Removal of Cu(II) and Cd(II) Ions from Aqueous Solutions by Methionine Functionalized Cobalt-Magnesium Ferrite Chitosan Beads: Performance and Adsorption Mechanism

Heavy metal ions are an extremely toxic and non-biodegradable wastewater pollutant that pose a major risk to both natural systems and human health. Adsorptive removal of metal ions is a proven technique for such waste water treatment. So fabricating efficient adsorbent material for the removal of toxic metal ions from the water is a key step. Contributing to this, here we report the synthesis of Methionine functionalized cobalt-magnesium ferrite chitosan bead, i.e., CMF@MF-CB adsorbent. CMF@MF-CB was prepared by entrapped methionine functionalized nanoparticles into chitosan beads. The structure, morphology and magnetic properties of synthesized adsorbents were investigated by XRD, FTIR, FESEM and EDS, BET, TGA and VSM techniques. The adsorption behavior of CMF@MF-CB was studied for Cu(II) and Cd(II) ions removal from solutions. Kinetic parameters, adsorption isotherms and thermodynamic studies were evaluated. The adsorption of Cu(II) and Cd(II) ions onto CMF@MF-CB was noted to follow pseudo second order kinetics (R 2 = 0.9908 for Cu(II) and 0.9902 for Cd(II)). The maximum adsorption capacities for Cu (II) and Cd (II) ions were calculated as 212.77 and 175.44 mg.g −1 from Langmuir isotherm model. The adsorption process was endothermic and spontaneous, according to the positive Δ H 0 (10.9 Cu(II) and Cd(II) 6.8 kJ.mol −1 ) and negative values of Δ G 0 . The CMF@MF-CB adsorbent was easily separable by external magnet and effectively recovered after adsorption completion. The admirable adsorption performance of CMF@MF-CB adsorbent for Cu(II) and Cd(II) ions with cost effectiveness make it noteworthy to reduce the water contamination issue. Graphical abstract