腐殖酸对石灰（岩）土中铅形态和分布的影响

通过室内土壤培养试验，探讨不同用量腐殖酸对石灰（岩）土中铅各形态的影响。结果表明院腐殖酸各处 理均能降低石灰（岩）土中交换态和残渣态Pb 含量，而有机结合态、铁锰氧化物结合态及碳酸盐结合态Pb 含量则增 加；施用腐殖酸降低了石灰（岩）土中Pb 的活性，且影响程度随腐殖酸施用量的增加而增大；腐殖酸对石灰（岩）土中 Pb 各形态含量在培养0耀36 d期间变化较明显，培养36 d后基本趋于平稳；随腐殖酸在石灰（岩）土中施用量的加 大，以铁锰氧化物结合态Pb 和有机结合态Pb 与之的相关性最明显，交换态Pb 和残渣态Pb 的分配比率随腐殖酸施 用量的增大而下降，碳酸盐结合态Pb、铁锰氧化物及有机结合态Pb 的分配比率则随腐殖酸施用量的增大而增大，说 明腐殖酸具有能暂时固定石灰（岩）土中重金属Pb 的功能。

Effect of humic acid on the form and distribution of lead in calcareous soil

Effects of humic acid on the form and distribution of lead in calcareous soil were explored, through the incubation experiment indoor. The results showed that all the humic acid treatments could decrease the contents of EX-Pb and Res-Pb, but increase the contents of FeMn-Pb, Ob-Pb and Cob-Pb. As more humic acid added, the more activity of Pb was restrained. The influence within 36 days was that the contents of all the speciations of lead changed clearly, and after 36 days the contents of each fractions did not change obviously as time went by. The lead in the fraction of FeMn-Pb and Ob-Pb have most obvious correlation with humic acid with increasing humic acid in calcareous soil. The distribution rate of the EX-Pb and Res-Pb are increased with more humic acid added,but FeMn-Pb,Ob-Pb and Cob-Pb were opposite. The results also showed that humid acid had function in complexing the lead temporarily in calcareous soil.