Key Laboratory of Nano-Minerals and Pollution Control of Anhui Higher Education Institutes, Hefei University of Technology, Hefei, 230009, China; Institute of Environmental Minerals and Materials, School of Resources and Environmental Engineering, Hefei University of Technology, Hefei, 230009, China.
Key Laboratory of Nano-Minerals and Pollution Control of Anhui Higher Education Institutes, Hefei University of Technology, Hefei, 230009, China; Institute of Environmental Minerals and Materials, School of Resources and Environmental Engineering, Hefei University of Technology, Hefei, 230009, China.
Chemosphere. 2023 Nov;341:139932. doi: 10.1016/j.chemosphere.2023.139932. Epub 2023 Aug 22.
Birnessite plays a crucial role in regulating the fate of contaminants in soil, which is affected by the crystal structure of birnessite. In this study, the transformation of triclinic birnessite to hexagonal birnessite was examined at various pH values, and their reactivity towards norfloxacin was investigated. The findings indicate that the conversion from triclinic birnessite to hexagonal birnessite occurs under pH conditions lower than 7. The lower of the solution pH where the birnessite formed, the higher the surface reactivity. Throughout the transformation process, the migration of Mn and the increased interlayer protons generated more reactive oxygen species, which enhanced the surface reactivity towards norfloxacin. Specifically, at a conversion pH of 1, the norfloxacin removal rate significantly increases from 14% to 97% compared to triclinic birnessite. The mechanism of norfloxacin removal by triclinic and hexagonal birnessite is illustrated. These findings provide valuable insights into the dynamic transformation of birnessites in aqueous environments with varying pH values and their impact on norfloxacin removal.
钠锰矿在调节土壤中污染物的命运方面起着至关重要的作用，而这一过程受到钠锰矿晶体结构的影响。在本研究中，我们考察了在不同 pH 值条件下斜方钠锰矿向六方钠锰矿的转化及其对诺氟沙星的反应活性。结果表明，在 pH 值低于 7 的条件下，斜方钠锰矿会转化为六方钠锰矿。在形成钠锰矿的溶液 pH 值越低的情况下，表面反应性越高。在整个转化过程中，Mn 的迁移和增加的层间质子产生了更多的活性氧物质，从而提高了其对诺氟沙星的表面反应性。具体来说，在转化 pH 值为 1 的条件下，与斜方钠锰矿相比，诺氟沙星的去除率从 14%显著增加到 97%。本文还阐述了斜方钠锰矿和六方钠锰矿去除诺氟沙星的机制。这些发现为了解在不同 pH 值条件下水溶液中钠锰矿的动态转化及其对诺氟沙星去除的影响提供了有价值的见解。
