Department of Earth Sciences, University of Oxford, Parks Road, Oxford OX1 3PR, UK.
Chemosphere. 2010 Apr;79(4):448-54. doi: 10.1016/j.chemosphere.2010.01.044. Epub 2010 Feb 13.
The use of nano-scale particles as a means of environmental remediation still provides a comparatively novel approach for the treatment of contaminated waters. The current study compares the reactivity of micro-scale Fe, nano-scale Fe and nano-scale Ni/Fe (nickel/iron) particles specifically for dechlorination of solutions containing 350 mg L(-1) of TCE (concentration measured at a contaminated site in Derbyshire, UK). The results indicated that employing 1 g L(-1) of reactive material for dechlorination in the monometallic form (both micro- and nano-scale) exhibited very little reduction capability compared with the bimetallic Ni/Fe nano-scale particles, containing 28.9% Ni (in molar), which achieved complete dechlorination of the TCE in solution within 576 h. Experiments were also performed to determine the optimum bimetallic composition of the Ni/Fe particles for TCE reduction. This revealed that 3.2% Ni was the optimum Ni/Fe molar ratio for both maximum dehalogenation performance and minimum release of Ni into solution. Using particles of the most effective bimetallic composition, experiments were carried out to determine the concentration required for optimal TCE reduction. Over the range of nano-scale particle concentrations tested (0.1-9 g L(-1)), reduction rates of TCE increased with greater TCE:nano-scale particle ratios. However, a concentration range of 1-3 g L(-1) was selected as the most appropriate for site remediation, since more concentrated solutions demonstrated only small increases in rates of reaction. Finally, in order to test the long term performance and reactivity of the 3.2% Ni/Fe bimetallic nano-scale particles, weekly spikes of 350 mg L(-1) TCE were injected into a 3 g L(-1) nano-scale particle batch reactor. Results showed that the bimetallic nano-scale particles had the ability to reduce 1750 mg L(-1) TCE and remained active for at least 13 weeks.
将纳米级颗粒用作环境修复手段仍然为受污染水的处理提供了一种相对新颖的方法。本研究比较了微尺度 Fe、纳米尺度 Fe 和纳米尺度 Ni/Fe（镍/铁）颗粒对含有 350mg/L TCE（在英国德比郡的污染现场测量的浓度）的溶液的脱氯反应性。结果表明，对于单金属形式（微尺度和纳米尺度）的脱氯，使用 1g/L 的反应性材料表现出的还原能力非常小，与包含 28.9%Ni（摩尔）的双金属 Ni/Fe 纳米颗粒相比，双金属 Ni/Fe 纳米颗粒在 576 小时内完全脱除了溶液中的 TCE。实验还进行了确定用于 TCE 还原的 Ni/Fe 颗粒的最佳双金属组成的实验。结果表明，对于最大脱卤性能和最小 Ni 释放到溶液中的 Ni/Fe 摩尔比为 3.2%。使用最有效的双金属组成的颗粒，进行了实验以确定最佳 TCE 还原所需的浓度。在测试的纳米级颗粒浓度范围内（0.1-9g/L），TCE 的还原速率随 TCE:纳米级颗粒比例的增加而增加。然而，选择 1-3g/L 的浓度范围作为最适合现场修复的范围，因为更浓的溶液仅显示出反应速率的微小增加。最后，为了测试 3.2%Ni/Fe 双金属纳米颗粒的长期性能和反应性，每周向 3g/L 的纳米颗粒批量反应器中注入 350mg/L 的 TCE 。结果表明，双金属纳米颗粒能够还原 1750mg/L 的 TCE，并且至少在 13 周内保持活性。
