无锡市区环境空气中PM10来源解析

于2005年采集了无锡市区PM₁₀源和受体样品,并测定了无机元素、水溶性离子和碳等组分的含量. 采用OC/EC〔即ρ(OC)/ρ(EC)〕最小比值法确定了二次有机碳(Secondary Organic Carbon)对PM₁₀的贡献,并据此重新构建了受体化学成分谱,使用化学质量平衡受体模型(CMB)和二重源解析技术对无锡市区的PM₁₀来源进行了解析. 结果表明:城市扬尘是无锡市环境空气中PM₁₀的主要来源,其分担率达50.49%;煤烟尘和机动车尾气尘的分担率也分别为13.97%和7.80%;其他重要源类按分担率依次为二次有机碳,SO₄2-,建筑水泥尘,NO₃-,土壤尘和钢铁尘等,其中二次有机碳年贡献值为6.94 μg/m3,年分担率为6.18%. 

Source Apportionment of Ambient PM10 in Urban Area of Wuxi City

Samples from both ambient particulate matter (PM₁₀) and PM10 sources were collected in Wuxi City in 2005. Their inorganic elements, water-solvent ionsand carbon species were analyzed to identify the sources of PM₁₀. Contribution of secondary organic carbon (SOC) to PM₁₀ was determined by the “OC/EC minimum ratio" technique, and the chemical profiles of sources and ambient PM10 were established. Sources of PM₁₀ in Wuxi City were analyzed based onthe chemical mass balance (CMB) receptor model and nested chemical mass balance(NCMB). The results showed that suspended dust was the most important PM10 source with a contribution of 50.49%; flying ash from coal combustion and vehicle exhaust were also important sources with contributions of 13.97% and 7.80%, respectively. Sources like SOC, SO₄2-, construction cement dust, NO₃-, soil dust and Ferrous dust were all significant contributive sources toambient PM₁₀. The annual average SOC concentration was 6.94 μg/m3, accounting for 6.18% of the total mass in ambient PM₁₀.