Removal of ciprofloxacin from aqueous solution using humic acid- and levulinic acid- coated Fe3O4 nanoparticles

Abstract

Humic acid (HA)- and levulinic acid (LA)-coated magnetic Fe3O4 nanoparticles were prepared and subsequently characterized using scanning electron microscopy, X-ray diffraction spectroscopy, Fourier transformer infrared spectroscopy, thermogravimetric analysis, particle size distribution analysis, and zeta-potential analysis. These magnetic nanoparticles were used for ciprofloxacin adsorption from aqueous solutions. Non-linear Langmuir and Freundlich adsorption isotherm models were used to explain the adsorption equilibria. The Langmuir adsorption capacities (qm) were 101.93 mg/g for HA-coated Fe3O4 and 53.76 mg/g for LA-coated Fe3O4. The appropriate contact times were 40 min for HA-coated Fe3O4 and 60 min for LA-coated Fe3O4. The adsorption rates and mechanisms were determined using pseudo-first-order and pseudo-second-order kinetic models. After the adsorption studies, the loaded nanoparticles were used for desorption studies, and their desorption kinetics were investigated.