Assessment of heavy metal accumulation in Anzali wetland, Iran, using a submerged aquatic plant, Ceratophyllum demersum

Abstract

The objective of this study in 2009 was to examine whether levels of cadmium (Cd), copper (Cu), zinc (Zn), lead (Pb) and chromium (Cr) were higher in the leaves than in the stems of a submerged aquatic plant Ceratophyllum demersum in Anzali wetland. Cadmium, Pb and Cr concentrations were highest in the leaves. The mean concentrations of Cd and Cr in the leaves at all the sampling sites ranged between 0.94–1.26 μg g⁻¹ and 1.03–2.71 μg g⁻¹, respectively. Lead also had its highest concentrations in the leaves. The mean concentration of Pb in the leaves at all sampling sites ranged between 7.49–11.88 μg g⁻¹. Copper and Zn concentrations were highest in the stems. The mean concentrations of Cu and Zn in the stems at all sampling sites ranged between 10.79–17.91 μg g⁻¹ and 19.89–40.01 μg g⁻¹, respectively. Cadmium and Pb concentrations were higher in the leaves than in the stems, while Zn concentration was higher in the stems than in the leaves. Accumulation of Cu and Cr in the organs of C. demersum was in descending order of leaf ∼ stem, since there was no significant difference between their mean concentrations in the leaves and stems.