硫化纳米零价铁对土壤中镉的高效固定与作用机制研究

Efficient Immobilization and Mechanism of Cadmium in Soil by Sulfidized Nanoscale Zero-valent Iron

通过液相还原法制备了硫化纳米零价铁(S-nZVI)颗粒,研究S-nZVI在不同投加量和反应时间下对镉的固定效果。结果表明:与对照组相比,修复15 d后,施加量为5%的S-nZVI处理组中有效态镉的质量分数由1.45 mg/kg降至0.03 mg/kg,镉的浸出质量浓度由0.0406 mg/L降至0.0004 mg/L。此外,施用S-nZVI后提高了土壤的pH值,降低了土壤氧化还原电位(E_(h))。结合p H值和E_(h)的变化及反应前、后材料的表征,讨论了S-nZVI对镉的固定机制。

Sulfidized nanoscale zero-valent iron(S-nZVI)particles were prepared by liquid-phase reduction method.The immobilization effect of S-nZVI on Cd under different dosage and reaction time were investigated.Results indicated that after 15 dremediation,the available mass fraction of Cd decreased from 1.45 mg/kg to 0.03 mg/kg,and the leaching mass concentration of Cd decreased from 0.0406 mg/L to 0.0004 mg/L,respectively.In addition,the application of S-nZVI increased soil pH value and decreased the soil redox potential(E_(h)),respectively.Combined with the changes of pH and E_(h) and the characterization of the materials before and after the reaction,the mechanism of S-nZVI on Cd in soil was discussed.