Uptake of Heavy Metals (Cadmium, Lead, Chromium and Copper) from Paint-based Effluent Using Azolla mycrophylla (Azolla) and Eicchornia crassipies (Water Hyacinth)

Heavy metals are a major risk to life in general that requires urgent attention when found in any environment. The use of plants specifically aquatic macrophytes in the uptake and accumulation of these toxic elements may proffer a more advantageous and economically doable approach. In this study, two aquatic macrophytes Azolla mycrophylla and Eichhornia crassipies were evaluated for the uptake of four heavy metals (cadmium, chromium, lead and copper) from a paint-based effluent under hydroponic media using two varying dilution factors (50%, TRT 1 and 25%, TRT 2) of the effluent. The test plants were cultivated in the two effluent concentrations in a greenhouse on a randomized block design. Results obtained revealed significant (P<0.05) removal efficiencies after a 63 days (both acclimatization and treatment) period of treatment for both plants. Azolla mycrophylla reduced cadmium concentration by 90 % and 95%, lead 89% and 78%, chromium 39% and 48% and copper 72% and 99% in both treatments. Eichhornia crassipies significantly reduced cadmium by 82% and 48%, lead 51% and 36%, chromium 29% and 11% and copper by 76% and 8% in both treatments respectively. The results obtained from this study suggest the applicability of these two plants grown under hydroponically for bioremediation which promises to be a sustainable and viable option for heavy metal containing effluents.