Carbonate complexes of vanadate

McCann, Nichola; Imle, Michael; Hasse, Hans

doi:10.1016/j.poly.2015.03.004

Cited by 3 publications

(2 citation statements)

References 43 publications

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“…Thermodynamic equilibrium modeling of aqueous V species was performed using the PHREEQCi (Version 3.1.5) code with a modified Minteq version 3.1 database. , Vanadium speciation was modeled using the Davies activity model in a 0.05 M NaCl background electrolyte. Mononuclear and polynuclear V protonation reactions and equilibrium constants were also considered from Baes and Mesmer, Cruywagen et al, , Elvingson et al, Larson, McCann et al, , and Smith et al and compared to the Minteq database (Table S1). Aqueous Na-decavanadate (NaH x V 10 O 28 (5– x )– ) complexes can represent up to ∼40% of the total V species at 5000 μM and low ionic strength ( I = 0.05 M) and are therefore considered in thermodynamic modeling (Table S1).…”

Section: Methodsmentioning

confidence: 99%

“…47,48 Vanadium speciation was modeled using the Davies activity model in a 0.05 M NaCl background electrolyte. Mononuclear and polynuclear V protonation reactions and equilibrium constants were also considered from Baes and Mesmer, 18 Cruywagen et al, 20,49 Elvingson et al, 50 Larson, 51 McCann et al, 52,53 and Smith et al 54 and compared to the Minteq database (Table S1). 47 Aqueous Nadecavanadate (NaH x V 10 O 28…”

Section: ■ Materials and Methodsmentioning

confidence: 99%

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Adsorption of (Poly)vanadate onto Ferrihydrite and Hematite: An In Situ ATR–FTIR Study

Vessey

Schmidt

Abdolahnezhad

et al. 2020

ACS Earth Space Chem.

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Vanadium (V) geochemistry offers insight into Earth’s global biogeochemical cycles over geologic time. Additionally, increasing anthropogenic release of this redox-sensitive metal has led to elevated V concentrations in soils, sediments, and waters. Although Fe (oxyhydr)oxides are important sinks for aqueous V in soils and sediments, our understanding of adsorption mechanisms is currently limited to mononuclear species (i.e., H x VO4 (3–x)–). Here, we use in situ attenuated total reflectance–Fourier transform infrared spectroscopy to examine the sorption mechanisms for (poly)vanadate attenuation by ferrihydrite and hematite from pH 3 to 6. Adsorption isotherms illustrate the low affinity of polyvanadate species for ferrihydrite surfaces compared to that for hematite. Mononuclear V species (i.e., [H x VO4](3–x)– and VO2 +) were present at all experimental conditions. At low surface loadings and pH values of 5 and 6, H2VO4 – adsorption onto ferrihydrite and hematite surfaces results in the formation of inner-sphere complexes. At [V]T above 250 μM, adsorbed polynuclear V species in this study include H2V2O7 2– and V4O12 4–, whereas, HV10O28 6–, H3V10O28 5–, and NaHV10O28 4– are the predominant adsorbed species at pH values of 3 and 4 and elevated [V]T’s. Surface polymers were identified on hematite at all experimental pH values, whereas polymeric adsorption onto ferrihydrite was limited to pH values of 3 and 4. Results also suggest that hematite is a more suitable substrate for polymer complexation than ferrihydrite. Our results demonstrate the pH- and concentration-dependent removal of (poly)vanadate species by Fe(III) (oxyhydr)oxides, which has implications for understanding V mobility, behavior, and fate in the environment.

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