A cross-section study of the seasonal features of PM2.5and inorganic components in Lanzhou City
Objective To analyze the inorganic components of PM2.5 in Lanzhou,Gansu Province,and to identify the major pollutants and pollution seasons,in order to provide reference for the municipal government to control air pollution.Methods Air samples were collected from 2 surveillance sites in Chengguan District and Xigu District of Lanzhou in 2015.The PM2.5 and 4 types of inorganic components were detected to reveal their seasonal trends.Results No significant difference in the concentration of PM2.5 was observed between samples collected from the 2 sites(Z=-1.932,P=0.053).In samples collected from Chengguan District,the concentration of sulphate was not significantly different(HC=9.793,P=0.020)among 4 seasons,ranging from 10.9 to 15.5 μg/m3.The concentrations of nitrate salt,chloride ion and ammonium salt were significantly different(P<0.05)among 4 seasons.The concentration of nitrate salt was the highest in the winter(11.8 μg/m3),and the lowest in the autumn(2.80 μg/m3).The concentration of chloride ion was the highest in the spring(4.62 μg/m3),and the lowest in the summer(2.12 μg/m3).The concentration of ammonium salt was the highest in the spring(1.09 μg/m3),and the lowest in the autumn(0.099 μg/m3).In Xigu district,the concentration of sulphate was not significantly different(HC=10.841,P=0.013)among the 4 seasons,ranging from 11.5 to 15.7 μg/m3.There were significant differences in the concentrations of nitrate salt,chloride ion and ammonium salt(P>0.05).The concentration of nitrate salt was the highest in the winter(15.6 μg/m3),and the lowest in the summer(2.32 μg/m3).The concentration of chloride ion was the highest in the winter(5.28 μg/m3),and the lowest in the summer(2.10 μg/m3).The concentration of ammonium salt was the highest in the spring(1.13 μg/m3),and the lowest in the summer(0.12 μg/m3).Conclusions The concentrations of the 4 types of inorganic components in PM2.5 are not significantly different between the 2 districts.The concentrations of nitrate salt,chloride ion and ammonium salt have obvious seasonal trend through 2015.Hence,the measures to prevent air pollution should accord with the seasonal characteristics.
NETL
NSTL
万方数据
维普
