Removal of Zn(II) from Aqueous Solutions Using NiFe2O4 Coated Sand as an Efficient and Low Cost Adsorbent: Adsorption Isotherm, Kinetic and Thermodynamic Studies

In this study, NiFe2O4 magnetic nanoparticles, as adsorbent for zinc (Zn), were coated on sand particles. Adsorption studies were conducted to investigate the efficacy of contact time, pH, adsorbent dosage, initial zinc ion concentration, and temperature on the removal efficiency. To choose the most fitting kinetic model, the suitability of pseudo-first order and pseudo-second order model was compared and the most appropriate kinetic model was determined to be pseudo-second-order. Langmuir, Freundlich and Dubinin-Radushkevich isotherms were assessed and the most suitable isotherm was observed to be Langmuir model. The maximum adsorption capacity obtained from Langmuir model was 57.14 mg g-1. The calculated thermodynamic parameters indicated the endothermic and spontaneous character of the adsorption process. In addition, the adsorbent can easily be removed by a simple filtration process.