Impedance Tomography Research Articles

On-line monitoring of membrane fouling based on an improved electrical measurement method.

On-line monitoring of membrane fouling is essential in the water treatment process. Drawbacks such as low-sensitivity and off-line limitations limit the application of existing methods. An on-line monitoring method based on Electrical Resistance Tomography (ERT) sensors is put forward in this paper. The Particle Swarm Optimization with Simulated Annealing (PSO-SA) algorithm is used in optimizing the topologies of finite element models in order to decrease the ill-posedness of sensitivity matrices. The deep denoising extreme learning machine with an auto-encoder model and the K-singular value decomposition algorithm are used in ERT reconstruction to improve imaging quality. The lift-wavelet is adopted in measuring the permeate flux to improve measuring accuracy. The ERT pixel values of the membrane module and the result of flux are used to analyze the fouling status. The results of membrane fouling experiments demonstrate the following: (1) Based on the local ERT pixels, the "two stage" phenomenon of membrane fouling can be observed. (2) In the early stage, the fouling distribution of the localized membrane module is consistent with its ERT pixels. (3) The deposition process of foulants for the localized membrane module is synchronized with the variation of ERT pixels. (4) The integrity of the membrane module can be detected according to the ERT pixels. Therefore, the novel method can effectively reflect the membrane fouling process, especially in the early stages of membrane fouling.

Identification of sliding surface using electrical-resistivity tomography for landslide mitigation: A case study of the Cibitung Landslide

Landslide mitigation efforts require a knowledge of the geometry and depth of the sliding surface present in a landslide body. Electrical resistivity tomography is the most common geophysical method used in landslide investigation. This paper presents the results of a series of electrical resistivity tomography surveys performed using a dipole-dipole array configuration to identify the sliding surfaces within a landslide body located in the Cibitung landslide area. The ERT images parallel the landslide body suggest that the sliding surface located below the crown is characterized by a bedrock layer with very low resistivity values. This bedrock layer continues down-slope at a maximum depth of 9 m below the ground surface. In contrast, the landslide body is characterized by a higher resistivity value. Based on the interpretation of the ERT images, the landslide involved a non-circular deep sliding surface. The results of this study have been used, in combination with the geotechnical drilling data, to construct the landslide cross-section necessary to analyze landslide stability and subsequently to recommend a landslide stabilization measure.

Mapping Permafrost Variability and Degradation Using Seismic Surface Waves, Electrical Resistivity, and Temperature Sensing: A Case Study in Arctic Alaska

AbstractSubsurface processes significantly influence surface dynamics in permafrost regions, necessitating utilizing diverse geophysical methods to reliably constrain permafrost characteristics. This research uses multiple geophysical techniques to explore the spatial variability of permafrost in undisturbed tundra and its degradation in disturbed tundra in Utqiaġvik, Alaska. Here, we integrate multiple quantitative techniques, including multichannel analysis of surface waves (MASW), electrical resistivity tomography (ERT), and ground temperature sensing, to study heterogeneity in permafrost’s geophysical characteristics. MASW results reveal active layer shear wave velocities (Vs) between 240 and 370 m/s, and permafrost Vs between 450 and 1,700 m/s, typically showing a low‐high‐low velocity pattern. Additionally, we find an inverse relationship between in situ Vs and ground temperature measurements. The Vs profiles along with electrical resistivity profiles reveal cryostructures such as cryopeg and ice‐rich zones in the permafrost layer. The integrated results of MASW and ERT provide valuable information for characterizing permafrost heterogeneity and cryostructure. Corroboration of these geophysical observations with permafrost core samples’ stratigraphies and salinity measurements further validates these findings. This combination of geophysical and temperature sensing methods along with permafrost core sampling confirms a robust approach for assessing permafrost’s spatial variability in coastal environments. Our results also indicate that civil infrastructure systems such as gravel roads and pile foundations affect permafrost by thickening the active layer, lowering the Vs, and reducing heterogeneity. We show how the resulting Vs profiles can be used to estimate key parameters for designing buildings in permafrost regions and maintaining existing infrastructure in polar regions.

Application of Multi-Near-Surface Geophysical Surveys for Geothermal Spring: A Case Study in Kon Tum Province, Vietnam

The occurrence of geothermal spring not only enhances human health, but also plays a crucial role in generating community’s revenue that boosts up the standard living of locals. An endeavor has been made to delineate the prospective areas of geothermal spring in Kon Tum province, Vietnam by the utilization of joint-geophysical techniques. The blended mode as mentioned is opted for its superiority in providing the rapidassesments of temperature in shallow temperature survey, comprehensive understanding the subsurface structure in electrical resistivity tomography in copporating with the validation in well log interpretation. The results found that the overlapping region of high temperature (35°C) region and low resistivity (200 Ωm) is observed in the east in the vicinity of Dlak Bla river, and it probably broadens to the west of the study area. The outcome of geophysical approaches strongly concur with the well log interpretation, revealing the presence of water-bearing zone encountered in fractured granite. The results also corroborated the existence of concealing fault F5 as a branch of the NE-SW fault F2 which is favorable for creating a route to form the geothermal spring. The output of this research could be considered as an intentive consultation for Kon Tum’s planners and makers on expanding the investigation and exploitation.

Integrating near-surface geophysical methods and remote sensing techniques for reconstructing fault-bounded valleys (Mellieha valley, Malta)

The island of Malta (central Mediterranean) is dissected by several WSW-trending fault-line valleys related to Miocene-Pliocene extensional tectonics. Some valleys host remnants of alluvial deposits that could provide information on possible Quaternary faulting, but the thickness of these deposits and their subsurface extent is poorly constrained. Our study aimed to investigate the structural configuration of the southern sector of the Mellieha valley, which is located in the north-west part of the island and is limited by the ENE-WSW general trending Mellieha and Ghadira faults, and their relation with a thin layer of infill sediments. We employed different near-surface geophysical techniques (electrical resistivity tomography, active and passive seismic methods, ground-penetrating radar), as well as remote sensing techniques (unmanned aerial vehicle digital photogrammetry and ground-based Light Detection and Ranging) to complement classic structural surveys. The valley structure has an asymmetric graben configuration, being bounded by a normal fault to the southeast (Mellieha Fault) and other to the north-west (Ghadira Fault). Our study provides insights of possible Quaternary fault displacements and revealed the presence of an additional fault splay, the previously unmapped NNW-dipping Mellieha Fault 2 at the south-eastern edge of the valley. Additionally, by integrating results from geophysical surveys, we estimated the thickness of the valley's recent deposits, being thicker towards the Mellieha Bay sector, with maximum values of 8–10 m. Our study aligns with the general model of horst and graben structuring with associated regional tilting since the late Miocene, and supports the hypothesis that some segments of NW-trending normal faults within the North Malta Graben exhibit Quaternary activity, although with minimal throw rates (<< 0.1 mm/yr).

Images of Resistance

Barrio Logan, San Diego, California, contains Chicano Park, a small parcel of land claimed in 1970 by community members. The park has since been recognized for its numerous Chicano murals. Our article analyzes two murals that speak on the issue of gentrification in the community and the dispossession that it leads to. We employ Alvesson and Willmott’s theory on emancipation, and specifically the term “microemancipations,” to examine how the Chicano community in Barrio Logan resists dispossession. We complicate the notion of emancipation, showing how murals sometimes facilitate resistance and, at other times, impede successful emancipation.

Determining the geological structure and underground caves using a multi-electrode resistivity imaging method

Subsidence hazards are common in Vietnam, occurring not only in mountainous regions but also in densely populated delta areas. There have been numerous subsidence incidents recorded in Thanhhoa province in the past. The results of geophysical measurements using the multi-electrode resistivity imaging method show: 1) The study area is located in an area of karst topography which includes a complex network of large and dense underground caves. 2) The geological structure of the study area can be divided into four layers with different resistivity anomalies, including a sedimentary cover ( = 13  39 m), strongly weathered layer ( = 40  150 m), less weathered layer ( = 151  214 m), and bedrock layer ( &gt;214 m); 3) Caves in the research area have 3 characteristics including cleft-shaped caves filled with sediment originating from the soil surface and containing a lot of water with an average depth of 7  15m; sealed caves surrounded by heavily weathered bedrock and no water inside; sealed caves containing water or hydrated material have a high risk of causing subsidence.

Analysis of two-dimensional magnetotelluric inversion for the delineation of the petroleum system in the Kutai basin, East Kalimantan, Indonesia

The Kutai Basin in East Kalimantan is known as a potential area for oil and gas exploration. Two-dimensional magnetotelluric (MT) analysis is applied to investigate the geological structure and distribution of subsurface resistivity. This study aims to delineate the petroleum system using MT data and identify zones with potential for the accumulation of hydrocarbons. MT data has been collected at several strategic locations in the Kutai Basin, and two-dimensional cross-sections have been constructed to obtain vertical resistivity imaging at several depths. In this study, there were nine measurement points located on one line. The data is then inverted to obtain a two-dimensional resistivity model, which qualitatively represents the subsurface structure. The results of this study indicate that there is a low resistivity anomaly zone that identifies the presence of source rock with a resistivity value of 1-12 Ωm. In this line, it is suspected that the petroleum system that allows trapped hydrocarbons is found in the area, below the KT36 and KT13 measurement points. In this area there are folded structures in the form of synclines and anticlines, which raises suspicions about the types of traps formed from structural traps.

Integrated geophysical approach for detection and size-geometry characterization of a multiscale karst system in carbonate units, semiarid Brazil

Abstract The karstification of carbonate rocks creates 3D maze voids that are normally controlled by fracture networks and sedimentary bedding. The spatial distribution and density of karst systems are usually complex and difficult to predict, demanding multidisciplinary studies at different scales of investigation to determine the spatial distribution and density of karst features and their possible links with cave systems controlled by the regional structural setting. The present study integrates geophysical datasets (gravity, electrical resistivity tomography - ERT, and ground penetrating radar - GPR) with a digital elevation model to investigate a karst system in the Irecê basin, a semiarid region of Brazil. Morphostructural lineaments reveal a NNW-SSE- and E-W-oriented structural setting of the crystalline basement, which is imprinted on the internal basin architecture, and surface drainage network. Negative gravity anomalies and high-gradient gravity zones indicate the main karstic zone, where karst landforms are concentrated. In addition, 2.5D gravity modeling provides the internal basin geometry, demonstrating that the karst system has evolved in the thickest sector of the basin. ERT profiles delineate the underground passages that connect dolines at depth. Finally, GPR data image shallow subsurface ghost-rock karstification that spread out from the surface to depth and that took advantage of vertical fractures and slightly arched bedding planes. Our results point out the role of the fracture corridors in channelizing hydrodynamic energy at a sufficiently high level to create caves by the total removal of dissolved material, whereas in the surrounding areas under low hydrodynamic conditions, overall shallow ghost-rock karstification took place, creating residual weathered rocks (alterites).

CBR Mapping Prediction from 2D Resistivity Imaging Using Regression Following Archie’s Formula

Indirect geophysical methods are increasingly associated with direct underground methods in investigating the subsurface to address environmental and geotechnical problems and reduce the cost of underground studies. These methods make it possible to explore large areas with acceptable precision, time, and cost. The present study combines the electrical resistivity method with the California Bearing Ratio for exploring an area located west of the Nouakchott port in Mauritania. The study aims firstly to verify that the thickness of the backfill layer must be less than 2 m throughout the entire study area and secondly to map areas with low California Bearing Ratio values (&lt;80%) indicating substandard backfill compaction using 2D Electrical Resistivity Tomography imaging survey and regression. The measured Electrical Resistivity values exhibit a good nonlinear regression with California Bearing Ratio, following Archie's equation. A map of California Bearing Ratio variation was derived from the Electrical Resistivity values, indicating the distribution and variation of soil strength in the study area. The results revealed that the backfill layer did not meet the standards, with approximately 35% of the total area having a California Bearing Ratio value below 80%. The areas with poor compaction requiring treatment were primarily located in the southern sector, followed by the middle and eastern sectors.

The Practicality of Resistivity Method for Recognizing Vertically Distributed Anomalies Using Simulated Models

In brownfield sites, two proposed shallow horizontal targets were numerically modelled to mimic variable underground conditions; these targets were sequenced vertically in a different manner. Synthetic 2D electrical resistivity datasets were generated using the RES2DMOD and then inverted by using RES2DINVx64. These targets have different lengths, one with a higher and the second with a lower resistivity value relative to the background resistivity. The effectiveness of dipole-dipole, Wenner, and Wenner-Schlumberger configurations was tested by conducting a qualitative comparison. The inverted resistivity images suggest that the target sequence has a significant effect on the configuration detectability. The high resistivity target was conveniently recognized when it overlies a low resistivity target. Dipole-dipole configuration showed optimum results in recognizing complicated underground conditions.

Electrical Resistivity Tomography (ERT) for investigating subsurface structures in the karst area of the Ek Leuntie Cave, Aceh Province

Ek Leuntie Cave, in the southern city of Banda Aceh, Aceh Province, is recognized as an educational media based on geopark sites because it holds a 7400-year paleotsunami track record. As a karst area, Ek Leuntie Cave is vulnerable to the impact of geological disasters such as earthquakes, sinkholes and subsidence. As an effort to reduce the negative impact of geological disasters, geophysical studies have been applied in the Ek Leuntie Cave Karst area. The study aims to identify the subsurface geological structure of the Karst area. The identification was carried out using the Electrical Resistivity Tomography (ERT) method of Wenner-Schlumberger configuration applied to two measurement trajectories that have South-North and West-East directions in front of the Ek Leuntie Cave door. ERT data acquisition results were then modeled in inversion using Res2Dinv software to produce a 2D model of the subsurface geological structure of the Ek Leuntie Cave karst area based on variations in rock resistivity values. Interpretation of subsurface geological structure modeling is validated with shallow drilling data (Hand Auger). The inversion modeling results show that the rock resistivity value in the Ek Leuntie Cave area reaches a depth of 30 m which has a resistivity value of 0 - 1000 Ωm. The results of the interpretation of resistivity values and validation of drill data show that the Ek Leuntie Cave area is covered by a layer of sand with fine to coarse texture and the layer below is a layer of limestone at a depth of ± 0.4 meters with a resistivity value of 50 - 250 Ωm. Limestone generally shows porosity with the possibility of caves or pores in the rock formation at Ek Leuntie Cave, making it vulnerable to damage from earthquakes, landslides, and subsidence. The results of the study are expected to provide updated information in efforts to develop the Ek Leuntie Cave geopark area.

Integrated Geotechnical and Electrical Resistivity Tomography to Map the Lithological Variability Involved and Breaking Surface Evolution in Landslide Context: A Case Study of the Targa Ouzemour (Béjaia)

The specific lithology of the southern part of Bejaia city represents a major limitation to urban settlement and expansion. This is partly due to landslides that tend to affect this region. To date, one of these landslides in this region has occurred in the Targa Ouzemour area, where the damage extended approximately six hectares. The main purpose of this study is to identify the failure surfaces characterizing the internal structure of this landslide as well as the significant influence of groundwater on slope instability, which manifests as surface cracking and subsidence. We have combined several geotechnical and geophysical methods, including field observations. The exploitation of the collected geotechnical data from the six (06) boreholes drilled in the landslide zone has allowed for knowledge to be gained on the lithological components, as well as the characterizations of physical and mechanical properties on a range of different types of affected rocks, whereas electrical resistivity tomography (ERT) data allowed an in-depth examination, leading us to reconstruct the landslide geometry and particularly to evaluate the hydrological characteristics of the studied site. Moreover, the resistivity contrast patterns provided more clarity to discern between the various lithological formations that are still stable or actively moving within this landslide. All these findings have contributed to the construction of a characteristic geomodel that highlights the failure surfaces over which displacement is still experienced. Finally, with the evidence of rainfall effects on the deformation and stability of the slope, specific landslide remedial measures were accordingly suggested.

An effective multiphysics toolkit for lithium prospecting: From geophysics to the static reservoir model in the Pozuelos salt flat, Argentina

Energy transition drives the energy sector to renewable energy and electrification, being the critical minerals key players in the industrial development map. They comprise rare-earth elements and 35 other elements, including lithium, which holds 60% of its world reserves in the so-called lithium triangle located in Argentina, Bolivia, and Chile. The low electrical resistivities, variations in salt concentrations, low acoustic impedances, and dynamics of the hydrogeologic system make brine monitoring a complex geophysical exploratory problem. So, the objective is to find a suitable combination of geophysical techniques that fit the lithium exploration objectives, which are the characterization of the salt flat in-depth, fluid detection, basement delineation, definition of the main structures and main faults, and detection of semifresh water aquifers that contribute to its recharge and that are key to the reservoir water balance of an endorheic basin, which has the resource in solution. For this purpose, the evaluation of several prospecting methods in different salt flats was executed, concluding that full tensor magnetotellurics (MT), electrical resistivity tomography, and gravity comprise a toolkit that fits the objectives set. The methodology was validated at the Pozuelos salt flat. The results show that the fresh water-brines contact and the recharge system were well-defined and imaged by ERT. The full tensor MT detected two ultraconductive units: a shallower multilayer system saturated with brines, has a 400 m thickness, whereas the deeper unit has a 500 m thickness. Both MT and gravity characterized the basement, and gravity successfully delineated the main structures. The geophysical interpretation is in concordance with shallow and deep exploration wells. Finally, the integration of geophysical and well data allowed the construction of a 3D static reservoir model that finds the deepest basement area at approximately 900 m depth and discriminates eight lithofacies.

Near-surface imaging by joint inversion of ERT and seismic traveltime data with guided FCM clustering

We present a novel joint inversion strategy for electrical resistivity tomography (ERT) and seismic first-arrival traveltime data with guided fuzzy c-means (GFCM) clustering coupling to increase the accuracy of inversion results and improve the characterization of heterogeneous near-surface materials. The physical parameter correlation between the resistivity and seismic velocity is enforced using a GFCM clustering coupling term in the objective function, which also includes misfit and regularization terms. The physical property models estimated by joint inversion are guided by the clustering centers of a priori petrophysical parameters. A limited-memory quasi-Newton approach is used to optimize the objective function. To validate the proposed approach and describe its implementation in detail, tests were first performed using two synthetic models. The stratigraphic structures recovered by joint inversion with GFCM clustering coupling are more consistent with the true model than those inverted by individual inversion, cross-gradient and fuzzy c-means (FCM) joint inversion. Furthermore, the physical parameters estimated using GFCM joint inversion are significantly more accurate than those estimated using individual inversion and the other two joint inversion methods. The joint inversion algorithm was applied to field data from the Liangzhu site in Hangzhou, China. The depth and shape of the stratigraphic interface imaged by GFCM joint inversion are consistent with the drilling results. However, when using individual inversion and the other two joint inversion methods, the recovered stratigraphic structures have some differences with the drilling data. Therefore, GFCM joint inversion is an effective and reliable method for near-surface fine imaging.

Characterization of Stronghold Fortifications by 2D/3D/4D Electrical Resistivity Tomography: Major Push Towards Quantitative Interpretation

AbstractGeophysical methods are widely used as noninvasive tools for archaeological prospection. In a first step is usually applied basic prospection of vast areas, when data are evaluated only in qualitative way. Sometimes is performed second step, during which take place more detailed multidimensional or combined surveys in order to image archeological monuments complexly, allowing quantitative interpretation. Hence, we used a unique and novel combination of multidimensional electrical resistivity tomography (ERT) on the Early Middle Ages stronghold fortifications at Vinoř (Czechia) to achieve such interpretation. The joint results of 2D/3D/4D (time-lapse) surveys allowed us to precisely characterize individual construction components of the fortifications, including a ditch and rampart enhanced by a front wall with a berm. The ERT results recovered the fortification dimensions and the volume of building material used. The surveyed fortification section was verified by excavations directly after the ERT measurements. A comparison of the excavated section with geophysics proved that ERT was able to infer all the important fortification characteristics. In addition, illustrative picture of the resistivity manifestations of the basic components of this very typical fortification construction were obtained. The results show that multidimensional ERT provide access to quantitative interpretation allowing to explain archaeological structures behind investigated anomalies. In result, sites containing cultural heritage can be leaved intact, excavations can be substituted in surprisingly large extent, while unprecedented amount of archaeological information is still retrieved.

Investigation of mixing miscible liquids with high viscosity contrasts in turbulently stirred vessels using electrical resistance tomography

The time required to attain a sufficient degree of homogeneity i.e., mixing time, is an important parameter in mixing processes. This paper presents results from a study employing an experimental approach to estimate mixing times for a miscible Newtonian liquid mixture system with high viscosity contrasts in a turbulent stirred vessel. An Electrical Resistance Tomography (ERT) based technique has been adopted to monitor dimensionless mixing time across a range of additive viscosities, impeller designs, sizes, and speed. Dimensional analysis has been used to interpret these mixing time results in terms of the magnitude of the bulk inertia forces relative to the initial viscous forces within the added fluid. Critical non-dimensional numbers, uniting the properties of the two liquids, have been proposed as the criterion for avoiding undesirable operating conditions under which the mixing time is much longer than that required for mixing fluids with similar properties. The work proposes novel correlations for mixing time and incorporates a new dimensionless group, thereby enabling a more nuanced and accurate characterisation of mixing behaviours. This research stands to contribute to energy saving and waste minimisation efforts in the industry. It provides insights for process designers and simulation engineers, propelling a leap forward in the design and operation of mixing processes when dealing with liquid systems that have significant viscosity differences.

Integrating geological, hydrogeological and geophysical data to identify groundwater resources in granitic basement areas (Guéra Massif, Chad)

In Chad, hard-rock aquifers are the main source of drinking water for the population located on basement areas. In these basement aquifers, and in particular those of the Guéra region, water drilling failure rates remain high despite research on one- and two-dimensional electrical resistivity techniques and lineaments as a means to improve access to the resource, mainly because these techniques are only used on an observational and structural basis to locate fractures. This study combines electrical resistivity tomography (ERT) with geology, hydrogeology and geomorphology, in order to characterise the structure and geometry of the aquifer system, assess borehole productivity and determine the factors controlling it. After validating the large dataset and its representativeness, 315 high- and low-yield wells, of which 41 have complete geophysical datasets, were selected. This large dataset allows a multi-parameter approach to (1) better characterise each facies according to its electrical resistivity and (2) clearly identify the main formations constituting the local conceptual hydrogeological model. The most suitable areas for productive boreholes are characterised by the presence of an overburden of <20 m depth, well-developed weathered and fractured horizons of granites and biotite granites (preferably) containing little or no clay, and a nearby drainage network. The most substantial flow rates are found in the first 30 m of the fissured horizon, below the base of the alterites. The experience gained from the present study will guide future analysis of ERT sections in order to reduce the probability of drilling dry wells.

Design of Three-Dimensional Electrical Impedance Tomography System for Rock Samples

Research on the electrical properties of rocks and ores plays a crucial role in the development of geophysical electromagnetism methods. However, currently available instruments suffer from high power consumption, a limited number of electrodes, inaccurate measurements, poor portability, and a limited ability to measure the electrical parameters of rocks and ores. To address these issues, this paper presents a three-dimensional electrical impedance tomography system for rock samples with high-density microelectrodes based on an Android system and STM32 microcontroller. The system features high observation accuracy, dense electrode arrays (with 384 current and potential electrodes), flexible electrode selection, user-friendly human–computer interaction, good stability, and real-time performance. Powered by a single power bank, the entire instrument can be controlled and monitored wirelessly via Bluetooth and Wi-Fi technology using an Android smartphone. Additionally, the system not only enables accurate measurement of electrical parameters, but also facilitates the generation of three-dimensional impedance imaging of specimens via inversion algorithms after data export, allowing for a comprehensive understanding of the electrical properties of rocks and ores. This system holds great potential for future research in this field.

Managing the remediation strategy of contaminated megasites using field-scale calibration of geo-electrical imaging with chemical monitoring

Groundwater contamination is a threat to drinking water resources and ecosystems. Remediation by injection of chemical reagents into the aquifer may be preferred to excavation to reduce cost and environmental footprint. Yet, successful remediation requires complete contact between contamination and reagents. Subsurface heterogeneities are often responsible for diffusion into low-permeable zones, which may inhibit this contact. Monitoring the spatial distribution of injected reagents over time is crucial to achieve complete interaction. Source zone contamination at megasites is particularly challenging to remediate and monitor due to the massive scale and mixture of contaminants. Source zone remediation at Kærgård Plantation megasite (Denmark) is monitored here, with a new methodology, using high-resolution cross-borehole electrical resistivity tomography (XB-ERT) imaging calibrated by chemical analyses on groundwater samples. At this site, high levels of toxic non-aqueous phase liquids (NAPL) are targeted by in-situ chemical oxidation using activated persulfate. It may take numerous injection points with extensive injection campaigns to distribute reagents, which requires an understanding of how reagent may transport within the aquifer. A geophysical (XB-ERT) monitoring network of unprecedented size was installed to identify untreated zones and help manage the remediation strategy. The combination of spatially continuous geophysical information with discrete but precise chemical information, allowed detailed monitoring of sulfate distribution, produced during persulfate activation. Untreated zones identified in the first remediation campaign were resolved in the second campaign. The monitoring allowed adjusting the number of injection screens and the injection strategy from one campaign to the next, which resulted in better persulfate distribution and contaminant degradation in the second campaign. Furthermore, geophysical transects repeated over the timespan of a remediation campaign allowed high-resolution time-lapse imaging of reagent transport, which could in the future improve the predictability of transport models, compared to only using on a-priori assumptions of the hydraulic conductivity field.