Removal of heavy metals from aqueous solutions using cyanobacteria

Abstract

In recent years, researchers have resorted to biological methods to remove toxic heavy metals from industrial wastewater. In the present study, the ability of cyanobacteria Nostocs sp. to absorb heavy metal ions (Cd2+, Cu2+, Pb2+, Ni2+, Zn2+) from aqueous solutions was investigated by optimizing the absorption conditions for cyanobacteria live cells. The results revealed that the metal concentrations had a significant impact on the uptake of metals through biosorption. The greatest accumulation of Cd2+, Cu2+, Zn2+, and Ni2+ occurred at an initial concentration of 20 mg/l, except for Pb2+, which showed the highest bioaccumulation at a concentration of 80 mg/l. The lowest bioaccumulation power of 38% was achieved for Ni2+, while the highest bioaccumulation of 98.15% was achieved for Pb2+. The obtained results highlight the significance of cyanobacteria as a favorable and promising biosorbent for effectively removing heavy metals from aqueous solutions.