湘西铅锌矿区土壤和植物重金属污染现状

调查了湖南湘西铅锌矿区植物组成,研究了尾矿区土壤及周围植物根部土壤的Pb、Zn和Cd含量和基本理化性质,分析了在这些区域自然定居的11种优势植物体内的3种重金属元素的耐性、富集特性。结果表明,矿区土壤极端贫瘠,土壤中Pb、Cd和Zn含量分别达2 789.001、59.83和2 892.00 mg/kg,重金属污染极为严重。该矿区的主要优势物种为禾本科和菊科植物,其中野菊花、狗尾巴草和五节芒3种植物地上部生物量较大且对某些重金属向地上部转运能力较强,对重金属污染土壤有一定的修复潜力;地枇杷的地上部Cd含量最大,达152 mg/kg,转运系数为1.03,是潜在的Cd超富集植物。

Investigation of Contaminated Soil and Plants by Heavy Metals in Xiangxi Pb-Zn Mining Area

The ability of plant species to accumulate heavy metals was investigated in Xiangxi Pb-Zn mining area.The concentrations of Cd,Pb and Zn in roots and shoots of 11 dominant species and soil were analyzed.The result showed that the soil was serious lean and contaminated with a extremely high heavy metals concentration of Pb,Cd and Zn respectively due to the Pb-Zn mining tailings,which reached 2 789.00,159.83,2 892.00 mg/kg.The dominant species were Gramineae and Compositae on the investigated field.The biomass of above-ground part and ability of heavy metals up to transport of Chrysanthemum indicum L.,Setaira viridis(L.) Beauv and Miscanthusf loridulus were higher than other plant species,and the contents of some heavy metals in stems and leaves of above-mentioned three species were higher than that in roots,which indicating that these species had certain potential ability to remediate contaminated soil.The Cd concentration in shoots of Ficus tikoua reached 152 mg/kg,and the transfer coefficient was 1.03,which exceeded the threshold of Cd hyperaccumulator.