The invention relates to a polymeric material meant to be used in waste water treatment and to a process for preparing the same. According to the invention, the material comprises 2.5…3.5% starch, 25…35% acryl amide, 7…8% sodium chloride, 0.1…0.2 ppm silver nano particles and, for the remainder, distilled water, the percentage being expressed by mass. The process, as claimed by the invention, consists in simultaneously irradiating monomers in accelerated electron field of an average energy of 5.5 MeV, at the ambient temperature, at an irradiation dose of 0.8…1.2 kGy and a dose flow rate of 0.6…0.8 kGy/min.