Modeling the Permeability Loss of Metallic Iron Water Filtration Systems |
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| Authors: | Sabine Caré Richard Crane Paolo S Calabrò Antoine Ghauch Emile Temgoua Chicgoua Noubactep |
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| Institution: | 1. Université Paris‐Est, Laboratoire Navier (UMR 8205), CNRS, ENPC, IFSTTAR, Marne‐la‐Vallée, France;2. Interface Analysis Centre, University of Bristol, Bristol, UK;3. Faculty of Engineering, Mechanics and Materials Department, Università degli Studi Mediterranea di Reggio Calabria, MECMAT, Reggio Calabria, Italy;4. Faculty of Arts and Sciences, Department of Chemistry, American University of Beirut, Beirut, Lebanon;5. Faculty of Agronomy and Agricultural Science, University of Dschang, Dschang, Cameroon;6. Angewandte Geologie, Universit?t G?ttingen, G?ttingen, Germany;7. Kultur und Nachhaltige Entwicklung CDD e.V., G?ttingen, Germany |
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| Abstract: | Over the past 30 years the literature has burgeoned with in situ approaches for groundwater remediation. Of the methods currently available, the use of metallic iron (Fe0) in permeable reactive barrier (PRB) systems is one of the most commonly applied. Despite such interest, an increasing amount of experimental and field observations have reported inconsistent Fe0 barrier operation compared to contemporary theory. In the current work, a critical review of the physical chemistry of aqueous Fe0 corrosion in porous media is presented. Subsequent implications for the design of Fe0 filtration systems are modeled. The results suggest that: (i) for the pH range of natural waters (>4.5), the high volumetric expansion of Fe0 during oxidation and precipitation dictates that Fe0 should be mixed with a non‐expansive material; (ii) naturally occurring solute precipitates have a negligible impact on permeability loss compared to Fe0 expansive corrosion; and (iii) the proliferation of H2 metabolizing bacteria may contribute to alleviate permeability loss. As a consequence, it is suggested that more emphasis must be placed on future work with regard to considering the Fe0 PRB system as a physical (size‐exclusion) water filter device. |
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| Keywords: | Deep‐bed filtration Groundwater remediation Hydraulic conductivity Zerovalent iron |
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