Department of Plant Biology and Ecology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), Barrio Sarriena s/n, 48940, Leioa, Spain.
Department of Conservation of Natural Resources, Soil Microbial Ecology Group, NEIKER - Basque Institute for Agricultural Research and Development, Basque Research and Technology Alliance (BRTA), Parque Científico y Tecnológico de Bizkaia, P812, 48160, Derio, Spain.
Environ Sci Pollut Res Int. 2020 Sep;27(25):31726-31736. doi: 10.1007/s11356-020-09449-x. Epub 2020 Jun 5.
Chromium is considered an environmental pollutant of much concern whose toxicity depends, to a great extent, on its valence state, with Cr(VI) being more soluble, bioavailable, and toxic, compared to Cr(III). Nanoremediation is a promising strategy for the remediation of metal pollutants by changing their valence state. However, among other aspects, its effectiveness for soil remediation is seriously hampered by the interaction of nanoparticles with soil organic matter. In this study, soil was (i) amended with two doses of a municipal solid organic waste and (ii) artificially polluted with 300 mg Cr(VI) kg DW soil. After a period of aging, a nanoremediation treatment with nanoscale zero-valent iron particles (1 g nZVI kg DW soil) was applied. The efficiency of the remediation treatment was assessed in terms of Cr(VI) immobilization and recovery of soil health. The presence of the organic amendment caused (i) a decrease of redox potential, (ii) Cr(VI) immobilization via its reduction to Cr(III), (iii) a stimulation of soil microbial communities, and (iv) an improvement of soil health, compared to unamended soil. By contrast, nZVI did not have any impact on Cr(VI) immobilization nor on soil health. It was concluded that, unlike the presence of the organic amendment, nanoremediation with nZVI was not a valid option for soils polluted with Cr(VI) under our experimental conditions.
铬被认为是一种环境污染物，其毒性在很大程度上取决于其价态，与 Cr(III) 相比，Cr(VI) 具有更高的可溶性、生物可利用性和毒性。纳米修复是一种通过改变金属污染物价态来修复金属污染物的有前途的策略。然而，在其他方面，由于纳米颗粒与土壤有机质的相互作用，其对土壤修复的有效性受到严重阻碍。在本研究中，土壤（i）用两种剂量的城市固体废物进行了改良，（ii）用 300mg Cr(VI)kg DW 土壤进行了人为污染。经过一段时间的老化，用纳米零价铁颗粒（1gnZVIkg DW 土壤）进行了纳米修复处理。根据 Cr(VI)的固定化和土壤健康的恢复情况来评估修复处理的效率。与未改良的土壤相比，有机改良剂的存在导致（i）氧化还原电位降低，（ii）Cr(VI)通过还原为 Cr(III)而固定，（iii）土壤微生物群落受到刺激，（iv）土壤健康得到改善。相比之下，nZVI 对 Cr(VI)的固定化和土壤健康都没有影响。研究结论认为，与有机改良剂的存在不同，在我们的实验条件下，用 nZVI 进行纳米修复不是受 Cr(VI)污染土壤的有效选择。
