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.