biostudies-literatureAbernathy MJNational Institute of Environmental Health SciencesNIEHS NIH HHSNational Institute of Food and AgricultureUniversity of California, Riverside11703-11712https://www.ebi.ac.uk/biostudies/studies/S-EPMC11938697biostudies-literatureUnknown55(17)Vanadium is a redox-active metal that has been added to the EPA's Contaminant Candidate List with a notification level of 50 μg L^-1 due to mounting evidence that V^V exposure can lead to adverse health outcomes. Groundwater V concentration exceeds the notification level in many locations, yet geochemical controls on its mobility are poorly understood. Here, we examined the redox interaction between V^IV and birnessite (MnO₂), a well-characterized oxidant and a scavenger of many trace metals. In our findings, birnessite quickly oxidized sparingly soluble V^IV species such as häggite [V₂O₃(OH)₂] into highly mobile and toxic vanadate (H<i>_n</i>VO₄^{(3-<i>n</i>)-}) in continuouslyEnvironmental science & technologyOxidation of V(IV) by Birnessite: Kinetics and Surface Complexation.PMC11938697T32 ES018827CA-R-ENS-5151-HVessey CJLiu HSchaefer MVAbernathy MJYing SCfalseOxidation of V(IV) by Birnessite: Kinetics and Surface Complexation.Vanadium is a redox-active metal that has been added to the EPA's Contaminant Candidate List with a notification level of 50 μg L^-1 due to mounting evidence that V^V exposure can lead to adverse health outcomes. Groundwater V concentration exceeds the notification level in many locations, yet geochemical controls on its mobility are poorly understood. Here, we examined the redox interaction between V^IV and birnessite (MnO₂), a well-characterized oxidant and a scavenger of many trace metals. In our findings, birnessite quickly oxidized sparingly soluble V^IV species such as häggite [V₂O₃(OH)₂] into highly mobile and toxic vanadate (H<i>_n</i>VO₄^{(3-<i>n</i>)-}) in continuously2021-01-01T00:00:00Z2021 Sep2025-07-04T03:05:52.767Z2025-07-04T03:05:52.767ZS-EPMC119386973448834910.1021/acs.est.1c02464