Adsorptive removal of copper ions from aqueous solution using porous magnetic chitosan microspheres

Porous magnetic chitosan microspheres were prepared with reversed-phase suspension methodology using epichlorohydrin as cross-linking reagent and using CaCO₃ as porogen for adsorption copper (II). Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM) confirmed that the microsphere was homogeneous and highly porous. Experiments were performed at different pH of solution, contact time and appropriate conditions for the adsorption of copper (II) were determined. The optimum pH of solution was measured to be 5.5 and it was found that the adsorption reached equilibrium in 6h. The results showed that the Langmuir isotherm was better compared with the Freundlich isotherm, and the uptake of copper (II) was 96.5 mg/g. Porous magnetic chitosan microspheres are suitable for consecutive use for more than 8 cycles and the adsorption is 50.16% of the initial value.