湘潭市酸雨污染状况、化学组成及其防治对策

根据2001—2005年湘潭市城区降水环境质量监测数据，对湘潭城区酸性降水的变化特征、离子化学组成、变化趋势和酸雨成因进行了分析。“十五期间”湘潭市区酸雨频率在50％以上，pH值平均范围在4．56—4．91，属重酸雨区；SO4^2-／NO3^-比值为4．93～6．13，属典型硫酸型；湘潭城区酸雨有明显的季节变化规律，春季和冬季酸雨出现的频率最多，秋季最少；酸雨分布没有明显的地区差异。依据相关系数法检验，湘潭市的酸雨从总体上看污染趋势无显著性变化，呈现相对稳定状态。

Acid Rain Pollution Situation and its Chemical Components and Countermeasures in Xiangtan

The changing characteristics and chemical components and origin of acid rain in Xiangtan urban area are analyzed according monitoring data of precipitation quality from 2001 to 2005. The acid rain frequency in Xiangtan urban areas is above 50% during the tenth - five - year period, the average scale of pH value is from 4. 56 to 4.91, which represents serious acid rain area. The ration of SO4^2- to NO3^- is from 4. 93 to 6. 13, which represents typical sulfur acid rain. The changes of acid rain has distinct changing rules in different seasons, the most frequencies happen in spring and winter, the least in fall. However, there are no obvious district differences. In a word, there is no distinct difference of pollution trend in Xiangtan, which shows related stable state tested by coefficient of correlation method.