Novel adsorbent based on carbon-modified zirconia/spinel ferrite nanostructures: Evaluation for the removal of cobalt and europium radionuclides from aqueous solutions

Herein, a novel adsorbent based on carbon-modified zirconia/spinel ferrite (C@ ZrO2/Mn0.5Mg0.25Zn0.25Fe2O4) nanostructures were chemically prepared to remove Co-60 and Eu152+154 radionuclides from liquid media using batch experiments. The XRD pattern confirms the successful preparation of the C@ZrO2/MnMgZnFe2O4 composite. Also, SEM and TEM images confirmed that the composite owns a heterogeneous morphology in the nanoscale range. The optical band gap value of Mn0.5Mg0.25Zn0.25Fe2O4, ZrO2, and the composite samples was 1.45, 2.38, and 1.54 eV, respectively. Many parameters have been studied as the effect of time, solution pH, and initial ion concentration. The kinetics models for the removal process of Eu152+154 and Co-60 radionuclides were studied. The second-order kinetic equation could describe the sorption kinetics for both radionuclides. The Langmuir monolayer capacity for Co-60 was 82.51 mg/g and for Eu152+154 was 136.98 mg/g. The thermodynamic parameters such as free energy Delta G(o), the enthalpy Delta H-o, and the entropy DSo were calculated. The results indicated that the sorption process has endothermic nature for both two radionuclides onto C@ZrO2/MnMgZnFe2O4 composite. (C) 2021 Elsevier Inc. All rights reserved.

Automated summary

A novel adsorbent based on carbon-modified zirconia/spinel ferrite nanostructures was successfully prepared to remove Co-60 and Eu152+154 radionuclides. The composite showed a heterogeneous morphology at the nanoscale level and had optical band gap values of 1.45 eV, 2.38 eV, and 1.54 eV for Mn0.5Mg0.25Zn0.25Fe2O4, ZrO2, and the composite samples, respectively. Kinetic models suggested second-order kinetics for the removal process, with Langmuir monolayer capacities of 82.51 mg/g for Co-60 and 136.98 mg/g for Eu152+154. Thermodynamic analysis indicated an endothermic nature of the sorption process for both radionuclides onto the composite material.