Synthesis, characterization of a multi-component metal oxide (Al<sub>0.88</sub>Fe<sub>0.67</sub>Zn<sub>0.28</sub>O<sub>3</sub>) and elimination of As (III) from aqueous solution.

Abstract

The multi-component oxide (Al0.88Fe0.67Zn0.28O3)) surface (abbreviated as MCOS) was prepared to optimize the effectiveness of the elimination of As (III) from aqueous solution. The oxide surface was synthe-sized by co-precipitation method using corresponding metal carbonates. It was characterized by XRD, TGA and DSC. The surface morphology of MCOS was observed in SEM and the elemental analysis was accomplished by EDX. The composition of Al2O3, Fe2O3 & ZnO was 23.6, 39.9 and 20.6 wt% respectively in XRF analysis. The specific surface area was found 389.85 m2 g-1. Batch experiments were performed to remove As (III) from aqueous solution considering various parameters such as effect of pH, contact time, initial arsenic concentration, temperature and sor-bent dosage. The maximum sorption capacity of the surface was almost steady from pH 4 to pH 9. Kinetic study shows that As (III) sorption is following second order rate equation with the rate constant of 80×10-2 g mg-1 min-1 at room temperature and this rate was increased with increasing temperature which indicates the sorption was endothermic process. The free energy change, ΔGo was negative which proves that the sorption was spontaneous and thermodynamically favorable. Sorption isotherm was interpreted by Langmuir equation and the maximum sorption capacity of oxide monolayer was 13×10-2 mg g-1.