港口地区大气PM2.5中多环芳烃污染特征及来源分析

为探究港口地区污染大气中多环芳烃（PAHs）的污染特征和潜在来源，以青岛港为研究对象，于2018年8月至2019年5月期间采集了4个季节的PM_2.5样品（n=59），分析了PM_2.5中PAHs的季节变化和组成特征，使用相关性分析探索了气象因素对PAHs浓度的影响，并采用正定矩阵因子分解和潜在来源贡献函数模型对潜在来源进行解析.结果表明，ρ（PAHs）平均值为（8.11±12.31） ng·m^-3，秋冬季节高于春夏季节.PAHs的季节性分子组成相似，以4~5环PAHs （75.43%）为主.荧蒽、苯并［e］芘、苯并［a］蒽、菲、芘和䓛是研究区域PAHs的优势物种，这与船舶尾气中主要化合物组成相似.相关性分析表明，PAHs浓度与温度和相对湿度呈极显著负相关，与大气压和风向呈极显著正相关，与风速的相关性较差.PMF分析提取出6个贡献因子，结果表明，青岛港地区受航运排放（28.83%）影响最大，其次是机动车排放（20.49%）以及原油挥发（13.47%）等，夏季受航运排放影响最大.PSCF结果表明，京津冀、环渤海和鲁北地区是远距离传输的主要来源区域.

Pollution Characteristics and Source Analysis of Atmospheric PM2.5-bound Polycyclic Aromatic Hydrocarbons in a Port Area

In order to explore the pollution characteristics and potential sources of polycyclic aromatic hydrocarbons (PAHs) in the polluted air of a port area, PM_2.5 samples (n=59) were collected from Qingdao Port for four seasons from August 2018 to May 2019. The seasonal variation and composition characteristics of PM_2.5-bound PAHs were analyzed, the influence of meteorological factors on PAH concentrations was explored using correlation analysis, and the potential sources were analyzed using positive definite matrix factorization and potential source contribution function models. The results showed that the total mean concentration of PAHs was (8.11±12.31) ng·m^-3, which was higher in autumn and winter than that in spring and summer. The seasonal molecular compositions of PAHs were similar, dominated by 4-5 ring PAHs (75.43%). Fluoranthene, benzoe]pyrene, benzoa]anthracene, phenanthrene, pyrene, and chrysene were the dominant species of PAHs in the study area, which are similar to the major compounds in ship exhaust. Correlation analysis showed that PAH concentrations were significantly negatively correlated with temperature and relative humidity and significantly positively correlated with atmospheric pressure and wind direction and had a poor correlation with wind speed. PMF analysis extracted six contribution factors, and the results indicated that Qingdao Port was mainly influenced by shipping emissions (28.83%), followed by vehicle emissions (20.49%), as well as crude oil volatilization (13.47%). Summer had the greatest impact on shipping emissions. The PSCF results suggested that Beijing-Tianjin-Hebei, Bohai Rim, and northern Shandong were the main source regions for long-range transport.