Biosorption of heavy metals from aqueous solution by Gracilaria corticata varcartecala and Grateloupia lithophila

Objective: To study the biosorption of heavy metals viz., Cr (VI), Cr (III), Hg (II), Pb (II) and Cd (II) using Gracilaria corticata varcartecala (G. corticata varcartecala) and Grateloupia lithophila (G. lithophila) biomass. Methods: Batch biosorption and acid digestion methods were used. Different physical and chemical parameters were optimized for biosorption. Results: Both seaweeds absorb Hg (II) upto 99.9% and 98.2% in batch biosorption method; whereas in acid digestion method, Cr (III) absorbed upto 96.49% by G. corticata varcartecala and Pb (II) absorbed upto 93.71% by G. lithophila. FT-IR analysis was used to know the involvement of different functional groups in the biosorption process. Scanning electron microscopy was carried out to study the morphological cell surface changes due to biosorption. Conclusions: It can be concluded that G. corticata varcartecala and G. lithophila are potential algal species for effective removal of heavy metals namely Cr (VI), Cr (III), Hg (II), Pb (II) and Cd (II) from environmental sources.