纳米级二氧化锰材料阻控土壤砷向水稻迁移的研究

为了探究纳米级二氧化锰材料阻控土壤中砷向水稻迁移的影响,通过盆栽种植水稻,向砷污染土壤中分别添加0%(CK)、0.2%、0.5%、1.0%和2.0%的纳米级二氧化锰材料,分析土壤溶液p H值、砷和锰的含量变化,及水稻中砷和锰的含量变化.结果表明:添加不同浓度的纳米级二氧化锰材料,土壤溶液pH值没有显著变化,土壤溶液中砷、锰的浓度随着水稻生长的时间增加而降低;不同时期水稻中砷和锰的分布规律是根部茎部叶部糙米,水稻植株中锰和砷的含量呈显著负相关(p0.05);不同浓度的纳米级二氧化锰材料能有效控制水稻糙米中总砷含量,其中1.0%添加量的阻控效果最好,使糙米中总砷含量降低了65.4%,其无机砷含量低于《食品中污染物限量(GB2762—2012)》中砷限量.

Control of As soil-to-rice transfer (Oryza sativa L.) with nano-manganese dioxide

In order to investigate the effects of nano-MnO₂ on As transfer from soil to rice, the soil solution pH, the concentrations of As and Mn in soil solution and rice were analyzed after adding the different contents of (0, 0.2%, 0.5%, 1.0%, and 2.0%) nano-MnO₂ in As-contaminated soil under greenhouse condition. The results showed that the effect of different contents of nano-MnO₂ on soil solution pH were not significant. The concentrations of As and Mn in soil solution decreased during the rice growth period. The distributions of As and Mn in different parts of rice plant were: root>stem>leaf>brown rice. There were significantly negative correlation (p<0.05) between Mn and As concentrations in rice plant. The transfers of As from soil to rice were effectively controlled by different contents of nano-MnO₂. The total As concentration in brown rice was reduced by 65.4% with addition of 1.0% nano-MnO₂, and the corresponding inorganic As content was 0.19 mg·kg^-1 lower than the limited content of inorganic As in food.