基于在线监测的南京仙林PM2.5组分特征与来源解析

为了研究南京市PM_2.5的污染特征及来源贡献，于2018年3月至2019年2月在南京仙林地区进行PM_2.5组分的在线监测，运用PMF和CMB受体模型，开展PM_2.5的来源解析.结果表明，观测期间南京市PM_2.5平均质量浓度为54.3μg/m³，其中冬季平均浓度76.4μg/m³.PM_2.5的主要组分为NO₃^-（21.3%~30.8%）、SO₄^2-（18.9%~23.5%）、NH₄⁺（14.3%~16.2%）.从全年平均来看，PMF模型得到的PM_2.5解析结果为：二次无机气溶胶（54.9%）、燃煤源（17.4%）、二次有机气溶胶（7.4%）、机动车排放源（7.1%）、工业源（4.9%）、扬尘源（4.8%）、其他源（3.4%）；CMB模型得到的PM_2.5解析结果为：硝酸盐（33.0%）、硫酸盐（24.0%）、燃煤源（16.4%）、机动车排放源（8.4%）、二次有机气溶胶（7.1%）、扬尘源（5.7%）、其他源（2.9%）、工业源（2.4%）.不同季节PM_2.5来源有所差异，夏冬季二次无机气溶胶占比大于春秋季，春冬季燃煤占比最大，二次有机气溶胶在秋季占比最大.结合2017年南京市大气污染源排放清单，对二次气溶胶贡献进行再解析，得到南京仙林地区PM_2.5主要贡献来自燃煤源（PMF：34.14%，CMB：33.82%），机动车排放源（PMF：27.33%，CMB：29.33%）以及工业源（PMF：26.76%，CMB：24.77%）.可见，影响南京仙林地区PM_2.5的污染源主要来自燃煤源、机动车排放源和工业源，基于在线组分监测、利用PMF和CMB模型得到的PM_2.5源解析结果具有较好的一致性.

Chemical composition and source apportionment of fine particulate matter in Xianlin area of Nanjing basing on-line measurement

In order to study the pollution characteristics and source contribution of PM_2.5 in Nanjing, PM_2.5 and its chemical composition were measured on-line from March 2018 to February 2019 in Xianlin area of Nanjing. The PMF and the CMB models were used to analyze the source contribution of PM_2.5. The resulted show that the average mass concentration of PM_2.5 in Nanjing during the study period was 54.3μg/m³, and the average concentration in winter was 76.4μg/m³. The main chemical components of PM_2.5 were NO₃^-(21.3%~30.8%)、SO₄^2-(18.9%~23.5%)、NH₄⁺(14.3%~16.2%). In terms of annual average, the PMF model showed the source contribution as:secondary inorganic aerosol (54.9%), coal combustion (17.4%), secondary organic aerosol (7.4%), vehicle source (7.1%), industry source (4.9%), dust (4.8%), other sources (3.4%); the CMB model showed the source contribution as:nitrate (33.0%), sulfate (24.0%), coal (16.4%), vehicle source (8.4%), secondary organic aerosol (7.1%), dust (5.7%), other sources (2.9%), and industry source (2.4%). The sources of PM_2.5 in different seasons were slightly different. The proportion of secondary inorganic aerosol in summer and winter was greater than that in spring and autumn. The proportion of coal in spring and winter was the largest, and the proportion of secondary organic aerosol was the largest in autumn. Combined with the 2017 emission inventory of Nanjing, the contribution of secondary aerosol from PMF and CMB was reanalyzed, and it was found that the main contribution of PM_2.5 in Nanjing Xianlin area came from coal combustion (PMF:34.14%, CMB:33.82%), vehicle source (PMF:27.33%, CMB:29.33%) and industrial source (PMF:26.76%, CMB:24.77%). PM_2.5 in Xianlin area of Nanjing was more affected by sources from coal burning, transportation and industry. It could be seen that the results of PM_2.5 source apportionment from PMF and CMB models basing on-line measurement have good consistency.