Investigation of chlorinated solvent pollution with resistivity and induced polarization

Sparrenbom, Charlotte; Åkesson, Sofia; Johansson, Sara; Hagerberg, David; Dahlin, Torleif

doi:10.1016/j.scitotenv.2016.09.117

Cited by 28 publications

(13 citation statements)

References 21 publications

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“…Properties like electrical resistivity, chargeability and dielectric constant are parameters correlated with hydrogeological and geochemical aspects and, therefore, they are widely applied to environmental investigations [15][16][17][18], groundwater contamination studies [19][20][21], generation of leaching in uncontrolled landfills [22][23][24] and generation of acid mine drainage [14,25,26].…”

Section: Introductionmentioning

confidence: 99%

Structural analysis and geophysical survey for hydrogeological diagnosis in uranium mine, Poços de Caldas (Brazil)

et al. 2019

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The implementation of open pit mines promotes alterations on geological and hydrogeological processes, mainly on natural streamflow patterns. Drainage system tries to reach its equilibrium due to modification on slope profiling water flows through new pathways contributing to erosion and leaching processes. One of the impacts related to mining is the generation of acid mine drainage (AMD), which occurs as a product of sulfide minerals exposure to oxidizing environment and, in contact to water, favors the formation of sulfuric acid. Thus, a low pH promotes a higher mobility of heavy metals and radionuclides, which become a source of contamination. In order to understand the hydrogeological dynamic in rock masses that contribute to AMD production, this paper aimed to subsidize mitigation programs in fractured aquifers using a structural analysis and geophysical survey for the reduction of acid drainage generation. The study was carried at the four mining fronts that compose the mine pit of Osamu Utsumi Mine, named according to its cardinal position (NE, SE, SW and NW). Local structural survey indicated that fractures attitudes are mainly N20E/80NW and N55 W/75NE, with intersections between them. Evidence of water flows, like whitish kaolinite stains and small vegetation growth, was identified in fronts NE, SW and NW, in addition to water springs at the base of the slopes. The flows arise mainly in areas that coincide to intersection between fracture systems in an orthogonal arrangement and the fracturing pattern indicated that at all fronts most of the fracture planes project into the open pit area, which favor the water channeling to the center of the mine as a water catchment basin. Moreover, the relationship between the persistence and spacing among the discontinuities enables a good hydraulic conductivity within the rock masses and the water upwelling on the slopes surface. The geophysical data corroborated with the structural survey, which identified the fracture planes as linear structures associated with low resistivity zones. DC resistivity method showed a strong contrast between saturated zones, differing natural from acidic water. Delimitation of linear features in the inversion models indicated that water flows are channeled through fracture planes and promote an expressive weathering process inside the rock masses, observed at depths of up to 70 m.

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Section: Introductionmentioning

confidence: 99%

Structural analysis and geophysical survey for hydrogeological diagnosis in uranium mine, Poços de Caldas (Brazil)

et al. 2019

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“…As nonintrusive and low-cost investigation approaches, geophysical methods have been used to provide additional information for SZA characterization. For example, researchers have applied electrical resistivity tomography (ERT) to roughly map the SZA (e.g., Aghasi et al, 2013;Chambers et al, 2010Chambers et al, , 2004Deng et al, 2017;Johansson et al, 2015;Kang et al, 2018;Power et al, 2015Power et al, , 2014Sparrenbom et al, 2017), due to the high sensitivity of electrical properties to NAPL content. Nevertheless, geophysical methods cannot provide an accurate DNAPL image on their own due to their lower resolution.…”

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confidence: 99%

Hydrogeophysical Characterization of Nonstationary DNAPL Source Zones by Integrating a Convolutional Variational Autoencoder and Ensemble Smoother

Kang

Kokkinaki

Kitanidis

et al. 2021

Water Resources Research

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Detailed characterization of dense nonaqueous phase liquid (DNAPL) source zone architecture (SZA) is essential for designing efficient remediation strategies. However, it is difficult to characterize a highly irregular and localized SZA, because traditional drilling investigations provide limited information. With limited data, the estimation accuracy of traditional geostatistical methods is strongly affected by the parameterization of the prior description of the SZA. To improve characterization performance, we parameterized the DNAPL saturation field using a physics‐based approach. We trained a convolutional variational autoencoder (CVAE) using data from multiphase modeling that captures the physics of DNAPL infiltration. The trained CVAE network was used in SZA inversion to obtain an improved prior DNAPL saturation field, instead of the typical stationary prior covariances. We then integrated the CVAE network into an iterative ensemble smoother (ES), to formulate a joint inversion framework. To overcome difficulties from limited/sparse data, we incorporated hydrogeological and geophysical datasets in the proposed inversion framework. To evaluate the performance of our method, we conducted numerical experiments in a hypothetical heterogeneous aquifer with an intricate SZA. The results show that the CVAE was an effective and efficient parameterization method which can capture the DNAPL infiltration patterns better than a Gaussian prior. The improved prior, combined with multisource datasets, can result in better resolution, and overall improved SZA characterization. In contrast to the standard ES method, the proposed framework reconstructed the SZA more accurately. We also demonstrated that DNAPL depletion behavior and dissolved concentration profiles can be predicted accurately using the estimated SZA.

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“…As a result, DNAPL SZs can contain highly saturated DNAPL pools (high electrical resistivity) that are underlain by clayey lenses (high chargeability), indicating the potential of DCIP for providing enhanced information at DNAPL sites. A number of recent studies have applied DCIP at DNAPL sites (Johansson et al., 2015; Nivorlis et al., 2019; Sparrenbom et al., 2017); however, despite its potential, DCIP provided limited characterization of the DNAPL structure. All of these studies assessed the potential of DCIP directly at field sites that contain an unknown, complex DNAPL SZ superimposed upon an uncertain, heterogeneous soil matrix, thereby making interpretation of the recorded data highly challenging (Johansson et al., 2015).…”

Section: Introductionmentioning

confidence: 99%

Mapping and Monitoring of DNAPL Source Zones With Combined Direct Current Resistivity and Induced Polarization: A Field‐Scale Numerical Investigation

Almpanis

Gerhard

Power

2021

Water Resources Research

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Direct current (DC) resistivity has been widely investigated for non‐invasive mapping of dense non‐aqueous phase liquids (DNAPLs); however, due to its difficulty in distinguishing DNAPLs from adjacent soils, the DC method is limited for static detection of DNAPLs and more often employed for monitoring DNAPL changes over time. Time‐domain induced polarization (IP) can provide complementary information to better discriminate between DNAPL, water and surrounding soils. Since highly resistive DNAPLs tend to laterally spread and pool on polarizable (chargeable) clay lenses, combined DC and IP (DCIP) has the potential to enhance static detection, and also monitoring of DNAPL source zones (SZs). The objective of this study is to assess DCIP for characterizing and monitoring DNAPL SZs at the field‐scale. A new DNAPL‐DCIP numerical model was first developed that couples a 3D multiphase flow model, which simulates DNAPL release and remediation scenarios, with a 3D DCIP model, which calculates the corresponding resistivity and chargeability response. The sensitivity of the DCIP response to key DNAPL and soil properties was then analyzed at a single subsurface location, closely matching previous theoretical and experimental observations. Finally, a field‐scale simulation of DNAPL release and remediation was conducted, with simultaneous mapping by DCIP surveys. Results demonstrate that chargeability can provide enhanced understanding of the lithological distribution that controls the variability in the DNAPL SZ, with time‐lapse resistivity being used to monitor DNAPL mass changes during SZ remediation. This numerical study suggests that combined DCIP can be valuable for site characterization and time‐lapse monitoring performance at DNAPL‐impacted sites.

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Investigation of chlorinated solvent pollution with resistivity and induced polarization

Cited by 28 publications

References 21 publications

Structural analysis and geophysical survey for hydrogeological diagnosis in uranium mine, Poços de Caldas (Brazil)

Structural analysis and geophysical survey for hydrogeological diagnosis in uranium mine, Poços de Caldas (Brazil)

Hydrogeophysical Characterization of Nonstationary DNAPL Source Zones by Integrating a Convolutional Variational Autoencoder and Ensemble Smoother

Mapping and Monitoring of DNAPL Source Zones With Combined Direct Current Resistivity and Induced Polarization: A Field‐Scale Numerical Investigation

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