Green Approach in the Bio-removal of Heavy Metals from wastewaters

Abstract

Cultivation of microalgae has been suggested as a green approach for a sustainable wastewater treatment especially heavy metal bioremediation. This study investigated the bio-removal of zinc (Zn), iron (Fe), cadmium (Cd) and manganese (Mn) from domestic wastewater (DW) and food processing wastewater (FW) using green microalgae, Botryococcus sp.. The total of five treatments represented by five different cell concentrations (1×103, 1×104, 1×105, 1×106 and 1×107 cells/mL) of Botryococcus sp. in the wastewaters medium. The results revealed high removal efficiency of Zn, Fe, Cd and Mn after 18 days of the culture compared to control (wastewaters without algae). In DW , Zn, Fe, Cd and Mn were successfully removed at the highest efficiencies up to 71.5%, 51.2%, 83.5% and 97.2%, respectively while in FW, the same metal concentrations were reduced by up to 64.4%, 53.3%, 52.9% and 26.7%, respectively. Overall, most of the algae cell concentrations tested were successfully reducing the metals contaminant presence in both wastewaters and provides a baseline for further phycoremediation coupled with biomass production.