Application of electrical resistivity tomography to monitor the dewatering of vertical and horizontal wells in municipal solid waste landfills

Adagunodo

IOP Conf. Ser.: Earth Environ. Sci.

2022

This paper employs the geophysical surveying technique of two-dimensional electrical resistivity imaging (2D ERI) for gaining insights into the causes of incessant road failures being encountered at an industrial hub, along Idiroko Road, in Ota, Ogun State, Nigeria. These utilises occupation of three traverses, each of 100 m for the 2D ERI, constituting a control of a stable road portion, and a stable and unstable portions of a crucial turning along the dual carriage highway of Idiroko Road in Ota. The obtained 2D ERI measurements were rendered to the processing of the RES2DINV software for the derivation of the 2D resistivity inverse model. Results show that the portions of the roads that are stable exhibited higher values of apparent resistivity compared to portions exhibiting frequent road failures. Ensuing sub-surface layer characterisations by the 2D ERI revealed geo-electrical layers exhibiting permeable soil formations that allow water to percolate in the stable portion of the road while the unstable portion depicted presence of water in an impermeable soil formation. These engender recommendations for road construction durability issues that can culminate into system of sustainable road network at the studied industrial hub location in Ogun State, Nigeria.

Section: Survey Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Electrical resistivity application for road failure assessment at an industrial hub in Ogun State, Nigeria

Adagunodo

IOP Conf. Ser.: Earth Environ. Sci.

2022

“…To reduce the leachate levels of sanitary landfills, vertical pumping wells are commonly used for leachate drawdown and drainage. However, their performances vary dramatically as the pumping rate of leachate could be as low as 0 m 3 /d~2 m 3 /d but up to 50 m 3 /d, and previous field measurements demonstrate that the leachate levels commonly decrease insignificantly by using vertical pumping wells [15][16][17][18]. Field monitoring based on electrical resistivity tomography (ERT) shows that the accumulation of landfill gas normally occurs in the MSW beneath the leachate levels [17,18].…”

Section: Introductionmentioning

confidence: 99%

“…However, their performances vary dramatically as the pumping rate of leachate could be as low as 0 m 3 /d~2 m 3 /d but up to 50 m 3 /d, and previous field measurements demonstrate that the leachate levels commonly decrease insignificantly by using vertical pumping wells [15][16][17][18]. Field monitoring based on electrical resistivity tomography (ERT) shows that the accumulation of landfill gas normally occurs in the MSW beneath the leachate levels [17,18]. This causes some local MSW regions to have decreasing saturation degrees and even to be fully filled with entrapped gas.…”

Section: Introductionmentioning

confidence: 99%

Laboratory Model Tests of Leachate Drawdown Using Vertical Drainage Wells with Vacuum Pumping in Municipal Solid Waste Landfills with High Leachate Levels

Ni³

et al. 2022

Sustainability

Municipal solid waste (MSW) landfills in China generally have high leachate mounds, which potentially induce severe geotechnical and environmental issues. In this study, laboratory model tests were carried out to preliminarily investigate the performance of vertical drainage wells accompanied with vacuum pumping (VDW-VP) on leachate drawdown in MSW landfills with high leachate levels. Leachate drawdown tests through VDW-VP under conditions with and without gas injection were performed. Different vacuum pressures (0~−9.5 kPa) were imposed during the tests. Results indicated that the leachate pumping processes for both the two conditions were characterized by a stage of continuous effluent followed by a stage of discontinuous effluent, corresponding to the periods before and after the leachate level in the vertical well dropped to the bottom, respectively. During the stage of continuous effluent, as the vacuum pressure increased, the effluent rate decreased and the leachate level in the vertical well needed a longer time to reach the bottom. During the stage of discontinuous effluent, the leachate level in the MSW gradually approached that in the vertical well. A higher vacuum pressure rendered a larger cumulative leachate pumping volume for the condition with a gas injection, but this was not the case for the condition without a gas injection. In addition, some local pore water pressures were observed to suddenly increase and drop under the condition with the gas injection, attributed to the migration of entrapped gas zones. The increase in vacuum pressure might promote the migration of entrapped gas zones and hence increase the cumulative leachate pumping volume.

“…There are various methods to conduct this exploration. The resistivity method is effective in elucidating the structure and condition of landfills and has been examined in many studies [5][6][7][8][9][10]. The induced polarization (IP) method is effective for the exploration of sulfide minerals with strong polarizability, such as chalcopyrite and pyrite [11][12][13][14].…”

Section: Introductionmentioning

confidence: 99%

Visualization of Rare Metal-Enriched Zones in Waste Landfills Using Induced Polarization Method

Hidari¹,

Miyata²,

Yamazaki³

et al. 2020

Environments

We consider the studied landfill site an urban mine and developed a series of projects on metal endowment forms, nondestructive investigation methods for metal-enriched zones, metal extraction methods from enriched zones, and useful metal selection methods. This paper examines the exploration method. Induced polarization (IP) exploration was carried out at a T disposal site filled in the studied valley. In addition, three drillings were conducted in the studied exploration area. Using the core samples, IP parameters and metal contents were measured. Then, by comparing these data, we examined the effectiveness of the IP method for the visualization of metal-enriched zones in unsaturated landfills. The results of this experiment revealed that the iron-sulfide-enriched zone in the valley filling landfill can be identified by IP exploration. In addition, we clarified the types and contents of rare metals that coexist in iron sulfide. This process allows for further evaluation of landfills as a deposit.