Trace element accumulation in Salvinia natans from areas of various land use types

Abstract

Salvinia natans meets many criteria for accumulative bioindicators and phytoremediation agents. However, the majority of studies on its bioaccumulation capacity were performed under controlled culture conditions. In the present study, Salvinia natans was investigated in a field study. Plant and water samples were collected from aquatic reservoirs located in areas with various dominant land uses (forested, agricultural, residential and industrial). Contents of 10 trace elements (As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Zn) and phytomass were measured to estimate the bioindication and phytoremediation potential of the species. Results showed that contents of trace elements in S. natans were high compared with other aquatic ferns (Azolla japonica, A. pinata) as well as free-floating vascular plants (e.g. Pistia stratiotes, Hydrocharis morsus-ranae, Lemna sp., Eichhornia crassipes). High bioaccumulation factors for Cu, Fe, Mn, Ni, Pb and Zn confirm accumulative abilities of the plant. Application of neural networks (SOFMs) confirmed that the species may be used in bioindication: the land use type determined the composition of substances carried into water reservoirs with runoff and trace elements accumulated in Salvinia tissues. Ferns in industrial areas had the highest content of Cd, Cu and Zn, while in residential areas plants showed the highest content of As, Co, Fe, Mn, Ni and Pb. Element contents in S. natans in forested areas were the lowest. High standing stocks of Cd, Mn and Ni indicated an important role of S. natans in the cycling of elements and potential use in their removal from aquatic ecosystems.

Lithium Accumulation in Salvinia natans Free-Floating Aquatic Plant

“…Dhir et al [ 61 ] observed a higher accumulation rate for Cr, Fe, Ni, Cu, Pb, and Cd than for Co, Zn, and Mn. Polechońska et al reported S. natans as Cu, Fe, Ni, and Zn accumulator and Mn hyperaccumulator, while Reeves and Baker as Cd, Ni, Cu, Co, Pb, Cr, Zn, and Mn hyperaccumulator [ 16 , 62 ]. S. natans showed a considerable capacity to accumulate metals (Fe, Co, Cr, Pb, Cu, Zn, Cd, and Ni) by increasing the initial concentrations from 30 to 50 mg/L, but the tolerance index decreased, suggesting higher toxicity [ 17 ].…”

“…Free-floating aquatic plants are ideal for phytoextraction and rhizofiltration, as they are easy to grow and harvest [ 9 ]. The Salviniaceae aquatic species have a remarkable ability to uptake, tolerate and bioaccumulate toxic inorganic pollutants [ 14 , 15 , 16 , 17 ], phosphates [ 18 ], nitrogen [ 19 ], arsenic [ 20 ], and amino groups from aqueous solutions [ 21 ]. Salvinia natans (L.) All.…”

“…( S. natans ) is a free-floating fern from the Salviniaceae family and has a high tolerance to a wide range of pollutants and a rapid growth rate [ 22 ]. It is native to Europe and widely spread within temperate, tropical, and subtropical regions [ 16 , 23 , 24 ]. S. natans has two floating leaves and a submerged leaf, which functions as a root, assimilating nutrients and pollutants [ 25 ].…”

“…The leaves are predominantly composed and covered by eggbeater-shaped hairs, making them hydrophilic. In order to determine the accumulation potential of S. natans , its tolerance to various heavy metals and trace elements was studied [ 16 , 17 , 26 , 27 , 28 ].…”

Macrophytes as passive bioindicators of trace element pollution in the aquatic environment

“…After selection of a species that shows high accumulation abilities, the bioindicator should be validated based on a direct positive correlation between element concentrations in plants and their environment or differences/gradients between the contents of analyzed elements in plant tissues from sampling sites of different characteristics (Baldantoni et al, 2018; Bellino et al, 2020; Polechońska et al, 2019; Skorbiłowicz et al, 2018). However, accumulation efficiency, metal concentrations in tissues, and hence usefulness in bioindication in natural conditions depend on many factors and local conditions, so few only general patterns emerge from the literature review.…”