Uptake of Zn, Cu, and Cd in metal loaded Elodea canadensis

Since uptake of metals in submerged plants can have a positive effect on the total remediation efficiency in a wetland it is important to investigate factors that possibly can have an effect on uptake of metals. In this short term study we investigated whether the tissue concentration of Zn, Cu and Cd influenced further uptake by metals in Elodea canadensis. Stress effects in response to metal exposure were also investigated. Plants were first loaded with metals for 48 h followed by a metal exposure period of 72 h. Metals in plant tissue and stress effects on plants were analysed both prior to, and after exposure. The results showed that tissue concentration of Zn and Cu did not have effect on further uptake, however for Cd it did have an effect. During Cd exposure accumulated Cd started to leak out of the plants where a decreased leakage could be seen with increased exposure concentration of Cd. The degree of metals binding to the cell wall could explain the influence of tissue concentration on uptake. These results are relevant to the phytoremediation technology area, where it is of great importance to achieve knowledge of commonly used plant species in treatment wetlands to optimise treatment of polluted areas.