Estimating Moisture Content of Landfilled Municipal Solid Waste without Drilling: Innovative Approach

Abstract

The understanding of moisture content distribution within municipal solid waste (MSW) in a landfill due to leachate recirculation plays an important role in designing and optimizing the operation of a leachate recirculation system. Electrical resistivity imaging (ERI) is one of the many methods that have been used in the field to monitor the moisture distribution and moisture movement within the MSW in a landfill. The objective of this paper is to develop a correlation between electrical resistivity and moisture content of waste so that in situ moisture content of MSW can be determined without direct sampling and laboratory testing. To achieve this objective, an experimental program was developed to study the variation of electrical resistivity of MSW with moisture content and other factors that affect resistivity. The electrical resistivity of fresh MSW samples collected from the working face and partially degraded landfilled MSW samples collected from closed sections of the landfill using a bucket auger sampler were determined in the laboratory. The effect of moisture content, unit weight, stage of decomposition, temperature, waste composition, and pore fluid composition on electrical resistivity was correlated. Experimental results showed that electrical resistivity of MSW is affected by moisture content, unit weight, decomposition, temperature, and composition of waste. The effect of pore fluid composition on the resistivity of MSW was not significant. The test results indicate that ERI can provide the moisture content information within the landfilled solid waste, and direct sampling may not be needed to determine the moisture content within the MSW in a landfill.