Removal of cobalt from aqueous solution containing EDTA under UV-C irradiation by antimony oxide

Antimony oxide was synthesized by a simple method involving the mixing of 6 M HCl and antimony pentachloride, adjusting the synthesis pH with 25% ammonia. The obtained material was characterized using X-ray diffraction, field emission scanning electron microscopy, and surface area and pore size analysis. The material structure resembled that of Sb₆O₁₃. The cobalt sorption efficiency of the synthesized antimony oxide was tested in the dark and under UV-C irradiation. The 0.01 M NaNO₃ test solution contained varying concentrations of Co²⁺ and EDTA and was traced with ⁵⁷Co. The cobalt concentration in the solutions was determined by gamma spectroscopy. The synthesized material proved to have a high cobalt uptake. In the presence of 20 μM EDTA, 99.7% of cobalt was removed from the solution after 2 h of UV-C irradiation.