Calcium alginate beads, inactivated Saccharomyces cerevisiae and inactivated S. cerevisiae immobilized in calcium alginate beads (S. cerevisiae-calcium alginate beads) are examined as potential biosorption materials as regards their capacity to remove 241Am. In this study, initial experiments were carried out to evaluate the effects of pH (2 and 4) and 241Am initial concentration: 75, 150, and 300 Bq mL-1. The experiments were conducted in a batch reactor. Higher removal capacity was observed at pH 2 with the use of S. Cerevisiae, whereas pH 4 performed better for the essays with calcium alginate beads and S. Cerevisiae-calcium alginate beads. The pseudo-first-order kinetic model described the kinetics of biosorption. Calcium alginate was the adsorbent of choice to further experiments with synthetic organic liquid waste. A lower removal rate was observed in the organic waste, although calcium alginate beads have also been able to achieve high sorption capacity in less than 4 h. With the organic waste, the highest value of sorption capacity of 241Am was 4.38 × 10-7 mmol g-1 with an initial 241Am concentration of 2.31 × 10-8 mmol L-1.
Keywords: Americium-241; Immobilized Saccharomyces cerevisiae; Saccharomyces cerevisiae; calcium alginate beads.
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