title: Influence of the geomembrane on time-lapse ERT measurements for leachate injection monitoring.
abstract: Leachate recirculation is a key process in the operation of municipal waste landfills as bioreactors. To quantify the water content and to evaluate the leachate injection system, in situ methods are required to obtain spatially distributed information, usually electrical resistivity tomography (ERT). However, this method can present false variations in the observations due to several parameters. This study investigates the impact of the geomembrane on ERT measurements. Indeed, the geomembrane tends to be ignored in the inversion process in most previously conducted studies. The presence of the geomembrane can change the boundary conditions of the inversion models, which have classically infinite boundary conditions. Using a numerical modelling approach, the authors demonstrate that a minimum distance is required between the electrode line and the geomembrane to satisfy the good conditions of use of the classical inversion tools. This distance is a function of the electrode line length (i.e. of the unit electrode spacing) used, the array type and the orientation of the electrode line. Moreover, this study shows that if this criterion on the minimum distance is not satisfied, it is possible to significantly improve the inversion process by introducing the complex geometry and the geomembrane location into the inversion tools. These results are finally validated on a field data set gathered on a small municipal solid waste landfill cell where this minimum distance criterion cannot be satisfied.
authors: National Research Institute of Science and Technology for Environment and Agriculture (IRSTEA), Hydrosystems and Bioprocesses Research Unit, 1 rue Pierre Gilles de Gennes, CS 10030, 92761 Antony Cedex, France. Electronic address: marine.audebert@irstea.fr.
authors: M
authors: M
authors: Audebert
authors: National Research Institute of Science and Technology for Environment and Agriculture (IRSTEA), Hydrosystems and Bioprocesses Research Unit, 1 rue Pierre Gilles de Gennes, CS 10030, 92761 Antony Cedex, France. Electronic address: remi.clement@irstea.fr.
authors: R
authors: R
authors: Clément
authors: National Research Institute of Science and Technology for Environment and Agriculture (IRSTEA), Hydrosystems and Bioprocesses Research Unit, 1 rue Pierre Gilles de Gennes, CS 10030, 92761 Antony Cedex, France. Electronic address: j.grossin-debattista@irstea.fr.
authors: J
authors: J
authors: Grossin-Debattista
authors: Leibniz Institute for Applied Geophysics (LIAG), Stilleweg 2, D-30655 Hannover, Germany. Electronic address: thomas.guenther@liag-hannover.de.
authors: T
authors: T
authors: Günther
authors: National Research Institute of Science and Technology for Environment and Agriculture (IRSTEA), Hydrosystems and Bioprocesses Research Unit, 1 rue Pierre Gilles de Gennes, CS 10030, 92761 Antony Cedex, France. Electronic address: nathalie.touze@irstea.fr.
authors: N
authors: N
authors: Touze-Foltz
authors: National Research Institute of Science and Technology for Environment and Agriculture (IRSTEA), Hydrosystems and Bioprocesses Research Unit, 1 rue Pierre Gilles de Gennes, CS 10030, 92761 Antony Cedex, France. Electronic address: sylvain.moreau@irstea.fr.
authors: S
authors: S
authors: Moreau
mesh_terms: D019149:Bioreactors; D017097:Electric Impedance; D018505:Waste Management; D014867:Water / Q000032:analysis
chemical_list: D014867:Water
keywords: ERT; Geomembrane; Landfill; Leachate; Monitoring; Resistivity