桂林市酸雨的时空分布及汞污染

Time-Space Distribution and Mercury Pollution of the Acid Rain in Guilin

对桂林市进行了连续一年的降雨监测和一次降雨面状监测研究。共采集雨水样74件,测定pH值、电导率、汞和10种阴阳离子含量。结果表明,桂林市属典型酸雨区,pH值月平均值范围为3.84~5.38,雨水酸雨频率为81%,酸雨强度为冬季>秋季>春季>夏季。雨水汞含量月平均值与雨水酸度、电导率值呈正相关。雨水汞含量在空间分布上具有北低南高、市区高周边低、沿交通干线最高的基本规律。Hg与SO_4^(2-)、F^-属同一因子组合。燃煤释放为桂林市雨水汞污染的主要来源。汽车尾气汞污染亦是雨水汞污染的另一重要来源。

The rainfall has been monitored for a year in Guilin and a total of 74 rainwater samples has been collected to determinate pH,conductivity,mercury and 10 kinds of cation and anion content.The results show that Guilin is typical of acid rain area.A monthly average pH range varies from 3.84 to 5.38.The frequency of acid rain is 81%.Acid rain intensity is winter > autumn > spring > summer.There is a positive correlation between the monthly average mercury content of rainwater,acidity and conductivity.The mercury content of rainwater is form high to low from north to south in space,high in urban and low in suburb.The highest mercury content of rainwater is along the traffic trunk lines.Factor analysis show that Hg,SO_4^(2-)and F^- are of the same factor combination.The burning of coal is the main source of mercury pollution for rain in Guilin.The automobile exhaust pollution of mercury is also another important source of mercury pollution for rain.