煤炭飞灰颗粒中和物种的纳米级异质性:使用增强光谱成像和物种化技术进行分析
Nelson A Rivera1, Florence T Ling2,3, Zehao Jin1
1Department of Civil and Environmental Engineering, Duke University Box 90287 Durham North Carolina 27708 USA nelson.rivera@duke.edu hsukim@duke.edu.
概括
煤炭飞灰含有 (As) 和 (Se),造成环境风险. 这项研究揭示了它们与矿物颗粒的复杂纳米级关联,这对于理解灰管理和再利用至关重要.
科学领域:
- 环境科学 环境科学
- 地质化学 地质化学
- 材料科学 材料科学 材料科学
背景情况:
- 煤炭燃烧的副产品,如飞灰,富含 (As) 和 (Se).
- 从飞灰到水和土壤中的As和Se的调动对野生动物和人类构成风险.
- 了解As和Se的化学形式和粒子关联是评估它们的漏潜力和生物可访问性的关键.
研究的目的:
- 为了确定飞灰中As和Se的纳米和微观固体相矿物联体.
- 为了研究飞灰颗粒中As和Se的氧化状态.
- 阐明煤炭飞灰中微量元素物种化的异质性和复杂性.
主要方法:
- 使用硬X射线纳米探针 (HXN) (30-50nm点大小) 进行纳米尺度的2D成像.
- 采用微探针X射线能力 (≥5μm分辨率) 用于元素关联分析.
- 使用纳米到微尺度X射线吸收光谱测量了As和Se的分化.
主要成果:
- 在纳米尺度上,HXN揭示了与富含 (Ca) 和铁 (Fe) 的粒子相关的As和Se.
- 观察到Se的纳米粒子附着在飞灰颗粒的表面.
- 分析强调了As和Se与矿物相的分散分布和混合.
结论:
- 飞灰中As和Se的化学结合在纳米到微观尺度中是异质的和复杂的.
- 了解这些纳米级关联对于预测飞灰中As和Se的环境命运和行为至关重要.
- 这项研究提供了关于As和Se的固体阶段特异化的见解,为煤炭燃烧副产品的安全处理,处置和再利用策略提供了信息.
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