不同纳米修复剂对污染土壤中胡萝卜吸收、转运Cd的影响

通过盆栽实验研究不同纳米修复剂(羟基磷灰石HAP、赤泥RM、Fe3O4、胡敏酸-Fe3O4)对2种不同污染土壤Cd吸收、转运的影响。结果表明,上述纳米修复剂均可显著增加胡萝卜植株生物量,显著提高植株Cd胁迫的耐受指数;不同土壤施用不同纳米修复剂均显著降低胡萝卜植株Cd的含量,并且随着修复剂施加浓度的增加而显著降低;与对照相比,植株茎叶Cd含量最大降低达78.8%,根中Cd的含量最大降低67.8%;添加不同修复剂能不同程度地降低了土壤中Cd的转运系数和富集系数,这可能与施用不同纳米修复剂促进了土壤中非残留态Cd向残留态Cd的转化有关,总体而言,不同纳米型修复剂对降低Cd的有效性顺序为:RM～HAP>胡敏酸-Fe3O4>Fe3O4。

Effects of nanoscale amendments on uptake and transfer of Cd by carrot (Daucus carota) in polluted soils

A pot experiment was conducted to study the effects of different nanoscale amendments (hydroxyapatite, red mud, Fe₃O₄, humic acid (HA)-Fe₃O₄) on the uptake and transfer of Cd by carrot in two kinds of Cd-polluted soils. The results showed that nanoparticles (NPs) mentioned above could increase plant biomass and tolerance index (TI) of carrot significantly. The application of NPs could decrease the concentration of Cd of different carrot parts, the Cd concentrations in both shoots and roots of carrot decreased with increasing quantities of added NPs. The Cd concentrations in shoots of carrot decreased 78.8%, and in roots 67.8% with the most scope respectively, as compared with the control treatment. The application of nanoscale amendments in polluted soils could decrease transfer factors (TF) and biological concentration factors (BCF) of Cd by carrot with different extent, the transformation of soil Cd from nonresidual fractions to residual fraction substantially after addition of the nano-amendments may contribute to the decrease of TF and BCF. In general, the efficiency of different amendments on the Cd bioavailability reduction followed this order at the equivalent additions: RM~HAP>HA-Fe₃O₄ > Fe₃O₄.