| 典型铁、锰矿物对稻田土壤砷形态与酶活性的影响 |
| 摘要点击 1748 全文点击 515 投稿时间：2021-08-01 修订日期：2021-10-21 |
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| 中文关键词 砷 水铁矿 水钠锰矿 形态 土壤酶活性 |
| 英文关键词 arsenic ferrihydrite birnessite speciation soil enzyme activities |
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| 中文摘要 |
| 为了探究铁、锰矿物对稻田土壤砷（As）形态与酶活性的影响，将实验室合成的水铁矿和水钠锰矿添加到As污染稻田土壤中进行持续淹水土壤培养实验.结果表明与对照（CK）相比，添加0.1%水铁矿（+Fe）和0.1%水钠锰矿（+Mn）能延缓土壤Eh降低，增加土壤溶液中Fe和Mn的浓度，但是对土壤pH影响较小.与预期相符，+Fe和+Mn处理显著降低大部分监测点土壤溶液中总As （TAs）浓度，提高土壤溶液中砷酸盐[As （Ⅴ）]占TAs的比例，促使固相As形态向晶型铁氧化物结合态As （F5）转化.此外，与CK相比，+Fe和+Mn处理土壤脲酶活性分别提高5.01%和101.36%，土壤蔗糖酶活性分别提高394.51%和688.84%，土壤过氧化氢酶活性分别提高30.44%和64.71%.因此，外源添加水铁矿和水钠锰矿可以降低As污染土壤的环境风险，提高土壤养分利用率. |
| 英文摘要 |
| Artificially synthesized ferrihydrite and birnessite were added to As-contaminated paddy soil to explore their effects on arsenic (As) speciation and soil enzyme activity in continuously flooding soil. Compared with that of the control treatment (CK), the addition of 0.1% ferrihydrite(+Fe) and 0.1% birnessite (+Mn) delayed the decrease in soil Eh and increased the contents of Fe and Mn in porewater; however, it had little effect on soil pH. Consistent with our expectations, the +Fe and +Mn treatments significantly reduced the content of total As (TAs) in porewater at most monitoring points, increased the proportion of arsenate[As(Ⅴ)]in porewater to TAs, and promoted the transformation of the soil solid As occurrence form to well-crystallized hydrous oxides of Fe and Al (F5). In addition, compared with that of CK, the soil urease activity of the +Fe and +Mn treatments increased by 5.01% and 101.36%, the soil sucrase activity increased by 394.51% and 688.84%, and the soil catalase activity increased by 30.44% and 64.71%, respectively. Therefore, the exogenous addition of ferrihydrite and birnessite can reduce the ecological risk of As-contaminated soil and improve the utilization rate of soil nutrients. |
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