Uptake of Radionuclides 60Co, 137Cs, and 90Sr with α-Fe2O3 and Fe3O4 Particles from Aqueous Environment

In the paper, investigation results of the uptake efficiency of radionuclides Co-60, Sr-90, and Cs-137 dissolved in water onto iron oxides alpha-Fe2O3 and Fe3O4 are presented. It was found that sorption efficiency increased for higher pH values. Independent of the oxide nature, the uptake characteristics are the best toward Co-60 and the worst toward Cs-137, forming the row as follows: Co-60 > Sr-90 > Cs-137. The highest sorption ability at pH 9 was found for magnetite Fe3O4, which was 93%, 73%, and 26% toward Co-60, Sr-90, and Cs-137, respectively, while the respective percentages for hematite alpha-Fe2O3 were 85%, 41%, and 18%. It was assumed that the main sorption mechanism was ion exchange. That may explain some decrease of the sorption efficiency in drinking water due to the interfering presence of magnesium and calcium cations. The obtained results indicated the feasibility of the tested sorbents and their merits, especially in terms of relatively high uptake coefficients, low costs, availability, and lack of toxicity.