Arsenic availability and transportation in soil-rice system affected by iron-modified biochar

Iron-modified biochar (FeOS) is known to be effective at immobilization of arsenic (As) in soils. A pot experiment was conducted to investigate the effects of FeOS on As availability and ttransportation in the soil-rice system at different growth stages of rice with different pollution levels. The results showed that Fe concentration decreased and As concentration increased in paddy soils with the FeOS addition, especially in 120 mg/kg As treatment, the As concentration decreased by 16.46% and 30.56% at the maturity stage with 0.5% and 1% FeOS additions, respectively. Compared with the control, the application of FeOS reduced the arsenic content in rice tissues and increased the biomass, with the root biomass increased by 12.68% and the shoot biomass was increased by 8.94% with the addition of 1% FeOS. This may be related to the promotion of iron plaque formation and the transformation of microbial community structure in FeOS treatments, in accordance with the result of gene abundance and Fe/As contents of iron plaque in the study. This study is expected to provide further support and theoretical basis for the application of FeOS in the remediation of As contaminated paddy soil.
鐵改性生物炭(FeOS)能有效地促進土壤中砷的固定。本文通過盆栽實驗研究了鐵改性生物炭對砷在土壤-水稻系統中有效性和遷移的影響。本實驗研究了不同砷污染水準下，施用鐵改性生物炭對水稻土壤溶液，鐵膜中砷和鐵的含量的影響，以及對水稻根，莖生物量和砷積累量的影響。結果表明，施用鐵氧化物提高了土壤溶液中鐵的濃度，降低了砷的濃度；特別是在120 mg/kg As 處理中，添加0.5%和1% FeOS 後，成熟期砷濃度分別降低16.46%和30.56%。與對照相比，施用FeOS 降低了水稻組織中的砷含量，增加了水稻根和莖的生物量。添加1% FeOS 後，水稻根系生物量增加12.68%，地上部生物量增加8.94%。這可能與FeOS 的添加促進了鐵膜形成和微生物群落結構的轉變有關，與本實驗中土壤的鐵砷相關基因豐度和鐵膜的鐵含量所呈現的結果一致。該研究可為FeOS 在砷污染水稻土修復中的應用提供進一步的支援和理論依據。 Copyright © 2021 Central South University Press and Springer-Verlag GmbH Germany, part of Springer Nature.