Synthesis, characterization and γ-rays irradiation of cobalt-based metal-organic framework for adsorption of Ce(III) and Eu(III) from aqueous solution

Metal-organic frameworks (MOFs) have important applications in adsorption, because of high porosity, diverse functionalities, and easy modification. Cobalt metal organic frame work (Co-MOF) based on diallylamine as the ligand was synthesized for the adsorption of Ce(III) and Eu(III) from aqueous solutions. Co-MOF was characterized by different spectroscopic techniques such as Fourier Transform-Infrared (FT-IR), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX) and scanning electron microscopy (SEM). The effects of adsorbent weight, pH of solutions, contact time, metal ion concentrations and gamma irradiation dose were studied. The adsorption efficiency of Ce(III) and Eu(III) onto Co-MOF was 93.3 and 27.47%, respectively, at pH 5.1. The distribution coefficient (Kd) of Ce(III) increased from 17.46 to 2791.30 ml/g, while for Eu(III) increased from 13.15 to 75.75 ml/g with changed the pH from 1.01 to 5.1. The Ce(III) and Eu(III) adsorption data were well fitted to the pseudo second order kinetic and Langmuir adsorption model. The maximum adsorption capacity of Ce(III) and Eu(III) onto Co-MOF were 102.24 and 52.93 mg/g respectively. The adsorption of Ce and Eu was slightly reduced by about 10% with increase dose of gamma radiation up to 400 kGy.