Correlation Between Electrical Resistivity and Moisture Content of Municipal Solid Waste in Bioreactor Landfill

Abstract

The changes in electrical resistivity of municipal solid waste (MSW) measured with electrical resistivity tomography (ERT) have been used to assess the influence of leachate recirculation events at bioreactor landfills. An attempt is made in this study to develop a direct correlation between the electrical resistivity and the moisture content of MSW. This correlation is based on a field testing program at Orchard Hills landfill (Illinois, USA) that included (1) ERT at three different locations that have been subjected to leachate recirculation events, and (2) moisture content of waste samples obtained at different depths from boreholes at the same three locations of ERT. It is shown that Archie's law can reasonably correlate the electrical resistivity and the moisture content of the waste; however, the two parameters, a and m, needed for the correlation appear to depend on the specific waste conditions. For the studied waste, the best fitted parameter a is 0.75 and the parameter m ranges from 1.6 to 2.15. Using this correlation, the influence of leachate recirculation on the distribution of moisture content at three locations of the landfill is evaluated. This study shows that the ERT can be a useful noninvasive technique to monitor the moisture content of MSW and to assess the effectiveness of recirculation systems at bioreactor landfills.