Concurrent removal and accumulation of Fe2+, Cd2+ and Cu2+ from waste water using aquatic macrophytes
By Abida Begum
The metal bioaccumulation capability and effectiveness of eight aquatic macrophytes Eicchornia crassipes (water hyacinth), Pistia stratiotes (water lettuce), Lemna major (duckweed), Ipomoea aquatica (kang kong), H.verticillata, Nymphaeae spp. (water lilies), Nelumbo nucifera (lotus), Nymphoides indica were investigated for the removal of three
heavy metals Fe(II), Cd(II) and Cu (II). These plants were grown at 2.0 mg/L concentrations of metals in laboratory experiment. Within a span of 6 days, the plants were capable of removing about 65- 95% of the selected heavy metals. The sorption process was very rapid for copper removal. Highest removal was observed on 6th day of experiment in all macrophytes. It was observed that macrophyte Nymphoides indica as the most efficient for the removal of selected heavy metals followed by Nelumbo nucifera (lotus), and Nymphaeae spp. (water lilies). The trend of the sorption is Fe (II) > Cd (II) > Cu (II). Results from analysis confirmed the accumulation of different metals within the plant and a corresponding decrease of metals in the water. Plants have accumulated heavy metals in its body without the production of any toxicity or reduction in growth. Selected plants shown a wide range of tolerance to all of the selected metals and therefore can be used for large scale removal of heavy metals from waste water.
Keywords : Aquatic macrophytes, Biosorption, Heavy metals.