Zeolitic material synthesised from fly ash: use as cationic exchanger

The potential use as a ‘once through’ cation exchanger of a zeolitic material (NaP1 zeolite as the main active component) synthesised from fly ash has been evaluated and compared with a commercial weak acid exchanger, Amberlite IRC‐50. The cationic exchange has been tested for different cations present in sewage: NH4+ (urban sewage) and Pb2+, Zn2+ and Cr3+ (waste from electrolytic baths). The NH4+ retention capacity was higher in the zeolite (0.7 meq g−1) than in Amberlite IRC‐50 (0.21 meq g−1). The retention capacities of metallic cations obtained for NaP1 zeolite (1.16 meq Pb2+ g−1, 1.45 meq Zn2+ g−1 and 1.57 meq Cr3+ g−1) were also higher than in Amberlite IRC‐50 (0.32 meq Pb2+ g−1, 0.25 meq Zn2+ g−1 and 0.35 meq Cr3+ g−1). When solutions containing all the metallic cations were used, lower retention capacities were obtained for both exchangers.The authors wish to thank Dr Feliciano Plana for his help in the XRD study. This work has been carried out with a financial grant from the European Coal and Steel Community through the ECSC 7220‐ED‐079 Contract.Peer reviewe