Handle URI:
http://hdl.handle.net/10754/625121
Title:
Reactive transport of aqueous protons in porous media
Authors:
McNeece, Colin J. ( 0000-0001-5094-3689 ) ; Hesse, Marc A. ( 0000-0002-2532-3274 )
Abstract:
The sorption of protons determines the surface charge of natural media and is therefore a first-order control on contaminant transport. Significant effort has been extended to develop chemical models that quantify the sorption of protons at the mineral surface. To compare these models’ effect on predicted proton transport, we present analytic solutions for column experiments through silica sand. Reaction front morphology is controlled by the functional relationship between the total sorbed and total aqueous proton concentrations. An inflection point in this function near neutral pH leads to a reversal in the classic front formation mechanism under basic conditions, such that proton desorption leads to a self-sharpening front, while adsorption leads to a spreading front. A composite reaction front comprising both a spreading and self-sharpening segment can occur when the injected and initial concentrations straddle the inflection point. This behavior is unique in single component reactive transport and arises due to the auto-ionization of water rather than electrostatic interactions at the mineral surface. We derive a regime diagram illustrating conditions under which different fronts occur, highlighting areas where model predictions diverge. Chemical models are then compared and validated against a systematic set of column experiments.
Citation:
McNeece CJ, Hesse MA (2016) Reactive transport of aqueous protons in porous media. Advances in Water Resources 97: 314–325. Available: http://dx.doi.org/10.1016/j.advwatres.2016.09.013.
Publisher:
Elsevier BV
Journal:
Advances in Water Resources
Issue Date:
9-Oct-2016
DOI:
10.1016/j.advwatres.2016.09.013
Type:
Article
ISSN:
0309-1708
Sponsors:
This work was supported in part by an Academic Excellence Alliance program award from King Abdullah University of Science and Technology (KAUST) Global Collaborative Research under the title “Simulation of Subsurface Geochemical Transport and Carbon Sequestration”. This work is also funded as part of the Center for Frontiers of Subsurface Energy Security, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences under Award #DE-SC0001114.
Appears in Collections:
Publications Acknowledging KAUST Support

Full metadata record

DC FieldValue Language
dc.contributor.authorMcNeece, Colin J.en
dc.contributor.authorHesse, Marc A.en
dc.date.accessioned2017-06-21T06:51:52Z-
dc.date.available2017-06-21T06:51:52Z-
dc.date.issued2016-10-09en
dc.identifier.citationMcNeece CJ, Hesse MA (2016) Reactive transport of aqueous protons in porous media. Advances in Water Resources 97: 314–325. Available: http://dx.doi.org/10.1016/j.advwatres.2016.09.013.en
dc.identifier.issn0309-1708en
dc.identifier.doi10.1016/j.advwatres.2016.09.013en
dc.identifier.urihttp://hdl.handle.net/10754/625121-
dc.description.abstractThe sorption of protons determines the surface charge of natural media and is therefore a first-order control on contaminant transport. Significant effort has been extended to develop chemical models that quantify the sorption of protons at the mineral surface. To compare these models’ effect on predicted proton transport, we present analytic solutions for column experiments through silica sand. Reaction front morphology is controlled by the functional relationship between the total sorbed and total aqueous proton concentrations. An inflection point in this function near neutral pH leads to a reversal in the classic front formation mechanism under basic conditions, such that proton desorption leads to a self-sharpening front, while adsorption leads to a spreading front. A composite reaction front comprising both a spreading and self-sharpening segment can occur when the injected and initial concentrations straddle the inflection point. This behavior is unique in single component reactive transport and arises due to the auto-ionization of water rather than electrostatic interactions at the mineral surface. We derive a regime diagram illustrating conditions under which different fronts occur, highlighting areas where model predictions diverge. Chemical models are then compared and validated against a systematic set of column experiments.en
dc.description.sponsorshipThis work was supported in part by an Academic Excellence Alliance program award from King Abdullah University of Science and Technology (KAUST) Global Collaborative Research under the title “Simulation of Subsurface Geochemical Transport and Carbon Sequestration”. This work is also funded as part of the Center for Frontiers of Subsurface Energy Security, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences under Award #DE-SC0001114.en
dc.publisherElsevier BVen
dc.subjectAcid-base chemistryen
dc.subjectChromatographyen
dc.subjectPorous mediaen
dc.subjectReactive transporten
dc.subjectSurface complexationen
dc.titleReactive transport of aqueous protons in porous mediaen
dc.typeArticleen
dc.identifier.journalAdvances in Water Resourcesen
dc.contributor.institutionThe University of Texas at Austin, Department of Geological Sciences, 2275 Speedway Stop C9000, Austin, TX, 78712-1722, , United Statesen
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