Adsorption and thermodynamic study of Cephalosporins antibiotics from aqueous solution onto MgO nanoparticles

• This study aims to investigate adsorption of Cephalosporins antibiotics on MgO NPs.
• The MgO NPs showed large adsorption capacity for Cephalosporins antibiotics.
• Equilibrium data were fitted well in the Langmuir model.
• Pseudo-second-order model best describes the absorption process.

The adsorption characteristics of Cephalosporins antibiotics from aqueous solution were investigated using magnesium oxide (MgO) nanoparticles. Liquid phase adsorption experiments were conducted. Batch adsorption studies are carried out by observing the effect of experimental parameters, namely amount of adsorbents, pH, temperature and contact time. The drug removal data were fitted on Langmuir adsorption equations. The pseudo second-order kinetic model was indicated with the activation energy of 7.6682 and 5.3745 kJ/mol for Cephalexin and Cefixime, respectively. The values of the enthalpy (ΔH#) and entropy of activation (ΔS#) were 5.0851 kJ/mol and −286.67 J/mol K for Cephalexin; 3.1952 kJ/mol and −303.70 J/mol K for Cefixime, respectively. The free energy of activation (ΔG#) at 30 °C was 97.9 kJ/mol. Thermodynamic analysis showed negative values of ΔG° indicating adsorption was favourable and spontaneous, negative values of ΔH° indicating exothermic physical adsorption of Cephalosporins using MgO nanoparticles.