宁夏、青海等地的排放水平较低。

Estimation of CH4 Emissions from Landfills in China Based on Point Emission Sources

The CH₄ emissions from landfills in China in 2007 were estimated based on three-dimensional emission factors matrix and point emission sources database, by FOD model recommended by IPCC. The region, scale and operating time of landfills constitute the three dimensions of the emission factors matrix, which were obtained by laboratory analysis and in situ investigation. The key parameters, i.e., waste composition, degradable organic carbon ratio, CH₄ correction factor, oxidation factor and recovery rate, were carefully analyzed regarding to the three dimensions. The point emission sources database consists of 2107 landfills in cities and towns of China in 2007. The results show that the CH₄ emissions from landfills were 1.186 million tons in 2007. Compared with the CH₄ emission of 2.20 million tons in 2005 reported in the Second National Communication on Climate Change of the People’s Republic of China, the significant discrepancy mainly comes from statistical data of landfills, e.g., number of landfills and amount of waste disposed in landfills. The annual CH₄ emissions of most landfills were less than 700 tons, whereas there were 279 landfills with emissions larger than 1000 tons, and only 10 larger than 10000 tons. Jiangsu Province ranked the largest emitter with 98700 tons while Tibet ranked the smallest one with 2100 tons. Generally speaking, the emissions from eastern provinces, such as Jiangsu, Guangdong and Zhejiang, were larger than those from western provinces (Ningxia, Tibet and Qinghai).