深圳市宝安区酸雨成分及相关分析

在深圳宝安区黄麻布收集了2006年5-12月的52次降雨水样，测定了水样中的F^-、Cl^-、NO3^-、 SO4^2-、H^＋、NH4^＋、Na^＋、K^＋、Mg^2＋、Ca^2＋的离子浓度，结果显示，宝安区酸雨较为严重，加权平均pH值为4.72；每月降雨量与pH值成负相关关系，一般雨季pH值低，旱季pH值高，但在异常的极端气候条件下，如台风对pH值的变化有很大的影响；宝安区的酸雨有由过去的硫酸型酸雨向硝酸型酸雨转变的趋势；宝安区靠近海洋，水样中富含Cl^-和Na^＋，海洋源对雨水中Cl^-和Mg^2＋的贡献较高，有时达到100%，对K^＋为10%左右，对Ca^2＋和SO4^2-几乎没有贡献，仅为1%-4%；在旱季时碱性离子的缓冲作用强，而雨季较弱；通过分析当地空气中的SO2和水样中的SO4^2-、NO2和NO3^-之间的关系发现NO2和NO3^-之间相关性较好，NO3^-主要来源于当地机动车辆尾气中的NO2；而SO2和SO4^2-相关性相对较差，SO4^2-除本地的污染外可能来源于龙岗区和南山区等周边地区传输的污染气体SO2。

Acid Rain Composition and Its Correlation Analysis in Baoan Area of Shenzhen City

52 times rainfall water sample were collected from May 2006 to December 2006 in Huangmabu Village,Baoan area of Shenzhen City,and the concentration of F-,Cl-,NO-3,SO2-4 NH+4,Na+,K+,Mg2+ and Ca2+ were determined.The results showed that acid rain was severe and weighted mean pH value was 4.72 in Baoan area.The correlations of monthly precipitation and pH value were negative,the pH value was low in the rainy season,and was high in the dry season,the extreme weather such as typhoon had a great effect on the pH value change.In Baoan area,the acid rain type changed from sulphuric acid rain to nitric acid rain.Baoan area is close to sea,the content of Cl-and Na+ are rich,the marine contribution to Cl-and Mg2+ is high,sometimes reaching 100%,the contribution to K+ is about 10%,the contribution to Ca2+ and SO2-4 is so little only 1%-4%.The bufferaction of basic ions is strong in the dry season,and is weaker in the rainy season.Through analyzing the relationships between SO2 in local air and SO2-4 in water sample,between NO2 and NO-3,the relationship between NO2 and NO-3 is good,NO-3 originates from NO2 which is produced by local motor vehicles,the relationship between SO2 and SO2-4 is bad,SO2-4 comes from SO2 which is carried form other area where is close to Baoan area.