摘要
降水是大气中主要和次要污染物的重要收集器,是大气中颗粒物和气态污染物最好的清除剂。本文利用离子色谱分析了2011年伊宁市90个降水样品,结果表明,该区降水pH月均值在5.27—7.1之间,年均值为6.26,电导率变化范围为34.64~63μs·cm^(-1),年均值为45.7μs·cm^(-1)。降水中主要离子浓度排序为Ca^(2+)>SO_4^(2-)>NH_4^+>Mg^(2+)>Cl^->NO_3^->Na^+>F^->K^+,Ca^(2+)是最主要的阳离子,年均值为421.76μeq·L^(-1),SO_4^(2-)是最主要的阴离子,年均值为149.09μeq·L^(-1),表明伊宁降水中的致酸物质主要是硫酸盐。总离子浓度季节变化特征表现为春夏季高,秋冬季低,总离子浓度明显低于乌鲁木齐和沈阳,与北京类似,远高于杭州、广州,表明伊宁降水污染比北方城市轻,但是陆源贡献远大于南方城市。FA平均值为0.003,表明99.7%的降水酸度被碱性成分中和,NF计算结果表明Ca^(2+)的中和能力最强,其次是NH_4^+。从相关分析和因子分析来看,F^-、SO_4^(2-)、NO_3^-、Cl^-、NH_4^+主要受人为源的控制,Ca^(2+)、K^+主要来源于土壤和浮尘,Na^+、Mg^(2+)主要来源为土壤盐碱化、风化、干旱浮尘等自然源。
Precipitation is the important collector of primary and secondary pollutants in the atmosphere, and the best scavenger of the particulate and gaseous pollutants in the atmosphere. This paper investigated the chemical characteristics of precipitation of the Yining, China in 2011. The 90 precipitation samples were collected from Yining stations in 2011 and analyzed by the ion chromatography. The results showed that the monthly values of pH varied from 5.27 to 7.1 with the annual average of 6.26, and the conductivity varied from 34.64 to 63 μs ·cm-1 with the annual average of 45.7 μs·cm-1. Ca2＋ is one of the most main cation with the average of 421.76 μeq·L-1, while SO 4^2- is one of the most main anion with the average of 149.09 μeq ·L-1. Acid-causing substance of precipitation in Yining is mainly sulfate. The seasonal variations of ions showed that the concentrations were the higher in spring and summer, and the lower in autumn and winter. Fractional acidity （FA） was 0.003, which indicates that 99.7% of the precipitation acidity was neutralized by alkaline composition. The results of neutralization factors （NF） indicated that Ca2＋ was the dominant neutralization substance and NH4＋ was the secondary. The correlation analysis and factor analysis indicated that F , SO 24, NO 3-, C1- and NH 4＋ were mostly attributed by the anthropogenic activities, Ca2＋ and K＋ came from soils and floating dust, while the Na＋ and Mg2＋ originated from natural sources, such as soil salinity, weathering and dry floating dust.
出处
《沙漠与绿洲气象》
2016年第3期77-82,共6页
Desert and Oasis Meteorology
基金
国家自然科学基金项目(41405124
41405141)共同资助
关键词
伊宁
降水
离子成分
来源
Yining
precipitation
ion composition
source
