| Atmospheric particles are increasingly become a hot research field of atmospheric science and become an increasing concern of experts in various fields, just because of its distribution in the atmosphere in a wide range of complex chemical composition, spatial variation, and the impact on regional and global climate, air quality. This paper chose Xi’an as the object of study, and select industrial and transportation area (Daqing Road), commercial traffic area (Xiaozhai), light industry and residential areas (Textile City), and educational residential area (southern suburbs) of four representative functional areas as sampling points. This study use TSP middle-flow sampler to collected atmospheric TSP samples in July2011to August and December2011to January2012. The paper use gravimetric method, ion chromatography and atomic absorption spectroscopy to analyze the mass concentration, soluble ions and heavy metal components of TSP samples, and draw the following conclusions:(1) The atmospheric TSPmass concentration in Xi’an generally appeared higher in winter than summer. The summer average concentration is391.6μg/m’, the average winter concentration is569.6μg/m3. Different pollution levels in each district depends on the distribution of district pollution sources. Industrial area and traffic area TSP mass concentrations are higher than the residential areas and cultural and educational area. From1999to2001, the atmosphere TSP mass concentrations overall show a downward trend in Xi’an, but the TSP pollution in some areas is still a serious problem. The atmospheric TSP mass average concentration is480.6μg/m3, still in at a high level relative to other cities at home and abroad.(2) Xi’an atmospheric particulate matter is neutral, weakly alkaline in summer, and appears neutral, weak acid in winter. The water-soluble ions of particulate matter are mainly contribute by SO42-, NO3-, NH4+, K+and Ca2+composition. Water-soluble ion concentrations in atmospheric aerosol in winter were significantly higher than summer. Four functional areas of atmospheric particulate matter soluble ions, the F-, Cl-, Na+, K+and Mg2+the pollution degree of light, and regional differences in little; heavier of SO42-, NO3-, NH4+and Ca2+the pollution degree of industrial sources the relative concentration of the city of Daqing Road and textile SO42-high pollution levels, traffic source relative concentration of Daqing Road and the hamlet of NO3-pollution levels higher and higher; southern suburbs of NH4+and Ca2+concentration. Atmospheric particulate matter in Xi’an of NO3-, SO42-and NH4+concentration compared other cities are at a high level, with India Dadanagar levels. (3) Through the calculation of NO3-/SO42-ratio shows, Xi’an vehicle exhaust emissions in traffic-intensive areas had more contribution of NO2in atmosphere, a similar contribution of the industrial traffic vehicle exhaust and coal-fired emissions of SO2and NO2in the atmosphere, culture and education to residential and light industrial air of residential areasof SO2and NO2is mainly derived from coal.(4) The mass concentration of heavy metal components in the atmospheric particulate matter in winter are higher than summer in Xi’an, Pb, Cr, Zn pollution are both seriously in winter and summer, the concentration change with the seasons changes of Pb inseasonal variation is most intense; Cu, Ni, Co in Xi’an atmospheric particulate matter pollution is light. Daqing Road, heavy metals in atmospheric particulate matter pollution in the four functional areas are the most serious, of Pb, Cr, Zn three pollutants; the main hamlet, Pb, Zn pollution; Zn in the southern suburbs of atmospheric particulate matter. Xi’an atmosphere TSP heavy metal pollution levels in the country is a high level.areas are the most serious, of Pb, Cr, Zn three pollutants; the main hamlet, Pb, Zn pollution; Zn in the southern suburbs of atmospheric particulate matter. The Xi’an TSP heavy metal pollution is a higher level in China. |
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