铁基凝胶材料对镉砷复合污染土壤的稳定化效果研究

Simultaneous Stabilization of Cadmium-arsenic Co-contaminated Soil by Iron-based Gel Material

以镉砷复合污染土壤为研究对象,采用铁盐与海藻酸钠(SA)为原料,通过碱性-交联法制备了一类铁基凝胶稳定材料,考察了不同铁盐类型和铁盐掺入量制备的凝胶材料对污染土壤中Cd和As的同步稳定效果。结果表明:以FeCl_(3)作为铁盐原料,m(FeCl_(3))∶m(SA)=0.88∶1.00条件下制备的铁基凝胶材料F1(1)对Cd和As的同步稳定效果最佳。当铁基凝胶材料F1(1)添加质量比为5%时,土壤中Cd和As的稳定效率分别为87.76%和93.42%,镉砷同步稳定权衡值T显著降低至1.45。稳定15 d后,土壤中Cd的稳定效率降为82.94%,As的稳定效率上升至97.38%,镉砷同步稳定权衡值T为1.55。

In this study,a iron-based gel stabilization material was prepared by alkaline cross-linking process basing on ferric salts and sodium alginate(SA).The category and dosage of ferric salts were screened to evaluate the effect of the materials on stabilization of Cd and As in contaminated soil.Results showed thatthe prepared iron-based gel material F1(1)exhibited the optimal stabilization effect of Cd and As when FeCl_(3)was selected as raw material and m(FeCl_(3))∶m(SA)=0.88∶1.00.With 5%dosage of F1(1)in contaminated soil,the stabilization efficiency of Cd and As were 87.76%and 93.42%,respectively,while T value significantly reduced to 1.45.After 15 days,the stabilization efficiency of Cd in soil was 82.94%,the stabilization efficiency of As could be up to 97.38%,while T value could be maintained at 1.55.