Kinetics of nitrates adsorption on Amberlite IRA 400 resin

Ion-exchange technology was studied to remove nitrates using Amberlite IRA 400. Predicting the rate at which adsorption takes place for a given system is probably the single most important factor for adsorber design, with adsorbate residence time and ultimately the reactor dimensions controlled by the system’s kinetics. A fixed volume stirred tank reactor was used to study the kinetics of adsorption in a single-component system. Process parameters including the rate of agitation, pH and temperature were examined and the obtained data were modelled using five kinetic models including the pseudo-first-order equation, second-order equation, the modified Freundlich, the pore diffusion model and the Elovich equation. The best fit of experimental adsorption data was obtained by means of the pore diffusion and pseudo-second-order models. Equilibrium data were fitted to the Frumkin and Langmuir isotherm equations, and the equilibrium data were found to be well represented by the Langmuir isotherm equation.