Application of Ni0.5Zn0.5Fe2O4 magnetic nanoparticles for diclofenac adsorption: isotherm, kinetic and thermodynamic investigation

Ni0.5Zn0.5Fe2O4 magnetic nanoparticles were synthesized to obtain a new efficient adsorbent for diclofenac sodium (DF) removal. Fourier Transform Infrared (FTIR), Energy Dispersive Spectrometer (EDS), scanning electron microscope (SEM), Brunauer-Emmett-Teller (BET) and vibrating sample magnetometer (VSM) were applied to characterize the prepared adsorbent. These analyses revealed that adsorbent was successfully prepared with average particle diameter of about 50 nm and a BET surface area of 168.09 m(2)/g. The saturation magnetization value of magnetic nanoparticles (MNPs) was found to be 24.90 emu/g, thus, adsorbent was efficiently separated from the solution by a facile and rapid magnetic separation process. The effect of adsorption time, amount of adsorbent, initial pH of the solution, initial diclofenac concentration and temperature on the removal of DF were evaluated. Also, the adsorption data were best fitted to the pseudo-first-order kinetic model and Langmuir isotherm model. The thermodynamics studies suggested spontaneous and exothermic adsorption. The maximum diclofenac adsorption amount of the synthesized nanoadsorbent was 52.91 mg/g, which is higher than many recently studied adsorbents.