Research on the Yeast Biosorption of Urantum Under Culture Conditions

The biosorption capacities of uranium by yeast(Saccaromyces cerevisiae)under culture condition were examined.The uranium determined by spectrophotometry with Arsenazo Ⅲ.The growth curve,adsorption ratio and adsorption capacity were calculated with standard curve.Results showed that the growth curve of the yeast primary met the S-growth curve model;the repressive effect curve indicated that low concentration uranium and short time culture can promote the growth of the yeast,the obvious inhibition of yeast growth can be found when uranium concentration reaching 0.6mg/mL;the uranium concentration-adsorption rate curve met the isothermal adsorption curve model,the uranium concentration-the adsorption capacity curve demonstrated the total adsorption capacity was increased with the addition of the uranium concentration;the curve of the culture time-the adsorption rate suggested that the best culture time for the yeast adsorbing the uranium was 6-8 hours.The model of biosorption has been proved in agreement with Langmuir and Freundlich model by connection of uranium equilibrium concentration and adsorption capacity under low uranium concentration.