Comparative Study of Nickel-Iron Composite with Fe3O4 Nanoparticles for the Adsorption of Chromium from Aqueous Medium

Water contamination caused by hexavalent chromium [Cr(VI)] ions has attracted interest since Cr(VI) ions are highly poisonous and carcinogenic, posing major health risks. We report a simple and efficient approach for preparing Fe3O4 nanoparticles and Fe3O4/NiO composite using the chemical co-precipitation method for Cr(VI) removal. The produced magnetic adsorbents could be readily isolated from the solution using an external magnet and were used for Cr(VI) ion adsorption. The adsorbents were characterized by XRD, VSM, FT-IR, FE-SEM, EDX, and BET analyses. The Langmuir type 1 isotherm provided a good representation of the adsorption data when the Langmuir, Freundlich, Temkin, Harkins-Jura, Hasley, and Redlich-Peterson models were utilized to analyze the adsorption isotherm data. The adsorption capacities of Fe3O4 and Fe3O4/NiO composite calculated from the Langmuir type 1 model were 96.15 mg g(-1) and 150 mg g(-1), respectively. The saturation magnetization of Fe3O4 and Fe3O4/NiO composite was 60.54 emu/g and 11.09 emu/g, respectively. Both adsorbents may be easily and quickly separated from tainted water by an external magnetic field. According to the findings, both adsorbents are possibly reusable adsorbents for Cr(VI) adsorption. The main advantage of the material is that, due to its magnetic nature, it is easily separated from the adsorbate and may thus be used efficiently in sorption studies. As a result, this magnetic adsorbent provides a viable solution for the successful management of chromium-containing wastewater.