上海金山区酸雨分布特征及降水酸度主控因子探讨

依据上海金山区2006-2010年降水监测数据,分析了该地区降水pH年均值、酸度及酸雨频率的分布特征,并对降水化学组成及各离子间的相关性进行了分析。结果表明,2006-2010年金山区降水的酸化及酸化频率较高,pH均值为4.24,酸雨频率为86.4%。降水主要离子为SO42-、NO3-、NH4+、Ca2+和Na+,上述5种离子占降水离子总浓度的87.8%,主要酸性离子SO42-、NO3-与阳离子NH4+、Ca2+和Mg2+均具有较高相关性。通过对降水酸度主控因子的探讨发现,主要致酸物质为SO42-,但NO3-对降水酸度的影响越来越大,碱性物质中和作用中起主导地位的是NH4+,雨水酸化的最主要来源为人为污染源。

Distribution of Acid Rain and Primary Factors of Rainwater Acidity in Jinshan District, Shanghai

Distribution of annual pH value,acidity and frequency of acid rain in Jinshan District,Shanghai was analyzed based on local rainwater monitoring data from 2006 to 2010.Chemical composition of acid rain and correlation of ions were also analyzed.Results showed that pH value of the samples was 4.24,frequency of acid rain 86.4%.Ionic composition analysis indicated that SO42-,NO3-,NH4+,Ca2+and Na+were dominant ions in rainwater,and correlation coefficients between SO42-,NO3-,NH4+,Ca2+and Mg2+were comparatively high.SO42-remained the dominant acidic ion in terms of concentration,NO3-was becoming very important to the acidification of rainwater,and NH4+ appeared to play significant role in neutralizing the acidity in rainwater.Human pollution is the most important source of the acidity of rainwater.