Adsorption capacity and mechanism of uranium by Fusarium verticillioides HX-3 isolated from a uranium mining site

Microorganisms that survive in extreme environments may possess special survival abilities. In this study, the adsorption capacity and mechanism of F. verticillioides HX-3, a fungus isolated from uranium mine wastewater, for uranium were investigated. Single factor batch experiments such as adsorption time, biomass dosage, pH, temperature, initial uranium concentration and coexisting ion were used to study the uranium adsorption capacity of biomass. The adsorption mechanism was further explored using kinetic, isothermal, thermodynamic models, and microscopic characterization techniques. The results demonstrated that under optimal experimental conditions, the biomass reached an adsorption capacity of 10.47 mg/g at a uranium concentration of 15 mg/L, with an adsorption efficiencies of 93 %. The study also revealed that the biomass adsorption process involves inhomogeneous multilayer chemisorption and exhibits spontaneous endothermic behavior. SEM-EDS analysis revealed that U(IV) primarily adsorbs onto the biomass surface. FTIR analysis showed that the functions that played the main role in the adsorption process were amino, hydroxyl, carbonyl, and acylamino groups. In summary, F. verticillioides HX-3 holds great potential for treating uranium-containing wastewater and can serve as an environmentally friendly biosorbent.