Abstract：
In Southern China, the co-occurrence of arsenic (As) and antimony (Sb) contamination in soils around Sb mines presents an environmental challenge. During the flooding period of mining-impacted soils, anaerobic reduction of iron (Fe) oxides enhances the mobilization and bioavailability of Sb and As, further elevating the risk of Sb and As entering the food chain. To address this problem, activated carbon (AC) and biochar (BC) were applied to remediate flooded mining-impacted soils. Our results explored that AC can significantly decrease mobilization by 9-97 % for Sb and 9-67 % for As through inhibiting Fe(III) mineral reduction and dissolution in flooded soils. In contrast, there was no significant effect of BC. This was attributed to the strong adsorption of soil dissolved organic matter (DOM) by AC compared to BC, while DOM as electron shuttle is crucial for microbial Fe(III) reduction. Consequently, the DOM sequestration by AC effectively mitigates Sb and As leaching in contaminated mining soils.
摘要：
在中国南方,Sb矿山周围土壤中砷（As）和锑（Sb）污染的同时出现提出了环境挑战。在受采矿影响的土壤的洪水期间，铁（Fe）氧化物的厌氧还原增强了Sb和As的动员和生物有效性，进一步提升Sb和As进入食物链的风险。为了解决这个问题,活性炭（AC）和生物炭（BC）用于修复淹没的采矿影响土壤。我们的结果发现，通过抑制淹没土壤中Fe（III）矿物的减少和溶解，AC可以显着降低Sb的动员作用9-97％，降低As的动员作用9-67％。相比之下,BC无明显影响。这归因于与BC相比，AC对土壤溶解有机质（DOM）的强烈吸附，而DOM作为电子穿梭对于微生物Fe(III)还原至关重要。因此,AC的DOM固存有效地减轻了受污染的采矿土壤中Sb和As的浸出。
