Study on Biosorption Efficiency and Mechanism of Uranium by Bacillus subtilis

摘要

In order to search for the better biosorbent of uranium (VI) biosorption and its mechanism, Bacillus subtilis was employed in this research. The results showed that the adsorption capacity was achieved to 358.18 mg g-1 and with an optimum pH of 6.0. Cu2+, Fe2+, CO32- etc. would interfere with adsorption greatly. Better conformity of biosorption data with the Freundlich model suggested non-monolayered uranium biding. The adsorption results of the thermodynamic parameters indicated that biosorption of uranium were endothermic and spontaneous. TEM and SEM analysis of uranium loaded biomass revealed intracellular U sequestration and U absorbed on the cell surface respectively. It was confirmed that carboxyl, amino, and acylamino groups are responsible for biosorption using IR. More than 99% of biomass-bound uranium was recovered using sodium carbonate and sodium bicarbonate.