Induced Polarization Techniques Research Articles

The physicochemical interacting mechanisms and real-time spectral induced polarization monitoring of lead remediation by an aeolian soil

Compared to traditional lead-remediating materials, natural-occurring paleosol is ubiquitous and could be a promising alternative due to its rich content in calcite, a substance known for its lead-removal ability via carbonate dissolution-PbCO3 precipitation process. Yet, the capability of paleosol to remediate aqueous solutions polluted with heavy metals, lead included, has rarely been assessed. To fill this gap, a series of column permeation experiments with influent Pb2+ concentrations of 2000, 200, and 20 mg/L were conducted and monitored by the spectral induced polarization technique. Meanwhile, the SEM-EDS, XRD, XPS, FTIR and MIP tests were carried out to unveil the underlying remediation mechanisms. The Pb-retention capacity of paleosol was 1.03 mmol/g. The increasing abundance of Pb in the newly-formed crystals was confirmed to be PbCO3 by XRD, SEM-EDS and XPS. Concurrently, after Pb2+ permeation, the decreasing calcite content in paleosol sample from XRD test, and the appearance of Ca2+ in the effluent confirmed that the dissolution of CaCO3 followed by the precipitation of PbCO3 was the major mechanism. The accumulated Pb (i.e., the diminished Ca) in paleosol was inversely proportional (R2 >0.82) to the normalized chargeability (mn), an SIP parameter denoting the quantity of polarizable units (primarily calcite).

Complex electrical measurements of waste rock during acid mine drainage generation and release: Kinetic column tests

Acid mine drainage (AMD) emanating from waste rock piles (WRPs) at mining sites is a global concern. Successful rehabilitation of these sites requires effective characterization and monitoring of the waste rock during AMD generation/release. Traditional approaches involve ex-situ analysis of waste rock and porewater samples collected via corings and monitoring wells; however, this is highly disruptive, costly, and provides sparsely distributed point information across enormous volumes typical of WRPs. Geoelectrical techniques are a promising approach for non-invasive continuous imaging; however, their application has been limited to ‘one-off’ imaging with few studies on monitoring waste rock evolution. The objective of this study is to assess the geoelectrical signatures of changing waste rock during AMD generation/release. Field waste rock samples were extracted from three mine WRPs and first characterized for mineralogy and acid generation potential. Kinetic tests were then performed on each sample using leaching columns and humidity cells, with simultaneous measurements of effluent quality and complex electrical conductivity (real and imaginary components measure conduction and polarization, respectively). Results show that real conductivity was highly sensitive to changes associated with AMD leachate quality (e.g., 28,800 to 68 mg/L acidity) and surface of the waste material. Imaginary conductivity measurements identified changes in the waste mineralogy over time, though these signatures were not very distinct, which is likely due to low sulfide contents and limited oxidation (e.g., 0.59 wt% sulfide and 33% air saturation). This study improves our understanding of geoelectrical signatures associated with real waste rock, demonstrating the potential application of the electrical resistivity tomography and induced polarization techniques for mine waste investigations.

Monitoring the remediation of groundwater polluted by MSW landfill leachates by activated carbon and zeolite with spectral induced polarization technique.

The municipal solid waste (MSW) landfill in Hangzhou, China utilized zeolite and activated carbon (AC) as permeable reactive barrier (PRB) fill materials to remediate groundwater contaminated with MSW leachates containing ammonium, chemical oxygen demand (COD), and heavy metals. The spectral induced polarization (SIP) technique was chosen for monitoring the PRB because of its sensitivity to pore fluid chemistry and mineral-fluid interface composition. During the experiment, authentic groundwater collected from the landfill site was used to permeate two columns filled with zeolite and AC, and the SIP responses were measured at the inlet and outlet over a frequency range of 0.01-1000Hz. The results showed that zeolite had a higher adsorption capacity for COD (7.08mg/g) and ammonium (9.15mg/g) compared to AC (COD: 2.75mg/g, ammonium: 1.68mg/g). Cation exchange was found to be the mechanism of ammonium adsorption for both zeolite and AC, while FTIR results indicated that π-complexation, π-π interaction, and electrostatic attraction were the main mechanisms of COD adsorption. The Cole-Cole model was used to fit the SIP responses and determine the relaxation time (τ) and normalized chargeability (mn). The calculated characteristic diameters of zeolite and AC based on the Schwarz equation and relaxation time (τ) matched the pore sizes observed from SEM and MIP, providing valuable information on contaminant distribution. The mn of zeolite was positively linear with adsorbed ammonium (R2 = 0.9074) and COD (R2 = 0.8877), while the mn of AC was negatively linear with adsorbed ammonium (R2 = 0.8192) and COD (R2 = 0.7916), suggesting that mn could serve as a surrogate for contaminant saturation. The laboratory-based real-time non-invasive SIP results showed good performance in monitoring saturation and provide a strong foundation for future field PRB monitoring.

Integration of Electrical Resistivity and Induced Polarization Technique for Oil Spill Investigation in Kegbara-Dere, Gokana LGA, Rivers State

Oil spill is a very complex phenomenon which requires detailed investigation using integrated techniques to identify the major contaminant anomalies in the study area, hence the need to investigate the spill contaminant is very key to obtaining data that would aid in the provision of requisite information for remediation. The study area was modelled using 2-D resistivity and induced polarization tomography for delineation of plumes resulting from the oil spills and those caused by mineralized bodies. 2-D data acquisition techniques were used to obtain apparent resistivity and IP data. Interpretation of electrical resistivity and IP tomograms shows that the hydrocarbon plumes signatures are masked by signatures from polarized bodies within the subsurface. The identification and isolation of the resistivity anomalies from the IP anomalies are of major concern in this research. Resistivity and induced polarization tomograms are used to accurately delineate the plume boundaries and also identify of regions masked by the presence of clays and other mineralized bodies within the subsurface.

Evaluation of iron ore deposit using 2D resistivity imaging and induced polarization technique at Fakarau Potiskum, Northeastern Nigeria

2D Electric resistivity imaging and Induced polarization (IP) techniques were used to evaluate Iron Ore deposit at Potiskum area of Yobe State, Northeastern Nigeria. The area lies between latitudes 110 40' 00'' and 110 50' 00'' N, and longitude 110 00' 00'' and 110 10' 00'' E. The survey was targeted at determining resistivity and chargeability values that are associated with the iron ore deposit. The dipole-dipole array was used for 2D resistivity and induced polarization imaging. Data processing and interpretation were done using RES2DINV software. This research had characterized the study area into two portions: the alluvium deposit that is highly enriched of iron ore and alluvium deposit with disseminated iron ore. The portion of the iron rich alluvium, characterized by low resistivity and chargeability of 32 Ωm to 734 Ωm and 0.403 msec to 3.400 msec are inferred as alluvium that is highly enrich with iron ore, while the portion that are respectively characterized by resistivity and chargeability values of 734 Ωm to 1418 Ωm and 1.90 msec to 6.40 msec are inferred as alluvium with disseminated iron ore. It can be concluded that the occurrence of iron ore deposit is probably more at northeast part of the survey area. The iron ore deposit strikes in the Northeast-Southwest direction.

The use of Geoelectrical Methods for Delineation of Lead-Zinc Mineralization: A Case Study of Eziama Village, Abia State, South- East, Nigeria

2D Electrical Resistivity (ER) and Instantaneous Potential (IP) geophysical techniques were used at Eziama village in Abia state of Nigeria to investigate possible Pb-Zn mineralization. The dipole-dipole electrode configuration was employed for data acquisition and Earth Imager software was used for inversion of the acquired data. The analysis of the result of the study showed the presence of the Pb-Zn ore along traverses 1, 2 and 3 while traverses 4 and 5 appear barren. Along traverse 1, the mineralized zone falls within the fractured basement and is characterized by low resistivity (about 316 – 5623 ohm-m) and high chargeability (33.2 – 128 ns) at lateral distance of 73 – 103 m. On traverse two, the ore body was identified at lateral distance of about -18 to 53 m as delineated on the IP structure with resistivity and chargeability of the anomalous zone ranging from 4.6 – 677 ohm-m and 41.8 – 142 ns respectively at depth of about 21.4 m while on traverse three, two ore bodies labeled a, a’ and b, b’ on the ER and IP cross-sections were delineated at lateral distance of about -130 to -93 m and 78 to 98 m respectively with depth to the top of the suspected ore bodies ranging from about 7.1 m for body ‘a’ and about 14.3 m for ‘a’. Traverses four and five however showed no prospect for Pb-Zn mineralization.
 The result of this investigation has once again demonstrated the usefulness of combined electrical resistivity and induced polarization techniques in solid mineral exploration.

Monitoring lime and cement improvement using spectral induced polarization and bender element techniques

Abstract Spectral induced polarization (SIP) and bender element (BE) techniques show a high sensitivity to particle size, particle distribution and content of generated hydration products, which essentially govern the efficiency of ground improvement. In this context, both SIP and BE were integrated on a column setup to monitor the processes of lime and cement stabilization. A 5 mmol/L Na2CO3 solution was injected into the sand-lime mixture to produce CaCO3 precipitation, while deionized water was injected into the sand-cement mixture to induce the hydration of cement. The average diameters of the precipitated particles or clusters were calculated from the relaxation time, which was a significant parameter of SIP signals, via the Schwarz equation. Two pairs of BE were used to demonstrate the heterogeneity of the product precipitation, which was probably caused by the location of the inflow and outflow on the SIP-BE column. SIP and BE showed the capability of nondestructively monitoring the spatiotemporal chemical evolution processes, which could be helpful for engineering applications.

Biomedical Applications of the Dynamic Nuclear Polarization and Parahydrogen Induced Polarization Techniques for Hyperpolarized 13C MR Imaging.

Since the first pioneering report of hyperpolarized [1-13C]pyruvate magnetic resonance imaging (MRI) of the Warburg effect in prostate cancer patients, clinical dissemination of the technique has been rapid; close to 10 sites worldwide now possess a polarizer fit for the clinic, and more than 30 clinical trials, predominantly for oncological applications, are already registered on the US and European clinical trials databases. Hyperpolarized 13C probes to study pathophysiological processes beyond the Warburg effect, including tricarboxylic acid cycle metabolism, intra-cellular pH and cellular necrosis have also been demonstrated in the preclinical arena and are pending clinical translation, and the simultaneous injection of multiple co-polarized agents is opening the door to high-sensitivity, multi-functional molecular MRI with a single dose. Here, we review the biomedical applications to date of the two polarization methods that have been used for in vivo hyperpolarized 13C molecular MRI; namely, dissolution dynamic nuclear polarization and parahydrogen-induced polarization. The basic concept of hyperpolarization and the fundamental theory underpinning these two key 13C hyperpolarization methods, along with recent technological advances that have facilitated biomedical realization, are also covered.

Geophysical Prospecting Using ERT and IP Techniques to Locate Galena Veins

The aim of this study is to prove the effectiveness of two electrical geophysical prospecting techniques, namely electrical resistivity tomography (ERT) and induced polarization (IP), in locating thin vein structures of metal sulphides embedded in Palaeozoic materials underlying a sedimentary cover. For this purpose, a Quaternary basin known as La Garza was selected, located in the mining district of Linares-La Carolina (Southern Spain). Galena (PbS) veins appear abundantly throughout this area, hosted in the Palaeozoic granitic bedrock. The studied veins show thicknesses from 0.5 to 2.0 m, and most present a vertical planar distribution. The veins lose their continuity below the sedimentary cover due to normal fractures that control the subsidence of the basin. During the 1980s, geophysical research campaigns were carried out in La Garza using vertical electrical sounding and failed in detecting the hidden veins. For this reason, to carry out this study, a closed regular mesh was designed, composed by eight ERT and IP profiles, with variable lengths between 315 and 411 metres. An electrode spacing between 5 and 7 metres was selected, thus allowing the granite bedrock to be reached without significantly reducing the resolution capabilities of the method. Even though ERT and IP are well-known geophysical techniques for mapping ore deposits, this is a case study that shows the advantages of the simultaneous use of both techniques (ERT and IP), over their individual application. ERT allows for reconstructing the morphology of the basin and the fractures that control it due to high-resistivity contrast between the overlying sedimentary cover and the underlaying granitic basement. However, it cannot provide any insights about their degree of mineralization. At this point, it is the IP technique that makes it possible to differentiate which are the mineralized structures. Some of these fractures produce high (above 50 mV/V) and moderate (below 50 mV/V) chargeability values, suggesting the existence of several unexploited metal veins. Furthermore, the derived models enable researchers to analyse the morphology of this sedimentary basin controlled by normal faults.

Electrical resistivity and induced polarization techniques for groundwater exploration

Abstract: Electrical resistivity and induced polarization surveys have been conducted for groundwater exploration at two different sites of geological aged i.e. Carboniferous and Quaternary. This study discussed the earth materials resistivity and chargeability for metasedimentary rock and unconsolidated sediment for groundwater exploration at Kampung Jongok Batu, Dungun and Kampung Paya Rawa, Besut, respectively. For this study Terrameter LS2, cable, electrode, cable connector, battery and remote cable are tools for measurement. The spacing between electrodes is 5 m, maximum length of spread line is 400 m and using Pole-Dipole protocol. Via comparing between the resistivity and chargeability values able to provide better interpretation for ground water exploration for metasedimentary rock and unconsolidated quaternary sediment. The result shows the important of chargeability for refining the resistivity value for locating the groundwater position.

Identification and characterization of low resistivity low contrast zones in a clastic outcrop from Sarawak, Malaysia

Zones with low resistivity low contrast (LRLC) are usually overlooked due to the absence of high-end well logging techniques in the older oil/gas fields. The Nyalau Formation outcrop (stratigraphically equivalent to offshore cycles I and II) from Sarawak, offers a good opportunity to identify and characterize LRLC zones through integrated approaches. Seven facies of the Nyalau Formation had been identified, which are: 1) low angle cross-bedded sandstone (CBSS), 2) laminated sandstone (LSS), 3) heterolithic sandstone (HSS), 4) bioturbated sandstone (BSS), 5) clay-rich sandstone (CSS), 6) mudstone (MS), as well as 7) trough CBSS (TCBSS). Apparent resistivity was determined for brine (60 kpm) saturated core plugs at a temperature of 75 °F by employing the sample core induced polarization technique. The measurement of resistivity was calibrated based on offshore salinity, as well as surface and subsurface temperature of the Sarawak. The geological and petrophysical characteristics were analyzed through field observations and lab analyses. The findings of the study revealed that the cutoff value of resistivity found at LRLC zones in Nyalau Formation was 12.6 Ω-m. Accordingly; LSS, BSS, and CSS facies appeared to derive from LRLC zones. The main causes that generate such LRLC zones are laminations, thin bedding, bioturbation, and clay minerals. The dominant effect portrayed by mixed layers of illite/smectite and smectite in LRLC zones could be attributed to their high cation exchange capacity (CEC). Two varying resistivity trends were discovered based on the variances detected in clay types for different facies. A negative correlation was found between resistivity and porosity within high resistivity zones, while a positive relationship within the LRLC zones. Disparity in the resistivity-porosity correlation is deduced to be associated with clay mineralogy. This study suggests that LRLC zones are expected to be present in shallow marine clastic reservoirs of offshore cycles (I and II), where the offshore reflects Nyalau Formation.

Groundwater Exploration in Granitic Rock Formation Using Electrical Resistivity and Induced Polarization Techniques

Electrical resistivity and induced polarization surveys have been conducted for groundwater exploration at granitic formation. This study discusses the earth materials resistivity and chargeability of granitic for groundwater exploration at IIUM campus. In this study Terrameter model LS2, cables, electrodes, cable connectors, battery and remote cable were used as the tools for measurement. The spacing between electrodes is 5 m and maximum length of spread line is 400 m by using Pole-Dipole protocol. By comparing the resistivity values and the chargeability values, it would be able to provide better interpretation for ground water exploration for granitic rock. The result also shows the important of chargeability to verify the resistivity value for locating the groundwater position.

Characterization of the Iron Ore Deposit Using 2D Resistivity Imaging and Induced Polarization Technique at Diddaye-Potiskum Area, Northeastern Nigeria

Characterization of the Iron Ore Deposit Using 2D Resistivity Imaging and Induced Polarization Technique at Diddaye-Potiskum Area, Northeastern Nigeria

Characterization of the Iron Ore Deposit Using 2D Resistivity Imaging and Induced Polarization Technique at Diddaye-Potiskum Area, Northeastern Nigeria

Characterization of the Iron Ore Deposit Using 2D Resistivity Imaging and Induced Polarization Technique at Diddaye-Potiskum Area, Northeastern Nigeria

Preliminary Groundwater Assessment using Electrical Method at Quaternary Deposits Area

Alternative water sources using groundwater has increasingly demand in recent years. In the past, proper and systematic study of groundwater potential was varies due to several constraints. Conventionally, tube well point was drilled based on subjective judgment of several parties which may lead to the uncertainties of the project success. Hence, this study performed an electrical method to investigate the groundwater potential at quaternary deposits area particularly using resistivity and induced polarization technique. Electrical method was performed using ABEM SAS4000 equipment based on pole dipole array and 2.5 m electrode spacing. Resistivity raw data was analyzed using RES2DINV software. It was found that groundwater was able to be detected based on resistivity and chargeability values which varied at 10 – 100 Ωm and 0 – 1 ms respectively. Moreover, suitable location of tube well was able to be proposed which located at 80 m from the first survey electrode in west direction. Verification of both electrical results with established references has shown some good agreement thus able to convince the result reliability. Hence, the establishment of electrical method in preliminary groundwater assessment was able to assist several parties in term groundwater prospective at study area which efficient in term of cost, time, data coverage and sustainability.

Investigation of chlorinated solvent pollution with resistivity and induced polarization

Globally, an enormous number of polluted areas are in need of remediation to prevent adverse effects on health and environment. In situ remediation and especially the monitoring thereof needs further development to avoid costly and hazardous shipments associated with excavation. The monitoring of in situ remediation actions needs easier and cheaper nondestructive methods for evaluation and verification of remediation degree and degradation status of the contaminants. We investigate the Direct Current resistivity and time-domain Induced Polarization tomography (DCIP) method and its use within the context of a DNAPL (Dense Non-Aqueous Phase Liquids) contaminated site in Varberg, Sweden, where an in situ remediation pilot test has been performed by stimulated reductive dechlorination by push injection. Our results show that the DCIP technique is an emerging and promising technique for mapping of underground structures and possibly biogeochemical spatial and temporal changes. The methodology could in combination with drilling, sampling and other complementary methods give an almost continuous image of the underground structures and delineation of the pollutant situation. It can be expected to have a future in monitoring approaches measuring time lapse induced polarization (IP), if more research is performed on the parameters and processes affecting the IP-signals verifying the interpretations. The IP technique can possibly be used for verification of the effectiveness of in situ remediation actions, as the current sampling methodology is inadequate.

Using a combined electrical resistivity imaging and induced polarization techniques with the chemical analysis in determining of groundwater pollution at Al Misk Lake, Eastern Jeddah, Saudi Arabia

Waste management is one of the most important problems in developing countries. The major concern in this regard is waste dump sites, to both environmental scientists and the general public. At Al Misk (Buraiman) Lake, all the domestic and industrial waste of Jeddah was dumped without any treatment. A concrete dam was constructed to block the migration of contaminants from the lake. The purpose of this research is to determine the efficiency of geophysical methods in delineating the contaminant emanating from the seepage of sewage water from Al Misk Lake to the wadi downstream of the concrete dam. The geophysical studies are used, including the electrical resistivity and induced polarization techniques in conjunction with in-situ hydrogeological studies to define the extension of contamination in both sides of the dam. Two subsurface layers were identified by geophysical techniques. The most of the contamination is restricted in the first layer which is interpreted as a salty sandy layer with high porosity. The average thickness of contaminated layer is about 8 m and has very low resistivity ( 30 Ω.m) than the first layer due to the presence of boulders and gravels with silty sand and, in some places, accumulation of basement boulders also found with high resistivity values (>700 Ω.m). Induced polarization helps to differentiate between the clay and contaminated sandy layer due to the variation of their chargeability values. Induced polarization results show the presence of low resistivity and low chargeability values in the first layer and high chargeability in some parts of the second layer duo to the presence of clay. The contaminations may extend to the deep layers, in the areas of faults and more porosity sediments. The results of electrical conductivity (EC), total dissolved solids analysis, temperature, and pH reveal that the total dissolved solids are very high in the front and the back of the dam, which affect the other parameters. The results concluded that the contaminant plume exists on either side of the dam with the same degree of contamination.

Design of Frequency Domain Induced Polarization Equipment having Optimized Frequency of Signal Transmission

Soil resistivity is measured by resistivity or induced polarization methods. In induced polarization techniques, time domain or frequency domain methods are used. The frequency range of operation is 1-10 Hz. In this paper we have designed a frequency domain induced polarization equipment for 55 v/110 V/220 v range in dc and ac. Frequency selection is done as some cardinal parts 0.1, 1.0, 0.3 and 3.0… up to 10 Hz. The collected data for each of the frequency is used to compute the percentage of frequency effect. The values are to be obtained in different kinds of soil for optimization of frequency. This instrument has wide application in demarcating types of soil/rock for pollution and disaster management studies.

Spectral Induced Polarization Techniques in Soil Corrosivity Assessments

Abstract We presented a laboratory method for investigating the spectral induced polarization (SIP) response of soil samples and the implications for overall soil corrosivity. This study was important in order to advance the understanding of soil electrical properties, which can be used diagnostically to assess infrastructure integrity. Presently, isolated measurements of soil resistivity are the only (electrical) parameters that are routinely used to identify soil corrosivity. Our work showed that the low frequency soil spectral properties may lead to better soil corrosivity assessments when coupled effects from clay and salinity were present. In particular, unfolding and interpreting the soil spectral properties using the Cole-Cole model revealed that the normalized chargeability parameter mn was highly appropriate for identifying the character of potentially corrosive soils.

Achieving 1% NMR polarization in water in less than 1 min using SABRE

The development of biocompatible hyperpolarized media is a crucial step towards application of hyperpolarization in vivo. This article describes the achievement of 1% hyperpolarization of 3-amino-1,2,4-triazine protons in water using the parahydrogen induced polarization technique based on signal amplification by reversible exchange (SABRE). Polarization was achieved in less than 1min.