Heavy Metals Bioaccumulation Capabilities of Azolla filiculoides and Lemna minor in Anzali wetland

In this study, the concentrations of heavy metals in water and aquatic plants Azolla filiculoides and Lemna minor in three special zones of Anzali Wetland located in the north of Iran were investigated. Sampling was performed in summer 2018 and metal concentrations in water and plant samples were measured by ICP-OES. The results showed that the sequence of the average total concentration of metals in water samples is Fe>Mn>Ba>Ni>V>As>Ag>Ti>Co>Cu>Zn>Cr>Hg>Pb>Cd. The highest bioaccumulation was obtained in both plants belonging to Mn, Fe and Ba and the lowest concentrations were obtained for Cd and Ag. BCF results obtained for both plants for all metals were more than 1000 indicating that both plants are powerful hyper accumulators for heavy metals in the region. Although the potential of these species can be used with environmental considerations to reduce pollutants for various effluents, but the presence of these species in the food chain of the wetland might be a serious threat to the species consuming these plants by creating biological magnification.