Effect of salinity on the dielectric properties of geological materials: implication for soil moisture detection by means of remote sensing

Lasne, Y.; Paillou, G.; Ruffie, C.; Serradilla, F.; Freeman, A.; Farr, Tom G.; McDonald, K. C.; Chapman, B.

doi:10.1109/igarss.2007.4423644

Cited by 14 publications

(15 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The characteristics of the samples are listed in Table 1, including the maximum possible amount of bound water (volume fractions) Vt, and the volume fractions of the solid phase V s , water V w , and oil V o and the porosity K P , , the water saturation coefficient K w , and the oil saturation coefficient K o . This increase in ε′ with increasing concentration of the saturating solution is characteristic of rocks saturated with water only (Lasne and al., 2008). The samples contained a small fraction V A of entrained air, which in most samples did not exceed 0.1.…”

Section: Methodsmentioning

confidence: 91%

Dielectric permittivity spectra of oil–water-saturated sandy-clayey rocks of different mineralogical compositions and relaxation properties of water in these rocks

Бобров

Миронов

Repin

2015

Russian Geology and Geophysics

View full text Add to dashboard Cite

Experimental measurements of the dielectric permittivity and equivalent conductivity of sandy-clayey samples (a mixture of river sand with bentonite or kaolin) saturated with salt-solution-diesel-fuel emulsions were performed in the frequency range from 10 kHz to 1 GHz at temperatures of 25-65 ºC. It is shown that when the content of the salt solution in the saturating fluid does not exceed 10%, the dielectric permittivity in the frequency range from 1 MHz to 1 GHz depends little on the mineral composition of the sample and on the concentration of the saturating solution. When the portion of water is 33.3% or higher, increasing the concentration of the salt solution leads to an increase in the equivalent conductivity and the real part of the complex dielectric permittivity. Using the refractive model of the complex dielectric permittivity, we have estimated the dielectric properties of bound water, which depend on temperature and the type of clay (bentonite or kaolin) in the sand-clay mixture but are independent of the water saturation and the amount of clay in the sample.

show abstract

Section: Methodsmentioning

confidence: 91%

Dielectric permittivity spectra of oil–water-saturated sandy-clayey rocks of different mineralogical compositions and relaxation properties of water in these rocks

Бобров

Миронов

Repin

2015

Russian Geology and Geophysics

View full text Add to dashboard Cite

show abstract

“…Although this model was proposed to explain the phase difference observed over saline surfaces [6], [7], [15], the radar penetration depth at C-band radar in saline soils is very low that all the radar wave-soil material interaction is likely to occur at the surface only. Laboratory and field measurements performed for various salt mixtures [14], [15] show that the typical dielectric constant at 5.5 GHz presents a real part ranging from 3.2 to 8.5 and an imaginary part ranging from 3.5 to 12.8. For a wavelength λ, the 1/e attenuation depth δ P in a material of dielectric constant ε = ε − jε is given by [24] …”

Section: Modeling Of the Copolarized Phase Differencementioning

confidence: 99%

“…In that case, (8) and (9) indicate that f pp I k and F pp I c /8π 2 should be of the same order. Making the assumption that f pp and F pp coefficients are close, and taking in addition I k (I c /8π 2 ), allows to simplify relationship (14) into Both expressions for the copolarized phase difference given by (15) and (16) only depend on the incidence angle θ and on the dielectric constant ε of the interface. Setting an incidence angle value θ = 38.5 • , we then considered three types of surfaces, whose dielectric constants at the C-band were derived in [15], and which are representative of the evaporation process from a smooth liquid surface to a rough dry surface: -smooth saline water surface with ε = 53 − 26j (θ B = 82.6 • ); -wet crystallized NaCl medium-rough surface with ε = 7 − 11j (θ B = 74.5 • ); -dry crystallized NaCl rough surface with ε = 3.2 − 3.5j (θ B = 65.3 • ).…”

Section: E Cmentioning

confidence: 99%

“…They later derived an empirical relationship between the radar backscatter coefficient and the surface roughness, in order to estimate the rate of water evaporation [1], [26]. In parallel, several laboratory experiments were conducted using soil-water-salt mixtures, in order to study the dependence of the complex dielectric constant with respect to the water and salt concentrations [14], [20]. It was shown that the soil moisture affects the real part of the dielectric constant, whereas the presence of salt dramatically increases the imaginary part of the dielectric constant.…”

mentioning

confidence: 99%

See 1 more Smart Citation

The Chott El Djerid, Tunisia: Observation and Discussion of a SAR Phase Signature Over Evaporitic Soils

Paillou¹,

Sufyar²,

Freeman³

2014

IEEE Trans. Geosci. Remote Sensing

View full text Add to dashboard Cite

The presence of water in arid regions is correlated to large evaporitic deposits, with high concentration of salts. Polarimetric synthetic aperture radar (SAR) observations over such areas show high variations for both the amplitude and phase of the backscattered copolarized signal. This is due to a large dynamic range for both surface roughness and dielectric constant parameters, between the wet and dry seasons: crystallized salt is rough and presents a low dielectric constant, whereas saline water corresponds to smooth and conductive surfaces. We observed a complete seasonal cycle over the chott El Djerid playa, in southern Tunisia, using the 5.6-GHz C-band polarimetric SAR on-board RADARSAT-2. One SAR image acquisition was performed every 24 days, from February to September 2009. In addition to expected variations in the radar backscattered power, we observed significant changes in the phase difference between horizontally and vertically polarized channels. In order to explain such a phase effect, we first considered the arguments of the Fresnel reflectivity coefficient when approaching the Brewster angle, for materials presenting a high loss tangent. A more complete analytical modeling derived from the integral equation model approach confirmed this hypothesis.

show abstract

“…At the frequency of 2.45 GHz, sodium chloride was shown to have dielectric properties higher than those of soil or sediment minerals, which also greatly increase for temperatures higher than 90 °C. This allowed a relevant increase in the dielectric constants of geological materials respect to increasing values of salinity [46,47]. Figure 4 shows the Hg residual concentration (C) in sediments after MW treatments at different irradiation times.…”

Section: Sediment Temperature Profilesmentioning

confidence: 99%

Remediation of Hg-contaminated marine sediments by simultaneous application of enhancing agents and microwave heating (MWH)

Falciglia

Malarbì

Maddalena

et al. 2017

Chemical Engineering Journal

View full text Add to dashboard Cite

This version is available at https://strathprints.strath.ac.uk/60331/ Strathprints is designed to allow users to access the research output of the University of Strathclyde. Unless otherwise explicitly stated on the manuscript, Copyright © and Moral Rights for the papers on this site are retained by the individual authors and/or other copyright owners. Please check the manuscript for details of any other licences that may have been applied. You may not engage in further distribution of the material for any profitmaking activities or any commercial gain. You may freely distribute both the url (https://strathprints.strath.ac.uk/) and the content of this paper for research or private study, educational, or not-for-profit purposes without prior permission or charge.Any correspondence concerning this service should be sent to the Strathprints administrator: strathprints@strath.ac.ukThe Strathprints institutional repository (https://strathprints.strath.ac.uk) is a digital archive of University of Strathclyde research outputs. It has been developed to disseminate open access research outputs, expose data about those outputs, and enable the management and persistent access to Strathclyde's intellectual output. AbstractThe aim of this work was to investigate Hg removal ability of a novel microwave heating (MWH) treatment for marine sediment remediation enhanced by the application of several agents, biodegradable complexing agent (methylglycinediacetic acid, MGDA), surfactant (Tween ® 80), and citric acid. Main results revealed that MWH allowed a very rapid heating (~450 °C in 7 min) of the irradiated medium. However, without the addition of enhancing agents, a maximum Hg removal of ~72% can be achieved. The application of MGDA led to a higher contaminant removal of ~87% (residual concentration = 5.4 mg kg -1 ). For the treatment including the simultaneous addition of both chelating agent and surfactant, their synergetic action and stripping processes resulted in a very high Hg removal of ~99% for an irradiation time of 7 min, corresponding to a residual concentration of 0.56 mg kg -1 , which is lower than the Italian regulatory limit of 1 mg kg -1 . The use of citric acid resulted in a shortening of the removal kinetics, which allowed the successful application of a shorter remediation time of 5 min. The observed strong passive ability of sediments to convert a microwave irradiation energy into a rapid and large temperature increase undoubtedly represents a key factor in the whole remediation process, making the studied treatment an excellent choice. Kinetic data are suitable for a preliminarily assessment of the effectiveness of clean-up activities, and as basis for future scaling-up studies on MWH of Hgcontaminated sediments.

show abstract

Effect of salinity on the dielectric properties of geological materials: implication for soil moisture detection by means of remote sensing

Cited by 14 publications

References 23 publications

Dielectric permittivity spectra of oil–water-saturated sandy-clayey rocks of different mineralogical compositions and relaxation properties of water in these rocks

Dielectric permittivity spectra of oil–water-saturated sandy-clayey rocks of different mineralogical compositions and relaxation properties of water in these rocks

The Chott El Djerid, Tunisia: Observation and Discussion of a SAR Phase Signature Over Evaporitic Soils

Remediation of Hg-contaminated marine sediments by simultaneous application of enhancing agents and microwave heating (MWH)

Contact Info

Product

Resources

About