Biosorption of Strontium Ions by Magnetically Modified Yeast Cells

The sorption of Sr2+ ions from aqueous solutions on magnetically modified fodder yeast (Kluyveromyces fragilis) cells and their subsequent desorption were studied. The Sr2+ sorption increased with increasing pH and reached a plateau between pH 4.0 and 7.0. The changes of temperature slightly influenced the sorption process. The sorption values were 19.5mg g-1 and 53.5mg g-1 for 10mg L-1 and 40mg L-1 Sr2+ solutions respectively after 20min incubation at a pH higher than 4. The Langmuir isotherm was successfully used to fit experimental data; the maximum adsorption capacity was 140.8mg g-1 under optimal conditions. The adsorbed Sr2+ ions can be desorbed with nitric acid (0.1mol L-1).