Metoprolol Removal from Water Using Fe3O4/TiO2/Activated Carbon Nanocomposite: Adsorption Isotherm, Kinetics and Thermodynamics

Metoprolol (MTP), a selective beta-blocker with low biodegradability, is an important micro-pollutant that has been widely identified in surface waters and wastewaters. In this work, the removal of MTP from aqueous solutions was performed using Iron oxide/Titanium oxide/activated carbon (Fe3O4/TiO2/AC) nanocomposite as a new adsorbent. The nanocomposite was characterized by Fourier Transform Infrared (FT-IR), Energy Dispersive X-ray Spectroscopy (EDX), Field Emission Scanning Electron Microscopy (FESEM) and X-Ray Diffraction (XRD) techniques. The maximum efficiency of MTP removal was 96.2% at a dosage of 1.5 g l-1 of adsorbent, an initial concentration of 10 mg l-1 of the drug, a contact time of 60 min at 25 °C, and pH 8.0. Freundlich and Pseudo-second-order models were found to be the best fitting isotherm and kinetic models, respectively. In addition, the values of thermodynamic parameters including ΔH, ΔS, and ΔG were found to be -75.20, -0.23, and -7.55 kJ mol-1, respectively. These results confirmed that the adsorption process of MTP on Fe3O4/TiO2/AC is exothermic and spontaneous. Fe3O4/TiO2/AC nanocomposite was successfully used for the removal of MTP from real water solutions.