Evolution of Electrical Resistivity Measurements during Process of Waste Biodegradation

Electrical Resistivity Tomography (ERT) is applied in bioreactor landfill for many years to monitor leachate variation in waste body (Moreau et al., 2007, Rosqvist et al., 2006), mainly during recirculation events when moisture content variations induced by liquid diffusion are the most important. Influence of moisture content and temperature is recognised to be significant on waste electrical resistivity (Clément et al., 2011). Nevertheless, impact of waste biodegradation should not be forgotten (Moreau et al., 2011): the assumption of a medium, electrically neutral, could not be considered in waste studies. Influence of the different steps of waste mass biodegradation on electrical resistivity measurements was studied with laboratory tests. Resistivity of well known waste composition was compared to biogas production to achieve this goal. Resistivity device was evaluated using simulation software developed by Clément (F3D-Lab, 2011) and the interpreted resistivity was calculated using BERT software package (Guenther, 2011. The resistivity variation observed on one cell can be linked to biogas production, which can not be confirmed by the tests on the other cells for the moment. Field capacity seems limiting to induce a fast biodegradation of waste mass which can be problematic for landfill generally operated with that hydraulic condition.