Remediation of vanadium(V)-contaminated groundwater by the Shewanella oneidensis MR-1, Fe2O3, and biochar composite.

Vanadium, essential for steel production and energy storage, is increasingly found in groundwater due to extensive mining and industrial activities. Its high mobility and reactivity pose significant environmental risks. This study developed an Shewanella oneidensis MR-1- Fe2O3-biochar composite to enhance vanadium bioremediation. The composite exhibited strong vanadium resistance, achieving 92.5 ± 1.48% removal of pentavalent vanadium [V(V)] at 100 mg/l with an optimal biochar/Fe₂O₃ ratio of 10:1. Its efficiency was further assessed under varying pH, organic carbon levels, and V(V) concentrations. XPS analysis confirmed the presence of tetravalent vanadium [V (IV)] and divalent iron [Fe (II)], while FTIR spectroscopy identified functional groups (-OH, C=C, C=O) within the composite. These results suggest a synergistic removal mechanism involving complexation, dissimilatory iron reduction, and microbial V(V) reduction. This study provides a promising strategy for remediating V(V)-contaminated groundwater. PRACTITIONER POINTS: A novel composite consisted of Shewanella oneidensis MR-1, Fe2O3, and biochar was synthesized Complex promoted microbial life and increased resistance towards V(V) Complexation, Fe (II) oxidation, and bioreduction collectively contributed to V(V) removal.