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

铁改性生物炭对土壤-水稻系统中砷有效性和迁移的影响

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.

铁改性生物炭(FeOS)能有效地促进土壤中砷的固定。本文通过盆栽实验研究了铁改性生物炭对砷在土壤-水稻系统中有效性和迁移的影响。本实验研究了不同砷污染水平下,施用铁改性生物炭对水稻土壤溶液、铁膜中砷和铁的含量的影响,以及对水稻根、茎生物量和砷积累量的影响。结果表明,施用铁氧化物提高了土壤溶液中铁的浓度,降低了砷的浓度;特别是在120 mg/kg As处理中,添加0.5%和1%FeOS后,成熟期砷浓度分别降低16.46%和30.56%。与对照相比,施用FeOS降低了水稻组织中的砷含量,增加了水稻根和茎的生物量。添加1%FeOS后,水稻根系生物量增加12.68%,地上部生物量增加8.94%。这可能与FeOS的添加促进了铁膜形成和微生物群落结构的转变有关,与本实验中土壤的铁砷相关基因丰度和铁膜的铁含量所呈现的结果一致。该研究可为FeOS在砷污染水稻土修复中的应用提供进一步的支持和理论依据。