Study on micron Zero-valent Iron (mZVI) material for adsorption and removal of antimony (V)

In this study, micron Zero-valent Iron (mZVI), an affordable and well-dispersible reducing agent, was investigated for its potential application in removing Sb(V) from wastewater. Since Sb(V) primarily exists as Sb(OH) 6 - in aqueous solutions, the lower the pH, the more effective mZVI is in removing Sb(V). At a pH level of 3, mZVI (1.0 g/L) was able to remove more than 99 % of Sb(V) (20 mg/L) from the wastewater. The study also compared the influence of cations and anions on mZVI and found that anions had a greater impact on the material's performance. The paper further examined the impact of different heavy metal ions on mZVI and determined that the adsorption capacity of mZVI towards these ions follows the order of their reducing ability. Summarizing the removal mechanism of Sb(V) by mZVI, it was found that both adsorption and redox reactions played crucial roles and Sb(V) is ultimately removed from water through coprecipitation by combining with Fe-O on the mZVI surface. Theoretically, the maximum adsorption capacity of the mZVI material used in this study could reach 21.60 mg/g for Sb(V). This makes mZVI a promising environmental adsorption material and a potential solution for treating water pollution caused by antimony mining.