Adsorption of trace Iron from nickel sulfate solutions using Monophos resin

This paper deals with the removal of trace iron from nickel sulfate solution using Monophos resin. Kinetics, thermodynamics and adsorption mechanism of iron adsorption were studied. Kinetic and thermodynamic parameters as well as equilibrium constants were calculated based on various equilibrium models. Liquid film diffusion, particle diffusion and chemical reaction models were used to fit the experimental data. It was shown that the adsorption mechanism was well represented by particle diffusion model. And pseudo-second-order and intra-particle diffusion model were more consistent with the adsorption process and clearly predicted the intra-particle distribution of iron concentration. Langmuir isotherm well described the adsorption data. Thermodynamic parameters indicated that the adsorption process was spontaneous and endothermic. An iron adsorption rate of 89% was reached with iron concentration being reduced from 1.92 mg/L to 0.21 mg/L.