Biosorption of americium-241 by Candida sp.

摘要

As an important radioisotope in nuclear industry and other fields, americium-241 is one of the most serious contamination concerns duo to its high toxicity and long half-life. In this experiment, the biosorption of Am-241 from solution by Candida sp., and the effects of various experimental conditions on the adsorption were investigated. The preliminary results showed that the adsorption of Am-241 by Candida sp. was efficient. Am-241 could be removed by Candida sp. of 0.82 g/L (dry weight) from Am-241 solutions of 5.6-111 MBq/L (44.3-877.2 mug/L)(C-0), with maximum adsorption rate (R) of 98% and maximum adsorption capacities (W) of 63.5 MBq/g biomass (dry weight) (501.8 mug/g). The biosorption equilibrium was achieved within 4 hour and the optimum pH was pH = 2. No significant differences on Am-241 adsorption were observed at 10degreesC-45 degreesC, or in solutions containing Au3+ or Ag+, even 1500 times or 4500 times above the Am-241 concentration, respectively. The relationship between concentrations and adsorption capacities of Am-241 indicated the biosorption process should be described by a Langmuir adsorption isotherm. [References: 19]