Characterizations of fine particle compositions and organic aerosol source analysis during the 2022 epidemic lockdown in a city on the southern edge of the North China Plain
To investigate the changes in particulate matter(PM)and organic aerosols at different control stages during the COVID-19 epidemic lockdown in Luohe City,we collected online monitoring data of PM chemical compositions in the study city from 1 March to 31 May 2022,and used the positive matrix factorization(PMF)model to analyze the sources of organic aerosols.The results showed that the average mass concentrations of PM2.5 and PM10 during the observation period were 45 and 95μg/m3,respectively.The mass concentrations of PM2.5 compositions showed a decreasing and then an increasing trend in the three time periods before,during,and after the lockdown.In all three periods,the contribution of organic matter was the highest,followed by nitrate.The organic aerosol mass spectrometry data during the observation period were analyzed by PMF,and four types of organic aerosols were identified:more oxidized organic aerosol(MO-OOA),less oxidized organic aerosol(LO-OOA),hydrocarbon-like organic aerosol(HOA)and cooking organic aerosol(COA).The contribution of secondary organic aerosols was higher than that of primary organic aerosols throughout the observation and lockdown periods.In terms of pollutant transport,the three phases of transport were mainly concentrated in the western sector,and the impact of transport was reduced during the lockdown due to the implementation of control measures.
万方数据
维普
