Planta Piloto de Procesos Industriales Microbiológicos (PROIMI), CONICET, Av. Belgrano y Pasaje Caseros, Tucumán, 4000, Argentina; Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, Ayacucho 491, Tucumán, 4000, Argentina.
Department of Plant Biology and Ecology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), B° Sarriena S/n, Leioa, E-48940, Spain.
Environ Res. 2021 Mar;194:110666. doi: 10.1016/j.envres.2020.110666. Epub 2020 Dec 25.
Soils contaminated by organic and inorganic pollutants like Cr(VI) and lindane, is currently a main environmental challenge. Biological strategies, such as biostimulation, bioaugmentation, phytoremediation and vermiremediation, and nanoremediation with nanoscale zero-valent iron (nZVI) are promising approaches for polluted soil health recovery. The combination of different remediation strategies might be key to address this problem. For this reason, a greenhouse experiment was performed using soil without or with an organic amendment. Both soils were contaminated with lindane (15 mg kg) and Cr(VI) (100 or 300 mg kg). After one month of aging, the following treatments were applied: (i) combination of bioaugmentation (actinobacteria), phytoremediation (Brassica napus), and vermiremediation (Eisenia fetida), or (ii) nanoremediation with nZVI, or (iii) combination of biological treatments and nanoremediation. After 60 days, the wellness of plants and earthworms was assessed, also, soil health was evaluated through physico-chemical parameters and biological indicators. Cr(VI) was more toxic and decreased soil health, however, it was reduced to Cr(III) by the amendment and nZVI and, to a lesser extent, by the biological treatment. Lindane was more effectively degraded through bioremediation. In non-polluted soils, nZVI had strong deleterious effects on soil biota when combined with the organic matter, but this effect was reverted in soils with a high concentration of Cr(VI). Therefore, under our experimental conditions bioremediation might be the best for soils with a moderate concentration of Cr(VI) and organic matter. The application of nZVI in soils with a high content of organic matter should be avoided except for soils with very high concentrations of Cr(VI). According to our study, among the treatments tested, the combination of an organic amendment, biological treatment, and nZVI was shown to be the strategy of choice in soils with high concentrations of Cr(VI) and lindane, while for moderate levels of chromium, the organic amendment plus biological treatment is the most profitable treatment.
受有机和无机污染物（如六价铬和林丹）污染的土壤目前是一个主要的环境挑战。生物修复策略，如生物刺激、生物强化、植物修复和蚯蚓修复以及纳米零价铁（nZVI）纳米修复，是受污染土壤健康恢复的有前途的方法。不同修复策略的结合可能是解决这个问题的关键。出于这个原因，在没有或有有机添加剂的土壤中进行了温室实验。两种土壤都受到林丹（15 毫克/千克）和六价铬（100 或 300 毫克/千克）的污染。经过一个月的老化期后，施加了以下处理：（i）生物强化（放线菌）、植物修复（油菜）和蚯蚓修复（赤子爱胜蚓）的组合，或（ii）nZVI 纳米修复，或（iii）生物处理和纳米修复的组合。60 天后，评估了植物和蚯蚓的健康状况，还通过理化参数和生物指标评估了土壤健康状况。六价铬的毒性更强，降低了土壤健康水平，但通过添加物和 nZVI（在较小程度上通过生物处理）将其还原为三价铬。林丹通过生物修复更有效地降解。在未受污染的土壤中，当与有机物结合时，nZVI 对土壤生物群具有强烈的有害影响，但在含有高浓度六价铬的土壤中，这种影响会逆转。因此，在我们的实验条件下，对于六价铬和有机物浓度适中的土壤，生物修复可能是最佳选择。除了六价铬浓度非常高的土壤外，应避免在有机物含量高的土壤中应用 nZVI。根据我们的研究，在所测试的处理中，在高浓度六价铬和林丹的土壤中，有机添加剂、生物处理和 nZVI 的组合被证明是首选策略，而对于中等浓度的铬，有机添加剂加生物处理是最有利可图的处理。
