Ma Ke-Jing, Sun Li-Juan
Gansu Environmental Monitoring Center, Lanzhou 730000, China.
Huan Jing Ke Xue. 2023 Nov 8;44(11):5997-6006. doi: 10.13227/j.hjkx.202211331.
To study the pollution characteristics and sources of 16 PAHs in PM in Lanzhou, PM samples were collected in four seasons. GC-MS was employed to analyze the concentration of PAHs. Positive matrix factorization(PMF), trajectory cluster, and potential source contribution function(PSCF) were used to identify the sources of PAHs. The results indicated that the average concentration of PAHs in PM in Lanzhou decreased in the order of winter[(118±16.2) ng·m]>autumn[(50.8±21.6) ng·m]>spring[(22.2±8.87) ng·m]>summer[(4.65±1.32) ng·m]. The results of correlation analysis showed that PM and TPAHs in Lanzhou had an extremely significant negative correlation with temperature; an extremely significant positive correlation with atmospheric pressure; and a poor correlation with wind direction, wind speed, and relative humidity. The proportion of PAHs with 4-5 rings was much higher than that of those with 6 rings and 2-3 rings, with similar results across the four seasons. Source apportionment results illustrated that the contribution of industrial emissions and biomass and natural gas combustion were dominant in spring and summer seasons. Industrial emissions and coal combustion were dominant in autumn and winter, respectively. The vehicle emissions had no significant change across the four seasons. Trajectory cluster and PSCF analyses showed that the airflow coming from Mongolia, northeast Xinjiang, and Qinghai had important effects on the ambient air quality in Lanzhou.
为研究兰州市大气颗粒物（PM）中16种多环芳烃（PAHs）的污染特征及来源，于四季采集了PM样本。采用气相色谱 - 质谱联用仪（GC - MS）分析PAHs的浓度。运用正定矩阵因子分解法（PMF）、轨迹聚类法和潜在源贡献函数（PSCF）来识别PAHs的来源。结果表明，兰州市PM中PAHs的平均浓度大小顺序为：冬季[（118±16.2）ng·m⁻³]＞秋季[（50.8±21.6）ng·m⁻³]＞春季[（22.2±8.87）ng·m⁻³]＞夏季[（4.65±1.32）ng·m⁻³]。相关性分析结果显示，兰州市的PM和总PAHs（TPAHs）与温度呈极显著负相关；与大气压力呈极显著正相关；与风向、风速和相对湿度相关性较差。4 - 5环PAHs的占比远高于6环及2 - 3环PAHs，四季结果类似。源解析结果表明，工业排放以及生物质和天然气燃烧的贡献在春夏季占主导地位。工业排放和煤炭燃烧分别在秋冬季占主导地位。车辆排放四季变化不显著。轨迹聚类和PSCF分析表明，来自蒙古、新疆东北部和青海的气流对兰州市环境空气质量有重要影响。
