Magnetized microalgae: An efficient tool for Pb and Cd removal from aqueous media.

Microalgae show great potential to remove heavy metals from aqueous media. The present study aimed to prepare magnetized Chlorella vulgaris and Tetradesmus obliquus and consider their capability for facile removal of Pb(II) and Cd(II) from the aqueous media. The magnetic Fe3O4 nanoparticles (17–26 nm) were first incorporated into the cells. Thereafter, the optimal conditions for bioaccumulation were determined as pH 5.5, initial biomass 1 g L−1, and temperature 28 ºC. The accumulation kinetics of the ions with both magnetic microalgae were measured and well-fitted to the pseudo-second-order model (R2 > 0.99) for the media supplemented with Cd2+ (25–400 mg L−1) and Pb2+ (25–200 mg L−1). The accumulation isotherms for both magnetic microalgae were fitted to the Langmuir model with the Cd2+ and Pb2+ maximum sorption capacities of 280.8 and 144.0 mg g−1 for C. vulgaris as well as 331.4 and 131.1 mg g−1 for S. obliquus, respectively. Magnetized microalgae are proposed as an efficient tool for the removal of metal ions from water. [ABSTRACT FROM AUTHOR]