Insight into the mechanism of Cd(II) and Pb(II) removal by sustainable magnetic biosorbent precursor to Chlorella vulgaris

• Published in: Journal of the Taiwan Institute of Chemical Engineers 2017-02, Vol.71, p.206-213
• Main Authors: Lalhmunsiama, Gupta, Prabuddha L., Jung, Hyunhoon, Tiwari, Diwakar, Kong, Sung-Ho, Lee, Seung-Mok
• Format: Article
• Language: English
• Subjects: Chlorella vulgaris; Fe3O4; Magnetic biomaterial; Toxic metal ions; XPS
• ISSN: 1876-1070; 1876-1089
• DOI: 10.1016/j.jtice.2016.12.007

•Fe3O4 nanoparticles were successfully incorporated with Chlorella vulgaris biomass.•Characterization of material using SEM-EDX, TEM, FT-IR and XPS analyses.•Simultaneous sorption of Cd(II) and Pb(II) from aqueous solutions.•Application of magnetic biomaterial in real water matrix treatment.•Insight mechanism was discussed with FT-IR and XPS analyses. Iron oxide nanoparticles were impregnated with the Chlorella vulgaris (CV) microalgae in order to obtain the magnetic biomaterial (magnetic-CV). The materials were characterized by SEM-EDX, HR-TEM, FT-IR and XPS analyses. Further, the magnetic-CV was successfully employed in the removal of Cd(II) and Pb(II) from aqueous solutions. High percentage uptakes of these two toxic ions were observed in a wide range of pH and initial sorbate concentrations. The material was found to be efficient in the rapid uptake of Cd(II)/Pb(II) from aqueous solutions. The increases in background electrolyte concentrations (i.e., 0.001−0.1mol/L NaNO3) affected the uptake of Cd(II) to a greater extent whereas Pb(II) removal was almost unaffected. This implied that Cd(II) was sorbed with weaker forces whereas the Pb(II) ions were aggregated specifically onto the solid surface forming an inner sphere complexes. Moreover, a simultaneous sorption study inferred that Cd(II) and Pb(II) were sorbed at the different binding sites available at the hybrid biomaterial. Furthermore, the sorption mechanism discussed with FT-IR and XPS analyses has shown that Cd(II) bound with weak electrostatic forces to the dissociated carboxyl or hydroxyl groups available onto the solid surface whereas Pb(II) ions were chemically bound with the amino group of magnetic-CV. [Display omitted]