在活跃溶解石 (104) 表面的Pb2+离子的动态表面内置
Bektur Abdilla1, Sang Soo Lee2, Paul Fenter2
1Department of Earth Sciences, University of Delaware, Newark, Delaware 19716, United States.
Environmental science & technology
|September 5, 2024
概括
溶解的 (Pb2+) 与岩表面发生反应,在不平衡下形成一种新的富含Pb的层. 这一发现影响了在酸性矿井排水和CO2储存中的金属运输的理解.
科学领域:
- 地质化学 地质化学
- 表面科学是一门学科.
- 环境科学 环境科学
背景情况:
- Pb2+与石表面的相互作用在不同的平衡条件下表现出复杂的行为.
- 远离平衡的条件导致Pb2+融入石,抑制溶解并形成没有二次矿物沉的微观地形.
- 在持续不平衡下对Pb2+反应性的机制理解是有限的.
研究的目的:
- 为了研究在远离平衡条件下的石溶解过程中溶解的Pb2+的界面结合.
- 为了阐明石上富含Pb的表面层的形成和特征.
- 了解这种新的吸附方式对环境系统中的金属运输的影响.
主要方法:
- 利用流通反应细胞研究酸盐 (104) 在pH ~3.7.7的溶解.
- 使用共振异常X射线反射率 (RAXR) 来确定Pb分布.
- 应用X射线光 (XRF) 和纳米红外原子力显微镜 (AFM) 用于表面特征.
主要成果:
- 观察到在 (104) 表面上形成厚度为 ~ 1 nm 的富含 Pb 的酸盐层.
- 量化了大约1.4个单层 (ML) 的总Pb覆盖面.
- 通过持续不平衡稳定了Pb2+的新吸附模式.
结论:
- 富含Pb的表面层代表了在不平衡下石上的Pb2+吸附的新模式.
- 这种现象在诸如酸性矿井排水和CO2注射场所等环境中显著影响溶解金属运输.
- 考虑到这种改变的表面层,可以提高地化学反应运输模型的准确性.
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