Utilization of electrolytic manganese residue to synthesize zeolite A and zeolite X for Mn ions adsorption

Extensive research is being carried out to efficiently utilize electrolytic manganese residue (EMR) and convert it into useful materials. In this paper, phase pure zeolite A (ZA) and zeolite X (ZX) were synthesized by EMR for the first time. The EMR-based zeolites were characterized by XRD, TG, SEM and BET, and their zero point charges were tested. Then, the adsorption capacities of ZA and ZX on Mn ions were studied. On the adsorbent concentration = 3.0 g/L and C0 = 439 mg/L, the adsorption capacities of ZA and ZX on Mn ion were 119.5 and 96.7 mg/g, respectively. In addition, the adsorption kinetics and isotherms of the adsorption process were discussed, and the adsorption mechanism was clarified by means of XRD, FTIR, SEM, and XPS. The appearance of Mn-O functional groups indicated that Mn ions did enter the binding sites of zeolites. Moreover, ZA and ZX were successfully regenerated in this work. Furthermore, the influence of coexisting cations was explored, and the maximum adsorption capacities of ZA and ZX were compared with other adsorbents, which proved the excellent adsorption of Mn ions by ZA and ZX. In conclusion, the synthesized ZA and ZX were low-cost adsorption materials with high adsorption capacity.