菏泽市大气降水的化学组成特征及来源分析

Characteristics and Sources Analysis of Chemical Composition of Atmospheric Precipitation in Heze City

为了解菏泽市大气降水的化学组成特征和来源,本研究于2020年1-12月采集16组菏泽市大气降水样品,分析了降水中pH、电导率和NO_(3)-、SO_(4)^(2-)、Ca^(2+)、NH_(4)^(+)、Na^(+)、Cl^(-)、K^(+)、Mg^(2+)、F^(-)等9种无机离子。研究结果表明,菏泽市大气降水pH保持在6.54~8.62,总体呈弱碱性,未出现酸雨现象。样品的电导率保持在19.6~120μS/cm,平均值为52.56μS/cm。离子质量浓度分析表明,降水中总无机离子质量浓度为22.77 mg/L。NO_(3)-和SO_(4)^(2-)为主要的阴离子,占阴离子总量的91.21%,Ca^(2+)和NH_(4)^(+)为主要的阳离子,占阳离子总量的80.35%。皮尔逊相关性分析表明,9种无机离子质量浓度均成正相关,SO_(4)^(2-)和NO_(3)-的相关系数为0.862,二者主要来自人为活动。降水中SO_(4)^(2-)/NO_(3)-当量浓度比值为1.27,降水污染类型为硫酸、硝酸混合型。

In order to understand the chemical composition characteristics and sources of atmospheric precipitation in Heze City,this study collects 16 groups of atmospheric precipitation samples in Heze City from January to December 2020,and analyzes the pH,electrical conductivity and 9 inorganic ions(NO_(3)-,SO_(4)^(2-),Ca^(2+),NH_(4)^(+),Na^(+),Cl^(-),K^(+),Mg^(2+),F^(-))of the precipitation.The research results show that the pH of the atmospheric precipitation in Heze is maintained at 6.54~8.62,which is generally weakly alkaline,and there is no acid rain phenomenon.The conductivity of the samples is maintained at 19.6~120μS/cm with an average value of 52.56μS/cm.The ion mass concentration analysis shows that the total inorganic ion mass concentration in the precipitation is 22.77 mg/L.NO_(3)-and SO_(4)^(2-) are the main anions,accounting for 91.21%of the total anions,and Ca^(2+) and NH_(4)^(+) are the main cations,accounting for 80.35%of the total cations.Pearson correlation analysis shows that the mass concentrations of 9 inorganic ions are positively correlated,and the correlation coefficient of SO_(4)^(2-)and NO_(3)-is 0.862,which are mainly from human activities.The equivalent concentration ratio of SO_(4)^(2-)/NO_(3)-in the precipitation is 1.27,and the precipitation pollution type is a mixed type of sulfuric acid and nitric acid.