典型铁、锰矿物对稻田土壤砷形态与酶活性的影响  

Effects of Typical Iron and Manganese Minerals on Arsenic Speciation and Enzyme Activities in Paddy Soil

作　　者：周一敏 黄雅媛 刘凯 赵儒乐 李冰玉 雷鸣[1] ZHOU Yi-min;HUANG Ya-yuan;LIU Kai;ZHAO Ru-le;LI Bing-yu;LEI Ming(College of Resources and Environment,Hunan Agricultural University,Changsha 410128,China)

机构地区：[1]湖南农业大学资源环境学院,长沙410128

出　　处：《环境科学》2022年第5期2732-2740,共9页Environmental Science

基　　金：国家自然科学基金项目(41671475)。

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.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.

关 键 词：砷 水铁矿 水钠锰矿 形态 土壤酶活性 

分 类 号：X53[环境科学与工程—环境工程]