Role of Microalgae in Environmental Biotechnology to Remove Heavy Metals

Abstract

The objective of the study is to evaluate the role of microalgae in heavy metal remediation (Pb and Cd). Three microalgae species were used (Tetradesmus nygaardi, Scenedesmus quadricauda, and Coelastrella sp.) with four concentrations of both tested heavy metals (lead and cadmium) were, (5, 15, 35, and 50 ppm). Samples were analyzed every 4th day during the experimental study for 20 days. The result showed that during experimental days the lower concentration (5ppm) has the highest reduction percent for Pb and Cd by all microalgal species (Tetradesmus nygaardi, Scenedesemus quadricauda, and Coellastrella sp.). Whereas Coellastrella sp. had the highest efficiency for Pb and Cd uptake in all concentrations (5, 15, 35, and 50 ppm) for Pb removal percent were (86.8%, 86%, 82.85%, 78%) respectively, while for Cd were (84%, 80.66%, 77.14%, 76.94%) respectively. The lead had a higher reduction percent for all concentrations (5-50ppm) in comparison with cadmium by all microalgal strains during 20 days of the experiment. The removal of Cd and Pb by microalgal strains by order, Coellastrella sp. > Tetradesmus nygaardi > Scenedesemus quadricauda.