关键词: 垃圾填埋, CH₄排放, 点排放源

Abstract: 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).

Key words: landfill, CH₄ emissions, point emission sources