| 腐殖酸活性组分及其比例对紫色潮土中铅形态转化和有效性演变动态的影响 |
| 摘要点击 1436 全文点击 776 投稿时间：2016-10-04 修订日期：2016-12-05 |
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| 中文关键词 紫色潮土 腐殖酸 胡/富比 铅 形态 有效性 |
| 英文关键词 purple alluvial soil humic acids HA/FA ratio lead form availability |
| 作者 | 单位 | E-mail | | 王青清 | 西南大学资源环境学院, 重庆 400716
重庆市农业资源与环境研究重点实验室, 重庆 400716
三峡库区生态环境教育部重点实验室, 重庆 400715 | 1260388331@qq.com | | 蒋珍茂 | 西南大学资源环境学院, 重庆 400716
重庆市农业资源与环境研究重点实验室, 重庆 400716
三峡库区生态环境教育部重点实验室, 重庆 400715 | | | 王俊 | 西南大学资源环境学院, 重庆 400716
重庆市农业资源与环境研究重点实验室, 重庆 400716
三峡库区生态环境教育部重点实验室, 重庆 400715 | | | 魏世强 | 西南大学资源环境学院, 重庆 400716
重庆市农业资源与环境研究重点实验室, 重庆 400716
三峡库区生态环境教育部重点实验室, 重庆 400715 | sqwei@swu.edu.cn |
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| 中文摘要 |
| 腐殖酸（HAs）是制约土壤铅赋存形态与活性的重要因素.本研究通过室内模拟实验，结合化学连续提取形态分级方法，探讨HAs活性组分（胡敏酸，HA；富里酸，FA）添加量及其比例（HA/FA比）对紫色潮土中铅赋存形态、有效性变化动态的影响.结果表明：1外源铅进入土壤经60d转化平衡后，土壤中交换态、残渣态铅降低，铁锰氧化物结合态、有机结合态铅增加，碳酸盐结合态铅变化不明显.2紫色潮土以交换态铅和碳酸盐结合态铅对有效铅贡献最大，HA通过降低碳酸盐结合态而对土壤铅产生钝化作用，FA则通过增加交换态和碳酸盐结合态而活化土壤铅；随着HAs用量的增加，钝化或活化作用越强.当HAs用量为3% C时，添加HA的土壤碳酸盐结合态铅较对照降低13.4个百分点，有效铅相应降低14.19%；添加FA的土壤交换态铅较对照增加13.59个百分点，碳酸盐结合态铅增加2.15个百分点，有效铅较对照相应增加4.09倍.FA（1% C）是土壤铅活化的突变点，当FA>1% C时，土壤铅活化百分率增加了14%，土壤铅活性和生物有效性显著增大.3等量HAs（1% C）条件下，当HA/FA比≥7/3时，促进土壤铅向低活性的有机结合态和残渣态转化，HAs对土壤铅表现为钝化作用，而当HA/FA比≤5/5时，则表现为活化作用. |
| 英文摘要 |
| Humic acids (HAs) play important roles in mediating the occurring forms and activity of Lead (Pb) in soils. Simulating experiments together with chemical sequential extraction were carried out to understand the dynamics of lead transformation and availability in purple alluvial soil as influenced by humic acid (HA) and fulvic acid (FA) and their ratios (HA/FA). The main results obtained are as following:1 The distributions of Pb forms bound by Fe-Mn oxides and organic matter increased, while the proportions of exchangeable Pb and residual Pb fraction decreased after the establishment of transformation equilibrium in 60 d. 2The exchangeable-Pb and carbonate bound Pb showed highest positive contribution to the availability of Pb in the tested soil; and HA passivated soil Pb activity by decreasing the proportion of carbonate bound Pb and FA activated soil Pb by increasing the proportions of exchangeable Pb and carbonate bound Pb. The passivation or activation roles increased with increasing amount of HA or FA; A sharp increase of soil Pb availability occurred at FA dosage higher than 1% as C basis, suggesting that 1% (C) exogenous FA was the change-point for soil Pb activation;3The overall effects of HAs depended on its ratio of HA/FA at a constant addition of HAs (1% C). HAs suppressed soil Pb activity at a ratio of HA/FA ≥7/3, while they activated soil Pb activity at a ratio of HA/FA≤5/5. The transformation extent and direction of Pb in soils differed at various dosage and ratios of HA/FA, resulting in different overall effects on the Pb availability in soil. |
