Academia.eduAcademia.edu

Outline

Title
Abstract
Introduction
Materials and Methods
References
All Topics
Environmental Science
Pollution

Oxidative UO2 dissolution induced by soluble Mn (III)

Profile image of Zimeng WangZimeng Wang
https://doi.org/10.1021/ES4037308
visibility

…

description

10 pages

link

1 file

Abstract

The stability of UO 2 is critical to the success of reductive bioremediation of uranium. When reducing conditions are no longer maintained, Mn redox cycling may catalytically mediate the oxidation of UO 2 and remobilization of uranium. Ligand-stabilized soluble Mn(III) was recently recognized as an important redox-active intermediate in Mn biogeochemical cycling. This study evaluated the kinetics of oxidative UO 2 dissolution by soluble Mn(III) stabilized by pyrophosphate (PP) and desferrioxamine B (DFOB). The Mn(III)−PP complex was a potent oxidant that induced rapid UO 2 dissolution at a rate higher than that by a comparable concentration of dissolved O 2 . However, the Mn(III)−DFOB complex was not able to induce oxidative dissolution of UO 2 . The ability of Mn(III) complexes to oxidize UO 2 was probably determined by whether the coordination of Mn(III) with ligands allowed the attachment of the complexes to the UO 2 surface to facilitate electron transfer. Systematic investigation into the kinetics of UO 2 oxidative dissolution by the Mn(III)−PP complex suggested that Mn(III) could directly oxidize UO 2 without involving particulate Mn species (e.g., MnO 2 ). The expected 2:1 reaction stoichiometry between Mn(III) and UO 2 was observed. The reactivity of soluble Mn(III) in oxidizing UO 2 was higher at lower ratios of pyrophosphate to Mn(III) and lower pH, which is probably related to differences in the ligand-to-metal ratio and/or protonation states of the Mn(III)−pyrophosphate complexes. Disproportionation of Mn(III)−PP occurred at pH 9.0, and the oxidation of UO 2 was then driven by both MnO 2 and soluble Mn(III). Kinetic models were derived that provided excellent fits of the experimental results.

Related papers

Determination of Uranyl Incorporation into Biogenic Manganese Oxides Using X-ray Absorption Spectroscopy and Scattering
Bradley Tebo

Environmental Science & Technology, 2006

Βiogenic manganese oxides are common and an important source of reactive mineral surfaces in the environment that may be potentially enhanced in bioremediation cases to improve natural attenuation. Experiments were performed in which the uranyl ion, UO 2 2+ (U(VI)), at various concentrations was present during manganese oxide biogenesis. At all concentrations, there was strong uptake of U onto the oxides. Synchrotron-based extended X-ray absorption fine structure (EXAFS) spectroscopy and X-ray diffraction (XRD) studies were carried out to determine the molecular-scale mechanism by which uranyl is incorporated into the oxide and how this incorporation affects the resulting manganese oxide structure and mineralogy. The EXAFS experiments show that at low concentrations (<0.3 mol % U, <1 µM U(VI) in solution), U(VI) is present as a strong bidentate surface complex. At high concentrations (>2 mol % U, >4 µM U(VI) in solution), the presence of U(VI) affects the stability and structure of the Mn oxide to form poorly ordered Mn oxide tunnel structures, similar to todorokite. EXAFS modeling shows that uranyl is present in these oxides predominantly in the tunnels of the Mn oxide structure in a tridentate complex. Observations by XRD corroborate these results. Structural incorporation may lead to more stable U(VI) sequestration that may be suitable for remediation uses. These observations, combined with the very high uptake capacity of the Mn oxides, imply that Mn-oxidizing bacteria may significantly influence dissolved U(VI) concentrations in impacted waters via sorption and incorporation into Mn oxide biominerals.

View PDFchevron_right
Spectroscopic and kinetic evidence for redox cycling, catalase and degradation activities of Mn<sup>III</sup>(TPPS) in a basic aqueous peroxide medium
Łukasz Orzeł

Chemical Communications, 2016

View PDFchevron_right
Effect of Mn(II) on the Structure and Reactivity of Biogenic Uraninite
Rizlan Bernier-latmani

Environmental Science & Technology, 2009

The efficacy of a site remediation strategy involving the stimulation of microbial U(VI) reduction hinges in part upon the long-term stability of the product, biogenic uraninite, toward environmental oxidants. Geological sedimentary uraninites (nominal formula UO 2 ) reportedly contain abundant cation impurities that enhance their resistance to oxidation. By analogy, incorporation of common groundwater solutes into biogenic uraninite could also impart stability-enhancing properties. Mn(II) is a common groundwater cation, which has a favorable ionic radius for substitution reactions. The structure and reactivity of Mn(II)-reacted biogenic uraninite are investigated in this study. Up to 4.4 weight percent Mn(II) was found to be structurally bound in biogenic uraninite. This Mn(II) incorporation was associated with decreasing uraninite particle size and structural order. Importantly, the equilibrium solubility of Mn-reacted uraninite was halved relative to unreacted uraninite, demonstrating changes in thermodynamic properties, while the dissolution rate was up to 38-fold lower than that of unreacted biogenic uraninite. We conclude that structural incorporation of Mn(II) into uraninite has an important stabilizing effect, leading to the prediction that other groundwater solutes may similarly stabilize biogenic uraninite.

View PDFchevron_right
Effect of carbonate on U(VI) sorption by nano-crystalline α-MnO2
Bhupendra Tomar

Radiochimica Acta, 2018

U(VI) sorption on nano-crystalline α-MnO2 was studied in NaClO4 medium as a function of pH by batch sorption method in presence and absence of carbonate and subsequently employing surface complexation modeling (SCM) to predict species responsible for U(VI) sorption. The kinetic study of U(VI) sorption on nano-crystalline α-MnO2 was carried out to fix the time of equilibration. In presence of carbonate, U(VI) sorption on nano-crystalline α-MnO2 increases with pH of the suspension, leveling off in the pH range 5–8.5 thereafter decreasing at higher pH. However, in absence of carbonate, U(VI) sorption on nano-crystalline α-MnO2 remains close to 100% at pH&gt;5. The difference in sorption behavior of uranium in the presence and absence of carbonate can be explained in terms of uranium speciation in the two systems. The dissolution of nano-crystalline α-MnO2 was studied in presence and absence of carbonate to ascertain its role in sorption. Surface complexation modeling was satisfactorily...

View PDFchevron_right
Kinetics of oxidation and dissolution of uranium dioxide in aqueous acid solutions
jean radwan

Electrochimica Acta, 2012

The oxidation and dissolution of UO 2 has been studied using electrochemical methods with an UO 2 rotating disc electrode in acidic (pH 3) and non-complexing (trifluoromethanesulfonate: 0.1 mol L −1 NaCF 3 SO 3) media. The effect of the experimental parameters such as scan rate (v) and rotation rate (ω) on the electrochemical signal has been studied. The rotation rate of the electrode does not influence the resulting signal, which indicates that only a charge transfer is involved in the UO 2 oxidation kinetic. However, scan rate variations show different reactions involved in the UO 2 oxidation. Linear sweep voltammetry and cyclic voltammetry coupled to X-ray photoelectron spectroscopy (XPS) and inductively coupled plasma mass spectrometry (ICP-MS) measurements suggest two successive electrochemical reactions with an exchange of one electron for each of them and the formation of one intermediate species of U(V).

View PDFchevron_right
A Kinetic Study on the Efficient Formation of High-Valent Mn(TPPS)-oxo Complexes by Various Oxidants
Łukasz Orzeł

Catalysts

New, more efficient methods of wastewater treatment, which will limit the harmful effects of textile dyes on the natural environment, are still being sought. Significant research work suggests that catalysts based on transition metal complexes can be used in efficient and environmentally friendly processes. In this context, a number of compounds containing manganese have been investigated. A suitable catalyst should have the capacity to activate a selected oxidant or group of oxidants, in order to be used in industrial oxidation reactions. In the present study we investigated the ability of MnIII(TPPS), where TPPS = 5,10,15,20-tetrakis(4-sulphonatophenyl)-21H,23H-porphyrine, to activate five different oxidants, namely hydrogen peroxide, peracetic acid, sodium hypochlorite, potassium peroxomonosulfate and sodium perborate, via the formation of high valent Mn(TPPS)-oxo complexes. Kinetic and spectroscopic data showed that the oxidation process is highly pH dependent and is strongly ac...

View PDFchevron_right
Supporting Information Zimeng Wang 2013 EST U sorpiton to MnO2
Jeffery Catalano, Bradley Tebo
View PDFchevron_right
Thermodynamic Constraints on the Oxidation of Biogenic UO 2 by Fe(III) (Hydr)oxides
Matthew Ginder-Vogel

Environmental Science & Technology, 2006

Uranium mobility in the environment is partially controlled by its oxidation state, where it exists as either U(VI) or U(IV). In aerobic environments, uranium is generally found in the hexavalent form, is quite soluble, and readily forms complexes with carbonate and calcium. Under anaerobic conditions, common metal respiring bacteria can reduce soluble U(VI) species to sparingly soluble UO 2 (uraninite); stimulation of these bacteria, in fact, is being explored as an in situ uranium remediation technique. However, the stability of biologically precipitated uraninite within soils and sediments is not well characterized.

View PDFchevron_right
Adsorption of uranium (VI) to manganese oxides: X-ray absorption spectroscopy and surface complexation modeling
Zimeng Wang

2012

The mobility of hexavalent uranium in soil and groundwater is strongly governed by adsorption to mineral surfaces. As strong naturally occurring adsorbents, manganese oxides may significantly influence the fate and transport of uranium. Models for U(VI) adsorption over a broad range of chemical conditions can improve predictive capabilities for uranium transport in the subsurface. This study integrated batch experiments of U(VI) adsorption to synthetic and biogenic MnO 2 , surface complexation modeling, ζ-potential analysis, and molecular-scale characterization of adsorbed U(VI) with extended X-ray absorption fine structure (EXAFS) spectroscopy. The surface complexation model included inner-sphere monodentate and bidentate surface complexes and a ternary uranyl-carbonato surface complex, which was consistent with the EXAFS analysis. The model could successfully simulate adsorption results over a broad range of pH and dissolved inorganic carbon concentrations. U(VI) adsorption to synthetic δ-MnO 2 appears to be stronger than to biogenic MnO 2 , and the differences in adsorption affinity and capacity are not associated with any substantial difference in U(VI) coordination.

View PDFchevron_right
Oxidative and reductive processes contributing to manganese cycling at oxic-anoxic interfaces
George W Luther

Marine Chemistry, 2017

Manganese (Mn) is important in seawater as a micronutrient, scavenger (as MnO 2) and as a reactant in the redox cycles of many other biologically important elements. In seawater, Mn cycles between oxidized insoluble Mn(III/ IV) oxides (MnO x) and soluble Mn (II/III) species (dMn T), which includes Mn(III) complexed to organic ligands (Mn(III)-L) and reduced Mn(II). Mn(III)-L complexes have been shown to be stable in separate oxic, suboxic and anoxic systems, but not in an entire water column with a transition from an oxic to anoxic zone. Additionally, the formation pathways for these complexes have not been well described at one location over a short timescale. In order to better understand these pathways, dissolved and particulate Mn speciation was determined in the water column of the seasonally stratified Chesapeake Bay basin over a 2-day period, using pump profiling for better spatial resolution (10 cm) of redox active species and a modified, low-level spectrophotometric method for soluble Mn speciation (detection limit = 3 nM). Our data suggest that Mn(II) fluxes out of the anoxic sediments (bottom water total Mn: 2.23-3.80 μM; Mn(II) = 61-84% of total Mn) and is oxidized to MnO x at the top of suboxic zone of the water column at non-detectable dO 2 levels (≤3 μM). These biogenic Mn oxides are reduced at the suboxic-anoxic interface via a combination of strong ambient Mn(III)-binding ligands, H 2 S and/or microbial activity, resulting in the disappearance of MnO x and formation of Mn(III)-L complexes and Mn(II). The oxic water column has lower concentrations of dMn T (0.05-0.18 μM), with Mn(III)-L complexes present in all oxic samples (33-80% of dMn T). The complexes in the oxic water column arise from processes distinct from those occurring in the suboxic and anoxic zones.

View PDFchevron_right

References (65)

  1. Bargar, J. R.; Bernier-Latmani, R.; Giammar, D. E.; Tebo, B. M. Biogenic uraninite nanoparticles and their importance for uranium remediation. Elements 2008, 4 (6), 407-412.
  2. Bargar, J. R.; Williams, K. H.; Campbell, K. M.; Long, P. E.; Stubbs, J. E.; Suvorova, E. I.; Lezama-Pacheco, J. S.; Alessi, D. S.; Stylo, M.; Webb, S. M.; Davis, J. A.; Giammar, D. E.; Blue, L. Y.; Bernier- Latmani, R. Uranium redox transition pathways in acetate-amended sediments. Proc. Natl. Acad. Sci., U. S. A. 2013, 110 (12), 4506-4511.
  3. Bernier-Latmani, R.; Veeramani, H.; Vecchia, E. D.; Junier, P.; Lezama-Pacheco, J. S.; Suvorova, E. I.; Sharp, J. O.; Wigginton, N. S.; Bargar, J. R. Non-uraninite products of microbial U(VI) reduction. Environ. Sci. Technol. 2010, 44 (24), 9456-9462.
  4. Fletcher, K. E.; Boyanov, M. I.; Thomas, S. H.; Wu, Q. Z.; Kemner, K. M.; Loffler, F. E. U(VI) reduction to mononuclear U(IV) by Desulf itobacterium species. Environ. Sci. Technol. 2010, 44 (12), 4705-4709.
  5. Ulrich, K. U.; Ilton, E. S.; Veeramani, H.; Sharp, J. O.; Bernier- Latmani, R.; Schofield, E. J.; Bargar, J. R.; Giammar, D. E. Comparative dissolution kinetics of biogenic and chemogenic uraninite under oxidizing conditions in the presence of carbonate. Geochim. Cosmochim. Acta 2009, 73 (20), 6065-6083.
  6. Senko, J. M.; Suflita, J. M.; Krumholz, L. R. Geochemical controls on microbial nitrate-dependent U(IV) oxidation. Geomicrobiol. J. 2005, 22 (7-8), 371-378.
  7. Ginder-Vogel, M.; Stewart, B.; Fendorf, S. Kinetic and mechanistic constraints on the oxidation of biogenic uraninite by ferrihydrite. Environ. Sci. Technol. 2010, 44 (1), 163-169.
  8. Sani, R. K.; Peyton, B. M.; Dohnalkova, A.; Amonette, J. E. Reoxidation of reduced uranium with iron(III) (hydr)oxides under sulfate-reducing conditions. Environ. Sci. Technol. 2005, 39 (7), 2059- 2066.
  9. Fredrickson, J. K.; Zachara, J. M.; Kennedy, D. W.; Liu, C.; Duff, M. C.; Hunter, D. B.; Dohnalkova, A. Influence of Mn oxides on the reduction of uranium(VI) by the metal-reducing bacterium Shewanella putrefaciens. Geochim. Cosmochim. Acta 2002, 66 (18), 3247-3262.
  10. Liu, C. X.; Zachara, J. M.; Fredrickson, J. K.; Kennedy, D. W.; Dohnalkova, A. Modeling the inhibition of the bacterial reduction of U(VI) by β-MnO 2(s) . Environ. Sci. Technol. 2002, 36 (7), 1452-1459.
  11. Campbell, K. M.; Veeramani, H.; Urich, K. U.; Blue, L. Y.; Giammar, D. E.; Bernier-Latmani, R.; Stubbs, J. E.; Suvorova, E.; Yabusaki, S.; Lezama-Pacheco, J. S.; Mehta, A.; Long, P. E.; Bargar, J. R. Oxidative dissolution of biogenic uraninite in groundwater at Old Rifle, CO. Environ. Sci. Technol. 2011, 45 (20), 8748-8754.
  12. Zachara, J. M.; Long, P. E.; Bargar, J.; Davis, J. A.; Fox, P.; Fredrickson, J. K.; Freshley, M. D.; Konopka, A. E.; Liu, C.; McKinley, J. P.; Rockhold, M. L.; Williams, K. H.; Yabusaki, S. B. Persistence of uranium groundwater plumes: Contrasting mechanisms at two DOE sites in the groundwater-river interaction zone. J. Contam. Hydrol. 2013, 147 (0), 45-72.
  13. Borch, T.; Kretzschmar, R.; Kappler, A.; Van Cappellen, P.; Ginder-Vogel, M.; Voegelin, A.; Campbell, K. Biogeochemical redox processes and their impact on contaminant dynamics. Environ. Sci. Technol. 2010, 44 (1), 15-23.
  14. Morgan, J. J. Kinetics of reaction between O 2 and Mn(II) species in aqueous solutions. Geochim. Cosmochim. Acta 2005, 69 (1), 35-48.
  15. Tebo, B. M.; Bargar, J. R.; Clement, B. G.; Dick, G. J.; Murray, K. J.; Parker, D.; Verity, R.; Webb, S. M. Biogenic manganese oxides: Properties and mechanisms of formation. Annu. Rev. Earth Planet. Sci. 2004, 32 (1), 287-328.
  16. Clement, B. G.; Luther, G. W.; Tebo, B. M. Rapid, oxygen- dependent microbial Mn(II) oxidation kinetics at sub-micromolar oxygen concentrations in the Black Sea suboxic zone. Geochim. Cosmochim. Acta 2009, 73 (7), 1878-1889.
  17. Chinni, S.; Anderson, C. R.; Ulrich, K. U.; Giammar, D. E.; Tebo, B. M. Indirect UO 2 oxidation by Mn(II)-oxidizing spores of Bacillus sp Strain SG-1 and the effect of U and Mn concentrations. Environ. Sci. Technol. 2008, 42 (23), 8709-8714.
  18. Wang, Z.; Lee, S.-W.; Kapoor, P.; Tebo, B. M.; Giammar, D. E. Uraninite oxidation and dissolution induced by manganese oxide: A redox reaction between two insoluble minerals. Geochim. Cosmochim. Acta 2013, 100 (1), 24-40.
  19. Plathe, K. L.; Lee, S.-W.; Tebo, B. M.; Bargar, J. R.; Bernier- Latmani, R. Impact of microbial Mn oxidation on the remobilization of bioreduced U(IV). Environ. Sci. Technol. 2013, 47 (8), 3606-3613.
  20. Duckworth, O. W.; Bargar, J. R.; Sposito, G. Coupled biogeochemical cycling of iron and manganese as mediated by microbial siderophores. BioMetals 2009, 22 (4), 605-613.
  21. Johnson, K. S. Manganese redox chemistry revisited. Science 2006, 313 (5795), 1896-1897.
  22. Webb, S. M.; Dick, G. J.; Bargar, J. R.; Tebo, B. M. Evidence for the presence of Mn(III) intermediates in the bacterial oxidation of Mn(II). Proc. Natl. Acad. Sci., U. S. A. 2005, 102 (15), 5558-5563.
  23. Duckworth, O. W.; Sposito, G. Siderophore-manganese(III) interactions. I. Air-oxidation of manganese(II) promoted by desferriox- amine B. Environ. Sci. Technol. 2005, 39 (16), 6037-6044.
  24. Butterfield, C. N.; Soldatova, A. V.; Lee, S.-W.; Spiro, T. G.; Tebo, B. M. Mn(II,III) oxidation and MnO 2 mineralization by an expressed bacterial multicopper oxidase. Proc. Natl. Acad. Sci., U. S. A. 2013, 110 (29), 11731-11735.
  25. Ehrlich, H. L. Manganese oxide reduction as a form of anaerobic respiration. Geomicrobiol. J. 1987, 5 (3-4), 423-431.
  26. Lin, H.; Szeinbaum, N. H.; DiChristina, T. J.; Taillefert, M. Microbial Mn(IV) reduction requires an initial one-electron reductive solubilization step. Geochim. Cosmochim. Acta 2012, 99 (0), 179-192.
  27. Wang, Y.; Stone, A. T. Phosphonate-and carboxylate-based chelating agents that solubilize (hydr)oxide-bound Mn III . Environ. Sci. Technol. 2008, 42 (12), 4397-4403.
  28. Duckworth, O. W.; Sposito, G. Siderophore-manganese(III) interactions. II. Manganite dissolution promoted by desferrioxamine B. Environ. Sci. Technol. 2005, 39 (16), 6045-6051.
  29. Penã, J.; Duckworth, O. W.; Bargar, J. R.; Sposito, G. Dissolution of hausmannite (Mn 3 O 4 ) in the presence of the trihydroxamate siderophore desferrioxamine B. Geochim. Cosmochim. Acta 2007, 71 (23), 5661-5671.
  30. Gunary, D. Pyrophosphate in soil; Some physico-chemical aspects. Nature 1966, 210 (5042), 1297-1298.
  31. Harrington, J. M.; Parker, D. L.; Bargar, J. R.; Jarzecki, A. A.; Tebo, B. M.; Sposito, G.; Duckworth, O. W. Structural dependence of Mn complexation by siderophores: Donor group dependence on complex stability and reactivity. Geochim. Cosmochim. Acta 2012, 88 (0), 106-119.
  32. Trouwborst, R. E.; Clement, B. G.; Tebo, B. M.; Glazer, B. T.; Luther, G. W. Soluble Mn(III) in suboxic zones. Science 2006, 313 (5795), 1955-1957.
  33. Madison, A. S.; Tebo, B. M.; Luther, G. W. Simultaneous determination of soluble manganese(III), manganese(II) and total manganese in natural (pore)waters. Talanta 2011, 84 (2), 374-381.
  34. Madison, A. S.; Tebo, B. M.; Mucci, A.; Sundby, B.; Luther, G.
  35. W., III Abundant porewater Mn(III) is a major component of the sedimentary redox system. Science 2013, 341 (6148), 875-878.
  36. Weaver, R. M.; Hochella, M. F. The reactivity of seven Mn- oxides with Cr 3+ aq: A comparative analysis of a complex, environmentally important redox reaction. Am. Mineral. 2003, 88 (11-12), 2016-2027.
  37. Nico, P. S.; Zasoski, R. J. Importance of Mn(III) availability on the rate of Cr(III) oxidation on δ-MnO 2 . Environ. Sci. Technol. 2000, 34 (16), 3363-3367.
  38. Nico, P. S.; Zasoski, R. J. Mn(III) center availability as a rate controlling factor in the oxidation of phenol and sulfide on δ-MnO 2 . Environ. Sci. Technol. 2001, 35 (16), 3338-3343.
  39. Chen, W.-R.; Liu, C.; Boyd, S. A.; Teppen, B. J.; Li, H. Reduction of carbadox mediated by reaction of Mn(III) with oxalic acid. Environ. Sci. Technol. 2013, 47 (3), 1357-1364.
  40. Lafferty, B. J.; Ginder-Vogel, M.; Zhu, M. Q.; Livi, K. J. T.; Sparks, D. L. Arsenite oxidation by a poorly crystalline manganese- oxide. 2. Results from X-ray absorption spectroscopy and X-ray diffraction. Environ. Sci. Technol. 2010, 44 (22), 8467-8472.
  41. Nesbitt, H. W.; Canning, G. W.; Bancroft, G. M. XPS study of reductive dissolution of 7Å-birnessite by H 3 AsO 3 , with constraints on reaction mechanism. Geochim. Cosmochim. Acta 1998, 62 (12), 2097- 2110.
  42. Kostka, J. E.; Luther, G. W.; Nealson, K. H. Chemical and biological reduction of Mn(III)-pyrophosphate complexes -Potential importance of dissolved Mn(III) as an environmental oxidant. Geochim. Cosmochim. Acta 1995, 59 (5), 885-894.
  43. Klewicki, J. K.; Morgan, J. J. Kinetic behavior of Mn(III) complexes of pyrophosphate, EDTA, and citrate. Environ. Sci. Technol. 1998, 32 (19), 2916-2922.
  44. Rophael, M. Kinetics of the oxidation of chromium (III) by manganese (III) in sulphuric acid media. Chem. Scr. 1982, 20, 171- 173.
  45. Murray, K. J.; Tebo, B. M. Cr(III) is indirectly oxidized by the Mn(II)-oxidizing bacterium Bacillus sp strain SG-1. Environ. Sci. Technol. 2007, 41 (2), 528-533.
  46. Weaver, R. M.; Hochella, M. F., Jr.; Ilton, E. S. Dynamic processes occurring at the Cr III aq-Manganite (γ-MnOOH) interface: Simultaneous adsorption, microprecipitation, oxidation/reduction, and dissolution. Geochim. Cosmochim. Acta 2002, 66 (23), 4119-4132.
  47. Perez-Benito, J. F.; Arias, C. The pyrophosphate-assisted reduction of chromium(VI) by manganese(II) and its reverse reaction. New J. Chem. 2001, 25 (11), 1438-1446.
  48. Turner, B. L.; Newman, S. Phosphorus cycling in wetland soils. J. Environ. Qual. 2005, 34 (5), 1921-1929.
  49. Bi, Y.; Hesterberg, D. L.; Duckworth, O. W. Siderophore- promoted dissolution of cobalt from hydroxide minerals. Geochim. Cosmochim. Acta 2010, 74 (10), 2915-2925.
  50. Faulkner, K. M.; Stevens, R. D.; Fridovich, I. Characterization of Mn(III) complexes of linear and cyclic desferrioxamines as mimics of superoxide dismutase activity. Arch. Biochem. Biophys. 1994, 310 (2), 341-346.
  51. McElroy, W. D.; Glass, B. Phosphorus Metabolism; Johns Hopkins University Press: Baltimore, MD, 1951.
  52. Wazer, J. R. V.; Campanella, D. A. Structure and properties of the condensed phosphates. IV. Complex ion formation in poly- phosphate solutions. J. Am. Chem. Soc. 1950, 72 (2), 655-663.
  53. Schecher, W. D.; McAvoy, D. C. MINEQL+: A chemical equilibrium modeling system, version 4.6; Environmental Research Software: Hallowell, ME, 2007.
  54. Frazier, S. W.; Kretzschmar, R.; Kraemer, S. M. Bacterial siderophores promote dissolution of UO 2 under reducing conditions. Environ. Sci. Technol. 2005, 39 (15), 5709-5715.
  55. Duckworth, O. W.; Bargar, J. R.; Sposito, G. Quantitative structure-activity relationships for aqueous metal-siderophore complexes. Environ. Sci. Technol. 2009, 43 (2), 343-349.
  56. Stewart, B. D.; Girardot, C.; Spycher, N.; Sani, R. K.; Peyton, B. M. Influence of chelating agents on biogenic uraninite reoxidation by Fe(III) (hydr)oxides. Environ. Sci. Technol. 2013, 47 (1), 364-371.
  57. Ginder-Vogel, M.; Criddle, C. S.; Fendorf, S. Thermodynamic constraints on the oxidation of biogenic UO 2 by Fe(III) (hydr)oxides. Environ. Sci. Technol. 2006, 40 (11), 3544-3550.
  58. Gordienko, V. I.; Sidorenko, V. I.; Mikhailyuk, Y. I. Amperometric investigation of Mn(III) pyrophosphate complexes. Russ. J. Inorg. Chem. 1970, 15, 1241-1244.
  59. Ciavatta, L.; Palombari, R. On the equilibria of complex formation between manganese(III) and pyrophosphate ions. Gazz. Chim. Ital. 1983, 113, 557-552.
  60. Jiang, J.; Pang, S. Y.; Ma, J. Role of ligands in permanganate oxidation of organics. Environ. Sci. Technol. 2010, 44 (11), 4270-4275.
  61. Kolthoff, I.; Watters, J. Polarographic determination of manganese as tridihydrogen pyrophosphatomanganiate. Ind. Eng. Chem. Anal. Ed. 1943, 15 (1), 8-13.
  62. Taube, H. Catalysis by manganic ion of the reaction of bromine and oxalic acid. Stability of manganic ion complexes. J. Am. Chem. Soc. 1948, 70 (11), 3928-3935.
  63. Jiang, J.; Pang, S.-Y.; Ma, J.; Liu, H. Oxidation of phenolic endocrine disrupting chemicals by potassium permanganate in synthetic and real waters. Environ. Sci. Technol. 2011, 46 (3), 1774- 1781.
  64. Cerrato, J. M.; Ashner, M. N.; Alessi, D. S.; Lezama Pacheco, J. S.; Bernier-Latmani, R.; Bargar, J.; Giammar, D. E. Relative reactivity of biogenic and chemogenic uraninite and biogenic non-crystalline U(IV). Environ. Sci. Technol. 2013, 47 (17), 9756-9763.
  65. Wang, Z.; Lee, S.-W.; Catalano, J. G.; Lezama-Pacheco, J. S.; Bargar, J. R.; Tebo, B. M.; Giammar, D. E. Adsorption of uranium(VI) to manganese oxides: X-ray absorption spectroscopy and surface complexation modeling. Environ. Sci. Technol. 2013, 47 (2), 850-858.

Related papers

Supporting Information Zimeng Wang 2014 EST UO2 oxidation by soluble Mn(III)
Bradley Tebo
View PDFchevron_right
Effects of Mn(II) on UO2 Dissolution under Anoxic and Oxic Conditions
Zimeng Wang

Environmental Science & Technology, 2014

Groundwater composition and coupled redox cycles can affect the long-term stability of U(IV) products from bioremediation. The effects of Mn(II), a redox active cation present at uranium-contaminated sites, on UO 2 dissolution in both oxic and anoxic systems were investigated using batch and continuous-flow reactors. Under anoxic conditions Mn(II) inhibited UO 2 dissolution, which was probably due to adsorption of Mn(II) and precipitation of MnCO 3 that decreased exposure of U(IV) surface sites to oxidants. In contrast, Mn(II) promoted UO 2 dissolution under oxic conditions through Mn redox cycling. Oxidation of Mn(II) by O 2 produced reactive Mn species, possibly short-lived Mn(III) in solution or at the surface, that oxidatively dissolved the UO 2 more rapidly than could the O 2 alone. At pH 8 the Mn cycling was such that there was no measurable accumulation of particulate Mn oxides. At pH 9 Mn oxides could be produced and accumulate, while they were continuously reduced by UO 2 , with Mn(II) returning to the aqueous phase. With the rapid turnover of Mn in the redox cycle, concentrations of Mn as low as 10 μM could maintain an enhanced UO 2 dissolution rate. The presence of the siderophore desferrioxamine B (a strong Mn(III)-complexing ligand) effectively decoupled the redox interactions of uranium and manganese to suppress the promotional effect of Mn(II).

View PDFchevron_right
Uraninite oxidation and dissolution induced by manganese oxide: A redox reaction between two insoluble minerals
Zimeng Wang

The longevity of subsurface U(IV) produced by reduction of U(VI) during in situ bioremediation can be limited by reoxidation to more mobile U(VI) species. Coupling of the biogeochemical cycles of U and Mn may affect the fate and transport of uranium. Manganese oxides can act as a powerful oxidant that accelerates the oxidative dissolution of UO 2 . This study investigated the physical and chemical factors controlling the interaction between UO 2 and MnO 2 , which are both poorly soluble minerals. A multi-chamber reactor with a permeable membrane was used to eliminate direct contact of the two minerals while still allowing transport of aqueous species. The oxidation of UO 2 was not significantly enhanced by MnO 2 if the two solids were physically separated. Complete mixing of MnO 2 with UO 2 led to a much greater extent and rate of U oxidation. When direct contact is not possible, the reaction slowly progresses through release of soluble U(IV) with its adsorption and oxidation on MnO 2 . Continuously-stirred tank reactors (CSTRs) were used to quantify the steady-state rates of UO 2 dissolution induced by MnO 2 . MnO 2 dramatically promoted UO 2 dissolution, but the degree of promotion leveled off once the MnO 2 :UO 2 ratio exceeded a critical value. Substantial amounts of U(VI) and Mn(II) were retained on MnO 2 surfaces. The total production of Mn(II) was less than that of U(VI), indicating that the fate of Mn products and their impact on UO 2 -MnO 2 reaction kinetics were complicated and may involve formation of Mn(III) phases. At higher dissolved inorganic carbon concentrations, UO 2 oxidation by MnO 2 was faster and less U(VI) was adsorbed to MnO 2 . Such an inverse relationship suggested that U(VI) may passivate MnO 2 surfaces. A conceptual model was developed to describe the oxidation rate of UO 2 by MnO 2 . This model is potentially applicable to a broad range of water chemistry conditions and is relevant to other environmental redox processes involving two poorly soluble minerals.

View PDFchevron_right
Impact of Microbial Mn Oxidation on the Remobilization of Bioreduced U(IV)
Rizlan Bernier-latmani

Environmental Science & Technology, 2013

Effects of Mn redox cycling on the stability of bioreduced U(IV) are evaluated here. U(VI) can be biologically reduced to less soluble U(IV) species and the stimulation of biological activity to that end is a salient remediation strategy; however, the stability of these materials in the subsurface environments where they form remains unproven. Manganese oxides are capable of rapidly oxidizing U(IV) to U(VI) in mixed batch systems where the two solid phases are in direct contact. However, it is unknown whether the same oxidation would take place in a porous medium. To probe that question, U(IV) immobilized in agarose gels was exposed to conditions allowing biological Mn(II) oxidation (HEPES buffer, Mn(II), 5% O 2 and Bacillus sp. SG-1 spores). Results show the oxidation of U(IV) to U(VI) is due primarily to O 2 rather than to MnO 2. U(VI) produced is retained within the gel to a greater extent when Mn oxides are present, suggesting the formation of strong surface complexes. The implication for the long-term stability of U in a bioremediated site is that, in the absence of competing ligands, biological Mn(II) oxidation may promote the immobilization of U(VI) produced by the oxidation of U(IV).

View PDFchevron_right
Influence of Mn oxides on the reduction of uranium(VI) by the metal-reducing bacterium Shewanella putrefaciens
Martine Duff

Geochimica et Cosmochimica Acta, 2002

The potential for Mn oxides to modify the biogeochemical behavior of U during reduction by the subsurface bacterium Shewanella putrefaciens strain CN32 was investigated using synthetic Mn(III/IV) oxides (pyrolusite [␤-MnO 2 ], bixbyite [Mn 2 O 3 ] and K ϩ -birnessite [K 4 Mn 14 O 27 ⅐ 8H 2 O]). In the absence of bacteria, pyrolusite and bixbyite oxidized biogenic uraninite (UO 2 [s]) to soluble U(VI) species, with bixbyite being the most rapid oxidant. The Mn(III/IV) oxides lowered the bioreduction rate of U(VI) relative to rates in their absence or in the presence of gibbsite (Al[OH] 3 ) added as a non-redox-reactive surface. Evolved Mn(II) increased with increasing initial U(VI) concentration in the biotic experiments, indicating that valence cycling of U facilitated the reduction of Mn(III/IV). Despite an excess of the Mn oxide, 43 to 100% of the initial U was bioreduced after extended incubation. Analysis of thin sections of bacterial Mn oxide suspensions revealed that the reduced U resided in the periplasmic space of the bacterial cells. However, in the absence of Mn(III/IV) oxides, UO 2 (s) accumulated as copious fine-grained particles external to the cell. These results indicate that the presence of Mn(III/IV) oxides may impede the biological reduction of U(VI) in subsoils and sediments. However, the accumulation of U(IV) in the cell periplasm may physically protect reduced U from oxidation, promoting at least a temporal state of redox disequilibria.

View PDFchevron_right

Related topics

  • Radioactive Pollutants
  • Hydrogen-Ion Concentration

    • Cited by

    Stabilization Effects of Mn(II)-Salts on Metaschoepite in Soil under Different Water Regimes
    John H Ballard

    ACS earth and space chemistry, 2021

    ) is a product of the corrosion of depleted uranium munition and commonly found in former war zones and at military test sites. Understanding metaschoepite transformation and uranium (U) mobility is important for sustainable operation of U containing test-firing and nuclear waste disposal sites. In the present study, the stabilization effects of Mn(Ⅱ)salts on metaschoepite in soil under different water regimes (saturation and flooding) were investigated. Results indicated that the dissolution and transformation of metaschoepite were controlled by water regimes and redox processes in soil system. The concentrations of waterextractable U in the metaschoepite-amended soils after 270 days' incubation for the saturation and flooding groups were 299 and 173 mg kg -1 , respectively. The addition of Mn(II)-salts significantly retarded the releasing of U(VI) in the metaschoepite-amended soils. The U stabilization efficiency of Mn(II) were persistently > 90% during 270 days' incubation, irrespective of water regimes. The X-ray photoelectron spectroscopy results showed no detectable reduction of liberated U(VI) in the "open waterlogged" soil system, while the X-ray diffraction analyses confirmed the transformation of metaschoepite with signals of schoepites disappearing over the course of the experiment. The study highlights the potential for the use of Mn(II)-salts in practical application for in-situ stabilization of U-contaminated sites and nuclear waste disposal.

    View PDFchevron_right
    580 California St., Suite 400
    San Francisco, CA, 94104
    © 2025 Academia. All rights reserved