PHYTOREMEDIATION POTENTIAL OF LAGENANDRA OVATA L. AND NELUMBO NUCIFERA GAERTN. ASSOCIATED WITH ARUVIKKARA RESERVOIR, KERALA- SOUTH INDIAV.P. Ajin Sreekumar, A.A. Prasannakumari, V. Sumitha, B. Pramod and S. Scaria
Heavy metals such as copper, zinc, cadmium, chromium and lead in two selected macrophytes- Lagenandra ovata L. and Nelumbo nucifera Gaertn., sediment and water samples collected from Aruvikkara Reservoir were studied. It was observed that in both L. ovata and N. nucifera all the five metals studied remained higher when compared to their normal range in plants. Metal accumulation pattern observed in L. ovate was zinc > chromium > lead > copper > cadmium and in N. nucifera it was in the order of zinc > chromium> copper > lead > cadmium. Sediment analysis also revealed the presence of all the five elements except cadmium which was in below detection level, and it was in the order of chromium > zinc > lead > copper > cadmium. Presence of copper and lead in water samples lower than permissible limit of drinking water standard values is a sign of the non-polluted nature of Reservoir water with respect to copper and lead indicating its suitability for drinking purpose. A general pattern of metal accumulation was observed in both L. ovata and N. nucifera > sediment > water. Concentration factor for heavy metals observed in both the species were >1 for all the metals. This reveals the metal accumulation potential of both the species for different heavy metals and can be used as bioindicator for heavy metal pollution. Even though the plants under study showed heavy metal absorption potential periodic cleaning of the Reservoir is essential as the dead and decayed remnants will deposit all contaminants in the water body itself.