| 摘 要： | Nanostructured Zn Fe_2O_4 was synthesized by the heat treatment of a mechanically activated mixture of Zn O/α-Fe_2O_3. X-ray diffraction(XRD) and differential thermal analysis(DTA) results demonstrated that, after 5 h of the mechanical activation of the mixture, Zn Fe_2O_4 was formed by heat treatment at 750°C for 2 h. To improve the characteristics of Zn Fe_2O_4 for adsorption applications, the chemical activation process was performed. The 2 h chemical activation with 1 mol·L~(-1) HNO_3 and co-precipitation of 52%-57% dissolved Zn Fe_2O_4 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 m~2·g~(-1). In addition, the observed particle size reduction of chemically activated Zn Fe_2O_4 in field emission scanning electron microscopy(FESEM) micrographs was in agreement with the specific surface area increase. These improvements in Zn Fe_2O_4 characteristics considerably affected the adsorption performance of this adsorbent. Adsorption results revealed that mechano-thermally synthesized Zn Fe_2O_4 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 Fe_2O_4 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 Fe_2O_4 was improved by the chemical activation process.
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