Methylene blue adsorption on magnesium ferrite: Optimization study, kinetics and reusability

The magnesium ferrite spinel was studied as an efficient Methylene blue adsorbent. Herein, the optimization of Methylene blue adsorption on magnesium ferrite was executed. The optimal adsorption conditions (pH, dose of adsorbent, and contact time) in terms of kinetic constraints were found. It was revealed that the crucial impact of film diffusion as well as intraparticle diffusion relies on methylene blue and adsorbent concentrations. The pseudo-second kinetic model was in good agreement with experiential adsorption data. The calcination temperature showed a significant impact on the adsorption capacity of magnesium ferrite adsorbent, and it was observed that the adsorption capacity decreased from 57.7 to 12.5 mg/g when the calcination temperature was increased from 400° to 800°C. The crystallite size and content of surface hydroxyl group were established as the main factors influencing the magnesium ferrite adsorbent performance. The XRD, FTIR, and XPS analyses of magnesium ferrite during dye adsorption-desorption demonstrated the structure stability and successful reusability of the adsorbent. High adsorption capacity and excellent regeneration efficiency of magnesium ferrite adsorbents proved its advantages and perspectives for wastewater treatment.