Improved uranium bioleaching in brackish environments via microbial consortium using RSM based modelling and optimization

Bioleaching is a prominent method among eco-friendly techniques. The efficiency of bioleaching is reduced by the presence of brackish water. Moreover, it has been reported that the most successful bioleaching systems are those that include both autotrophic and heterotrophic microorganismes. This research focuses on enhancing uranium bioleaching in brackish waters using the halotolerant bacterium Acidithiobacillus ferrooxidans strain THA4 and the fungus Rhodotorula toruloides strain IR-1395. The experimental data were modeled by the Response Surface Methodology (RSM) approach. The suggested model for uranium extraction in a brackish environment using microorganisms demonstrated an alignment with the experimental data, with a correlation coefficient of R₂ = 0.94. The results showed that the amount of uranium bioleaching by the consortium increased by 24.22%, compared to the bacterium alone under the optimal conditions suggested by the software. The study employed SEM-EDS to investigate the morphological changes in ore samples exposed to the microorganisms. The findings offer insights into the relationship dynamics between acidophilic bacteria and heterotrophic yeasts in uranium bioleaching of brackish waters. Finally, this study has improved biohydrometallurgical methods for uranium extraction from low-grade ores, especially in saline and low-resources conditions.