Sulfamethazine Retention from Water Solutions by Ion Exchange with a Strong Anionic Resin in Fixed Bed

Abstract

Veterinary antibiotics such as sulfonamides were detected in the environment from animal excreta in soils, contaminating soil surface and then groundwaters by percolation. The contaminated waters can enter in this way into drinking water treatment plants (DWTPs). On the other hand, direct wastewaters from humans or animals or pharmaceutical industries disposals are discharged in wastewater treatment plants (WWTPs). These water and wastewater treatment plants are not designed to remove highly polar micropollutants like antibiotics. Removal of pharmaceuticals by adsorption and ion exchange constitutes a promising technique for its low cost, easy regeneration, and selective removal of pollutants. This work studies the removal of sulfamethazine (SMZ). The SMZ retention capacity of an anionic ion exchange resin, Lewatit MP500, was determined. Equilibrium and kinetics were studied and equilibrium constants and diffusivity values were obtained using different models. Load and elution breakthrough curves were plotted to evaluate ion exchange operation in a fixed bed column. In the elution step, 100% SMZ was recovered in all cycles and could be concentrated up to twelve times, thus facilitating its final treatment or removal. Load and elution breakthrough curves were simulated using a fixed bed model in which axial dispersion was considered the parameter model fit.