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Peel HR, Balogun FO, Bowers CA, Miller CT, Obeidy CS, Polizzotto ML, Tashnia SU, Vinson DS, Duckworth OW. Towards Understanding Factors Affecting Arsenic, Chromium, and Vanadium Mobility in the Subsurface. WATER 2022; 14:3687. [PMID: 36420182 PMCID: PMC9681123 DOI: 10.3390/w14223687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Arsenic (As), chromium (Cr), and vanadium (V) are naturally occurring, redox-active elements that can become human health hazards when they are released from aquifer substrates into groundwater that may be used as domestic or irrigation source. As such, there is a need to develop incisive conceptual and quantitative models of the geochemistry and transport of potentially hazardous elements to assess risk and facilitate interventions. However, understanding the complexity and heterogeneous subsurface environment requires knowledge of solid-phase minerals, hydrologic movement, aerobic and anaerobic environments, microbial interactions, and complicated chemical kinetics. Here, we examine the relevant geochemical and hydrological information about the release and transport of potentially hazardous geogenic contaminants, specifically As, Cr, and V, as well as the potential challenges in developing a robust understanding of their behavior in the subsurface. We explore the development of geochemical models, illustrate how they can be utilized, and describe the gaps in knowledge that exist in translating subsurface conditions into numerical models, as well as provide an outlook on future research needs and developments.
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Affiliation(s)
- Hannah R. Peel
- Department of Crop and Soil Sciences, North Carolina State University, Raleigh, NC 27695, USA
| | - Fatai O. Balogun
- Department of Earth Sciences, University of Oregon, Eugene, OR 97403, USA
| | - Christopher A. Bowers
- Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Cass T. Miller
- Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Chelsea S. Obeidy
- Department of Earth Sciences, University of Oregon, Eugene, OR 97403, USA
| | | | - Sadeya U. Tashnia
- Department of Geography and Earth Sciences, University of North Carolina at Charlotte, Charlotte, NC 28223, USA
| | - David S. Vinson
- Department of Geography and Earth Sciences, University of North Carolina at Charlotte, Charlotte, NC 28223, USA
| | - Owen W. Duckworth
- Department of Crop and Soil Sciences, North Carolina State University, Raleigh, NC 27695, USA
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Weigand TM, Miller CT. Microscale modeling of nondilute flow and transport in porous medium systems. Phys Rev E 2020; 102:033104. [PMID: 33075978 DOI: 10.1103/physreve.102.033104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Accepted: 07/29/2020] [Indexed: 06/11/2023]
Abstract
Nondilute transport occurs routinely in porous medium systems. Experimental observations have revealed effects that seemingly depend upon density, viscosity, velocity, and chemical activity. Macroscale models based upon averaged behavior over many pores have been relied upon to describe such systems to date, which require parametrization of important physical phenomena in material coefficients. To advance fundamental understanding of these complex systems, we examine nondilute transport from a fundamental microscale, or pore-scale, continuum modeling perspective. We approximate the solution of a model based upon the variable-density Navier-Stokes equations and a nondilute species transport equation. Known dependencies of the densities, viscosities, chemical activity, and diffusion for a salt solution on chemical composition are included in the model. Microscale model solutions are averaged to the macroscale and compared with extant experimental observations. Investigation of the effects of various physical phenomena on the microscale velocity distribution and the observed macroscale dispersion are considered using dimensional analysis and constrained simulations. Simulation results are used to explain observed experimental results in light of underlying mechanisms. Conditions under which the various physicochemical effects investigated are important are revealed.
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Affiliation(s)
- Timothy M Weigand
- Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina 27599, USA
| | - Cass T Miller
- Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina 27599, USA
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