Department of Plant Biology and Soil Science, University of Vigo, As Lagoas. Marcosende, 36310 Vigo, Spain.
GreenUPorto - Sustainable Agrifood Production Research Centre, Biology Department, Faculty of Sciences of University of Porto, Rua do Campo Alegre s/n, 4169-007 Porto, Portugal; Interdisciplinary Centre of Marine and Environmental Research (CIIMAR), University of Porto, Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos s/n, 4450-208 Matosinhos, Portugal.
Sci Total Environ. 2019 Nov 10;690:1151-1161. doi: 10.1016/j.scitotenv.2019.06.496. Epub 2019 Jun 29.
Shooting activities is an important source of Pb in contaminated soils. Lead accumulates in superficial soil horizons because of its low mobility, favouring its uptake by plants and representing a high transference risk to the trophic chain. A combination of phytoremediation with nanoremediation techniques can be used to recover firing range soils and decrease the mobility, bioavailability and toxicity of Pb. This study examines in depth the changes in Pb behaviour in firing range soils by adding hydroxyapatite nanoparticles (HANPs). These nanoparticles (NPs) may immobilise Pb and improve the quality of these areas. The use of HANPs and the Pb effects were assessed in three different species (Sinapis alba L., Lactuca sativa L. and Festuca ovina L.), focusing on their germination and early growth, through phytotoxicity assays. Single extractions with CaCl (0.01 M) in soils treated with HANPs show that these NPs retained Pb and reduced highly its availability and mobility. HR-TEM and TOF-SIMS were used to determine the interactions between HANPs and Pb, as well as with soil components. According to TOF-SIMS and HR-TEM/EDS analysis, Pb was mainly retained by HANPs but also associated lightly to organic matter, Fe compounds and silicates. Phytotoxicity assays exposed that S. alba, L. sativa and F. ovina were able to germinate and develop in the firing range soils despite the high available Pb contents before adding HANPs. After adding HANPs, Pb retention increased, favouring the germination and the growth of roots in the three species. These results suggest that HANPs can be used to decrease the availability and the toxicity of Pb without negative effects in the species growth. Accordingly, the combination of phytoremediation and nanoremediation techniques can be a great tool to stabilise these soils, avoiding the Pb transfer to nearby areas and its entry in the trophic chain.
射击活动是污染土壤中 Pb 的重要来源。由于 Pb 迁移性低，会在表土中积累，从而更容易被植物吸收，并对食物链造成高转移风险。可以将植物修复与纳米修复技术相结合，用于恢复射击场土壤，并降低 Pb 的迁移性、生物可利用性和毒性。本研究通过添加羟基磷灰石纳米颗粒（HANPs）深入研究了射击场土壤中 Pb 行为的变化。这些纳米颗粒（NPs）可以固定 Pb，并改善这些区域的质量。通过植物毒性测定，评估了 HANPs 的使用及其对三种不同物种（白芥菜、生菜和羊茅）的 Pb 效应，重点关注它们的发芽和早期生长。在添加 HANPs 的土壤中，用 0.01 M CaCl 进行单一提取表明，这些 NPs 保留了 Pb，并大大降低了其可利用性和迁移性。高分辨率透射电子显微镜（HR-TEM）和飞行时间二次离子质谱（TOF-SIMS）用于确定 HANPs 与 Pb 以及与土壤成分之间的相互作用。根据 TOF-SIMS 和 HR-TEM/EDS 分析，Pb 主要被 HANPs 保留，但也与有机物、Fe 化合物和硅酸盐轻微结合。植物毒性测定表明，尽管在添加 HANPs 之前土壤中含有高含量的有效 Pb，白芥菜、生菜和羊茅仍能发芽和在射击场土壤中生长。添加 HANPs 后，Pb 保留量增加，有利于三种植物的根发芽和生长。这些结果表明，HANPs 可用于降低 Pb 的生物有效性和毒性，而不会对物种生长产生负面影响。因此，将植物修复与纳米修复技术相结合，可以成为稳定这些土壤的有效工具，避免 Pb 向附近地区转移及其进入食物链。
