Reactive and Hydraulic Behavior of Granular Mixtures Composed of Zero Valent Iron

Zero valent iron (ZVI) is widely used in permeable reactive barriers (PRBs) for the remediation of contaminated groundwater. The hydraulic conductivity of ZVI can be reduced due to iron corrosion processes activated by water and its constituents including pollutants. To overcome this issue, ZVI part...

Full description

Bibliographic Details
Main Authors: Stefania Bilardi, Paolo S. Calabrò, Nicola Moraci
Format: Article
Language:English
Published: MDPI AG 2022-11-01
Series:Water
Subjects:
Online Access:https://www.mdpi.com/2073-4441/14/22/3613
_version_ 1797463796594245632
author Stefania Bilardi
Paolo S. Calabrò
Nicola Moraci
author_facet Stefania Bilardi
Paolo S. Calabrò
Nicola Moraci
author_sort Stefania Bilardi
collection DOAJ
description Zero valent iron (ZVI) is widely used in permeable reactive barriers (PRBs) for the remediation of contaminated groundwater. The hydraulic conductivity of ZVI can be reduced due to iron corrosion processes activated by water and its constituents including pollutants. To overcome this issue, ZVI particles can be mixed with granular materials that avoid a drastic reduction in the hydraulic conductivity over time. In light of the most recent studies concerning iron corrosion processes and recalling the basic principles of century-old chemistry of iron corrosion, we have revised the results of 24 long-term column tests investigating the hydraulic and reactive behavior of granular mixtures composed of ZVI and pumice or lapillus. From this analysis, we found a clear correlation between the reactive behavior, described by the retardation factor (i.e., the ratio between flow velocity and propagation velocity of the contamination front), and the hydraulic behavior, described by means of the permeability ratio of the reactive medium (i.e., the ratio between the final and initial value of hydraulic conductivity). In particular, the permeability ratio decreased with the increase in the retardation factor. Moreover, it was found that the retardation factor is a useful parameter to evaluate the influence of flow rate, contaminant concentration, and ZVI content on the reactive behavior of the granular medium.
first_indexed 2024-03-09T17:55:49Z
format Article
id doaj.art-03a7b655f97d4f15ab4dddf72acf47a1
institution Directory Open Access Journal
issn 2073-4441
language English
last_indexed 2024-03-09T17:55:49Z
publishDate 2022-11-01
publisher MDPI AG
record_format Article
series Water
spelling doaj.art-03a7b655f97d4f15ab4dddf72acf47a12023-11-24T10:20:06ZengMDPI AGWater2073-44412022-11-011422361310.3390/w14223613Reactive and Hydraulic Behavior of Granular Mixtures Composed of Zero Valent IronStefania Bilardi0Paolo S. Calabrò1Nicola Moraci2Department DICEAM, Via Graziella, Mediterranea University of Reggio Calabria, Loc. Feo di Vito, I-89122 Reggio Calabria, ItalyDepartment DICEAM, Via Graziella, Mediterranea University of Reggio Calabria, Loc. Feo di Vito, I-89122 Reggio Calabria, ItalyDepartment DICEAM, Via Graziella, Mediterranea University of Reggio Calabria, Loc. Feo di Vito, I-89122 Reggio Calabria, ItalyZero valent iron (ZVI) is widely used in permeable reactive barriers (PRBs) for the remediation of contaminated groundwater. The hydraulic conductivity of ZVI can be reduced due to iron corrosion processes activated by water and its constituents including pollutants. To overcome this issue, ZVI particles can be mixed with granular materials that avoid a drastic reduction in the hydraulic conductivity over time. In light of the most recent studies concerning iron corrosion processes and recalling the basic principles of century-old chemistry of iron corrosion, we have revised the results of 24 long-term column tests investigating the hydraulic and reactive behavior of granular mixtures composed of ZVI and pumice or lapillus. From this analysis, we found a clear correlation between the reactive behavior, described by the retardation factor (i.e., the ratio between flow velocity and propagation velocity of the contamination front), and the hydraulic behavior, described by means of the permeability ratio of the reactive medium (i.e., the ratio between the final and initial value of hydraulic conductivity). In particular, the permeability ratio decreased with the increase in the retardation factor. Moreover, it was found that the retardation factor is a useful parameter to evaluate the influence of flow rate, contaminant concentration, and ZVI content on the reactive behavior of the granular medium.https://www.mdpi.com/2073-4441/14/22/3613column testhydraulic conductivityiron corrosionpermeable reactive barriersretardation factor
spellingShingle Stefania Bilardi
Paolo S. Calabrò
Nicola Moraci
Reactive and Hydraulic Behavior of Granular Mixtures Composed of Zero Valent Iron
Water
column test
hydraulic conductivity
iron corrosion
permeable reactive barriers
retardation factor
title Reactive and Hydraulic Behavior of Granular Mixtures Composed of Zero Valent Iron
title_full Reactive and Hydraulic Behavior of Granular Mixtures Composed of Zero Valent Iron
title_fullStr Reactive and Hydraulic Behavior of Granular Mixtures Composed of Zero Valent Iron
title_full_unstemmed Reactive and Hydraulic Behavior of Granular Mixtures Composed of Zero Valent Iron
title_short Reactive and Hydraulic Behavior of Granular Mixtures Composed of Zero Valent Iron
title_sort reactive and hydraulic behavior of granular mixtures composed of zero valent iron
topic column test
hydraulic conductivity
iron corrosion
permeable reactive barriers
retardation factor
url https://www.mdpi.com/2073-4441/14/22/3613
work_keys_str_mv AT stefaniabilardi reactiveandhydraulicbehaviorofgranularmixturescomposedofzerovalentiron
AT paoloscalabro reactiveandhydraulicbehaviorofgranularmixturescomposedofzerovalentiron
AT nicolamoraci reactiveandhydraulicbehaviorofgranularmixturescomposedofzerovalentiron