Research On Characteristics Of Particulate Matter Pollution In Olympic Sports Center Monitoring Station Of Beijing And Impact Of Dust From Surrounding Construction

In order to reflect the particulate matter status and change trend of the Olympic Sports Center monitoring station for a long time,and improve the air quality in Chaoyang District,this paper analyzed the characteristics of particulate pollution and meteorological influence factors in the Olympic Sports Center monitoring station.The impact of construction dust was evaluated based on the distribution of surrounding construction sites.Finally,the construction dust control method around the monitoring station was proposed.The main conclusions of the paper are as follows:From 2014 to 2020,the pollution of fine particles in the Olympic Sports Center monitoring station has eased,and the pollution of coarse particles has deteriorated.Coarse particulate matter accounts for a larger proportion of PM10 in the Olympic Sports Center monitoring station in spring and winter.The monthly change of PM2.5 and PM10 concentration in the monitoring station showed a "U" shape distribution,the hourly concentration change showed a "bimodal" characteristic,and the hourly concentration of coarse particles showed a "trimodal" characteristic.The concentration of particulate matter at night was higher than during the day.In 2018,the particle pollution of the Olympic Sports Center monitoring station was more serious than that of other monitoring stations in Beijing.The dominant wind directions in the Olympic Sports Center monitoring station were northeast wind and southwest wind,and the wind speed had significant monthly and seasonal variations.Correlation analysis showed that the concentration of particulate matter was higher under low wind speed and high humidity,while the concentration of particulate matter was lower under high wind speed and low humidity.The higher particle concentration in the monitoring station in 2017 and 2018 may be due to the higher frequency of static wind.The dilution effect of wind speed on PM2.5 of the monitoring station was better than that on PM10.The emissions of PM10 and PM2.5 from 15 construction sites around the Olympic Sports Center monitoring station were 982.13 t and 363.28 t,respectively.The PM2.5 and PM10 concentration of the monitoring station during the construction site of Winter Olympic Village were 47.0%and 18.7%higher than those during the downtime on average,respectively.The concentration of particulate matter during the unearthed period was higher than that during the non-excavated period,and the concentration of coarse particles was 60.0%higher.The emission factors of PM2.5 and PM10 were different in each construction stage.During the simulation period,the dust from the Winter Olympic Village construction sites contributed 8.2%and 18.4%to the PM2.5 and PM10 concentration of the monitoring station.