Time Domain Reflectometry for Water Content Measurement of Municipal Solid Waste

Water content measurement of municipal solid waste (MSW) is critical to water balance analysis of landfill, leachate collection and recirculation, and acceleration of MSW degradation. Time domain reflectometry (TDR) is commonly applied to soils for the measurement of water content. Application of TDR methods for moisture measurement in MSW is difficult, because MSW is a heterogeneous and highly conductive material. This study investigated the application of TDR surface reflection method for the determination of apparent dielectric constant and water content of MSW. A series of experiments were conducted to study the dielectric properties of MSW and its main components such as paper, plastic, and organics. Results indicate that the effect of waste material type seems to be negligible on the measurement of water content. TDR technique can effectively measure the intrinsic water of organics in the absence of significant bound water effects. Results of dielectric constant by surface reflection method gave similar accuracy as the conventional travel time analysis for waste materials with low electrical conductivities. In addition, surface reflection method provides higher accuracy for waste materials with high electrical conductivities than travel time analysis. This research provides experimental basis for the use of TDR surface reflection method in landfills.