我国城市生活垃圾填埋处理CH4排放关键因子

CH₄是大气中主要的温室气体之一,研究我国城市生活垃圾填埋处理CH₄排放关键因子对于准确估算CH₄排放量具有重要意义. 在综合分析我国城市生活垃圾填埋处理场在不同历史发展阶段的处理技术类型、管理方式、垃圾成分和理化特性的基础上,结合北京阿苏卫垃圾填埋场对不同深度(至填埋层下18 m)钻井提取的12组垃圾样品数据,借鉴《2006年IPCC国家温室气体清单指南》推荐的CH₄排放关键因子,确定了MCF(CH₄修正因子)、DOC(可降解有机碳质量分数,下同)、t_1/2(半衰期)和k(CH₄产生率). 结果表明:MCF在不同历史阶段表现出鲜明的时间特征,1978年前、1979—1990年、1991—2000年、2001—2005年和2006—2011年5个阶段的MCF分别为0.40、0.60、0.75、0.92和0.96；我国南、北方城市生活垃圾DOC随时间变化均呈增加趋势,1959—1990年、1991—2000年和2001—2011年3个阶段的DOC分别为9.34%、15.22%和15.05%；我国城市生活垃圾t_1/2为2.30 a,k为0.30 a-1. 

Key Methane Emission Factors from Municipal Solid Waste Landfill Treatment in China

Methane emissions from municipal solid waste (MSW) landfill treatment is one of the most important sources of greenhouse gases. Determination of the key emission factors (EF) for methane emissions from MSW landfill treatment is an efficient method to estimate methane emissions. MSW disposal site processing types, management methods, waste compositions and physicochemical characteristics from 1979-2011 in China were analyzed. Referring to IPCC default EF values for methane emissions as well as previous reports from greenhouse gas inventory working group and sampling analysis in Asuwei waste disposal site in Beijing, key factor values for methane emissions in China were obtained, including the methane correction factor (MCF), content of degradable organic carbon (DOC), and half-life period (t_1/2). The results indicated that the IPCC default EF values are not suitable for the actual situation in China, and MCF values showed distinct time characteristics in different historical stages. The MCF values of the five stages-before 1978,9-1990,1-2000,1-2005 and 2006-2011-were 0.40,0.60,0.75,0.92 and 0.96, respectively. The MSW DOC content of the three stages-1959-1990,1-2000 and 2001-2011 were 9.34%, 15.22%, and 15.05%, respectively, revealing that the DOC values of northern and southern China showed an increasing trend. The value of t_1/2 was 2.30 a, and the value of the k was 0.30 a-1.