Nickel, lead and zinc accumulation and performance in relation to their use in phytoremediation of macrophytes Myriophyllum aquaticum and Egeria densa

Abstract

In order to study the accumulation of nickel, lead and zinc for their use in the phytoremediation of aquatic environments, the aquatic plants Myriophyllum aquaticum and Egeria densa were exposed to increase the concentrations of these metals (Ni: 0.05–10 mg L−1, Pb: 0.05–15 mg L−1, Zn: 0.15–20 mg L−1) for 7 days. The accumulation of Ni, Pb and Zn in plants was determined and their effects on physiological parameters (chlorophyll a concentration and degradation, lipid peroxidation measured as malondialdehyde) were evaluated in the leaves for both species. M. aquaticum showed a higher accumulation capacity of Pb and Zn than E. densa, particularly at the highest concentrations of exposure to these metals. Nevertheless, the physiological changes observed in these species, especially in M. aquaticum, at high metal concentrations and accumulations, did not represent a risk in relation to their survival during the study period. Therefore, taking into account their accumulation capacity and tolerance to heavy metals, M. aquaticum is more suitable for phytoremediation in aquatic environmental contaminated with Ni, Pb or Zn than E. densa.