Encapsulating Ag Nanoparticles into ZIF-8 as an Efficient Strategy to Boost Uranium Photoreduction without Sacrificial Agents

Photoreduction of hexavalent uranium (U(VI)) opens up an novel avenue to promoting the kinetics, capacity, and selectivity during uranium removal, where organic molecules are generally applied as the sacrificial agents...

Heteroatom engineering of polymeric carbon nitride heterojunctions for boosting photocatalytic reduction of hexavalent uranium

Two push–pull conjugated polymers termed PFB and PCB with different donors unit are innovatively applied to fabricate PFB/g-C3N4 and PCB/g-C3N4 heterojunctions for efficient photocatalytic reduction of uranium.

LEACHING OF URANIUM ORES IN THE PROCESS OF SODIUM SULPHATE ELECTROLYSIS

When uranium is extracted from concentrates with high silicon content, acid leaching is usually used. The disadvantage of this method is the high consumption, high cost and corrosion activity of the reagents. Moreover, for the oxidation of tetravalent uranium to highly soluble hexavalent uranium, it is necessary to process it with oxidizing agents, for example, oxygen. The work shows the possibility of development and chemical concentration of uranium ores using electrolysis of sodium sulfate. During electrolysis the pH in the anode chambers ranges from 2.2…2.5 to 0.5…0.7 in the near-electrode layer of the electrolyte, which corresponds to the pH range during leaching in agitators. Oxygen released at the anode is able to oxidize uranium to hexavalent one.

Graphene oxide based dopamine mussel-like cross-linked polyethylene imine nanocomposite coating with enhanced hexavalent uranium adsorption

GO-pDA-PEI with excellent stability provided enough movement space and active sites for highly preferential adsorption of U(vi).

Retardation of hexavalent uranium in muscovite environment: a batch study

The sorption of hexavalent uranium on muscovite as a function of pH, background electrolyte, temperature and humic acid (HA) was investigated in detail using batch experiments. The results showed that the uranium sorpiton on muscovite was kinetic fast, the kinetic process was fitted well by pseudo-second-order kinetic model. The sorption of uranium depended strongly on pH while weakly on background electrolyte concentration, indicating that surface complexation dominated the sorption process. The escalation of temperature and humic acid concentration were favorable to uranium sorption on muscovite. The sorption isotherms at pH 6.0 could be described better by Langmuir model than Freundlich or Dubinin-Radushkevich (D-R) model, thermodynamic data indicated that the uranium sorption process on muscovite was spontaneous and endothermic process. The findings in present work can provide important experimental reference for understanding the environmental behavior of uranium in mica-rich terrains.