【作者】 唐傲寒； 庄国顺；

【Author】 Aohan Tang Guoshun ZhuangThe Center for Atmospheric Environment Study, Beijing Normal University, Beijing, China,100875

【机构】 北京师范大学大气环境研究中心；

【摘要】 对2003年3-11月在北京师范大学采集的53个降水样品进行了分析,其结果显示,降水平均pH值为6.48,属非酸性降水;主要离子成分按浓度高低依次为SO42-、NH4+、Ca2+、NO3-、C1-、Mg2、Na+、F-、K+;SO42-是北京降水中的主要致酸物质,NO3-的致酸作用有所上升,Ca2+、NH4+中和缓冲降水中的酸性物质;降水的pH值与各离子浓度无明显相关性,但与大气中SO2、NO2,TSP,PM10的浓度明显相关;北京降水离子浓度大大增加,大气污染程度加剧;近二十年来Ca2+离子浓度和pH值的变化明显正相关,说明Ca2+耐北京降水起了最主要的缓冲中和作用,pH值虽有降低趋势但仍属非酸性降水范围。更多还原

【Abstract】 53 rain events collected from March to November 2003 at Beijing were analyzed: The average pH value is 6.48 and in alkaline range. Major soluble ions are SO42-, NO3-, Cl-, NH4+, Ca2+, Mg2+, K, F-. SO42- is the predominant acid anion but the acidic effect of NO3- is more and more important. NH4+ and Ca2+ act as acid neutralizers of the rain acidity. There are apparent correlations between pH and concentrations of SO2, NO2, TSP and PM10 at atmosphere, unlike the noncorrelation of pH and ion concentrations of rain samples. The higher ionic concentration of rainwater indicates that air pollution is more and more serious in Beijing. A remarkable positive correlation between pH and Ca2+ concentration illustrates that calcium play an important role in buffering rainwater acidity all the time. There is a decline tendency of pH value but it is still in non-acid range.更多还原