Shewanella oneidensis MR-1 and oxalic acid mediated vanadium reduction and redistribution in vanadium-containing tailings

• DOI: 10.1016/j.jhazmat.2023.131077
• Publication Date: 2023-02-24T17:27:14Z
• Authors: Chun-dan Gan; Qi-xuan Tang; Hao Wang; Jin-yan Yang; Aleksander Nikitin
• Keywords: Shewanella oneidensis; Oxalic Acid; Redistribution

The microbially- and chemically-mediated redox process is critical in controlling the fate of vanadium (V) in tailing environment. Although the microbial reduction of V has been widely studied, the coupled biotic reduction mediated by beneficiation reagents and the underlying mechanism remain unclear. Herein, the reduction and redistribution of V in V-containing tailings and Fe/Mn oxide aggregates mediated by Shewanella oneidensis MR-1 and oxalic acid were explored. The dissolution of Fe-(hydr)oxides by oxalic acid promoted the microbe-mediated V release from solid-phase. After 48-day of reaction, the dissolved V concentrations in the bio-oxalic acid treatment reached maximum values of 1.72 ± 0.36 mg L-1 and 0.42 ± 0.15 mg L-1 in the tailing system and the aggregate system, respectively, significantly higher than those in control (0.63 ± 0.14 mg L-1 and 0.08 ± 0.02 mg L-1). As the electron donor, oxalic acid enhanced the electron transfer process of S. oneidensis MR-1 for V(V) reduction. The mineralogical characterization of final products indicates that S. oneidensis MR-1 and oxalic acid promoted solid-state conversion from V2O5 to NaV6O15. Collectively, this study demonstrates that microbe-mediated V release and redistribution in solid-phase were promoted by oxalic acid, suggesting that the role of organic agents for the V biogeochemical cycle in natural systems deserves greater attention.