LAUSR

Abstract Phosphorylated magnetic chitosan composite (P-MCS) was successfully synthesized and applied to adsorb Pb(II) and Cd(II) from aqueous solutions. The as-prepared P-MCS composite was characterized by EDS, SEM, FTIR, XRD, XPS and zeta potential analysis. Factors affecting adsorption including adsorbent dose, pH value and contact time were optimized to improve the adsorption performance. The adsorption isotherm and kinetic model could well conform to Langmuir model and pseudo-second-order kinetic model. The as-prepared adsorbent exhibited good adsorption capacities for Pb(II) (151.06 mg g−1) and Cd(II) (71.53 mg g−1) from Langmuir isotherm. Besides, spectroscopic analysis after adsorption including FTIR and XPS were also performed to further reveal the adsorption mechanism. The results indicated that surface complexation and ion exchange between functional groups and metal ions played an important role in adsorption process. Thermodynamic studies (∆G   0, ∆S > 0) implied that the adsorption process is an endothermic and spontaneous reaction. Furthermore, the excellent magnetic separation and regeneration performance indicated the feasibility of using P-MCS composite for Pb(II)/Cd(II)-bearing wastewater remediation.