淮南潘集矿区农田土壤重金属污染特征及在小麦中累积特征研究

Study on the heavy metals pollution characteristics of agricultural soil and their accumulation characteristics in wheat in Panji mining area,Huainan

为探究淮南潘集矿区内农田土壤和小麦中重金属的污染状况,选取了16块研究样地,测定其农田土壤和小麦不同部位中Cu、Zn、Pb、Cd、As含量,利用生物富集系数(BCF)和转运系数(TCF)分析重金属在小麦中的迁运行为,并进行重金属化学形态分析和潜在生态风险指数分析。结果表明,矿区农田土壤Zn、Pb浓度平均值低于背景浓度,Cu、Cd、As浓度平均值分别是背景浓度的1.03、4.17、1.81倍。5种重金属的化学形态以残渣态为主,Cu、Zn、Pb、Cd、As的残渣态质量分数平均值分别为47.44%、50.33%、43.36%、46.84%、98.86%。矿区农田土壤重金属综合潜在生态风险指数处于轻度或中度等级,相对较轻,主要贡献重金属是Cd。Cu、Zn易于富集在小麦地上部分,Pb、Cd、As大部分富聚在地下部分。

In order to explore the pollution of heavy metals in agricultural soil and wheat in Panji mining area,Huainan,16 repesentative sites were selected.The concentrations of heavy metals(Cu,Zn,Pb,Cd and As)in agricultural soils and different parts of wheats were analyzed.The bioconcentration factor(BCF)and translocation factor(TCF)were used to discuss the transformation and migration behavior of heavy metals in wheats.The chemical forms and potential ecological risk index of heavy metals were also studied.Results showed that the mean concentrations of Zn and Pb were lower than background concentrations,but that of Cu,Cd and As were 1.03,4.17 and1.81 times of background concentrations.Residual fraction was the predominant chemical form for 5 heavy metals,which covered 47.44%,50.33%,43.36%,46.84% and 98.86% for Cu,Zn,Pb,Cd and As,respectively.The comprehensive potential ecological risk index of heavy metals were not serious(light or moderate level),which was mainly contributed by Cd.Cu and Zn were prone to accumulate in upper parts of wheat,while Pb,Cd and As to below parts.