含磷化合物生物矿化铀的形态转化与机理

Morphological Transformation and Mechanism of Phosphorus-containing Compounds Biomineralized Uranium

磷元素作为微生物生存生长的必要元素,能有效与铀结合矿化成稳定的U-P沉淀或相应矿物。采用混合细菌介导法,添加含磷化合物处理铀污染地下水-沉积物,探究磷和土著菌相互作用下铀的形态变化及产物稳定性。结果表明:含磷化合物的添加使得溶液中铀去除率高达99.84%;改进连续提取实验得知,沉积物中磷作用后的铀稳定态比例约75%。根据X射线光电子能谱分析和改进连续提取实验结果,细菌可以有效地介导U-P沉淀,含磷化合物可以与六价铀络合形成稳定的沉淀物,结合X射线衍射表明在细菌作用下,磷与铀发生生物矿化可生成Ca-U-P沉淀,实现铀从可转移相到稳定相的转化与固定。

As an essential element for the survival and growth of microorganisms,phosphorus can effectively combine with uranium to mineralize into stable U-P precipitates or corresponding minerals.A mixed bacterial-mediated method was applied to address uranium-contaminated groundwater-sediments with the addition of phosphorus-containing com-pounds to investigate the morphological variations and the stability of uranium products under the interaction of phosphorus and indigenous bacteria.The results showed that the addition of phosphorus-containing compounds resulted in 99.84%removal of uranium from the solution.The Modified Community Bureau of Reference revealed that the proportion of uranium in the sediment in the stable state after phosphorus action was about 75%.According to the results of the X-ray Photoelectron Spectroscopy and The Modified Community Bureau of Reference,bacteria can effectively mediate U-P precipitation and phosphate can complex with hexavalent uranium to form stable precipitates.Combined with the X-Ray Diffraction,it showed that phosphorus and uranium undergo biomineralization under the action of bacteria can generate Ca-U-P precipitates to realize the conversion and immobilization of uranium from metastable phase to stable phase.