A soil non-aqueous phase liquid (NAPL) flushing laboratory experiment based on measuring the dielectric properties of soil–organic mixtures via time domain reflectometry (TDR)

<p>The term non-aqueous phase liquid (NAPL) refers to a group of organic compounds with scarce solubility in water. They are the products of various human activities and may be accidentally introduced into the soil system. Given their toxicity level and high mobility, NAPLs constitute a seriou...

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Main Authors: A. Comegna, A. Coppola, G. Dragonetti, A. Sommella
Format: Article
Language:English
Published: Copernicus Publications 2019-09-01
Series:Hydrology and Earth System Sciences
Online Access:https://www.hydrol-earth-syst-sci.net/23/3593/2019/hess-23-3593-2019.pdf
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spelling doaj-1a222a4131c74a9786e3004ce3f942e42020-11-24T21:56:54ZengCopernicus PublicationsHydrology and Earth System Sciences1027-56061607-79382019-09-01233593360210.5194/hess-23-3593-2019A soil non-aqueous phase liquid (NAPL) flushing laboratory experiment based on measuring the dielectric properties of soil–organic mixtures via time domain reflectometry (TDR)A. Comegna0A. Coppola1G. Dragonetti2A. Sommella3School of Agricultural Forestry, Food, and Environmental Sciences (SAFE), University of Basilicata, Potenza, ItalySchool of Agricultural Forestry, Food, and Environmental Sciences (SAFE), University of Basilicata, Potenza, ItalyMediterranean Agronomic Institute, Land and Water Division, IAMB, Bari, ItalyDepartment of Agriculture, University of Naples Federico II, Naples, Italy<p>The term non-aqueous phase liquid (NAPL) refers to a group of organic compounds with scarce solubility in water. They are the products of various human activities and may be accidentally introduced into the soil system. Given their toxicity level and high mobility, NAPLs constitute a serious geo-environmental problem. Contaminant distribution in the soil and groundwater contains fundamental information for the remediation of polluted soil sites. The present research explored the possible employment of time domain reflectometry (TDR) to estimate pollutant removal in a silt-loam soil that was primarily contaminated with a corn oil as a light NAPL and then flushed with different washing solutions. Known mixtures of soil and NAPL were prepared in the laboratory to achieve soil specimens with varying pollution levels. The prepared soil samples were repacked into plastic cylinders and then placed in testing cells. Washing solutions were then injected upward into the contaminated sample, and both the quantity of remediated NAPL and the bulk dielectric permittivity of the soil sample were determined. The above data were also used to calibrate and validate a dielectric model (the <span class="inline-formula"><i>α</i></span> mixing model) which permits the volumetric NAPL content (<span class="inline-formula"><i>θ</i><sub>NAPL</sub></span>; m<span class="inline-formula"><sup>3</sup></span>&thinsp;m<span class="inline-formula"><sup>−3</sup></span>) within the contaminated sample to be determined and quantified during the different decontamination stages. Our results demonstrate that during a decontamination process, the TDR device is NAPL-sensitive: the dielectric permittivity of the medium increases as the NAPL volume decreases. Moreover, decontamination progression can be monitored using a simple (one-parameter) mixing model.</p>https://www.hydrol-earth-syst-sci.net/23/3593/2019/hess-23-3593-2019.pdf
collection DOAJ
language English
format Article
sources DOAJ
author A. Comegna
A. Coppola
G. Dragonetti
A. Sommella
spellingShingle A. Comegna
A. Coppola
G. Dragonetti
A. Sommella
A soil non-aqueous phase liquid (NAPL) flushing laboratory experiment based on measuring the dielectric properties of soil–organic mixtures via time domain reflectometry (TDR)
Hydrology and Earth System Sciences
author_facet A. Comegna
A. Coppola
G. Dragonetti
A. Sommella
author_sort A. Comegna
title A soil non-aqueous phase liquid (NAPL) flushing laboratory experiment based on measuring the dielectric properties of soil–organic mixtures via time domain reflectometry (TDR)
title_short A soil non-aqueous phase liquid (NAPL) flushing laboratory experiment based on measuring the dielectric properties of soil–organic mixtures via time domain reflectometry (TDR)
title_full A soil non-aqueous phase liquid (NAPL) flushing laboratory experiment based on measuring the dielectric properties of soil–organic mixtures via time domain reflectometry (TDR)
title_fullStr A soil non-aqueous phase liquid (NAPL) flushing laboratory experiment based on measuring the dielectric properties of soil–organic mixtures via time domain reflectometry (TDR)
title_full_unstemmed A soil non-aqueous phase liquid (NAPL) flushing laboratory experiment based on measuring the dielectric properties of soil–organic mixtures via time domain reflectometry (TDR)
title_sort soil non-aqueous phase liquid (napl) flushing laboratory experiment based on measuring the dielectric properties of soil–organic mixtures via time domain reflectometry (tdr)
publisher Copernicus Publications
series Hydrology and Earth System Sciences
issn 1027-5606
1607-7938
publishDate 2019-09-01
description <p>The term non-aqueous phase liquid (NAPL) refers to a group of organic compounds with scarce solubility in water. They are the products of various human activities and may be accidentally introduced into the soil system. Given their toxicity level and high mobility, NAPLs constitute a serious geo-environmental problem. Contaminant distribution in the soil and groundwater contains fundamental information for the remediation of polluted soil sites. The present research explored the possible employment of time domain reflectometry (TDR) to estimate pollutant removal in a silt-loam soil that was primarily contaminated with a corn oil as a light NAPL and then flushed with different washing solutions. Known mixtures of soil and NAPL were prepared in the laboratory to achieve soil specimens with varying pollution levels. The prepared soil samples were repacked into plastic cylinders and then placed in testing cells. Washing solutions were then injected upward into the contaminated sample, and both the quantity of remediated NAPL and the bulk dielectric permittivity of the soil sample were determined. The above data were also used to calibrate and validate a dielectric model (the <span class="inline-formula"><i>α</i></span> mixing model) which permits the volumetric NAPL content (<span class="inline-formula"><i>θ</i><sub>NAPL</sub></span>; m<span class="inline-formula"><sup>3</sup></span>&thinsp;m<span class="inline-formula"><sup>−3</sup></span>) within the contaminated sample to be determined and quantified during the different decontamination stages. Our results demonstrate that during a decontamination process, the TDR device is NAPL-sensitive: the dielectric permittivity of the medium increases as the NAPL volume decreases. Moreover, decontamination progression can be monitored using a simple (one-parameter) mixing model.</p>
url https://www.hydrol-earth-syst-sci.net/23/3593/2019/hess-23-3593-2019.pdf
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