北京市大气细颗粒物PM2.5的来源研究

2000-2001年在北京联合大学化学学院、中国预防科学研究院和中国环境科学研究院3个采样点采集北京市PM2.5样品,并对其中无机元素、阴阳离子、有机碳(OC)、元素碳(EC)和有机物进行测定.以多环芳烃和部分无机组分为示踪物,利用CMB受体模型对PM2.5来源进行解析.结果表明,北京市PM2.5的主要来源为燃煤、扬尘、机动车排放、建筑尘、生物质燃烧、二次硫酸盐和硝酸盐及有机物.污染源贡献率随地域变化不大,燃煤、扬尘、生物质燃烧、二次硫酸盐和硝酸盐随季节变化比较明显.与1989-1990年解析结果相比,10年间PM2.5来源发生了一定变化. 

Source Identification of Ambient PM2.5 in Beijing

PM_ 2.5 samples were collected at Lianda, Yufangyuan and Huankeyuan in Beijing during 2000—2001, and elements, ions, OC/EC, and organic compounds were determined. A chemical mass balance (CMB) receptor model using PAHs and some inorganic compounds as tracers was applied in this study to apportion source contributions to ambient PM_ 2.5 in Beijing. The results showed that the major sources of PM_ 2.5 in Beijing were coal burning, dust, vehicle exhaust, construction dust, biomass burning, secondary sulfate and nitrate, and organic matter. The variation of source contributions was not significant among the sampling sites, but distinct seasonality was observed for the sources of coal combustion, dust, biomass burning, and secondary sulfate and nitrate. A comparison with the results obtained in 1989—1990 indicated that source contributions to PM_ 2.5 were changing during the decade.