合肥市大气PM2.5中多环芳烃污染水平及来源解析

目的 分析合肥市大气PM_2.5中多环芳烃(polycyclic aromatic hydrocarbons,PAHs)污染水平及来源解析,为治理合肥市大气污染提供科学参考。 方法 采集2018年2月—2019年1月合肥市大气PM_2.5中PAHs,利用超声萃取-高效液相色谱-荧光检测器-PDA测定,采用特征比值、主成分分析和正定矩阵因子分解模型3种方法对大气PM_2.5中PAHs来源解析。 结果 合肥市大气PM_2.5中PAHs Σ16PAHs年平均浓度(9.25±6.72)ng/m³,其中7种致癌性ΣcPAHs 年平均浓度在(4.67±3.88) ng/m³。3种来源分析方法结果基本一致,滨湖新区大气PM_2.5中PAHs主要来源是汽油和柴油燃烧源、炼焦源、燃煤源、生物质燃烧源,贡献率分别占43.07%、15.21%、11.24%和10.93%;瑶海区大气PM_2.5中PAHs主要来源是汽油和柴油燃烧、燃煤源、炼焦源、生物质燃烧源,贡献率分别为45.93%、16.49%、11.73%和10.08%,合肥市市区(瑶海区)和郊区(滨湖新区)两监测点PAHs主要来源存在一定的差异。 结论 合肥市大气PM_2.5中PAHs含量总体水平较低,多环芳烃来源以交通石油和柴油燃烧源为主。

Pollution level and source apportionment of polycyclic aromatic hydrocarbons in atmospheric PM2.5 in Hefei city

Objective To analyze the pollution level and source apportionment of polycyclic aromatic hydrocarbons (PAHs) in atmospheric PM2.5 in Hefei city, and to provide a scientific basis for control and management of atmospheric PAHs pollution in Hefei city. Methods High performance liquid chromatography-fluorescence detector-PDA was used to detect the concentration of atmospheric PAHs in PM_2.5 samples collected in Hefei city from February 2018 to January 2019. Three kinds of analytical methods, including characteristic ratio, principal component analysis (PCA) and positive definite matrix factorization (PMF) model, were employed to perform source apportionment of PAHs. Results The annual average concentration of Σ16PAHs in atmospheric PM_2.5 in Hefei city was (9.25±6.72) ng/m³, and the annual average concentration of 7 kinds of carcinogenic ΣcPAHs was (4.67±3.88) ng/m³. The results of the source apportionment by characteristic ratio method, PCA and PMF model were basically similar. Gasoline and diesel combustion, coke combustion, coal combustion and biomass combustion were the main sources of PAHs in atmospheric PM_2.5 in Binhu new district, with the contribution rates being 43.07%, 15.21%, 11.24% and 10.93%, respectively. Gasoline and diesel combustion, coal combustion, coke combustion and biomass combustion were the main sources of PAHs in atmospheric PM_2.5 in Yaohai district, with the contribution rates being 45.93%, 16.49%, 11.73% and 10.08%, respectively. There existed some differences in the main sources of PAHs between urban area (Yaohai district) and suburban area(Binhu new district) in Hefei city. Conclusions The total pollution level of PAHs in atmospheric PM_2.5 in Hefei city is relatively low, and the main sources of PAHs are traffic petroleum and diesel combustion.