Mass Size Distributions Of Inorganic Water Soluble Ions In Atmospheric Particles In Jinan

To characterize mass size distributions of water-soluble inorganic ions of atmospheric particles in Jinan, the capital of Shandong Province, particle samples were collected and water-soluble ions include F-,Cl-,NO2-,NO3-,SO42-,Na+,NH4+,K+, Mg2+,Ca2+ were analyzed by ion chromatography. The main conclusions listed as follows:1. Particle pollution of Jinan is serious. The annual average concentrations of PM1.8 and PM10 is 136.01μg/m3 and 229.01μg/m3, The annual average concentration of PM10 is far over the national standard of our country, daily over standard rate is 54%。The concentrations of PM1.8 and PM10 in winter were the highest in all seasons, then is summer, spring and fall. The rate of PM1.8/PM10 in winter and summer is higher than in spring and autumn.2. The correlation between mass concentrations of PM1.8 and PM10 with the visibility was significant. The visibility reduced when the concentration of particle increased.The correlation between visibility with the concentrations of PM1.8 was better than that with PM10.3. The size distributions of the mass concentration of particles were tri-modal in winter and sping, while they were bi-modal in sumer and autumn. The peak in the coarse mode was in 3.2～5.6μm in all seasons. Two peaks appeared in the fine mode of the haze day in winter and spring with the size range of 0.32～0.56μm and 1.0～1.8μm. Size distribution of the fine particle in sumer and fall were singe-modal with the peak in 1.0～1.8μm and 0.56～1.0μm. Both fine particles and coarse particles increased in haze day, but the ratio of fine particles were bigger, indicate that fine particles are more important in the cause of haze.4. The annual average concentrations of TWSI was 92.83μg/m3. Water-soluble inorganic ions accounted for 37% and 47% of the concentrations of PM1.8 and PM10 respectively. The most aboundant ions were SO42,NO3- and NH4+.5. The mass concentrations of the ions in haze day were higher than non-haze day in all the season, especially SO42-,NO3- and NH4+. Mass size distributions of SO42-, NH4+, K+and Ca2+ were singe-modal while that of Cl- and NO3- were bi-modal. SO42-,NH4+ and K+ were dominant in the fine mode, Ca2+ were dominant in the coarse mode, Cl" and NO3" could be fine in both fine and coarse mode.Size distributions of SO42- and NH4+ were the same, peaked at 0.56～1.0μm in fall and 1.0-1.8μm in summer. There was a small peak at 0.32～0.56μm in spring and winter. The peak of NO3- in coarse mode was at 3.2～5.6μm, while the fine mode peak were at 0.56-1.0μm in spring and fall and at 1.0～1.8μm in summer.Two peaks existed in the fine mode of winter.6. According to the analysis during the typical haze episode, the concentration of the water soluble inorganic ions were influenced mainly by wind speed and direction. Size distributions of SO42- were singe-modal which were as the same as NH4+. Mass concentration of SO42- showed good correlation with the mass median diameter. NH4+ could completely neutralize SO42- and NO3- in fine particles. Size distribution of SO42-,NO3- and NH4+ showed little difference between day and night, SO42- and NH4+ were more abundent in daytime but NO3- was more abundent during the night in the fine particle.