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; Biology Department, Faculty of Sciences, University of Porto, 4169-007, Porto, Portugal.
Department of Plant Biology and Soil Science, Área de Edafoloxía e Química Agrícola, Facultade de Ciencias, Universidade de Vigo, As Lagoas 1, 32004, Ourense, Spain.
J Environ Manage. 2020 Aug 1;267:110640. doi: 10.1016/j.jenvman.2020.110640. Epub 2020 May 6.
Shooting range facilities in military areas have been indicated as a hotspot of land degradation with high contents of Potentially Toxic Elements (PTEs). Currently, based on the new nanomaterials with specific characteristics, nanoremediation technologies are used to immobilise and to reduce the availability of PTEs in field and laboratory conditions. In this study, the effects of nano-hydroxyapatite and/or hematite on PTEs immobilisation (As, Cd, Cu, Pb, Sb and Zn) in military shooting range soils were assessed through the measure of available and leachable forms with three single-extractions: calcium chloride (0.01M CaCl), low molecular weight organic acids (10 mM LMWOAs) and toxicity characteristic leaching procedure (TCLP). A sequential chemical extraction was used to determine the distribution of the PTEs in the different geochemical phases of the soils before and after the nanomaterial treatments. Results showed that the availability of PTEs decreased, especially for Pb (40-95%) and Zn (50-99%) after nanomaterial treatments. When both nanomaterial (hydroxyapatite + hematite) were combined, the immobilisation rate improved. However, when each nanomaterial was added individually to the soils, some elements, such as, Cu or Sb, showed a slight increment of their mobilisation. The sequential chemical extraction showed that the highest percentage of PTEs were mainly in the residual fraction before and after adding nanomaterials, being even higher in soils after the nanomaterial treatments. Likewise, the mobile fractions decreased after the treatment with nanomaterials. Our findings suggest that nanoremediation techniques improve the soil conditions, but they should be used carefully to avoid mobilisation of non-target PTEs or unexpected potentially impacts for soil biota.
军事射击场的设施已被认为是具有高含量潜在有毒元素（PTEs）的土地退化热点。目前，基于具有特定特性的新型纳米材料，纳米修复技术被用于固定和减少现场和实验室条件下 PTEs 的可用性。在这项研究中，通过三种单一提取方法（氯化钙（0.01M CaCl）、低分子量有机酸（10 mM LMWOAs）和毒性特征浸出程序（TCLP））来评估纳米羟基磷灰石和/或赤铁矿对军事射击场土壤中 PTEs 固定（As、Cd、Cu、Pb、Sb 和 Zn）的影响。使用连续化学提取来确定纳米材料处理前后 PTEs 在土壤不同地球化学相中的分布。结果表明，纳米材料处理后，PTEs 的可利用性降低，特别是 Pb（40-95%）和 Zn（50-99%）。当两种纳米材料（羟基磷灰石+赤铁矿）结合使用时，固定率提高。然而，当单独将每种纳米材料添加到土壤中时，一些元素，如 Cu 或 Sb，其迁移率略有增加。连续化学提取表明，PTEs 的最高百分比主要在添加纳米材料前后的残留部分，甚至在添加纳米材料后的土壤中更高。同样，添加纳米材料后，可移动部分减少。我们的研究结果表明，纳米修复技术可以改善土壤条件，但应谨慎使用，以避免非目标 PTEs 的迁移或对土壤生物群的意外潜在影响。
