广东韶关市大气降尘及尘中金属元素分布特征研究

为了解城市金属含量和大气降尘的时空分布,根据功能分区的原则,把广东韶关市分为7个功能区,按《空气和废气监测分析方法》中灰尘自然沉降量—重量法之湿法采样,用称重法测定,用原子吸收光谱法测定Cu、Pb、Zn、Cd、K、Ca元素,用标准曲线法计算其浓度。结果发现降尘的季节性分布是:秋季>冬季>春季>夏季;降尘空间分布是:工业区>居民区>商业区>交通区>混合区>近郊区,全市金属元素含量高低依次为Zn>Ca>Pb>Cu>K>Cd,其中Pb、Zn、Cd在工业区含量最高,Ca在居民区含量最高。结论是工业尘和建筑尘是本市最大污染源,Pb、Zn、Cd主要来源于工业尘,Ca主要来源于建筑尘。与国内外其他城市相比,除西安外,本市降尘中金属含量比其他城市均低。

Study on Distribution of the Atmospheric Dust-fall and its Metal Element Contents in Shaoguan City, Guangdong Province

Aim: to discuss the distribution of element contents and the temporal and spatial distribution of the atmospheric dust-fall in different parts of Shaoguan city,Guangdong Province,China.Methods: the city was divided into 7 function districts.The natural atmospheric dust-fall is collected in each district.And determine the dust weight,analyze the heavy metal elements in the samples with the atomic absorption spectrometry.And then compare the result with other cities both in China and in the foreign cities.Results: It indicates that the heaviest atmospheric dust-fall is in autumn,the lightest is in summer and between autumn and summer is winter and spring.The industrial district is the heaviest one,and the rural is the lightest one.The distribution of element contents in this city is Zn>Ca>Pb>Cu>K>Cd.The industrial district has the highest content of Pb,Zn,Cd.The resident district has the highest content of Ca.Conclusion: The main pollution courses are industrial dust and construction ash,and rain can reduce the atmospheric dust-fall.The contents of Pb,Zn,Ca and Cd are relative to mankind activity.Pb,Zn,Cd are come from industrial dust,and Ca is come from construction ash.Compared with other cities both domestic and abroad,the element contents are lower except for Xi'an city.