Governing Constraints of Chromium(VI) Formation from Chromium(III)-Bearing Minerals in Soils and Sediments

Hausladen, Debra; Fakhreddine, Sarah; Fendorf, Scott

doi:10.3390/soilsystems3040074

Title: Governing Constraints of Chromium(VI) Formation from Chromium(III)-Bearing Minerals in Soils and Sediments

Abstract

The potential for geogenic Cr(VI) contamination is vast, yet it is difficult to predict susceptible environments as groundwater Cr(VI) concentrations vary significantly, even within a given aquifer, due to physical and hydrologic heterogeneity. The physical structure of soils and sediments exerts a dominant control on Cr(VI) production by dictating the separation distance of reactive phases, the diffusion distance from Cr(VI) generation sites to advecting groundwater, and by influencing infiltration rates and porewater velocity. Here, we used a dual-pore domain model to investigate the relative control of these parameters on Cr(VI) production. The reaction distance between Cr(III)-bearing minerals and Mn oxides predominantly controls Cr(VI) export to advecting groundwater, while changes in diffusion distance between sites of Cr(VI) generation and advective flow channels generally have little impact on steady-state Cr(VI) concentrations. Changes in Cr(VI) diffusion distance can, however, increase the time required for groundwater Cr(VI) concentrations to reach a steady-state; thus, under fluctuating hydrologic and biogeochemical conditions, long diffusion distances still have the potential to suppress Cr(VI) supply to advecting water. Furthermore, we show that high porewater flow velocities effectively dilute Cr(VI) diffusing from soil/sediment aggregates, thus minimizing Cr(VI) concentrations relative to lower porewater velocities. The strong control that the physical/hydrologic parametersmore »« less

Authors:

; Fakhreddine, Sarah; Fendorf, Scott

Publication Date:: 2019-11-13

Sponsoring Org.:: USDOE

OSTI Identifier:: 1574078

Grant/Contract Number:: Contract No. DE-AC02-76SF00515

Resource Type:: Published Article

Journal Name:: Soil Systems

Additional Journal Information:: Journal Name: Soil Systems Journal Volume: 3 Journal Issue: 4; Journal ID: ISSN 2571-8789

Publisher:: MDPI AG

Country of Publication:: Netherlands

Language:: English

Citation Formats


                    Hausladen, Debra, Fakhreddine, Sarah, and Fendorf, Scott. Governing Constraints of Chromium(VI) Formation from Chromium(III)-Bearing Minerals in Soils and Sediments.  Netherlands: N. p., 2019. 
Web.  doi:10.3390/soilsystems3040074.

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                    Hausladen, Debra, Fakhreddine, Sarah, & Fendorf, Scott. Governing Constraints of Chromium(VI) Formation from Chromium(III)-Bearing Minerals in Soils and Sediments.  Netherlands.  https://doi.org/10.3390/soilsystems3040074

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                    Hausladen, Debra, Fakhreddine, Sarah, and Fendorf, Scott. Wed .  
"Governing Constraints of Chromium(VI) Formation from Chromium(III)-Bearing Minerals in Soils and Sediments".  Netherlands.  https://doi.org/10.3390/soilsystems3040074.

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@article{osti_1574078,

  title        = {Governing Constraints of Chromium(VI) Formation from Chromium(III)-Bearing Minerals in Soils and Sediments},

  author       = {Hausladen, Debra and Fakhreddine, Sarah and Fendorf, Scott},

  abstractNote = {The potential for geogenic Cr(VI) contamination is vast, yet it is difficult to predict susceptible environments as groundwater Cr(VI) concentrations vary significantly, even within a given aquifer, due to physical and hydrologic heterogeneity. The physical structure of soils and sediments exerts a dominant control on Cr(VI) production by dictating the separation distance of reactive phases, the diffusion distance from Cr(VI) generation sites to advecting groundwater, and by influencing infiltration rates and porewater velocity. Here, we used a dual-pore domain model to investigate the relative control of these parameters on Cr(VI) production. The reaction distance between Cr(III)-bearing minerals and Mn oxides predominantly controls Cr(VI) export to advecting groundwater, while changes in diffusion distance between sites of Cr(VI) generation and advective flow channels generally have little impact on steady-state Cr(VI) concentrations. Changes in Cr(VI) diffusion distance can, however, increase the time required for groundwater Cr(VI) concentrations to reach a steady-state; thus, under fluctuating hydrologic and biogeochemical conditions, long diffusion distances still have the potential to suppress Cr(VI) supply to advecting water. Furthermore, we show that high porewater flow velocities effectively dilute Cr(VI) diffusing from soil/sediment aggregates, thus minimizing Cr(VI) concentrations relative to lower porewater velocities. The strong control that the physical/hydrologic parameters exert on Cr(VI) production appears to overwhelm the impact of Cr(III)-mineral solubility within soils and sediments.},

  doi          = {10.3390/soilsystems3040074},

  journal      = {Soil Systems},

  number       = 4,

  volume       = 3,

  place        = {Netherlands},

  year         = {2019},

  month        = {11}

}

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Works referenced in this record:

Hexavalent Chromium in the Ground Water in Paradise Valley, Arizona
journal, November 1975

Robertson, Frederick N.
Ground Water, Vol. 13, Issue 6
DOI: 10.1111/j.1745-6584.1975.tb03621.x

Rates of Cr(VI) Generation from Cr _x Fe _{1– x} (OH) ₃ Solids upon Reaction with Manganese Oxide
journal, October 2017

Pan, Chao; Liu, Huan; Catalano, Jeffrey G.
Environmental Science & Technology, Vol. 51, Issue 21
DOI: 10.1021/acs.est.7b04097

Inhibitory mechanisms of Cr(III) oxidation by δ-MnO2
journal, October 1992

Fendorf, Scott E.; Fendorf, Mark; Sparks, Donald L.
Journal of Colloid and Interface Science, Vol. 153, Issue 1
DOI: 10.1016/0021-9797(92)90296-X

Chromium Geochemistry of Serpentine Soils
journal, February 2004

Oze, Christopher; Fendorf, Scott; Bird, Dennis K.
International Geology Review, Vol. 46, Issue 2
DOI: 10.2747/0020-6814.46.2.97

The fate of chromium during tropical weathering: A laterite profile from Central Madagascar
journal, January 2014

Berger, Alfons; Frei, Robert
Geoderma, Vol. 213
DOI: 10.1016/j.geoderma.2013.09.004

Chromium(III) oxidation by .delta.-manganese oxide (MnO2). 1. Characterization
journal, January 1992

Fendorf, Scott E.; Zasoski, Robert J.
Environmental Science & Technology, Vol. 26, Issue 1
DOI: 10.1021/es00025a006

Pedogenesis in a wetland meadow and surrounding serpentinitic landslide terrain, northern California, USA
journal, February 2004

Lee, Brad D.; Graham, Robert C.; Laurent, Thomas E.
Geoderma, Vol. 118, Issue 3-4
DOI: 10.1016/S0016-7061(03)00214-3

A regional-scale study of chromium and nickel in soils of northern California, USA
journal, August 2009

Morrison, Jean M.; Goldhaber, Martin B.; Lee, Lopaka
Applied Geochemistry, Vol. 24, Issue 8
DOI: 10.1016/j.apgeochem.2009.04.027

Cr(VI) occurrence and geochemistry in water from public-supply wells in California
journal, December 2015

Izbicki, John A.; Wright, Michael T.; Seymour, Whitney A.
Applied Geochemistry, Vol. 63
DOI: 10.1016/j.apgeochem.2015.08.007

Chromium, chromium isotopes and selected trace elements, western Mojave Desert, USA
journal, May 2008

Izbicki, John A.; Ball, James W.; Bullen, Thomas D.
Applied Geochemistry, Vol. 23, Issue 5
DOI: 10.1016/j.apgeochem.2007.11.015

Delta Chromium-53/52 isotopic composition of native and contaminated groundwater, Mojave Desert, USA
journal, April 2012

Izbicki, John A.; Bullen, Thomas D.; Martin, Peter
Applied Geochemistry, Vol. 27, Issue 4
DOI: 10.1016/j.apgeochem.2011.12.019

Chromium(III) Hydroxide Solubility in the Aqueous K+-H+-OH−-CO2-HCO 3 − -CO 3 2− -H2O System: A Thermodynamic Model
journal, September 2007

Rai, Dhanpat; Moore, Dean A.; Hess, Nancy J.
Journal of Solution Chemistry, Vol. 36, Issue 10
DOI: 10.1007/s10953-007-9179-5

Cr(OH) ₃ (s) Oxidation Induced by Surface Catalyzed Mn(II) Oxidation
journal, August 2014

Namgung, Seonyi; Kwon, Man Jae; Qafoku, Nikolla P.
Environmental Science & Technology, Vol. 48, Issue 18
DOI: 10.1021/es503018u

Manganese-rich olivines: Identification from spectral reflectance properties
journal, November 1997

Cloutis, Edward A.
Journal of Geophysical Research: Planets, Vol. 102, Issue E11
DOI: 10.1029/97JE02497

Can chromite weathering be a source of Cr in soils?
journal, February 2008

Garnier, J.; Quantin, C.; Guimarães, E.
Mineralogical Magazine, Vol. 72, Issue 1
DOI: 10.1180/minmag.2008.072.1.49

Chromium(VI) generation in vadose zone soils and alluvial sediments of the southwestern Sacramento Valley, California: A potential source of geogenic Cr(VI) to groundwater
journal, August 2011

Mills, Christopher T.; Morrison, Jean M.; Goldhaber, Martin B.
Applied Geochemistry, Vol. 26, Issue 8
DOI: 10.1016/j.apgeochem.2011.05.023

Genesis of hexavalent chromium from natural sources in soil and groundwater
journal, April 2007

Oze, C.; Bird, D. K.; Fendorf, S.
Proceedings of the National Academy of Sciences, Vol. 104, Issue 16
DOI: 10.1073/pnas.0701085104

Trace metals distribution from a serpentinite weathering at the scales of the weathering profile and its related weathering microsystems and clay minerals
journal, March 2009

Caillaud, J.; Proust, D.; Philippe, S.
Geoderma, Vol. 149, Issue 3-4
DOI: 10.1016/j.geoderma.2008.11.031

Quantifying Cr(VI) Production and Export from Serpentine Soil of the California Coast Range
journal, December 2016

McClain, Cynthia N.; Fendorf, Scott; Webb, Samuel M.
Environmental Science & Technology, Vol. 51, Issue 1
DOI: 10.1021/acs.est.6b03484

Hexavalent Chromium Sources and Distribution in California Groundwater
journal, June 2018

Hausladen, Debra M.; Alexander-Ozinskas, Annika; McClain, Cynthia
Environmental Science & Technology, Vol. 52, Issue 15
DOI: 10.1021/acs.est.7b06627

Solid speciation and availability of chromium in ultramafic soils from Niquelândia, Brazil
journal, January 2006

Garnier, J.; Quantin, C.; Martins, E. S.
Journal of Geochemical Exploration, Vol. 88, Issue 1-3
DOI: 10.1016/j.gexplo.2005.08.040

Chromium availability in ultramafic soils from New Caledonia
journal, January 2003

Becquer, T.; Quantin, C.; Sicot, M.
Science of The Total Environment, Vol. 301, Issue 1-3
DOI: 10.1016/S0048-9697(02)00298-X

XANES Evidence for Oxidation of Cr(III) to Cr(VI) by Mn-Oxides in a Lateritic Regolith Developed on Serpentinized Ultramafic Rocks of New Caledonia
journal, October 2009

Fandeur, Dik; Juillot, Farid; Morin, Guillaume
Environmental Science & Technology, Vol. 43, Issue 19
DOI: 10.1021/es900498r

Distributed microbially- and chemically-mediated redox processes controlling arsenic dynamics within Mn-/Fe-oxide constructed aggregates
journal, March 2013

Ying, Samantha C.; Masue-Slowey, Yoko; Kocar, Benjamin D.
Geochimica et Cosmochimica Acta, Vol. 104
DOI: 10.1016/j.gca.2012.08.020

Insights into controls on hexavalent chromium in groundwater provided by environmental tracers, Sacramento Valley, California, USA
journal, November 2015

Manning, Andrew H.; Mills, Christopher T.; Morrison, Jean M.
Applied Geochemistry, Vol. 62
DOI: 10.1016/j.apgeochem.2015.05.010

Understanding the Roles of Dissolution and Diffusion in Cr(OH) ₃ Oxidation by δ-MnO ₂
journal, January 2019

Pan, Chao; Liu, Huan; Catalano, Jeffrey G.
ACS Earth and Space Chemistry, Vol. 3, Issue 3
DOI: 10.1021/acsearthspacechem.8b00129

Geogenic Cr oxidation on the surface of mafic minerals and the hydrogeological conditions influencing hexavalent chromium concentrations in groundwater
journal, May 2015

Kazakis, N.; Kantiranis, N.; Voudouris, K. S.
Science of The Total Environment, Vol. 514
DOI: 10.1016/j.scitotenv.2015.01.080

Occurrence of hexavalent chromium in ground water in the western Mojave Desert, California
journal, July 2004

Ball, James W.; Izbicki, J. A.
Applied Geochemistry, Vol. 19, Issue 7
DOI: 10.1016/j.apgeochem.2004.01.011

Cr(VI) genesis and dynamics in Ferralsols developed from ultramafic rocks: The case of Niquelândia, Brazil
journal, February 2013

Garnier, Jérémie; Quantin, Cécile; Guimarães, Edi Mendes
Geoderma, Vol. 193-194
DOI: 10.1016/j.geoderma.2012.08.031

Hexavalent Chromium Generation within Naturally Structured Soils and Sediments
journal, February 2017

Hausladen, Debra M.; Fendorf, Scott
Environmental Science & Technology, Vol. 51, Issue 4
DOI: 10.1021/acs.est.6b04039

Properties of iron oxides in some new caledonian oxisols
journal, December 1986

Schwertmann, U.; Latham, M.
Geoderma, Vol. 39, Issue 2
DOI: 10.1016/0016-7061(86)90070-4

Fungal oxidative dissolution of the Mn(II)-bearing mineral rhodochrosite and the role of metabolites in manganese oxide formation: Dissolution and oxidation of rhodochrosite by fungi
journal, November 2012

Tang, Yuanzhi; Zeiner, Carolyn A.; Santelli, Cara M.
Environmental Microbiology, Vol. 15, Issue 4
DOI: 10.1111/1462-2920.12029

BIOGENIC MANGANESE OXIDES: Properties and Mechanisms of Formation
journal, May 2004

Tebo, Bradley M.; Bargar, John R.; Clement, Brian G.
Annual Review of Earth and Planetary Sciences, Vol. 32, Issue 1
DOI: 10.1146/annurev.earth.32.101802.120213

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Title: Governing Constraints of Chromium(VI) Formation from Chromium(III)-Bearing Minerals in Soils and Sediments

Abstract

Citation Formats

Hexavalent Chromium in the Ground Water in Paradise Valley, Arizona journal, November 1975

Rates of Cr(VI) Generation from Cr x Fe 1– x (OH) 3 Solids upon Reaction with Manganese Oxide journal, October 2017

Inhibitory mechanisms of Cr(III) oxidation by δ-MnO2 journal, October 1992

Chromium Geochemistry of Serpentine Soils journal, February 2004

The fate of chromium during tropical weathering: A laterite profile from Central Madagascar journal, January 2014

Chromium(III) oxidation by .delta.-manganese oxide (MnO2). 1. Characterization journal, January 1992

Pedogenesis in a wetland meadow and surrounding serpentinitic landslide terrain, northern California, USA journal, February 2004

A regional-scale study of chromium and nickel in soils of northern California, USA journal, August 2009

Cr(VI) occurrence and geochemistry in water from public-supply wells in California journal, December 2015

Chromium, chromium isotopes and selected trace elements, western Mojave Desert, USA journal, May 2008

Delta Chromium-53/52 isotopic composition of native and contaminated groundwater, Mojave Desert, USA journal, April 2012

Chromium(III) Hydroxide Solubility in the Aqueous K+-H+-OH−-CO2-HCO 3 − -CO 3 2− -H2O System: A Thermodynamic Model journal, September 2007

Cr(OH) 3 (s) Oxidation Induced by Surface Catalyzed Mn(II) Oxidation journal, August 2014

Manganese-rich olivines: Identification from spectral reflectance properties journal, November 1997

Can chromite weathering be a source of Cr in soils? journal, February 2008

Chromium(VI) generation in vadose zone soils and alluvial sediments of the southwestern Sacramento Valley, California: A potential source of geogenic Cr(VI) to groundwater journal, August 2011

Genesis of hexavalent chromium from natural sources in soil and groundwater journal, April 2007

Trace metals distribution from a serpentinite weathering at the scales of the weathering profile and its related weathering microsystems and clay minerals journal, March 2009

Quantifying Cr(VI) Production and Export from Serpentine Soil of the California Coast Range journal, December 2016

Hexavalent Chromium Sources and Distribution in California Groundwater journal, June 2018

Solid speciation and availability of chromium in ultramafic soils from Niquelândia, Brazil journal, January 2006

Chromium availability in ultramafic soils from New Caledonia journal, January 2003

XANES Evidence for Oxidation of Cr(III) to Cr(VI) by Mn-Oxides in a Lateritic Regolith Developed on Serpentinized Ultramafic Rocks of New Caledonia journal, October 2009

Distributed microbially- and chemically-mediated redox processes controlling arsenic dynamics within Mn-/Fe-oxide constructed aggregates journal, March 2013

Insights into controls on hexavalent chromium in groundwater provided by environmental tracers, Sacramento Valley, California, USA journal, November 2015

Understanding the Roles of Dissolution and Diffusion in Cr(OH) 3 Oxidation by δ-MnO 2 journal, January 2019

Geogenic Cr oxidation on the surface of mafic minerals and the hydrogeological conditions influencing hexavalent chromium concentrations in groundwater journal, May 2015

Occurrence of hexavalent chromium in ground water in the western Mojave Desert, California journal, July 2004

Cr(VI) genesis and dynamics in Ferralsols developed from ultramafic rocks: The case of Niquelândia, Brazil journal, February 2013

Hexavalent Chromium Generation within Naturally Structured Soils and Sediments journal, February 2017

Properties of iron oxides in some new caledonian oxisols journal, December 1986

Fungal oxidative dissolution of the Mn(II)-bearing mineral rhodochrosite and the role of metabolites in manganese oxide formation: Dissolution and oxidation of rhodochrosite by fungi journal, November 2012

BIOGENIC MANGANESE OXIDES: Properties and Mechanisms of Formation journal, May 2004

Hexavalent Chromium in the Ground Water in Paradise Valley, Arizona
journal, November 1975

Rates of Cr(VI) Generation from Cr _x Fe _{1– x} (OH) ₃ Solids upon Reaction with Manganese Oxide
journal, October 2017

Inhibitory mechanisms of Cr(III) oxidation by δ-MnO2
journal, October 1992

Chromium Geochemistry of Serpentine Soils
journal, February 2004

The fate of chromium during tropical weathering: A laterite profile from Central Madagascar
journal, January 2014

Chromium(III) oxidation by .delta.-manganese oxide (MnO2). 1. Characterization
journal, January 1992

Pedogenesis in a wetland meadow and surrounding serpentinitic landslide terrain, northern California, USA
journal, February 2004

A regional-scale study of chromium and nickel in soils of northern California, USA
journal, August 2009

Cr(VI) occurrence and geochemistry in water from public-supply wells in California
journal, December 2015

Chromium, chromium isotopes and selected trace elements, western Mojave Desert, USA
journal, May 2008

Delta Chromium-53/52 isotopic composition of native and contaminated groundwater, Mojave Desert, USA
journal, April 2012

Chromium(III) Hydroxide Solubility in the Aqueous K+-H+-OH−-CO2-HCO 3 − -CO 3 2− -H2O System: A Thermodynamic Model
journal, September 2007

Cr(OH) ₃ (s) Oxidation Induced by Surface Catalyzed Mn(II) Oxidation
journal, August 2014

Manganese-rich olivines: Identification from spectral reflectance properties
journal, November 1997

Can chromite weathering be a source of Cr in soils?
journal, February 2008

Chromium(VI) generation in vadose zone soils and alluvial sediments of the southwestern Sacramento Valley, California: A potential source of geogenic Cr(VI) to groundwater
journal, August 2011

Genesis of hexavalent chromium from natural sources in soil and groundwater
journal, April 2007

Trace metals distribution from a serpentinite weathering at the scales of the weathering profile and its related weathering microsystems and clay minerals
journal, March 2009

Quantifying Cr(VI) Production and Export from Serpentine Soil of the California Coast Range
journal, December 2016

Hexavalent Chromium Sources and Distribution in California Groundwater
journal, June 2018

Solid speciation and availability of chromium in ultramafic soils from Niquelândia, Brazil
journal, January 2006

Chromium availability in ultramafic soils from New Caledonia
journal, January 2003

XANES Evidence for Oxidation of Cr(III) to Cr(VI) by Mn-Oxides in a Lateritic Regolith Developed on Serpentinized Ultramafic Rocks of New Caledonia
journal, October 2009

Distributed microbially- and chemically-mediated redox processes controlling arsenic dynamics within Mn-/Fe-oxide constructed aggregates
journal, March 2013

Insights into controls on hexavalent chromium in groundwater provided by environmental tracers, Sacramento Valley, California, USA
journal, November 2015

Understanding the Roles of Dissolution and Diffusion in Cr(OH) ₃ Oxidation by δ-MnO ₂
journal, January 2019

Geogenic Cr oxidation on the surface of mafic minerals and the hydrogeological conditions influencing hexavalent chromium concentrations in groundwater
journal, May 2015

Occurrence of hexavalent chromium in ground water in the western Mojave Desert, California
journal, July 2004

Cr(VI) genesis and dynamics in Ferralsols developed from ultramafic rocks: The case of Niquelândia, Brazil
journal, February 2013

Hexavalent Chromium Generation within Naturally Structured Soils and Sediments
journal, February 2017

Properties of iron oxides in some new caledonian oxisols
journal, December 1986

Fungal oxidative dissolution of the Mn(II)-bearing mineral rhodochrosite and the role of metabolites in manganese oxide formation: Dissolution and oxidation of rhodochrosite by fungi
journal, November 2012

BIOGENIC MANGANESE OXIDES: Properties and Mechanisms of Formation
journal, May 2004