【摘要】 为了解庐山降水的化学特征和酸化趋势,于2011年夏季及2012年春季在庐山进行降水采集,对降水的p H、主要阴阳离子和有机酸进行分析。结果表明,酸性降水出现频率为100%,p H均值为4.44。降水中SO₄^2-、NH₄⁺、NO₃^-和Ca²⁺占总离子的70.1%,降水酸度主要贡献为H₂SO457%、HNO₃25%及有机酸19%。降水的相对酸度较高,在2011年夏季和2012年春季分别为0.47和0.32。而SO₄^2-/NO₃^-则分别为2.28和2.63。相对于1993年春季,庐山降水酸度趋于降低,SO₄^2-、Ca²⁺浓度水平下降明显,而NH₄⁺、NO₃^-略有升高,HNO₃对酸度的贡献增加,降水已由硫酸型污染转成混合型污染。相对于国内其他背景站点,庐山降水酸度较高,但总离子浓度水平较低,因此庐山作为研究中国东南酸雨区的背景站点具有一定的科学意义。更多还原

【Abstract】 In order to investigate the chemical characteristics and acidification trend of precipitation at Mount Lushan,precipitation samples were collected during the summer of 2011 and spring of 2012,and p H value and concentrations of major ions and organic acids were analyzed. Results indicated that all precipitation samples had been acidified with the volume weighted mean p H 4.44. The dominant ions of precipitation were SO₄^2-,NH₄⁺,NO₃-and Ca²⁺,which accounted for70.1% of the total ions. The acidities were mainly attribute to H₂SO457%,followed by HNO₃25% and organic acid 19%. The fractional acidity of precipitation was 0.47 in 2011 and 0.32 in 2012 respectively,while the ratio of SO₄^2-/NO₃^-was 2.28 and2.63,indicting high acidity. Compared with precipitation in 1993,the acidity tended to reduce,the concentrations of SO₄^2-and Ca^{2 +}decreased and NH₄⁺,NO₃^-slightly increased. The increase contribution of HNO₃ to acidity put the precipitation pollution type into sulfuric acid- nitrate component. The acidity was found higher and total ions concentration levels lower than other background sites in China,indicating Mount Lushan is a significant background site for acid precipitation researches.更多还原