基于高分辨率一次重污染过程PM2.5中水溶性无机离子分布特征及影响因素OA

To study the temporal and spatial variation characteristics and potential sources of water-soluble inorganic ions during clean and polluted periods in the five cities of the Guanzhong region,high-resolution real-time online monitoring was employed.Correlation analysis,principal component analysis,multiple linear regression modeling,and potential source contribution analysis were used to analyze atmospheric water-soluble inorganic ions in the five cities of Guanzhong in December 2023.The results showed that during polluted and clean periods,the ρ(PM2.5)in the Guanzhong region were(117.7±40.7)μg/m3 and(47.9±17.1)μg/m3,respectively.During polluted periods,ρ(PM2.5)exceeded the Class II standard(75 μg/m3)by 59.0%and was 2.7 times higher than during clean periods.The proportion of secondary inorganic ions(SNA)in total water-soluble ions was above 85%in both periods.The spatial variation characteristics of water-soluble ions indicated that during polluted periods,the distribution of SNA and PM2.5 was higher in the east and lower in the west,while during clean periods,it was higher in the east and west and lower in the central region,which was consistent with the distribution characteristics of PM2.5.The pollution sources during clean and polluted periods in the Guanzhong region were the same,including secondary formation sources,combustion sources,and dust sources.During the monitoring period,polluted air masses in the five cities of Guanzhong were mainly locally distributed.The trajectories carrying the highest PM2.5 concentrations originated from within Shaanxi Province,primarily from the Guanzhong region,indicating a strong linkage effect of air pollution.