IMIDRA, Finca "El Encín", Alcalá de Henares, Madrid, Spain.
IMIDRA, Finca "El Encín", Alcalá de Henares, Madrid, Spain.
Sci Total Environ. 2017 Apr 15;584-585:1324-1332. doi: 10.1016/j.scitotenv.2017.02.011. Epub 2017 Feb 9.
Nanoscale zero valent iron (nZVI) particles obtained by different methods differ in their structure, which lead to different reactivity, and therefore a likely difference in the remediation efficiency. The present study compares the effectiveness of three commercial ZVI nanoparticles to immobilize As and Hg in two soils (A and B) collected from a brownfield highly contaminated by mining and metallurgy activities. Scarce data are available on the effectiveness of nZVI for Hg immobilization in soil. Two commercial nZVI slurries from Toda (RNIP and RNIP-D) and one from Nano Iron (25S) were used at different doses (1, 5 and 10%). The metal(loid) availability and mobility was evaluated with the TCLP test and Tessier extraction procedure. The influence of nZVI application on As and Hg speciation was also evaluated as well as its impact on soil pH, electrical conductivity and soil phytotoxicity to vetch germination. The three commercial nZVI particles significantly reduced As and Hg availability in the two soils studied, which led to a decrease in soil phytotoxicity. At the dose of 5% of nZVI a decrease of exchangeable-As higher than 70% was observed for both soils, whereas in the case of Hg, a higher dose of nZVI (10%) was necessary to achieve reductions of exchangeable-Hg between 63 and 90% depending on the type of nZVI and soil. No impact on soil pH and electrical conductivity was observed. The effectiveness of metal(loid) immobilization depended on type of nZVI, soil properties and metal(loid) characteristics. Nanoparticles from Nano Iron showed better results for As immobilization whereas RNIP nanoparticles were more effective for Hg. Overall, 25S at the dose of 5% resulted more effective than RNIP nanoparticles for the reduction of exchangeable-As (in the range of 6-14%), whereas RNIP and RNIP-D were 10 and 13% more effective, respectively, for the reduction of exchangeable-Hg at the dose of 10% in soil B. Thus, nZVI can be used for the remediation of highly As and Hg polluted soils, although previous experiments at lab scale are necessary to determine the most viable type of nZVI and its dose.
纳米零价铁（nZVI）颗粒通过不同的方法获得，其结构不同，导致反应性不同，因此修复效率可能也不同。本研究比较了三种商业 ZVI 纳米颗粒在两种土壤（A 和 B）中固定 As 和 Hg 的效果，这两种土壤均来自一个受到采矿和冶金活动高度污染的棕地。关于 nZVI 固定土壤中 Hg 的有效性的数据很少。使用来自 Toda 的两种商业 nZVI 悬浮液（RNIP 和 RNIP-D）和一种来自 Nano Iron（25S），剂量分别为 1、5 和 10%。用 TCLP 试验和 Tessier 提取程序评估金属（类）的可用性和迁移率。还评估了 nZVI 应用对 As 和 Hg 形态的影响以及对土壤 pH、电导率和对雀麦发芽的土壤植物毒性的影响。三种商业 nZVI 颗粒显著降低了两种研究土壤中 As 和 Hg 的有效性，从而降低了土壤的植物毒性。在 nZVI 用量为 5%的情况下，两种土壤中可交换的 As 减少了 70%以上，而对于 Hg，则需要更高剂量的 nZVI（10%）才能实现可交换-Hg 的减少，减少幅度在 63%到 90%之间，具体取决于 nZVI 的类型和土壤。没有观察到对土壤 pH 和电导率的影响。金属（类）固定的有效性取决于 nZVI 的类型、土壤特性和金属（类）的特性。Nano Iron 的纳米颗粒在固定 As 方面表现更好，而 RNIP 纳米颗粒在固定 Hg 方面更有效。总体而言，25S 在 5%的剂量下，对于降低可交换的 As（在 6-14%的范围内）比 RNIP 纳米颗粒更有效，而 RNIP 和 RNIP-D 在土壤 B 中 10%的剂量下，对于降低可交换的 Hg 分别更有效 10%和 13%。因此，nZVI 可用于修复高度污染的 As 和 Hg 土壤，尽管需要在实验室规模上进行前期实验，以确定最可行的 nZVI 类型及其剂量。
