胡敏素钝化修复重金属Cu(Ⅱ)、Pb(Ⅱ)污染土壤

Remediation of heavy metal Cu( Ⅱ),Pb( Ⅱ) contaminated soils using humin

通过土壤培养实验,研究了添加胡敏素对污染土壤中Cu、Pb生物有效性和化学形态的影响。结果表明,添加胡敏素可显著降低重金属的浸出浓度。当投加2%的胡敏素5 d后,土壤中重金属Cu^(2+)和Pb^(2+)的浸出浓度分别下降45.16%和56.97%,并且投加胡敏素10 d后对重金属的钝化基本达到稳定。尿素、硫酸铵、磷酸二氢钾可显著提高胡敏酸对Pb的钝化效果,浸出浓度分别下降了29.36%、23.57%和28.69%,但对Cu的影响不明显。进一步的研究表明,投加2%的胡敏素钝化处理30 d后土壤中交换态铜和铅的所占的比例由原来的15.68%和15.79%下降到了0.48%和1.22%,而有机态铜和铅的比例则由5.35%和10.93%上升到了13.24%和27.32%。因此,采用胡敏素作为重金属污染土壤的钝化剂具有广阔的应用前景。

The effects of humin addition on the mobility and bioavailability of Pb and Zn in soil were studied through a batch soil column incubation experiment. The results showed that the treatments with humin could significantly reduce the leaching concentration of Cu and Zn. Compared with the control,the treatments with 2%humin could reduce the leaching concentration of Cu and Zn by 45. 16% and 56. 97%,respectively after five days incubation. And the leaching concentration of heave metal became stable after ten days incubation. Three kinds of fertilization,urea,ammonium sulfate and potassium dihydrogen phosphate,could enhance the passivation effects of humin on Pb. The leaching concentration of Pb decreased 29. 86%,23. 71% and 28. 69%,respectively. However,there was no significant impact on Cu. The treatments with 2% humin could reduce the exchangeable fraction of Cu and Pb from 15. 68%,15. 79% to 0. 48%,1. 22%,while the proportion of organic fraction increased from 5. 35%,10. 93% to 13. 24%,27. 32%,respectively after 30 days incubation. The results highlighted the potential of humin amendment to reduce the mobility and bioavailability of heavy metal in contaminated soils.