Application of Fe3O4@activated carbon magnetic nanoparticles for the adsorption of metronidazole from wastewater: optimization, kinetics, thermodynamics and equilibrium studies
Amir Sheikhmohammadi, Esrafil Asgari, Jaber Yeganeh
Abstract
ABSTRACT This study was conducted to investigate the application of activated carbon magnetic nanoparticles (AC-MNPs) as an adsorbent to remove metronidazole (MTZ) from aqueous solutions. Response surface methodology (RSM) using R software was employed to investigate the influence of operating parameters on the performance of AC-MNPs in the removal of MTZ. The obtained experimental data for AC-MNPs were tested with three RSM models. According to the obtained results of ANOVA, experimental data agreed with second-order model. The maximum removal efficiency (100%) was obtained under selected conditions (pH, 3.0; AC-MNPs dosage, 1.05 g/L; contact time, 90 min; MTZ concentration, 10 mg/L). The Freundlich isotherm and the pseudo- second-order kinetic models indicated reasonable correlation with the experimental data. The maximum adsorption capacity was 95.06 mg/g. Thermodynamic studies identified that MTZ adsorption onto AC-MNPs is spontaneous and endothermic. AC-MNPs show easy regeneration and good potential reusability, and its adsorption efficiency was preserved effectively even after five successive cycles of use. Therefore, AC-MNPs could be considered as an excellent adsorbent in the treatment of antibiotics and other organic pollutants.