Phytoremediation potential of invasive plant species for potentially toxic elements along the Sava River upstream

Abstract

Invasive plant species (IPS) have many characteristics that are necessary for successful phytoremediation and the accumulation of large amounts of potentially toxic elements (PTEs). The most common IPS from the source of the Sava River are Reynoutria japonica, Solidago canadensis and Impatiens glandulifera. Considering that the riparian soils of the Sava River are classified as moderately polluted, this study investigated their enrichment with PTEs (As, B, Cd, Cr, Cu, Ni, Pb, Zn) and the potential for accumulation of these elements in roots and leaves of the most common IPS. The soil and plant samples were prepared using the wet digestion method in CEM Mars 6 microwave oven. The content of PTEs in soil and plant samples was determined by ICP-OES. The results showed a moderate to very high enrichment of Cu in the soils. Impatiens glandulifera has the highest uptake capacity in leaves and phytoextraction ability of B, Cd, Cu and Zn. Reynoutria japonica has some potential for phytoextraction of Pb, Zn and especially B, while Solidago canadensis has potential for phytoextraction of B and Zn, while excluding Cr and Cu. The analyzes have shown that the studied species are not suitable for bioindication of PTEs in the riparian soils of the Sava River. Considering the enrichment of soils with Cu, Impatiens glandulifera is the most suitable species for phytoremediation of these elements among the studied species.

Keywords: Heavy metals; Impatiens glandulifera; Potentially toxic elements; Reynoutria japonica; Solidago canadensis; Trace elements.

Fig. 1

Position of the Sava River on Balkans with marked sampling sites.

Fig. 2

PTE content in soils presented as average values with standard deviation, in mg kg⁻¹.

Fig. 3

MAI index.

Fig. 4

CBCI index.

Fig. 5

Spearman correlations of PTE contents in: a) Solidago canadensis roots and soil; b) Solidago canadensis leaves and soil; c) Reynoutria japonica roots and soil; d) Reynoutria japonica leaves and soil; e) Impatiens glandulifera roots and soil; f) Impatiens glandulifera leaves and soil; * for p < 0.05, ** for p < 0.01, and *** for p < 0.001.