[Characteristics of Water-soluble Inorganic Ions in PM2.5 and PM2.5-10 in Mountain Background Region of East China in Spring].

PM2.5 and PM2.5-10 samples were collected during March to May of 2014 at the National atmospheric background monitoring station (Wuyishan station) in Fujian Province. Water-soluble inorganic ions in PM2.5 and PM2.5-10 were determined. Meteorological parameters and air pollutants including SO2, NO2, O3, PM10 and PM2.5 were also recorded. The results showed the total water-soluble inorganic ions concentrations were (8.3 ± 2.8 ) µg x m(-3) and (1.3 ± 0.9) µg x m(-3), which accounted for (43.7 ± 7.5) % and (24.4 ± 6.4) % of the PM2.5 and PM2.5-10 mass, respectively. Sulfate and nitrate were the dominant ions in PM2.5 and PM2.5-10, respectively, which accounted for (32.4 ± 6.3) % and (8.9 ± 3.7) % of them, respectively. Sulfate mainly existed in fine particle in the forms of (NH4)2SO4 and K2SO4, while nitrate mainly existed in coarse particle in the form of Mg(NO3)2. The water-soluble inorganic ions at the Wuyishan background monitoring station in spring mainly came from long-distance transportation of dust , sea salt and pollutant of heavy polluted regions.

[Influence of atmospheric transport on air pollutant levels at a mountain background site of East China].

Transport characteristics of air pollutants transported to the background atmosphere of East China were investigated using HYSPLIT (Hybrid Single Particle Lagrangian Integrated Trajectory) 4.8 model driven by NCEP reanalysis data during June 2011 to May 2012. Based on the air pollutants monitoring data collected at the National atmospheric background monitoring station (Wuyishan station) in Fujian Province, characteristics of different clustered air masses as well as the origins of highly polluted air masses were further examined. The results showed that 65% of all the trajectories, in which air masses mainly passed over highly polluted area of East China, Jiangxi province and upper air in desert areas of Northwest China, carried polluted air to the station, while the rest of trajectories (35%) with air masses originated from ocean could effectively remove air pollutants at the Wuyishan station. However, the impact on the air pollutants for each air mass group varied with seasons. Elevated SO2 concentrations observed at the background station were mainly influenced by coal burning activities in Northern China during heating season. The high CO concentrations were likely associated with the pollutants emission in the process of coal production and consumption in Anhui province. The elevated NO(x), O3, PM10 and PM2.5 concentrations were mostly impacted by East China with high levels of air pollutants.