Study On The Characterization And Sources Identification Of Surface Organic Active Substances In Atmospheric Fine Particles In Beijing

At present, the physical and chemical characteristics and processes of atmospheric fine particles have become the forefront research area of atmospheric chemistry and environmental chemistry, in which the study on anion surface organic active substances in atmospheric fine particles is one of the important aspects. The presence of anion surface organic active substances can affect the surface characteristics of atmospheric fine particles such as surface tension and hygroscopicity, thus influencing global climate, atmospheric environment and human health. Based on the theories of atmospheric environmental chemistry, spectroscopy and chromatography, the mass concentrations of anion surface organic active substances and water-soluble inorganic ions were determined by using Ethyl violet Spectrophotometric Method and Ion Chromatography, respectively. Then the pollution characteristics of anion surface organic active substances were studied, such as the mass concentration levels, the diurnal variation characteristics, the relationships with meteorological factor, effect on atmospheric visibility, and seasonal variation characteristics. On this basis, based on the correlation between anion surface organic active substances and water-soluble inorganic ions in atmospheric fine particles, the sources of anion surface organic active substances in atmospheric fine particles were discussed and the the pollution control countermeasures and suggestions of atmospheric fine particles in Beijing were put forward.The results showed that the average mass concentration of anion surface organic active substances in atmospheric fine particles was0.1736μg/m3, and the proportion of anion surface organic active substances in atmospheric fine particles was0.1797%. Compared to other overseas cities, the mass concentrations of anion surface organic substances in atmospheric fine particles were higher. The relationship of mass concentrations of anion surface organic active substances in atmospheric fine particles in four seasons was summer> autumn> spring> winter, and the relationship of the load per unit of mass anion surface organic active substances in atmospheric fine particles in four seasons was winter> summer> autumn> spring. The mass concentrations of anion surface organic active substances in atmospheric fine particles and atmospheric fine particles had the same variation trend, but the load per unit of mass anion surface organic active substances in atmospheric fine particles and the mass concentrations of atmospheric fine particles had the opposite variation trend. The mass concentrations of anion surface organic active substances in atmospheric fine particles in nighttime were basically higher than in daytime. The average mass concentrations in day and night were0.1521μg/m3,0.1893μg/m3, respectively.The mass concentrations of atmospheric fine particles in Beijing were not affected by Atmospheric environmental temperature. Atmospheric environmental temperature had little influence on the mass concentrations of anion surface organic active substances in atmospheric fine particles in Beijing. Relative humidity had small influence on the mass concentrations of atmospheric fine particles in Beijing but had great influence on the mass concentrations of anion surface organic active substances in atmospheric fine particles. Precipitation had the scouring effect on anion surface organic active substances in atmospheric fine particles. Atmospheric fine particles in Beijing had little negative impact on solar radiaton intensity. The anion surface organic active substances in atmospheric fine particles had small negative impact on solar radiaton intensity, which had a certain contribution to the influence of atmospheric fine particles. Moreover, the anion surface organic active substances in atmospheric fine particles was one of the main reasons of atmospheric fine particles negative influence on atmospheric visibility, and the effect was largest in spring but was smallest in summer.The mass concentrations of anion surface organic active substances and NE4+, NO3-, SO42-in atmospheric fine particles had better correlation at all seasons in Beijing. What’s more, the correlation of anion surface organic active substances and K+in atmospheric fine particles was also better in autumn because of biomass combustion. Combined with the Principal Component Analysis results of water-soluble inorganic ions, the main sources of anion surface organic active substances in atmospheric fine particles in Beijing were the motor vehicle exhaust in spring, summer and autumn, In spring and autumn, the sources of anion surface organic active substances in atmospheric fine particles were also influenced by coal burning activities and biomass combustion, respectively. The coal burning activities were the main source of anion surface organic active substances in winter. Therefore, in order to reduce the negative impact of anion surface organic active substances in atmospheric fine particles on atmospheric environment, the motor vehicle pollution prevention and control should be strengthened, the motor vehicle exhaust pollution should be controled effectively, the large motor vehicle should be strictly controlled at nighttime, the energy structure should be further improved, the coal emissions should be reduced, and the environmental supervision of the biomass burning combustions should be strengthened.