To restore highly degraded soil with severe arsenic (As) contamination, effective mitigation of As mobility and bioavailability is considered as the primary step. In this study, the capability of an air-stabilized nano zero-valent iron (A-nZVI) to decrease soil As solubility and leachability was investigated. Further, the effect of A-nZVI on recovery of soil biological function was analyzed by measuring changes in dehydrogenase activity, bacterial community and development of two pioneering plant species. Results showed that A-nZVI exhibited a prominent sorption capacity for both arsenite and arsenate (92.4 and 44.1 mg g^-1). With A-nZVI application at ≥0.2%, 44.2–74.7% decline in soil As solubility was achieved in neutral water extraction, while consistently higher As extractability was determined with synthetic precipitation leaching procedure (SPLP, pH 4.2). Compared to adjacent forest soil (F-CK), microbial community of the tested soil was featured by 66% lower abundance of Actinobacteria while an elevated richness of Gemmatimonadetes, both of which showed apparent shift toward F-CK with A-nZVI. 0.2% A-nZVI was most effective in promoting dehydrogenase activity and ryegrass growth. Further, by two-dimensional mapping with the Zr-oxide diffusive gradients in thin films (DGT), averaged DGT-As in rhizosphere of alfalfa (a green manure species) decreased by 47.1% with 0.2% A-nZVI. These results highlight that A-nZVI is critically essential for fixation of soil labile As and thus provides a favorable starting point for recovery of soil health.

为了恢复砷含量严重污染的高度退化的土壤，有效降低砷的迁移率和生物利用度被视为首要步骤。在这项研究中，研究了一种空气稳定的纳米零价铁（A-nZVI）降低土壤As溶解度和浸出能力的能力。此外，通过测量脱氢酶活性，细菌群落和两种先锋植物物种发育的变化，分析了A-nZVI对土壤生物学功能恢复的影响。结果表明，A-nZVI对亚砷酸盐和砷酸盐均具有突出的吸附能力（92.4和44.1 mg g ^-1）。当A-nZVI用量≥0.2％时，土壤中As的溶解度下降了44.2–74.7％，而合成沉淀浸出程序（SPLP，pH 4.2）则确定了较高的As提取率。相比相邻森林土壤（F-CK），微生物群落的供试土壤的被降低66％丰度的功能的放线菌，而升高的丰富的芽单胞菌门，两者都显示出明显的向A-nZVI向F-CK转移的趋势。0.2％A-nZVI最有效地促进脱氢酶活性和黑麦草生长。此外，通过在薄膜（DGT）中使用Zr-氧化物扩散梯度进行二维映射，苜蓿（一种绿色肥料）的根际中平均DGT-As降低了47.1％，其中A-nZVI的含量为0.2％。这些结果表明，A-nZVI对于固定土壤不稳定的砷至关重要，因此为恢复土壤健康提供了有利的起点。