磷基固化剂处理矿区酸性重金属污染土现场试验研究OA

Field tests are conducted to evaluate the effectiveness of binders(SS-H and SS-E)for solidifying/stabilizing iron(Fe)and manganese(Mn)contaminated soils at a gold mining acid waste collection reservoir.The field-stabilized soils are subjected to the toxicity characteristic leaching procedure(TCLP),pH,dry density,dynamic cone penetrometer tests,and heavy metal speciation analysis.The results indicate that field stabilization using SS-H and SS-E can significantly reduce the leached concentrations of Fe and Mn,with the leached concentrations of Fe and Mn being below the national groundwater quality standard(GB/T 14848-2017,Class III).SS-H is more effective in immobilizing Mn,with its leached concentration decreasing from 23 mg/L to 0.02 mg/L.SS-E is more effective in immobilizing Fe,reducing its leached concentration from 34.3 mg/L to 0.04 mg/L.Both SS-H and SS-E significantly improve the strength of the solidified soils.The dynamic cone penetration index of SS-H and SS-E solidified soils decreases by 93.1%and 93.2%,respectively,as compared to the untreated soils.The results demonstrate that both SS-H and SS-E binders are promising in solidifying/stabilizing multi-heavy metals contaminated soils with low pH.After stabilization,the water-soluble Mn fractions in the SS-H-and SS-E solidified soils are reduced from 16.5%to 0.19%and to 0.34%respectively,while alterations in Fe speciation are insignificant.