Long-term settlement magnitude is influenced by changes in external and internal factors that control the microbiological activity in the landfill waste body. To improve the understanding of settlement phenomena, it is instructive to study lysimeters filled with MSW. This paper aims to understand the settlement behavior of MSW by correlating internal and external factors that influence waste biodegradation in a lysimeter. Thus, a lysimeter was built, instrumented and filled with MSW from the city of Campina Grande, the state of Paraíba, Brazil. Physicochemical analysis of the waste (from three levels of depth of the lysimeter) was carried out along with MSW settlement measurements. Statistical tools such as descriptive analysis and principal component analysis (PCA) were also performed. The settlement/compression, coefficient of variation and PCA results indicated the most intense rate of biodegradation in the top layer. The PCA results of intermediate and bottom levels presented fewer physicochemical and meteorological variables correlated with compression data in contrast with the top layer. It is possible to conclude that environmental conditions may influence internal indicators of MSW biodegradation, such as the settlement.

Municipal solid waste (MSW) settlement can be understood as volume reduction of the waste mass disposed in a landfill. Such phenomenon is mainly the result of organic matter degradation. Settlement can also be generated by MSW distortions, particle rearrengements, and other factors. These factors can be accurately analyzed if studied in an MSW experimental cell once it simulates the landfill behavior in a known and controlled way. This study aims to analyze the behavior of an experimental cell filled with MSW and how the biodegradation can influence the settlement over time and depth. The methodology was composed of waste sampling, experimental cell construction and filling, volatile solids analysis, and settlement measurements. The MSW gravimetric and volumetric analyses were performed in order to quantify the amount of organic matter contained inside the experimental cell. The tests indicated that the amount of organic matter drastically decreased in all MSW layers, and settlement varied according to the depth of the experimental cell due to mechanical factors and organic matter consumption.