Kinetic modelling of liquid-phase adsorption of nitrates on ionized adsorbent

The risks associated with the contamination of drinking water by nitrates are methemoglobinemy in infants, the potential risks of cancerogenicity and teratogenicity. Membrane processes and resins are very efficient in the elimination of nitrates. The resin used in this work was an ionised adsorbent Amberlite IRA 400. The objective of the work was to improve the knowledge concerning the adsorption mechanism and to determine the kinetic parameters. The study was undertaken in a batch reactor at controlled pH and temperature. The effect of some parameters, like the size of particles, the stirring velocity, the nitrate concentration and the mass of adsorbent used, were examined. The chemical reaction was found to control the global process; two kinetic models, a pseudo first and a second-order reaction were then compared to describe the process. It was found that the adsorption follows the second-order kinetic.