Regional transport analysis of water-soluble ions in PM2.5 in the southeast transmission channel of Wuhan during the military game
The 7th world military game was held in Wuhan,in October 2019.PM2.5samples were collected in Wuhan and Huangshi from October 10,2019 to November 5,2019,for investigating the concentration cha-racteristics and regional transmission of atmospheric fine particles during the world military game.And the concentration characteristics of water-soluble ions(WSIs)in PM2.-were analyzed.Potential source contri-bution factor(PSCF)and concentration weighted trajectory(CWT)through the backward trajectory of air mass were applied to studying the regional transmission of pollutants between the two stations.The results demonstrate that the PM2.5 concentration of 21.7%(Wuhan)and 17.4%(Huangshi)samples exceed 75μg/m3,which is the second limit value of 24-hour average concentration in the China's National Ambient Air Quality Standards(GB 3095-2012).In addition,NO3-、SO42-,and NH4+are the main components of the WSIs in PM2 5.The fitting curve rate of CE/AE ratio at Huangshi station is lower than 1,indicating that PM2.5 are weakly acidic,while the fitting curve slope of CE/AE ratio at Wuhan station is greater than 1,indicating that the PM2.5 are neutral or weakly alkaline.The main forms of WSIs in PM2.5 are NH4HSO4 or(NH4)2SO4 for two sites.The proportion of ammonia deficient samples at Wuhan site is 30.4%,while the proportion at Huangshi site is 43.5%.The results of principal component analysis(PCA)indicate that the pollution sources at the two sites are consistent,with secondary pollution sources,dust sources,and biomass combustion sources as the main sources.The results of PSCF and CWT analysis reveal that Huangshi is the main potential source area of PM2.5 at Wuhan station.The results of PSCF and CWT anal-ysis revealed that Huangshi is the main source area of PM2.5 at Wuhan station,with the WPSCF factor greater than 0.7 and a concentration contribution weight exceeding 45 μg/m3.The main potential source area of Huangshi station is located at the border of Hubei and Anhui Province and Anqing City,Anhui Province.
PM2.5water-soluble ionregional transportPSCTCWTWuhan CityHuangshi City