Efficiency of chitosan-algal biomass composite microbeads at heavy metal removal

A new chitosan/algal (Cladophora sp.) composite microbead was produced and used in removal of heavy metal ions. Bleached algal biomass was incorporated into the chitosan matrix through cross-linking with glutaraldehyde. Fourier transform infrared spectroscopy analysis demonstrated that bleached algal biomass consisted of mainly cellulosic residues. Scanning electron microscopy images exhibited that algal particles were immobilised in the polymeric matrix. Sorption capacity of the microbeads was determined; Cd(II): 0.240, Cr(III): 1.128, Cu(II): 1.059, Ni(II): 0.239 and Zn(II): 0.310 mmol g^{- 1}. The microbeads with bleached algal biomass exhibited higher sorption capacity for Cd(II) and Zn(II) ions than the plain glutaraldehyde cross-linked chitosan microbeads, demonstrating that the contribution of the algal biomass to the sorption. Equilibrium, kinetic and thermodynamic evaluation of the experimental data was performed. The findings revealed that chitosan-algal composite microbeads can be used in heavy metal removal.