RESEARCH ARTICLE The impact of nanoparticles zero-valent iron (nZVI) and rhizosphere microorganisms on the phytoremediation ability of white willow and its response Sahar Mokarram-Kashtiban 1 & Seyed Mohsen Hosseini 1 & Masoud Tabari Kouchaksaraei 1 & Habibollah Younesi 2 Received: 26 September 2018 /Accepted: 28 January 2019 # Springer-Verlag GmbH Germany, part of Springer Nature 2019 Abstract 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 microor- ganisms. 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 -1 ) 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. Keywords Metal accumulator plant . Mixed contaminated soil . Phytotoxicity . Phytoremediation techniques . Soil amendments . Trace metals remediation Abbreviations AMF Arbuscular mycorrhizal fungus BCF Bioconcentration factor C Organic carbon Ci Intercellular CO 2 concentration CMC Carboxymethyl cellulose E Transpiration rate EC Electrical conductivity EL Electrolyte leakage Gs Stomatal conductance HMs Heavy metals MDA Malondialdehyde N Total nitrogen nZVI Nano-sized zero-valent iron PGPR Plant growth promoting rhizobacteria Pn Photosynthetic rates SLA Specific leaf area TF Translocation factors Ti Tolerance index WUE Water-use efficiency Introduction Decline in soil health and quality poses a threat to food secu- rity and sustainable development (Gomiero 2016). Soil con- tamination by heavy metals (HMs) is one of the most serious Responsible editor: Elena Maestri Electronic supplementary material The online version of this article (https://doi.org/10.1007/s11356-019-04411-y) contains supplementary material, which is available to authorized users. * Seyed Mohsen Hosseini hosseini@modares.ac.ir 1 Department of Forestry, Faculty of Natural Resources, Tarbiat Modares University, Noor, Iran 2 Department of Environmental Science, Faculty of Natural Resources, Tarbiat Modares University, Noor, Iran Environmental Science and Pollution Research https://doi.org/10.1007/s11356-019-04411-y