Phytoremediation Study of Aquatic Macrophytes Collected from Five Lakes of Bangalore, India

A phytoremediation study was carried out at 5 major lakes of Bangalore to ascertain the degree of heavy metal contamination. The study focused on assessment of heavy metal accumulation in three aquatic macrophytes used as biomonitors, in comparison with water and sediments (abiotic monitors) for phytoremediation. The aquatic plants (biomonitors) Hydrilla verticillata, Nelumbo nucifera, Eichhornia crassipes were analysed along with sediments and water for Cu, Co, Pb, Zn and Ni contamination in five lakes (Aggrahara, Arakere, Naganaikanakere, Amblipura and Hulimavu). The order of accumulation of heavymetals was observed, in general, was Hulimavu >Ambalipura > Naganaikanakere >Arakere>Aggrahara. Based on the concentration, the toxicity status observed in macrophytes was H. verticillata > N. nucifera > E. crassipes. The heavy metals are arranged in the following descending order: Cu > Zn > Pb > Co > Ni in macrophytes; Zn > Cu > Ni > Pb > Co in water and Zn > Cu > Ni > Co > Pb in sediments. The selected biotic species showed maximum absorption of copper and zinc in all the lakes.