医学物理与技术中心知识库

The bioaccumulation and transformation of U(VI) by sporangiospores of Mucor circinelloides under different environmental conditions (e.g., reaction time, pH, carbonate, sporangiospores concentration, and temperature) was investigated by batch, XPS and EXAFS techniques. The bioaccumulation kinetics and isotherms can be fitted by the pseudo-second-order kinetic mode and Langmuir model, respectively, due to the high correlation coefficient. The maximum bioaccumulation capacity of sporangiospores for U(VI) was 166.13 mg/g at pH 6.0, which was significantly higher than that of other mycelia or spores. The intracellular and extracellular morphology of sporangiospores were significantly changed after U(VI) bioaccumulation, and levels of intracellular H2O2, O-3(-), GPx and SOD compounds in sporangiospores increased significantly. XANES analysis confirmed that the intracellular U(VI) was reduced to U(IV) by sporangiospores, and U(IV) might be stably associated with oxygen-bearing functional groups by EXAFS analysis. These results show that the sporangiospores can be used a promising adsorbent for the bioaccumulation and transformation of U(VI) from aqueous solutions, which has important scientific significance for the immobilization of U(VI) in environmental remediation.