河流沉积物中的通过不同修饰的纳米级零价值铁的固定:性能,机制和Fe溶解
Wenjing Xue1, Hongdou Liu1, Jun Li1
1College of Environmental Science and Engineering, Yangzhou University, Yangzhou, 225009, People's Republic of China.
Environmental science and pollution research international
|October 24, 2023
概括
改性纳米级零价值铁 (NZVI) 有效地稳定了河流沉积物中的. 用氧化石墨烯加载的NZVI显示出最高的效率,铁漏率低,pH条件有利于修复.
科学领域:
- 环境科学 环境科学
- 材料科学 材料科学 材料科学
- 地质化学 地质化学
背景情况:
- 河流沉积物的重金属污染对环境构成重大风险.
- 纳米级零价值铁 (NZVI) 显示出对补救的希望,但其机制和风险需要进一步研究.
- 修改后的NZVI材料提供了增强重金属稳定性的潜力.
研究的目的:
- 系统地评估改性NZVI材料在河流沉积物中的 (Cd) 稳定性的性能和机制.
- 为了研究在各种pH值下修改后的NZVI的稳定性,并评估铁的溶解速度.
- 探索修改NZVI用于沉积物整治的环境风险和有效性.
主要方法:
- 用酸 (SNZVI),脂 (RNZVI) 和石墨烯氧化物 (GNZVI) 来修改NZVI.
- 用Cd污染的沉积物56天化修改后的NZVI.
- 使用毒性特征漏程序 (TCLP) 和生理基础提取试验 (PBET) 评估Cd的漏性.
- 使用弗洛伊德利希模型分析吸附行为,并通过SEM-EDX,XRD和FTIR描述稳定机制.
- 在一系列的pH值中评估Fe的溶解和稳定性.
主要成果:
- 固定效率按照以下顺序进行:GNZVI > RNZVI > SNZVI > NZVI.
- 在TCLP中,可浸的Cd下降了52.66%至96.28%,在PBET中,可提取的Cd下降了44.68%至70.21%.
- 在Cd吸附过程中,采用了内热,自发的化学过程,主要涉及对二次Fe矿物质的吸附和Cd的沉.
- 最佳的Cd稳定发生在pH值7-11时,Fe漏到上面的水中最小.
结论:
- 修改后的NZVI,特别是GNZVI,是稳定污染的河流沉积物中的Cd的高效材料.
- 稳定机制包括吸附,与二级Fe矿物质复合和沉.
- 这些材料在特定的pH值范围内表现出良好的稳定性和较低的环境风险,为有效的沉积物修复策略铺平了道路.
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