Evaluation of the Sagittaria montevidensis Cham. & Schltdl. as a bioindicator and phytoextractor of toxic metals

Abstract

This study evaluated the bioindication and phytoremediation capacity of the aquatic macrophyte Sagittaria montevidensis by using it to assess the bioconcentration and translocation of heavy metals. A simple sampling was conducted at four sites in the region of Pelotas, southern Brazil, where plants, water and sediments were collected. The plants were subjected to nitric-perchloric acid digestion and the sediments underwent pseudo-total acid digestion. The determination of the elements Cr, Cu, Pb, Ni and Zn in the extracts was performed by flame atomic absorption spectrometry. Physicochemical tests were also carried out on water samples, including pH, electrical conductivity, chlorides, alkalinity, hardness and organic matter, and in sediment samples, moisture and organic matter content. The macrophyte study indicated a Bioconcentration Factor (BCF) and a Translocation Factor (TF), especially for Ni. The results showed that the aquatic macrophyte species S. montevidensis has a phytoextraction capacity, mainly for Ni, and potentially for bioindication of Cu, Ni and Zn.Keywords: aquatic macrophyte, heavy metals, phytoremediation. Avaliação da Sagittaria montevidensis Cham. & Schltdl. como bioindicador e fitoextrator de metais tóxicos RESUMOEste estudo teve como objetivo avaliar a capacidade de fitorremediação e bioindicação da macrófita aquática Sagittaria montevidensis, utilizando como parâmetros a bioconcentração e translocação de metais pesados. Foi realizada uma amostragem simples em quatro locais na região de Pelotas, sul do Brasil, na qual foram coletadas plantas, águas e sedimentos. As plantas foram submetidas a digestão ácida nítrico-perclórica e os sedimentos sofreram a extração pseudo-total de digestão ácida. A determinação dos elementos Cr, Cu, Pb, Ni e Zn nos extratos foi realizada por espectrometria de absorção atômica em chama. Também foram realizados ensaios físico-químicos em amostras de água, incluindo pH, condutividade elétrica, cloretos, alcalinidade, dureza e matéria orgânica e, em amostras de sedimentos, umidade e teor de matéria orgânica. A macrófita aquática estudada apresentou

Metals Uptake by Sagittaria montevidensis in Contaminated Riparian Area of Matanza-Riachuelo River (Argentina)

“…TF >1 was obtained for Cu and Ni, behaving as a metal accumulator for these elements. The TFs for Cu, Ni and Zn obtained in this work were lower than those reported by Kickhöfel Ferrer et al [16] for this species. For Cr and Pb they were similar to those detected by Demarco et al [23] (0.4 and 0.5, respectively).…”

“…The highest concentration of this metal was found in the roots (252 ± 44 mg kg −1 d.w.) and it was distributed within the plant in the following decreasing order: root > stem and leaves > flower. Kickhöfel Ferrer et al [16] found Zn values in roots in a range between 41.3 and 168.8 mg kg −1 d.w. while Demarco et al [23] found concentrations of 235 ± 33 mg kg −1 d.w. in the total plant.…”

“…Ali et al [8] described that high metal concentrations in soil could result in a BCF < 1 even though the plant had incorporated high concentrations, for example soils with 3000 mg kg −1 Ni and 2000 mg kg −1 Ni in a plant. Kickhöfel Ferrer et al [16] worked with this same species in sites contaminated by heavy metals and they obtained a BCF < 1 in those sites where the concentration of Zn was higher than 200 mg kg −1 d.w. and the concentration of Cu was higher than 18 mg kg −1 d.w. In contrast, they obtained a BCF > 1 when Zn concentration in the soil was 26.7 ± 0.7 mg kg −1 d.w. and also in soils which Ni concentration range was between 2.3-5.1 mg kg −1 d.w. For sites with a high degree of contamination within the MRB, de Cabo et al [46] obtained BCF values of 1 for Zn, Pb, Cu and Ni in T. fluminensis, while for Cr they obtained values of 6.5.…”

“…The emergent aquatic macrophytes of the genus Sagittaria (Alismataceae), have a wide worldwide distribution. They can be found in America, Europe, and Asia [14][15][16]. A particularity of this genus is its phenotypic plasticity [14], it possesses striking variability within and among populations in both vegetative structures, particularly leaf shape [17,18].…”

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

“…• Using one or few representative species to draw conclusions about the condition of the whole ecosystem (Markert, 2007) may lead to loopholes in conclusions. Usually, the selection of a bioindicator species is based on its abundance in the region studied (Kickhofel Ferrer et al, 2017) while its accumulation abilities and a clear relation with the pollution of abiotic compartments of a habitat should be the main criteria.…”