酸性淋溶下湘西钒矿区废渣及土壤重金属的释放特征

The release characteristics of heavy metals in vanadium waste and contaminated soil in the west of Hunan under acid leaching condition

利用室内模拟方法,探讨酸性淋溶条件下钒矿废渣及矿区污染土壤重金属的释放特征。结果表明,经过酸性淋溶后,尾矿、冶炼废渣和矿区污染土壤的pH范围在5.61～6.87、6.00～6.63和5.18～6.17之间,电导率(γ)的范围分别在0.117～1.325、0.004～0.349和0.001～0.411μS/cm之间;随着淋溶时间的延长,淋出液中的V、As、Cu、Pb、Zn和Cd含量都呈现波动性下降,范围分别在7.489 0～0.006 5、0.198 3～0.004 1、5.609 0～0.009 7、0.014 3～0.000 2、13.821 4～0.000 8和2.336 1～0.000 1 mg/L之间,其中Cu的下降最为明显;在各种重金属中,以V和Cd污染为主。淋溶前期,尾矿所释放的重金属对当地环境危害最大。淋溶后期,冶炼废渣释放的重金属对当地的危害最大。

We use the indoor simulation method to study the release characteristics of heavy metals in vanadium waste and contaminated soil under acid leaching condition.The results show that after acid leaching,the pH value of the tailings,smelting slags and contaminated soil is in the range of 5.61 to 6.87,6.00 to 6.63 and 5.18 to 6.17,respectively.Conductivity（γ） is in the range of 0.117 to 1.325,0.004 to 0.349 and 0.001 to 0.411μS/cm.With the leaching time extension,the concentrations of V,As,Cu,Pb,Zn and Cd are decreased in the range of 7.489 0 to 0.006 5,0.198 3 to 0.004 1,5.609 0 to 0.009 7,0.014 3 to 0.000 2,13.821 4 to 0.000 8 and 2.336 1 to 0.000 1 mg/L,respectively,and the concentration of Cu is declined obviously.The soli is mainly polluted by V and Cu compared with other heavy metals.In the first several days,the content of heavy metals released by tailings is the most.In the later period of leaching,smelting slags release most harmful heavy metals.