Assessment of Chromium Waste Contamination by Electrical Resistivity Tomography: A Case Study

2019 ◽  
Vol 24 (1) ◽  
pp. 163-167
Author(s):  
Yuling Wang ◽  
Ya Xu ◽  
Changxin Nai ◽  
Lu Dong

This study aims to determine the chromium contamination at an abandoned chemical factory by electrical resistivity tomography (ERT). Five ERT survey lines were conducted in the main production plant and two boreholes were drilled to collect soil samples for soil analysis. The 2D and 3D resistivity model were constructed to evaluate the pollution plumes. The ERT results showed that seven low-resistivity zones are observed in the 2D resistivity profiles, which may indicate the main pollution areas at the site. The 3D electrical resistivity model further showed that the soil pollution is more severe in the southwest than in the other areas of the site. The ERT results were partly verified by chemical analysis of soil samples. These ERT results can be further used for additional designs of soil and groundwater sampling.

Geophysics ◽  
2006 ◽  
Vol 71 (6) ◽  
pp. B231-B239 ◽  
Author(s):  
Jonathan E. Chambers ◽  
Oliver Kuras ◽  
Philip I. Meldrum ◽  
Richard D. Ogilvy ◽  
Jonathan Hollands

A former dolerite quarry and landfill site was investigated using 2D and 3D electrical resistivity tomography (ERT), with the aims of determining buried quarry geometry, mapping bedrock contamination arising from the landfill, and characterizing site geology. Resistivity data were collected from a network of intersecting survey lines using a Wenner-based array configuration. Inversion of the data was carried out using 2D and 3D regularized least-squares optimization methods with robust (L1-norm) model constraints. For this site, where high resistivity contrasts were present, robust model constraints produced a more accurate recovery of subsurface structures when compared to the use of smooth (L2-norm) constraints. Integrated 3D spatial analysis of the ERT and conventional site investigation data proved in this case a highly effective means of characterizing the landfill and its environs. The 3D resistivity model was successfully used to confirm the position of the landfill boundaries, which appeared as electrically well-defined features that corresponded extremely closely to both historic maps and intrusive site investigation data. A potential zone of leachate migration from the landfill was identified from the electrical models; the location of this zone was consistent with the predicted direction of groundwater flow across the site. Unquarried areas of a dolerite sill were imaged as a resistive sheet-like feature, while the fault zone appeared in the 2D resistivity model as a dipping structure defined by contrasting bedrock resistivities.


2022 ◽  
Vol 8 (1) ◽  
pp. 39-44
Author(s):  
Evi Fazriati ◽  
Asep Purnama ◽  
Gian Agistian Algifari ◽  
Irene Siti Amilah Muslimah ◽  
Fitria Hapsari Puteri Sumanto ◽  
...  

The existence of trees is very beneficial for humans’ life. There are utilizations of tree such as urban planning and reforestation. However, the tree can be dangerous when the tree is aged and decay because of several factors that might be cause fallen tree. Furthermore, the monitoring activity is needed to know the condition of the tree. One of the methods that can be used to detect hollow in living tree is Electrical Resistivity Tomography (ERT). The ERT is an efficient and nondestructive method that can be potential to estimate resistivity cross section. The measurement of ERT conducted on Swietenia mahagoni and Gmelina with unhealthy and healthy condition visually. The data processed using Res2Dinv and reconstructed for obtaining 2D resistivity cross section. The results shows that the unhealthy Swietenia mahagoni has logarithmic resistivity value range between 0.1-1 Ωm and the healthy Swietenia mahagoni has 1-4 Ωm. Meanwhile, the unhealthy and healthy Gmelina has logarithmic resistivity value range between 0.5-4.5 Ωm and 0.5-3 Ωm, respectively. It is shows that the tree indicated health visually from biological view does not mean the tree is decay. It might be influenced by phenology factor and/or the species of the tree.


2021 ◽  
Author(s):  
Lieyana Azffri ◽  
Stefan Herwig Gödeke ◽  
Mohammad Faizan Ibrahim

Abstract Electrical Resistivity Tomography (ERT) and Induced Polarization (IP) study was carried out for groundwater exploration at eight agricultural development areas in Brunei Darussalam. The study was undertaken to meet the growing demands of water supply in the Brunei agricultural sector, particularly for paddy field irrigation. A total of nineteen survey lines with survey lengths of up to 800 m and investigation depths of up to 150 m below ground level were conducted to delineate subsurface geological structures, formations and aquifer zones in the study area. Aquifer zones with resistivity values ranging from 1 to 100 ohm-m and chargeability values of less than 1 mV/V were detected in all surveyed locations. New groundwater well drilling was conducted at two of the surveyed sites based on interpretations of 2D resistivity and chargeability inversion models. Water well drilling encountered aquifer zones, which were primarily in sandy layers. Hydraulic tests revealed groundwater yields of 4.3 and 288 m³/day. Estimated transmissivity values of the aquifer units based on pumping tests are 0.53 and 109 m²/day, while their hydraulic conductivity values are 0.05 and 2.75 m/day. Estimated parameters of the aquifer units indicate weak to moderate groundwater yield for withdrawal and distribution for irrigation purposes at the investigated sites. The present study helped decision-makers take suitable measures for placing future irrigation wells and achieve significant groundwater exploration results in the study area.


Minerals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 491 ◽  
Author(s):  
Sebastian Uhlemann ◽  
Jonathan Chambers ◽  
W. Falck ◽  
Avelino Tirado Alonso ◽  
José Fernández González ◽  
...  

In this study, the use of electrical resistivity tomography (ERT) as a tool to guide ornamental stone extraction is investigated. ERT is not conventionally used in highly resistive environments, such as on rock faces, due to the high contact resistances that can impede current injection. Here, the challenges of conducting ERT in such environments are discussed and possible solutions suggested. For this, an example of the application of ERT in a deep and narrow marble quarry is used. The marble deposit is affected by fracturing and karstification. Due to the nature of these features, they present a significant resistivity contrast to the background resistivity of the marble and thus excellent targets to test the application of ERT. Their location was mapped using field observations and complementary ground penetrating radar data. By using an appropriate sensor deployment, a suitable resistivity meter, and advanced data processing routines, the derived 3D resistivity model is in good agreement with the independent observations. This shows that despite the challenges, ERT can be used as a non-invasive tool to obtain information on the stone properties prior to extraction. This will help in guiding quarry operations and will allow for a targeted, safe and efficient extraction of high quality stone, thereby increasing sustainability and economical competitiveness.


2019 ◽  
Vol 9 (15) ◽  
pp. 2963 ◽  
Author(s):  
Yin-Chun Hung ◽  
Chih-Ping Lin ◽  
Chin-Tan Lee ◽  
Ko-Wei Weng

Electrical resistivity tomography (ERT) is one of the most widely used geophysical methods in geological, hydrogeological, and geo-environmental investigations. Although 3D ERT is now available, 2D ERT remains state-of-the-practice due to its simplicity in fieldwork and lower space requirements. 2D ERT assumes that the ground condition is perpendicular to the survey line and outside the survey line is homogeneous. This assumption can often be violated in conditions such as geologic strikes not perpendicular to the survey line and topographic changes or buried objects near the survey line. Possible errors or artifacts in the 2D resistivity tomogram arising from violating the 2D assumption are often overlooked. This study aimed to numerically investigate the boundary effects on 2D ERT under various simplified conditions. Potential factors including resistivity contrast, depth and size of buried objects, and electrode spacing were considered for the parametric studies. The results revealed that offline geologic features may project onto the 2D tomogram to some extent, depending on the aforementioned factors. The mechanism and implications of boundary effects can be drawn from these parametric studies.


2021 ◽  
Vol 13 (1) ◽  
pp. 1328-1344
Author(s):  
Amr Abd El-Raouf ◽  
Ibrar Iqbal ◽  
Julia Meister ◽  
Kamal Abdelrahman ◽  
Hassan Alzahrani ◽  
...  

Abstract In this study, we investigated the stability and reactivation of preexisting Tonghua landslide deposits in China, including the adjacent stable slope. We used an integrated approach, combining a multichannel analysis of surface waves (MASW) and electrical resistivity tomography (ERT). We used ERT to determine groundwater seepage paths, weathering conditions, water content, and the depth to bedrock. High-resolution two-dimensional (2D) shear-wave velocity MASW images, on the other hand, played an essential role in detecting both horizontal and vertical compositions, disjointedness, and sliding surfaces related to lithological borders. Based on seismic models, we considered four geological layers encountered in the stable slope, including fractured (gravel) and weathered (phyllite) materials, as a sliding mass. We combined the 2D resistivity profiles obtained to create pseudo-three-dimensional ERT images to estimate water-saturated and unsaturated masses. From the tomography results, we identified different preexisting deposits, including buried arable clay deposits, old accumulated earthflow deposits, a water accumulation zone, and a fissure runoff. Based on the resistivity results, the bottom of the earthflow deposits is susceptible to water, and oversaturation can reactivate the earthflow.


2021 ◽  
Vol 47 (2) ◽  
pp. 597-608
Author(s):  
Mutiu A Fakunle ◽  
Muhydeen A Ibraheem ◽  
Wasiu B Agbaje ◽  
Luqman A Abidoye

The presence of Petroleum Hydrocarbons (PHCs) in hand-dug wells has become a concern to the residents of Ayetoro area, Osogbo. Consequently, the detection of PHCs was evaluated using, nine Vertical Electrical Soundings (VES) and 2D electrical resistivity tomography surveys. Soil samples collected were analyzed for porosity and permeability. Hand-dug well water samples were screened for PHCs. VES revealed that second layer had high apparent resistivity of 14415.0 Ωm, indicating presence of PHCs that had penetrated to maximum depth of 19.1 m. The highest resistivity of the control points was 48.0 Ωm, indicating absence of PHCs. The 2D resistivity revealed highest value of 3622 Ωm and had migrated to a depth of 10.0 m. The porosity (0.40) and permeability (6.87516 x 10–4 cm/s) were typical of silty clay which allowed passage of PHCs. Hydro-chemical analysis indicated presence of PHCs (0.50–11.00 mg/L). The study has established presence of PHCs in soils and hand-dug wells. Keywords: Petroleum Hydrocarbons, Soil, Groundwater, Electrical resistivity tomography


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
A. Troiano ◽  
R. Isaia ◽  
M. G. Di Giuseppe ◽  
F. D. A. Tramparulo ◽  
S. Vitale

Abstract The central sector of the Campi Flegrei volcano, including the Solfatara maar and Pisciarelli fumarole field, is currently the most active area of the caldera as regards seismicity and gaseous emissions and it plays a significant role in the ongoing unrest. However, a general volcano-tectonic reconstruction of the entire sector is still missing. This work aims to depict, for the first time, the architecture of the area through the application of deep Electrical Resistivity Tomography. We reconstructed a three-dimensional resistivity model for the entire sector. Results provide useful elements to understand the present state of the system and the possible evolution of the volcanic activity and shed solid bases for any attempt to develop physical-mathematical models investigating the ongoing phenomena.


2008 ◽  
Vol 45 (3) ◽  
pp. 367-387 ◽  
Author(s):  
Richard Fortier ◽  
Anne-Marie LeBlanc ◽  
Michel Allard ◽  
Sylvie Buteau ◽  
Fabrice Calmels

A systematic approach was used for the interpretation of the electrical resistivity tomography carried out on two permafrost mounds at Umiujaq in Nunavik, Canada, to assess their internal structure and conditions. Prior information under the form of a geocryologic model of the permafrost mounds was integrated in the inversion of the pseudo-section of apparent electrical resistivity. The geocryologic model was developed from the synthesis of previous field investigations, including shallow and deep sampling, temperature and electrical resistivity logging, and cone penetration tests performed in the permafrost mounds. Values of electrical resistivity were ascribed to the different layers making of the geocryologic model to define a synthetic resistivity model of the permafrost mounds used as a reference model to constrain the inversion. The constrained resistivity model clearly show the presence of ice-rich cores in the permafrost mounds underscored by high resistivity values in excess of 30 000 Ωm, while the unfrozen zones surrounding the permafrost mounds are characterized by resistivity values lower than 1000 Ωm. The spatial distribution of unfrozen water and ice contents in the permafrost mounds were also assessed according to empirical relationships between the electrical resistivity and water contents. The ice content is highly variable and can be as high as 80% in the ice-rich cores, while the unfrozen water content varies between 2% and 5%. The integration of prior information in the inversion process leads to a more realistic constrained resistivity model showing sharp resistivity contrasts expected at the boundaries such as the permafrost table and base.


2020 ◽  
Vol 60 ◽  
pp. 139-145
Author(s):  
Dilli Ram Thapa

The presence of collapse masses in the subsurface causes severe problems in the geotechnical design activities. In this study, two dimensional Electrical Resistivity Tomography (2D-ERT) synthetic modelling techniques were used to detect collapse masses commonly found in the river bank. Two dimensional (2D) resistivity models are first created utilizing prior information of collapsed masses in the river bank and afterward inverted to reconstruct the resistivity distribution in the subsurface. The resulting two dimensional models exhibits that collapsed masses can be better detected particularly  at low resistivity noise level (2%) than the high noise levels (5% and 10%). The models are particularly very useful prior to executing the field investigations in the river bank sites and furnish the subsurface geology as well as the successful interpretation of the results withconfidence.


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