Removal of Sb(III) and Sb(V) from Aqueous Solutions Using nZVI

Nanoscale zero-valent iron (nZVI) was synthesized and used for the removal of Sb(III) and Sb(V) from aqueous solutions. Results showed that more than 90 % of antimony would be removed in 15 min and that all of antimony could be removed with appropriate nZVI dosage in 90 min. The influence of pH value and possible impurities was investigated. The pH of 4 was found as the optimum pH. Discussion and speculation about the mechanism were presented according to X-ray photoelectron spectroscopy and transmission electron microscopy data. A sheet-like structure was observed after a 90-min reaction, and antimony was detected on the surface by energy-dispersive X-ray spectroscopy. Both Sb(III) and Sb(V) partially reduced in the process. The presence of humic acid transformed the morphology of nZVI but barely influenced the removal efficiency. Competing ions showed diverse influence between Sb(III) and Sb(V). The overall results indicated that nZVI was an efficient and suitable material for the removal of antimony.