广西河池锑冶炼区周边苔藓对大气重金属的记录

借助苔藓对广西河池锑冶炼区周边大气中的10种重金属(Sb、Pb、As、Cu、Cd、Mn、Fe、Al、Ba、Sr)的分布迁移规律进行了研究. 结果表明:苔藓可有效反映重金属的沉降. 苔藓中w(Sb)、w(Pb)、w(As)和w(Cd)的范围分别为41.0～5.77×103、1.05×102～1.39×104、25.0～1.07×103和8.00～263 mg/kg,分别是背景值的1.5～213.6、24.5～322.5、3.6～1 980.9和3.2～105.2倍. 元素相关性的主成分分析表明,Sb、Pb、As、Cd和Cu为密切相关的一类元素,来源于原料矿石的冶炼排放；Mn、Fe和Al为第2类,主要来源于燃料煤的释放,此外,Mn还可能来源于城市气溶胶的输送和水泥厂的排放；Ba与Sr为第3类,来源与扬尘有关. 随着采样点与冶炼厂烟囱距离的增加,w(Sb)、w(Pb)、w(As)、w(Cu)和w(Cd)呈非线性下降,可用方程y=ae-x拟合. w(Sb)与w(Pb)的衰减速率相似,而w(As)衰减要快于二者. 

Heavy Metal Deposition Recorded by Mosses around a Hechi Antimony Smelter in Guangxi, China

The distributions of Sb,Pb,As,Cu,Cd,Mn,Fe Al,Ba and Sr in the atmosphere around a smelter were investigated by using mosses as the indicator.Moss proved to be an effective indicator for the deposition of trace metals from the smelter.Contents of Sb,Pb and As in mosses were in the range of 41.0-5.77×103,1.05×102-1.39×104,25.0-1.07×103 and 8.00-263 mg/kg,which are 1.5-213.6,24.5-322.5,3.6-1980.9 and 3.2-105.2 times higher,respectively,than the background values.Factor and correlation analysis show that the first group of elements,Sb,Pb,As,Cu and Cd,were significantly related to the smelter,and that these elements originated from ore smelting.The second group,Mn,Fe and Al,mainly originated from coal combustion in the smelter.Mn also originated from the transport of airborne urban pollutants and cement plants.The third group,Ba and Sr,probably originated from dust.The relationships between the contents of Sb,Pb,As,Cu,Cd and the distance from the sampling sites to the smelter could be best fitted by the model y=ae-x.Sb and Pb contents show a highly similar attenuation trend,whereas As content decreased more rapidly than Sb or Pb content.