Ma Yingqun, Yang Chenchen, Liu Zhichao, Qin Yanwen
National Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; Institute of Water Ecology and Environment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
Institute of Water Ecology and Environment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
J Environ Sci (China). 2025 Nov;157:833-849. doi: 10.1016/j.jes.2024.06.015. Epub 2024 Jun 26.
Pyrrhotite oxidation poses a big threat to water environment duo to its high potential for generating pollutants. Hydrogen peroxide, commonly found in natural water at micromolar concentrations, possesses much more aggressive oxidation ability than oxygen and can complicate the pyrrhotite oxidation process. Here, the effects of micromolar HO on the biotic and abiotic oxidation of pyrrhotite were examined at pH 1.93 and 6.45, respectively. Pyrrhotite oxidation was much more severe in acidic solutions compared to near neutral solutions. Jarosite with a high Fe/S molar ratio was widely detected in the precipitate collected in acidic solutions, and the introduction of external HO influenced the crystallinity of jarosite. A layer of iron-deficient iron-sulfur oxide formed on the surface of pyrrhotite prevents its continuous oxidation, and the presence of Acidithiobacillus ferrooxidans enhanced this situation by promoting the release of Fe from the pyrrhotite. Additionally, the presence of external micromolar HO also determined the elemental state on pyrrhotite surface, as it found that the contribution of Fe and S (S and S) species on pyrrhotite surface increased with the increase of HO concentration in the solutions, especially in the presence of Acidithiobacillus ferrooxidans.
磁黄铁矿氧化因其产生污染物的高潜力而对水环境构成重大威胁。过氧化氢在天然水中通常以微摩尔浓度存在，其氧化能力比氧气更强，会使磁黄铁矿氧化过程变得复杂。在此，分别在pH值为1.93和6.45的条件下，研究了微摩尔浓度的过氧化氢对磁黄铁矿生物氧化和非生物氧化的影响。与近中性溶液相比，酸性溶液中磁黄铁矿的氧化更为严重。在酸性溶液收集的沉淀物中广泛检测到铁/硫摩尔比高的黄钾铁矾，外部过氧化氢的引入影响了黄钾铁矾的结晶度。磁黄铁矿表面形成的一层缺铁铁硫氧化物可防止其持续氧化，嗜酸氧化亚铁硫杆菌的存在通过促进磁黄铁矿中铁的释放而加剧了这种情况。此外，外部微摩尔浓度过氧化氢的存在还决定了磁黄铁矿表面的元素状态，因为发现磁黄铁矿表面铁和硫（S和S）物种的贡献随溶液中过氧化氢浓度的增加而增加，尤其是在嗜酸氧化亚铁硫杆菌存在的情况下。
