Department of Forestry, Faculty of Natural Resources, Tarbiat Modares University, Noor, Iran.
Department of Environmental Science, Faculty of Natural Resources, Tarbiat Modares University, Noor, Iran.
Environ Sci Pollut Res Int. 2019 Apr;26(11):10776-10789. doi: 10.1007/s11356-019-04411-y. Epub 2019 Feb 18.
Soil contaminated with heavy metals (HMs) is a serious problem throughout the world that threatens all living organisms in the soil. Therefore, large-scale remediation is necessary. This study investigated a new combination of remediation techniques on heavy metal contaminated soil, phytoremediation, and soil amendment with nano-sized zero-valent iron (nZVI) and rhizosphere microorganisms. White willow (Salix alba L.) was grown for 160 days in pots containing Pb, Cu, and Cd and amended with 0, 150, and 300 (mg kg) of nZVI and rhizosphere microorganisms, including the arbuscular mycorrhizal fungus (AMF), Rhizophagus irregularis, and the plant growth promoting rhizobacteria (PGPR), Pseudomonas fluorescens. The results showed that inoculation with PGPR and AMF, particularly dual inoculation, improved plant growth as well as the physiological and biochemical parameters of white willow, and increased the bioconcentration factor (BCF) of Pb, Cu, and Cd. The low dose of nZVI significantly increased the root length and the leaf area of the seedlings and increased the BCF of Cd. In contrast, the high dose of nZVI had negative effects on the seedlings growth and the BCF of Pb and Cu, about - 32% and - 63%, respectively. Our results demonstrate that nZVI at low doses can improve plant performance in a phytoremediation context and that the use of beneficial rhizosphere microorganisms can minimize nZVI stress in plants and make them less susceptible to stress even under high dose conditions.
受重金属（HMs）污染的土壤是一个全球性的严重问题，威胁着土壤中的所有生物。因此，需要进行大规模的修复。本研究调查了一种新的修复技术组合，即植物修复和用纳米零价铁（nZVI）和根际微生物改良受重金属污染的土壤。在含有 Pb、Cu 和 Cd 的花盆中种植白柳（Salix alba L.）160 天，并添加 0、150 和 300（mg kg）nZVI 和根际微生物，包括丛枝菌根真菌（AMF）、不规则根瘤菌（Rhizophagus irregularis）和植物促生根际细菌（PGPR）荧光假单胞菌。结果表明，接种 PGPR 和 AMF，特别是双重接种，改善了白柳的生长以及生理生化参数，并提高了 Pb、Cu 和 Cd 的生物浓缩系数（BCF）。低剂量的 nZVI 显著增加了幼苗的根长和叶面积，并增加了 Cd 的 BCF。相比之下，高剂量的 nZVI 对幼苗的生长和 Pb 和 Cu 的 BCF 有负面影响，分别约为-32%和-63%。我们的结果表明，低剂量的 nZVI 可以改善植物在植物修复中的性能，而有益的根际微生物的使用可以减轻 nZVI 对植物的胁迫，即使在高剂量条件下，也能使它们不易受到胁迫。
