Antimony (Sb) in mine wastewater poses a serious threat to surrounding ecosystems. In this study, biosynthesized iron-manganese nanoparticles (Fe-Mn NPs) were devised to remove Sb species. The resultant removal efficiencies were 100% for Sb(III) and 82.6% for Sb(V) utilizing a Sb(III) and Sb(V) concentration of 1 mg·L. To understand the removal process, Fe-Mn NPs before and after exposure to Sb species were characterized by various advanced techniques, which indicated that while both Sb(III) and Sb(V) were adsorbed onto the surface of Fe-Mn NPs, Sb(III) was also partly oxidized to Sb(V). Furthermore, removal of both Sb(III) and Sb(V) followed pseudo-second-order kinetics and best fit the Freundlich adsorption isotherm model, suggesting that the removal process involved non-homogeneous chemisorption. These studies provided the evidence for an adsorption and oxidation mechanism for Sb(III) removal and an adsorption-dominated mechanism for Sb(V) removal by Fe-Mn NPs. When the produced Fe-Mn NPs were applied to remove Sb from mine wastewater, 92.7% removal was attained, demonstrating the significant practical potential of these nanoparticles to Sb species from mine wastewaters. This study provides novel insights for future exploration for Sb removal from mine wastewaters.

中文翻译：

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生物合成铁锰纳米粒子去除矿山废水中的锑：功能和机制

矿山废水中的锑（Sb）对周围的生态系统构成严重威胁。在这项研究中，设计了生物合成的铁锰纳米颗粒（Fe-Mn NP）来去除锑物质。当Sb(III)和Sb(V)浓度为1 mg·L时，Sb(III)的去除率为100%，Sb(V)的去除率为82.6%。为了了解去除过程，通过各种先进技术对暴露于 Sb 物质之前和之后的 Fe-Mn 纳米粒子进行了表征，这表明虽然 Sb(III) 和 Sb(V) 都吸附在 Fe-Mn 纳米粒子的表面上，但 Sb (III)也被部分氧化成Sb(V)。此外，Sb(III)和Sb(V)的去除均遵循准二级动力学，并且最符合Freundlich吸附等温线模型，表明去除过程涉及非均相化学吸附。这些研究为 Fe-Mn 纳米粒子去除 Sb(III) 的吸附和氧化机制以及去除 Sb(V) 的吸附主导机制提供了证据。当所生产的铁锰纳米粒子用于去除矿井废水中的锑时，去除率达到了 92.7%，这表明这些纳米粒子对矿井废水中的锑具有巨大的实际潜力。这项研究为未来探索矿山废水中除锑提供了新的见解。