Influence of sulfate and nitrate uptake from aqueous solutions on surface exchange in Purolite A-520E resin

Removal of nitrate anions from aqueous solutions is the principal goal of many studies concerning water treatment. The ion exchanger capacity to remove nitrate from water was investigated using commercial type A-520E anion exchange resins. The nitrate and sulfate ion exchanger capacity, in static conditions, depends on the concentration of ions and on the pH value of the aqueous solution. The local structural environment exchanged on A-520E has been investigated by scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDX) and 2D and 3D atomic force microscopy (AFM). All images of the ion exchanger were obtained before and after contact with solutions that contain NO3− and SO42− separately as well as mixtures of both.