THE REMOVAL OF Cd, Cr, Cu, Ni, AND Pb FROM A SYNTHETIC WASTEWATER EFFLUENT BY AN ENVIRONMENTAL BACTERIAL CONSORTIUM

This study describes the removal of heavy metals (Cd, Cr, Cu, Ni, and Pb) from a synthetic wastewater effluent by consortium culture (CC), an environmental bacterial consortium. The metal removal capability of growing (active) and non-growing (inactive) CC cells in heavy metal containing synthetic wastewater (SWW) and deionised distilled water (ddH2O) were examined by determining percentage metal removal (% MR) over a 7 day period. Metal removal capability was tested at both high (1/5) and low (1/10) metal concentration strengths to imitate occurrence of heavy metal pollution in the natural environment due to industrial activities. Growing cells of CC showed higher removal of Pb (49-69 %), Cu (45-61 %) and Cr (55-67 %) in SWW whereas non-growing cells removed more of Cd (100 %) and Ni (7294%) (p < 0.05). It was observed that non-growing cells achieved equilibrium earlier with quicker metal removal (by day 1-3) as opposed to growing cells. However, % MR by growing cells was higher in samples with elevated initial concentration of total metals (p < 0.05). Results of this study indicate the possibility of employing CC in both growing (active) and non-growing (inactive) variety to fulfill varying waste conditions and to cater for in situ and ex situ heavy metal laden waste treatment.