Research On The Physical And Chemical Properties Of Atmospheric Particulates In Nanjing

Pollutions with aerosol and of the polycyclic aromatic hydrocarbons is the main forms of atmospheric pollution in many City at present. With the study of the distribution of PAHs and the water-soluble in atmospheric pollution, it has an important theoretical and practical value in the development of pollution control measures to improve the quality of human life.Field observations, sample analysis and statistical methods are used in this study. Different Atmospheric particles samples is collected in different function zones of Nanjing during 2007 and 2008. The extractable PAHs and WISC are obtained. Their pollution level, distribution characteristics, seasonal variation is illustrated. Spatial-temporal variation and sources of Polycyclic Aromatic Hydrocarbons(PAHs) and water-soluble inorganic ions in atmospheric particle are analyzed detailed. We discuss their spatial and seasonal variations,reveal the mechanism of pollution into research of various sources of particles contribute to the rate of components, and the conclusions as follow:(1) For all the functional areas,the concentration of fine particles in the fall is lower than that in the summer.The PM10 particles in most functional area appears bimodal distribution, PM10 mass concentration were related with both coarse and fine particles. The daily concentrations of PM2.1 and PM10 had the similar trend.The diurnal range of the concentration of PM10 was greater than PM2.5,which showed changes in weather conditions had more obvious impact in coarse particles than fine particles.During the daytime,concentration of PM10 was 1.08 times than the national standard,which was 2.08 times in PM2.1.(2) PAHs concentration of fine particles in the summer were significantly lower than that in autumn in Nanjing, the PAHs in PM2.1 are mostly adsorbed on the PM1.1.The fine particles in the PAHs in Summer and autumn, have apparent distribution characteristics in space and time, The summer low-ring PAHs content of functional areas to be significantly less than in autumn.Adopting Source identification parameters method to analysis the resource of the PAHs of the fine particles in different functional atomosphere areas in Nanjing,it has found that PAHs mainly come from the incomplete combustion of fossil fuels.(3) Major anions were water-soluble SO42- in Nanjing,and sea salt to the northern suburb of atmospheric in Nanjing had little effect on the concentration of SO42-.SO42-,Cl-and F- had similar distribution,showed bimodal distribution;NO3- and NO2" showed single mode.There were significant correlation between SO42- and NO3-,F-and NO3-,SO42-and Cl-, indicating there were some homology.NO3-/SO42-during the day and night were much smaller than 1,indicating that the main source of air pollution in northern suburb of Nanjing was stationary sources.The highest concentration in the WSIC is SO42-,which proved the main pollution in the northern suburb of Nanjing is from coal.The correlation coefficient between WSIC and coarse particles(PM2.1-20) was better than with fine particles (PM2.1),which showed most WSIC latches on PM2.1-10.