PM2.5and its ionic components at a roadside site in Wuhan, China

Özet

PM2.5samples were collected at a roadside site in Wuhan, China, for one year period. Ion chromatography wasused to determine the water soluble ions in PM2.5samples. Results showed that the overall average of PM2.5masswas 118.1 ± 70.3μgm−3, being slightly higher than those measured in urban sites in Wuhan, China. The majorwater soluble ions were NH4+(8.7 ± 4.0μgm−3), NO3−(12.1 ± 9.5μgm−3), SO42−(15.2 ± 8.2μgm−3),accounting for 21%、29%、37% of quantified total ions, respectively. NH4+,NO3−, and SO42−were closelycorrelated, and (NH4)2SO4and NH4NO3were possibly their main existing forms. Ion concentrations differedgreatly in different seasons, with inconsistent variation pattern for individual ions. Values of NOR (nitrogenoxidation ratio) and SOR (sulfur oxidation ratio) peaked in winter and in summer, respectively. NO3−/SO42−ratio revealed that emission from stationary sources was still remarkable. Significant correlation was observedbetween Mg2+and Ca2+, possibly due to their common source of soil dust. On the other hand, Cl−linked withK+,NO3−,NH4+, and SO42−. The data reported here will provide inputs for human exposure and air pollutioncontrol studies in Wuhan, China.