宁波市冬季PM_(2.5)污染特征与来源解析

Analysis of Pollution Characteristics and Sources of PM_(2.5) in Winter of Ningbo City

为了了解宁波市大气中PM2.5污染特征及来源,于2012年冬季在宁波5个环境受体点采集PM2.5样品,分析它们的质量浓度及多种无机元素、水溶性离子、金属元素和碳等组分的含量,并使用PMF模型对宁波市PM2.5来源进行了解析。结果表明：宁波冬季PM2.5浓度较高,5个点位PM2.5中主要化学组分均为有机物、SO42-、NO3-、NH4＋和元素碳,约占PM2.5总质量浓度78.2%~92.4%。对宁波市PM2.5有重要贡献的源类分别为钢铁冶炼源、混合扬尘源、生物质燃烧源、二次硝酸盐、高氯源、机动车排放源、重油燃烧源和二次硫酸盐,其分担率分别为5.6%、3.3%、3.2%、28.8%、6.8%、22.2%、0.7%和29.4%。

To understand the concentrations and sources of PM2.5 in Ningbo City, Zhejiang Province, samples of PM2.5 and sources of particulate matter were collected in winter of 2012 at five sites in Ningb0． The inorganic elements, water solvent ions, metallic element and carbon species were analyzed to identify the sources of PM2.5. The sources of PM2.5 in the City were analyzed based on PMF receptor model, and results showed that the concentration of PM2.5 was relatively high in winter. For the five sites, the dominant chemical components in PM2.5 were SO42-, NO3-, NH4＋, organics and EC, accounting for 78.2%- 92,4% of PM2.5.The most important PM2.5 sources were suspended iron and steel smelting source, mixed dust, biomass burning, nitrates, high chloride source, vehicle exhaust, heavy oil combustion and sulfates, with contributions of 5.6%, 3.3%, 3.2%, 28.8%, 6.8%, 22.2%, 0.7% and 29.4% respectively.