Study on Biosorption of Uranium by Rhodotorula Glutinis

Characteristic of uranium biosorption in water solution by Rhodotorula glutinis was investigated in the present study and the optimal pH for uranium adsorption was found to be 6-7. At the same time, maximum adsorption capacity of 1.49. 4 mgU/(g dry cell)was identified, and Langmuir adsorption models can be used to simulate the isothermal biosorption process with high correlation coefficient of 0.99. According to Fourier transform infrared spectra, a new peak at wave number of 904 cm(-1), which can be assigned to the stretch vibration of UO(2), was detected in the cell which was contacted by the uranium, indicated that uranium was really absorbed by Rhodotorula glutinis. Changes in the uranium-exposed yeast biomass were in the stretching vibrations of amino or hydroxyl groups, which shift from 3 309 to 3 287 cm(-1), and in the stretching vibrations of C-O band, which shift from 1 068 to 1080 cm(-1), and these are all attributed to the important role that they may played in the binding of uranium. Hardly any changes can be found in the characteristic IR adsorbing peaks of protein at wave numbers of 1 653, 1 540 and 1 237 cm(-1) before and after uranium adsorption, making it clear that the major component and the structure of the biomass remained intact. 96% of the absorbed uranium can be easily desorbed by 0.1 mol . L(-1) NaHCO(3). Obviously, the application potential of this yeast in the uranium wastewater treatment was very wide and expansive, and more more work should be done to realize its industrial use.