在降解和再氧化过程中,在土中的天然合物和纳米颗粒的多金属污染物动员
Xinyang Li1, Zhenyu Cao1, Yanpei Du1
1CAS Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.
Journal of hazardous materials
|October 7, 2023
概括
在土中的铜,和等重金属是由天然的合物和纳米粒子运输的. 它们的释放受到纳米级的氧化还原波动,pH值和有机物相互作用的影响.
科学领域:
- 环境科学 环境科学
- 土壤科学 土壤科学
- 地质化学 地质化学
背景情况:
- 自然存在的合物和纳米颗粒是土壤水系统中重金属的关键载体.
- 关于在土中经历氧化还原波动的颗粒结合金属的尺寸分布和元素组成的数据有限.
研究的目的:
- 为了研究铜 (Cu), (Cd) 和 (Pb) 含有纳米颗粒和合物在受污染的土中的调动.
- 了解氧化还原波动 (还原和再氧化) 对金属载体粒子特性的影响.
主要方法:
- 使用非对称流场流分离与紫外线和感应合等离子体质谱 (AF4-UV-ICP-MS) 来分离和量化颗粒.
- 使用扫描传输电子显微镜与能量分散式X射线光谱 (STEM-EDS) 进行元素组成分析.
- 分析了四个具有不同地质化学性质的污染土壤.
主要成果:
- 颗粒结合的金属主要存在两个大小范围:0.3-40 kDa (F1) 和130 kDa-450 nm (F2),与有机物 (OM),氧化铁和粘土矿物质有关.
- Cu和Pb比Cd更频繁地与合物结合,而不是Cd. 在土壤降解过程中,Cu,Pb和Cd的体分数显著 (分别为83.2%,72.4%,19.8%),但在再氧化后下降.
- 合金属比例与pH值和溶解有机碳 (DOC) 有正相关,与氧化还原潜力 (Eh) 有负相关.
- 定量分析显示,纳米尺度上的Cu/Cd和OM之间存在正相关性 (F1).
结论:
- 这项研究提供了对土中多金属污染物载体颗粒在氧化还原波动下大小,组成和丰度的定量见解.
- 有机物和有毒的阴离子金属之间的纳米相互作用对于金属在土环境中的释放和调动至关重要.
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