Phytoaccumulation potential of nine plant species for selected nutrients, rare earth elements (REEs), germanium (Ge), and potentially toxic elements (PTEs) in soil.

ABSTRACT

Given the possible benefits of phytoextraction, this study evaluated the potential of nine plant species for phytoaccumulation/co-accumulation of selected nutrients, rare earth elements, germanium, and potentially toxic elements. Plants were grown on 2 kg potted soils for 12 weeks in a greenhouse, followed by a measurement of dry shoot biomass. Subsequently, elemental concentrations were determined using inductively coupled mass spectrometry, followed by the determination of amounts of each element accumulated by the plant species. Results show varying accumulation behavior among plants for the different elements. Fagopyrum esculentum and Cannabis sativa were better accumulators of most elements investigated except for chromium, germanium, and silicon that were better accumulated by Zea mays, the only grass species. F. esculentum accumulated 9, 24, and 10% of Copper, Chromium, and Rare Earth Elements in the mobile/exchangeable element fraction of the soils while Z. mays and C. sativa accumulated amounts of Cr and Ge ∼58 and 17% (for Z. mays) and 20 and 9% (for C. sativa) of the mobile/exchangeable element fraction of the soils. Results revealed co-accumulation potential for some elements e.g., (1) Si, Ge, and Cr, (2) Cu and Pb, (3) P, Ca, Co, and REEs based on chemical similarities/sources of origin.

This is a novel study because it focuses on evaluating plant species not only the accumulation behavior but the possibilities of co-accumulation of elements comprising selected nutrients, PTEs and CRMs (Ge and REEs) by plants. It provides new information on the biomass production and accumulation behavior of some plant species for some elements, some of which have not been previously studied. It also provides information on the possibility of predicting species accumulation behavior for some elements based on similarities in the source of origin, chemical similarities, or antagonism.