scholarly journals Electrical resisitivity to detect zones of biogas accumulation in a landfill

2015 ◽  
Vol 54 (4) ◽  
Author(s):  
César Augusto Moreira ◽  
Thais Munhoz ◽  
Fernanda Cavallari ◽  
Lívia Portes Innocenti Helene
Keyword(s):  
Electrical Resistivity ◽  
Organic Matter ◽  
Oil And Gas ◽  
Biogas Production ◽  
High Resistivity ◽  
Resistivity Tomography ◽  
Resistivity Measurements ◽  
Sanitary Landfills ◽  
Surface Drains

Biogas produced in sanitary landfills consists in a potential source, formed by degradation of organic matter, this gas is constituted by CH4, CO2 and water vapor. Sanitary landfills represent important depository of organic matter with great energetic potential in Brazil, although presently with inexpressive use. Estimates for production or maintenance of productive rates of CH4 represent one of the main difficulties of technical order to the planning and continuity of collection systems for rational consumption of this resource. Electrical resistivity measurements are routinuously used in profiling oil wells for the determination of levels with accumulations of oil and gas, facing the contrast among fluids and rocks. This paper aims to evaluate eventual relationship among biogas flow quantified in surface drains of a waste cell in landfill, with characteristic patterns of in depth electrical resistivity. The integration of Electrical Resistivity Tomography (ERT) lines allowed for the generation of 3D blocks and a clear distinction among zones of high biogas production, quantified in surface drains, with areas of high resistivity in depth. The results suggest the possibility of use of the method in studies to place drains in areas promising to the collection of biogas for energetic generation in sanitary landfill.

scholarly journals Determination of dipping contacts using electrical resistivity tomography

2012 ◽  
Vol 42 (2) ◽  
pp. 161-180
Author(s):  
René Putiška ◽  
Ivan Dostál ◽  
David Kušnirák
Keyword(s):  
Electrical Resistivity ◽  
Electrical Resistivity Tomography ◽  
Image Resolution ◽  
High Resistivity ◽  
Depth Range ◽  
Electrode Arrays ◽  
Resistivity Tomography ◽  
Imaging Geometry ◽  
Lithostratigraphic Units

Determination of dipping contacts using electrical resistivity tomographyGenerally, all electrode arrays are able to delineate the contact of two lithostratigraphic units especially with very high resistivity contrast. However, the image resolution for the location of vertical and dipping structures is different. The responses of dipole-dipole (DD), Wenner alpha (WA), Schlumberger (SCH) and combined pole-dipole (PD) arrays have been computed using the finite difference method. Comparison of the responses indicates that: (1) The dipole-dipole array usually gives the best resolution and is the most detailed method especially for the detection of vertical structures. This array has shown the best resolution to recognize the geometrical characterisation of the fault. (2) The pole-dipole has shown the second best result in our test. The PD is an effective method for detection of vertical structures with a high depth range, but the deepest parts are deformed. (3) Wenner alpha shows a low resolution, inconvenient for detailed investigation of dip structures. (4) The Schlumberger array gives a good and sharp resolution to assess the contact between two lithological units but gives poor result for imaging geometry of dipping contact.

scholarly journals RELATIONSHIP BETWEEN BIOGAS PRODUCTION AND VARIATIONS IN ELECTRIC RESISTIVITY IN LANDFILL OF RIO CLARO CITY, BRAZIL

2015 ◽  
Vol 33 (2) ◽  
Author(s):  
César Augusto Moreira ◽  
Marcus Cesar Avezum Alves De Castro ◽  
Leonardo Paioli Carrazza ◽  
Fernanda Cavallari ◽  
Lívia Portes Innocente Helene ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Organic Matter ◽  
Seasonal Variation ◽  
Biogas Production ◽  
Gas Production ◽  
Electric Resistivity ◽  
High Resistivity ◽  
Dc Resistivity ◽  
Geophysical Logging ◽  
Resistivity Logging

ABSTRACT. This work relates measures of the biogas flow in drains located on landfill with measurements of electric resistivity, obtained by the technique of geophysical logging by measuring cable installed in two vertical boreholes near to two biogas drains, with different flows. The results indicate that variation in rainfall, generation and accumulation of biogas in landfill, are repairable correlation with oscillations in electrical resistivity measures. The biogas production is apparently conditioned by age of residues and organic matter available from the degradation. The biogas drain in region with low production of biogas does not present resistivity pattern directly or indirectly correlated to biogas production, while the biogas drain in region with high gas production was characterized by high resistivity values, with seasonal variation by influence of rainfall.Keywords: methane, organic matter, rainfall, DC resistivity, logging. RESUMO. Este trabalho relaciona medidas da vazão de biogás, em drenos localizados em aterro sanitário, com medidas de resistividade elétrica, obtida pela técnica de perfilagem geofísica por meio de cabos instalados próximos a dois drenos de biogás com diferentes vazões. Os resultados indicaram que variações de pluviosidade, geracão e acumulação de biogás no aterro são passíveis de correlação com oscilações em medidas de resistividade elétrica. A produção de biogás é aparentemente condicionada à idade dos resíduos e à disponibilidade de matéria orgânica passível de degradação. O dreno de baixa vazão não apresentou um padrão de resistividade direta ou indiretamente correlacionável com a produção de biogás. A região do dreno de alta vazão foi caracterizada por alta resistividade, com variações sazonais por influencia de chuvas.Palavras-chave: metano, matéria orgânica, chuva, eletrorresistividade, perfilagem.

scholarly journals Comparative Analysis between Biogas Flow in Landfill and Electrical Resistivity Tomography in Rio Claro City, Brazil

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
César Moreira ◽  
Marcus Castro ◽  
Ana Gonsalez ◽  
Fernanda Cavallari ◽  
Thais Munhoz ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Organic Matter ◽  
Comparative Analysis ◽  
Anaerobic Degradation ◽  
Electrical Resistivity Tomography ◽  
Dc Resistivity ◽  
Resistivity Tomography ◽  
Resistivity Method ◽  
Methods And Techniques ◽  
Hydrogeological Studies

The biogas originated from anaerobic degradation of organic matter in landfills consists basically in CH4, CO2, and H2O. The landfills represent an important depository of organic matter with high energetic potential in Brazil, although with inexpressive use in the present. The estimation of production of the productive rate of biogas represents one of the major difficulties of technical order to the planning of capture system for rational consumption of this resource. The applied geophysics consists in a set of methods and techniques with wide use in environmental and hydrogeological studies. The DC resistivity method is largely applied in environmental diagnosis of the contamination in soil and groundwater, due to the contrast of electrical properties frequent between contaminated areas and the natural environment. This paper aims to evaluate eventual relationships between biogas flows quantified in drains located in the landfill, with characteristic patterns of electrical resistivity in depth. The drain of higher flow (117 m3/h) in depth was characterized for values between 8000 Ω·m and 100.000 Ω·m, in contrast with values below 2000 Ω·m, which characterize in subsurface the drain with less flow (37 m3/h), besides intermediary flow and electrical resistivity values, attributed to the predominance of areas with accumulation or generation of biogas.

scholarly journals Electrical resistivity tomography applied to geologic, hydrogeologic, and engineering investigations at a former waste-disposal site

Geophysics ◽  
2006 ◽  
Vol 71 (6) ◽  
pp. B231-B239 ◽  
Author(s):  
Jonathan E. Chambers ◽  
Oliver Kuras ◽  
Philip I. Meldrum ◽  
Richard D. Ogilvy ◽  
Jonathan Hollands
Keyword(s):  
Electrical Resistivity ◽  
Electrical Resistivity Tomography ◽  
Site Investigation ◽  
High Resistivity ◽  
Potential Zone ◽  
Resistivity Tomography ◽  
L2 Norm ◽  
Resistivity Model ◽  
2D And 3D ◽  
2D Resistivity

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.

scholarly journals Exploring the regolith with electrical resistivity tomography in largescale surveys: electrode spacing related issues and possibility

2020 ◽  
Author(s):  
Laurent Gourdol ◽  
Rémi Clément ◽  
Jérôme Juilleret ◽  
Laurent Pfister ◽  
Christophe Hissler
Keyword(s):  
Electrical Resistivity ◽  
Apparent Resistivity ◽  
Large Scale ◽  
Electrical Resistivity Tomography ◽  
Subsurface Layer ◽  
Electrode Spacing ◽  
High Resistivity ◽  
Constant Thickness ◽  
Resistivity Tomography

Abstract. Within the Critical Zone, regolith plays a key role in the fundamental hydrological functions of water collection, storage, mixing and release. Electrical Resistivity Tomography (ERT) is recognized as a remarkable tool for characterizing the geometry and properties of the regolith, overcoming limitations inherent to conventional borehole-based investigations. For exploring shallow layers, a small electrode spacing (ES) will provide a denser set of apparent resistivity measurements of the subsurface. As this option is cumbersome and time-consuming, smaller ES – albeit offering poorer shallow apparent resistivity data – are often preferred for large horizontal ERT surveys. To investigate the negative trade-off between larger ES and reduced accuracy of the inverted ERT images for shallow layers, we use a set of synthetic conductive/resistive/conductive three-layered soil–saprock/saprolite–bedrock models in combination with a reference field dataset. Our results suggest that an increase in ES causes a deterioration of the accuracy of the inverted ERT images in terms of both resistivity distribution and interface delineation and, most importantly, that this degradation increases sharply when the ES exceeds the thickness of the top subsurface layer. This finding, which is obvious for the characterization of shallow layers, is also relevant even when solely aiming for the characterization of deeper layers. We show that an oversized ES leads to overestimations of depth to bedrock and that this overestimation is even more important for subsurface structures with high resistivity contrast. To overcome this limitation, we propose adding interpolated levels of surficial apparent resistivity relying on a limited number of ERT profiles with a smaller ES. We demonstrate that our protocol significantly improves the accuracy of ERT profiles when using large ES, provided that the top layer has a rather constant thickness and resistivity. For the specific case of large-scale ERT surveys the proposed upgrading procedure is cost-effective in comparison to protocols based on small ES.

scholarly journals An Extension of the Data-Adaptive Probability-Based Electrical Resistivity Tomography Inversion Method (E-PERTI)

Geosciences ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 380
Author(s):  
Marilena Cozzolino ◽  
Paolo Mauriello ◽  
Domenico Patella
Keyword(s):  
Electrical Resistivity ◽  
Apparent Resistivity ◽  
Electrical Resistivity Tomography ◽  
Inversion Method ◽  
Resistivity Tomography ◽  
Synthetic Test ◽  
Statistical Determination ◽  
Data Adaptive ◽  
Tomography Inversion

About a decade ago, the PERTI algorithm was launched as a tool for a data-adaptive probability-based analysis of electrical resistivity tomography datasets. It proved to be an easy and versatile inversion method providing estimates of the resistivity values within a surveyed volume as weighted averages of the whole apparent resistivity dataset. In this paper, with the aim of improving the interpretative process, the PERTI method is extended by exploiting some peculiar aspects of the general theory of probability. Bernoulli’s conceptual scheme is assumed to comply with any resistivity dataset, which allows a multiplicity of mutually independent subsets to be extracted and analysed singularly. A standard least squares procedure is at last adopted for the statistical determination of the model resistivity at each point of the surveyed volume as the slope of a linear equation that relates the multiplicity of the resistivity estimates from the extracted data subsets. A 2D synthetic test and a field apparent resistivity dataset collected for archaeological purposes are discussed using the new extended PERTI (E-PERTI) approach. The comparison with the results from the original PERTI shows that by the E-PERTI approach a significantly greater robustness against noise can be achieved, besides a general optimisation of the estimates of the most probable resistivity values.

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