The ability of a Fe-Mn binary oxide waste to adsorb arsenic (As) in a historically contaminated soil was investigated. Initial laboratory sorption experiments indicated that arsenite [As(III)] was oxidized to arsenate [As(V)] by the Mn oxide component, with concurrent As(V) sorption to the Fe oxide. The binary oxide waste had As(III) and As(V) adsorption capacities of 70 mg g⁻¹ and 32 mg g⁻¹ respectively. X-ray Absorption Near-Edge Structure and Extended X-ray Absorption Fine Structure at the As K-edge confirmed that all binary oxide waste surface complexes were As(V) sorbed by mononuclear bidentate corner-sharing, with 2 Fe at ∼3.27 Ǻ. The ability of the waste to perform this coupled oxidation-sorption reaction in real soils was investigated with a 10% by weight addition of the waste to an industrially As contaminated soil. Electron probe microanalysis showed As accumulation onto the Fe oxide component of the binary oxide waste, which had no As innately. The bioaccessibility of As was also significantly reduced by 7.80% (p < 0.01) with binary oxide waste addition. The results indicate that Fe-Mn binary oxide wastes could provide a potential in situ remediation strategy for As and Pb immobilization in contaminated soils.

中文翻译：

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Fe-Mn二元氧化物废物在土壤中的原位砷氧化和吸附。

研究了Fe-Mn二元氧化物废物在历史污染土壤中吸附砷（As）的能力。最初的实验室吸附实验表明，亚砷酸盐[As（III）]被Mn氧化物组分氧化为砷酸盐[As（V）]，同时As（V）吸附到Fe氧化物上。二元氧化物废物具有分别为70 mg g ^-1和32 mg g ^-1的As（III）和As（V）吸附容量。As K处的X射线吸收近边缘结构和扩展X射线吸收精细结构边证实了所有二元氧化物废料表面复合物都被单核双齿角共享的As（V）吸附，其中2 Fe在〜3.27Ǻ。通过将废物按重量计10％添加到工业上被As污染的土壤中，研究了废物在真实土壤中进行这种耦合的氧化吸附反应的能力。电子探针显微分析表明，As积累在二元氧化物废物的Fe氧化物组分上，而二价氧化物废物本来就没有As。添加二氧化氧化物废物后，As的生物可及性也显着降低了7.80％（p <0.01）。结果表明，Fe-Mn二元氧化物废物可为砷和铅在污染土壤中的固定化提供潜在的原位修复策略。