Frontiers in Microbiology (Jan 2023)

Sulfur enhancement effects for uranium bioleaching in column reactors from a refractory uranium ore

  • Qian Li,
  • Qian Li,
  • Yu Yang,
  • Yu Yang,
  • Jinfang Ma,
  • Jinfang Ma,
  • Jing Sun,
  • Jing Sun,
  • Guangyue Li,
  • Guangyue Li,
  • Ruiyong Zhang,
  • Ruiyong Zhang,
  • Zhao Cui,
  • Zhao Cui,
  • Ting Li,
  • Ting Li,
  • Xiaobei Liu,
  • Xiaobei Liu

DOI
https://doi.org/10.3389/fmicb.2023.1107649
Journal volume & issue
Vol. 14

Abstract

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The feasibility of sulfur enhancement for uranium bioleaching in column reactors was assessed with a designed mixed Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans and Leptospirillum ferriphilum from a refractory uranium ore. The uranium extraction reached 86.2% with the sulfur enhancement (1 g/kg) in 77 days leaching process, increased by 12.6% vs. the control without sulfur addition. The kinetic analysis showed that uranium bioleaching with sulfur enhancement in columns followed an internal diffusion through the product layer-controlled model. Ore residue characteristics indicated that sulfur enhancement could strengthen the porosity of passivation layer, improving the ore permeability. Notably, bacterial community analysis showed that sulfur enhancement at 1 g/kg could make the iron-oxidizing and sulfur-oxidizing bacteria on the ore surface maintain a good balance (approx. 1:1), and thus decomposing ore more effectively. Lastly, a possible mechanism model for uranium bioleaching with sulfur enhancement was proposed.

Keywords