Effect of chemical activation process on adsorption of As(Ⅴ) ion from aqueous solution by mechano-thermally synthesized zinc ferrite nanopowder

作者：Mohammad Sefidmooy Azar; Shahram Raygan^*; Saeed Sheibani

来源：International Journal of Minerals,Metallurgy and Materials, 2020, 27(04): 526-537.

Nanostructured Zn Fe2O4 was synthesized by the heat treatment of a mechanically activated mixture of Zn O/α-Fe2O3. X-ray diffraction(XRD) and differential thermal analysis(DTA) results demonstrated that, after 5 h of the mechanical activation of the mixture, Zn Fe2O4 was formed by heat treatment at 750°C for 2 h. To improve the characteristics of Zn Fe2O4 for adsorption applications, the chemical activation process was performed. The 2 h chemical activation with 1 mol·L-1 HNO3 and co-precipitation of 52%-57% dissolved Zn Fe2O4 led to an increase in the saturated magnetization from 2.0 to 7.5 emu·g-1 and in the specific surface area from 5 to 198 m2·g-1. In addition, the observed particle size reduction of chemically activated Zn Fe2O4 in field emission scanning electron microscopy(FESEM) micrographs was in agreement with the specific surface area increase. These improvements in Zn Fe2O4 characteristics considerably affected the adsorption performance of this adsorbent. Adsorption results revealed that mechano-thermally synthesized Zn Fe2O4 had the maximum arsenic adsorption of 38% with the adsorption capacity of 0.995 mg·g-1 in a 130 mg·L-1 solution of As(V) after 30 min of agitation. However, chemically activated Zn Fe2O4 showed the maximum arsenic adsorption of approximately 99% with the adsorption capacity of 21.460 mg·g-1 under the same conditions.These results showed that the weak adsorption performance of mechano-thermally synthesized Zn Fe2O4 was improved by the chemical activation process.