comparative study on arsenic [III] removal from aqueous solution using nano and micro sized zerovalent iron

The present study was conducted for Arsenic [III] removal, one of the most poisonous groundwater pollutants, by synthetic nano and micro size zerovalent iron [n-mZVI]. Batch experiments were performed to investigate the influence of As [III], nZVI and mZVI concentration, pH of solution and reaction time on the efficiency of As [III] removal by Fe[o] particles. Nano ZVI was synthesized by reduction of ferric chloride by sodium borohydrid. Scanning Electron microscope and X-Ray diffraction were used to determine particle size and characterization of produced nanoparticles. Results showed up to 99.9% removal efficiency for arsenic [III] that was obtained by nZVI dosage of 1 g/L at equal time of 10 min and pH=7. The maximum removal efficiency by mZVI obtained in initial arsenic concentration of 1 mg/L and mZVI dosage of 10 g/L after 120 min. and pH=7. It could be concluded that the removal efficiency was enhanced with increasing n-mZVI dosage and reaction time, but decreased with increasing of arsenic concentration and pH for both nano and micro sized ZVI. Nano ZVI presented an outstanding ability to remove As [III] due to not only a high surface area and low particle size but also to high inherent activity