广东云浮市降水的离子组成特征分析

2005年4~9月在广东省云浮市采集到28场降水样品进行降水化学分析. 结果表明，SO42-和Ca2+是浓度最高的阴、阳离子，平均浓度依次为291.71eq/L和284.65eq/L, 占离子总浓度的75%；SO42-/NO3-的物质量浓度比平均为8.64, 降水污染主要为硫酸型；但降水中碱性离子对酸性离子的中和作用显著。另外，离子浓度高值出现在5月和8月的汛期过渡期, 低值则发生在6~7月的主汛期；除NH4+离子外，其他离子的月平均浓度的变化趋势比较类似，说明这些离子有相近的来源以及类似的传输途径。

CHEMICAL CHARACTERISTICS OF RAINWATER AT YUNFU CITY IN GUANGDONG PROVINCE

A short term study of the chemical composition of rainwater was carried out from April to September 2005 at Yunfu city in Guangdong province. The major ions are SO42 for anions and Ca2+ for cations, with mean volume weight concentrations of 291.71eq/L and 284.65eq/L, respectively, both of which accounts for 75% to the total ion concentration. The SO42-/NO3- ratio was 8.64, indicating the sulfate was the major pollution matter. The cation Ca2+ appears to play significant role in neutralizing the acidity rainwater. Moreover, the higher ion concentrations are found in the transitional period between the flood seasons, and the lower ones in flood seasons. Except the NH4+, similar temporal variation was shown among other ions, suggesting they have the common source and similar transport channel.