典型矾矿区土壤及优势植物重金属分布特征

Distribution characteristics of heavy metals in soil and dominant plants in typical alum mining area

矾矿资源的开采导致重金属元素暴露地表,在土壤中富集并将对周边居住人群产生潜在的健康风险。通过系统采集某矾矿区周边土壤及植物样品,利用ICP-MS测定样品中重金属元素含量,对矾矿区周边土壤典型重金属元素分布规律及富集特征、矿区范围内长势良好优势植物对典型重金属元素的吸收与富集能力进行深入的分析。结果表明,矾矿区周边土壤中As、Cu、Cd和Pb 4种重金属元素含量较高,其中As和Cd污染较为严重,As的平均值达110.7 mg/kg,Cd的平均值为2.9 mg/kg;优势植物中沿阶草和小二仙草对于土壤中As元素具有良好的富集和转运能力,富集系数分别为2.81和5.00;紫花地丁对于Cd的富集系数和转运系数较高,富集系数为1.79,转运系数为2.50。因此,可以采用植物修复为主的方式治理矾矿区土壤重金属污染。

The exploitation of alunite resources results in the exposure of heavy metals to the surface,enrichment in soil and potential health risks to surrounding residents.Soil and plant samples around an alum mining area were collected systematically,and the contents of typical heavy metals in the samples were determined by ICP-MS.The distributuion and enrichment characteristics of typical heavy metals,and the corresponding absorption and enrichment capacity of dominant well-growing plants in mining area were analyzed strictly.The results showed that,the contents of As,Cu,Cd and Pb in the soil of mining area were relatively high,pollution caused by As and Cd was serious,The average mass concentrations of As and Cd were 110.7 and 2.9 mg/kg respectively,Among dominant plants,Ophiopogon bodinieri Levl and Halorogis micrantha(Thunb.)R.Br showed good enrichment and transfer capacity on As in soil,and the enrichment coefficients were 2.81 and 5.00 respectively;while Viola philippica held high enrichment and transfer coefficient for Cd,the corresponding values were 1.79 and 2.50 respectively.Therefore,phytoremediation can be adopted as the main treatment mode to control heavy metals pollution in alum mining area.