Adsorption of Co(II) ions from aqueous solutions using NiFe2O4 nanoparticles

In this study, NiFe2O4 nanoparticles (NiFe2O4 NPs) were prepared through co-precipitation method and subsequently used for the removal of Co(II) ions from aqueous solutions. The NiFe2O4 NPs were characterized by transmission electron microscopy (TEM), X-ray diffraction spectrometry (XRD), and Brunauer-Emmett-Teller (BET) surface area analysis. In batch tests, the effects of variables such as pH (2-10), adsorbent dose (0.006-0.08 g), contact time (0-90 minutes), and temperature (25-55 ◦C) on Co(II) ions removal were examined and optimized values were found to be 7, 0.02 g, 70 minutes, and 25 ◦C, respectively. In addition, the experimental data were fitted well to the Langmuir isotherm model and the maximum adsorption capacity was found to be 322.5 mg/g. Kinetic experiments were also conducted to determine the rate at which Co(II) ions are adsorbed onto the NiFe2O4 NPs.