National Collaborative Innovation Center for Nuclear Waste and Environmental Safety, Southwest University of Science and Technology, Mianyang621000, China.
School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000, China.
Environ Sci Technol. 2024 Feb 27;58(8):3974-3984. doi: 10.1021/acs.est.3c05753. Epub 2024 Feb 2.
In contaminated water and soil, little is known about the role and mechanism of the biometabolic molecule siderophore desferrioxamine-B (DFO) in the biogeochemical cycle of uranium due to complicated coordination and reaction networks. Here, a joint experimental and quantum chemical investigation is carried out to probe the biomineralization of uranyl (UO, referred to as U(VI) hereafter) induced by (abbreviated as ) in the presence of DFO and Fe ion. The results show that the production of mineralized solids {hydrogen-uranium mica [H(UO)(PO)·8HO]} via binding with UO is inhibited by DFO, which can both chelate preferentially UO to form a U(VI)-DFO complex in solution and seize it from U(VI)-biominerals upon solvation. However, with Fe ion introduced, the strong specificity of DFO binding with Fe causes re-emergence of biomineralization of UO {bassetite [Fe(UO)(PO)·8(HO)]} by , owing to competitive complexation between Fe and UO for DFO. As DFO possesses three hydroxamic functional groups, it forms hexadentate coordination with Fe and UO ions via these functional groups. The stability of the Fe-DFO complex is much higher than that of U(VI)-DFO, resulting in some DFO-released UO to be remobilized by . Our finding not only adds to the understanding of the fate of toxic U(VI)-containing substances in the environment and biogeochemical cycles in the future but also suggests the promising potential of utilizing functionalized DFO ligands for uranium processing.
在受污染的水和土壤中，由于复杂的配位和反应网络，对于生物代谢分子铁载体去铁胺 B（DFO）在铀的生物地球化学循环中的作用和机制知之甚少。在这里，进行了联合实验和量子化学研究，以探究在 DFO 和 Fe 离子存在下，（简称为）诱导的铀酰（UO，简称 U(VI)）的生物矿化作用。结果表明，通过与 UO 结合生成矿化固体{氢铀云母[H(UO)(PO)·8HO]}的过程受到 DFO 的抑制，DFO 既能在溶液中优先螯合 UO 形成 U(VI)-DFO 配合物，又能在溶剂化时从 U(VI)-生物矿物中夺取 UO。然而，引入 Fe 离子后，DFO 与 Fe 结合的强特异性导致 UO 的生物矿化{蓝铁矿[Fe(UO)(PO)·8(HO)]}重新出现，这是由于 DFO 与 Fe 和 UO 之间的竞争配位所致。由于 DFO 具有三个偕羟肟官能团，因此它通过这些官能团与 Fe 和 UO 离子形成六配位。Fe-DFO 配合物的稳定性远高于 U(VI)-DFO，导致一些 DFO 释放的 UO 被重新移动。我们的发现不仅增加了对未来环境中有毒 U(VI)物质和生物地球化学循环中命运的理解，还表明了利用功能化 DFO 配体进行铀处理的广阔前景。
