乌鲁木齐近十二年(1997～2009)降水中化学组分变化趋势分析

Analysis on the Chemical Composition Change Rule of Precipitation between 1997～2009 in Urumqi

通过对乌鲁木齐市近12年(1997～2009)降水的化学组分分析,表明大气环境中的年际pH值在6.04～7.42间波动。∑阴离子所占百分比约为∑阳离子2倍。SO42-和Ca2+分别是阴离子和阳离子中占比重最大的离子,直接影响降水的化学性质。近年来,SO42-在阴离子中所占比重呈下降趋势,而NO 3-则逐年增加,说明乌鲁木齐市在控制燃煤型污染方面采取的措施取得了一定效果,而机动车尾气污染日益加重,大气环境中各阴离子的组分比例在不断变化。

On the Chemical Compostition Change Rule of Precipitation Between 1997 ～ 2009 in Urumqi.The results show that annual average pH value was fluctuate between 6.04 and 7.42.The total anion station was almost two times of total cation station.SO42-and Ca2 ＋ take the leade of anion cation station respectively.They were influenced the property of Precipitation chemical directly.In recent years,SO24 ＋ was decreasing in anion concentration and NO 3-was increasing in cation concentration gradually.The tendency proven that the local governments measurement has taken good effect in the control of coaling pollution,and automobile off-gas pollution increasingly aggravate.Different anionic equivalece rate varies much of Atmospheric environment.