IMIDRA, Instituto Madrileño de Investigación y Desarrollo Rural, Agrario y Alimentario, Finca "El Encín", Alcalá de Henares, 28805, Madrid, Spain.
Sci Rep. 2020 Sep 28;10(1):15927. doi: 10.1038/s41598-020-73144-7.
In the last few years, the effectiveness of nanoscale zero-valent iron (nZVI) as a treatment for polluted waters and soils has been widely studied. However, little data are available on its efficacy for metal immobilization at low and moderate doses. In this study, the effectiveness of two doses of commercial nZVI (1 and 5%) to immobilize Cu and/or Ni in water and acidic soil samples was evaluated. The influence of the nanoremediation technology on iron availability, physico-chemical soil properties and soil phytotoxicity was also assessed. The results show that the effectiveness of nZVI to immobilize Cu and Ni in water and soil samples was determined by the dose of the nanomaterial and the presence of both metals. Nickel immobilization was significantly decreased by the presence of Cu but the opposite effect was not observed. nZVI showed better immobilization capacity in water than in soil samples. In water, the dose of 5% completely removed both metals, whereas at a lower dose (1%) the percentage of immobilized metal decreased, especially for Ni in Cu + Ni samples. In soil samples, 5% nZVI was more effective in immobilizing Ni than Cu, with a 54% and 21% reduction of leachability, respectively, in single contaminated samples. In Cu + Ni soil samples, nZVI treatment led to a significant decrease in Ni immobilization, similar to that observed in water samples. The application of nZVI induced a dose-dependent increase in available Fe-a relevant effect in the context of soil rehabilitation. Germination assays of Medicago sativa and Vicia sativa seeds revealed that treatment with nZVI did not induce phytotoxicity under the experimental conditions tested, and that the phytotoxicity induced by Ni decreased significantly after the treatment. Thus, the use of nZVI emerges as an interesting option for Cu and/or Ni immobilization in water samples. The effectiveness of nZVI to remove Cu from acidic soil samples was moderate, while for Ni it was strongly dependent on the presence of Cu. These observations therefore indicate that the results in water samples cannot be extrapolated to soil samples.
在过去的几年中，纳米零价铁（nZVI）作为一种处理受污染水和土壤的方法已经得到了广泛的研究。然而，关于其在低剂量和中等剂量下对金属固定化的效果的数据很少。在这项研究中，评估了两种剂量的商业 nZVI（1%和 5%）对水和酸性土壤样品中 Cu 和/或 Ni 的固定化效果。还评估了纳米修复技术对铁可用性、理化土壤性质和土壤植物毒性的影响。结果表明，nZVI 对水和土壤样品中 Cu 和 Ni 的固定化效果取决于纳米材料的剂量和两种金属的存在。Ni 的固定化因 Cu 的存在而显著降低，但没有观察到相反的效果。nZVI 在水中的固定化能力优于土壤样品。在水中，5%的剂量完全去除了两种金属，而在较低的剂量（1%）下，固定化金属的百分比降低，特别是在 Cu+Ni 样品中 Ni 的固定化百分比降低。在土壤样品中，5%的 nZVI 对 Ni 的固定化效果比对 Cu 的效果更好，分别在单一污染样品中减少了 54%和 21%的可浸出性。在 Cu+Ni 土壤样品中，nZVI 处理导致 Ni 的固定化显著减少，与在水样中观察到的情况相似。nZVI 的应用导致可利用 Fe 的剂量依赖性增加——这在土壤修复的背景下是一个相关的影响。紫花苜蓿和野豌豆种子的萌发试验表明，在试验条件下，nZVI 处理不会引起植物毒性，而且 Ni 引起的植物毒性在处理后显著降低。因此，nZVI 的使用成为水样品中 Cu 和/或 Ni 固定化的一个有趣选择。nZVI 去除酸性土壤样品中 Cu 的效果适中，而对于 Ni 的效果则强烈依赖于 Cu 的存在。因此，这些观察结果表明，水样品中的结果不能外推到土壤样品中。
