Journal of Geography, Environment and Earth Science International

Environmental pollution is no doubt a global problem. Heavy metals are pollutants of great concern. In this study, the heavy metal bioremediation potential of Cymbopogon citratus (lemon grass) was carried out. Four dilution concentrations of the effluent (100 %, TRT 1, 75% TRT 2, 50% TRT 3 and 25% TRT 4) were used hydroponically under greenhouse conditions to evaluate the uptake of chromium, copper cadmium and lead in a randomized block design. The uptake (P<0.05) of four heavy metals was studied and the concentration of chromium in effluent was reduced in the range of 65-98% across all the treatments, copper 6-69%, cadmium 12-46% and lead 42-83%. The bioaccumulation of chromium into the root of the plant was between 0.45-0.63 mg/kg and for the shoot 0.28-0.39 mg/kg, copper had 0.68-0.91 mg/kg for the root and 0.42 -0.57 mg/kg. Cadmium was concentrated about 0.14 -0.20 mg/kg for the root and 0.09-0.13 mg/kg. Lead was found within 0.34-0.43 mg/kg for the root and 0.18-0.26 mg/kg for the shoot. The Bio-concentration factor (BCF) of chromium, copper and lead were >1 and <1 for cadmium. Translocation factor (TF) for the four heavy metals were >1. There were significant reductions in some physico-chemical parameters (COD 79%), BOD (50%), Total solids (52%) and Electrical conductivity (10%). The results obtained from this study revealed that Cymbopogon citratus is a hyper accumulator plant and can be effective in the remediation of polluted systems with multiple heavy metals.