Chemical Compositions and Long-range Transport of PM2.5 in Downtown Area of Wuhan
YUAN Chang
ZHOU Jiabin
XIONG Ying
LI Kuan
SHAO Xuan
Abstract：In order to determine the chemical composition of PM2.5 in the downtown area of Wuhan City, as well as investigate its pollution characteristics and the influences of PM2.5 regional transportation, PM2.5 sampling were conducted in Hongshan District for seasons. The findings of the investigation indicated that the annual mean concentration of PM2.5 was 112.7μg/m3; water soluble ions, inorganic elements respectively accounted for 31.3％ and 25.8％ of the PM2.5, and as to carbon, the main component of the PM2.5, including organic carbon (OC) and elemental carbon (EC) accounted for 17.2％ and 4.6％ of the PM2.5, respectively. SO42-, NO3- and NH4+ were the three water soluble ions with the highest concentration accounting for 82.6％ of the total water soluble ions. In autumn and winter there was a high degree of correlation between equivalent concentration of NH4+ and the sum of SO42- plus NO3-. The analysis on enrichment factor (EF) , which evaluated 18 elements in the PM2.5, showed that EFs of Pb, Sb, Ni and Cd were more than 100, being 200.75, 338.4, 360.0 and 500.9 respectively, indicating the anthropogenic influences. The fact that OC concentrations were higher in autumn was related to the biomass burning in the Wuhan's surrounding areas. In this study, the HYSPLIT model was employed to explore the influences of regional transportation of PM2.5 in Wuhan, the 48 h backward trajectories starting at the sampling site (Jianhu campus of Wuhan Univ.of Science & Technology) were calculated every 6 h from 2011-2012. The result indicated that the backward trajectories could be divided into four categories: from Inner Mongolia, Shandong, Henan and Hainan Provinces, among which, PM2.5 concentration of the air mass was the lowest.
Keywords：water soluble ionsinorganic elementanalysis of air mass trajectorylocal emissionanthropogenic source
Publication Date：2018-01-01
Pages：8( 79-86 )