PRELIMINARY STUDY OF THE COMPRESSIBILITY OF MUNICIPAL SOLID WASTE IN INDONESIAN LANDFILL

Abstract

The lack of studies on the compressibility of Municipal Solid Waste (MSW) increase the uncertainty in the design and monitoring of the landfill settlement in Indonesia. This study aims to assess the compressibility of MSW in Indonesian landfill. Compression cell was made with a diameter and height of the mold at 350- and 500 mm. Compression test performed with the initial pressure of 2.04 kPa, and was increased every 24 hours, with the constant addition of 2.04 kPa, until reached a pressure of 10.20 kPa. Test performed on; paper waste with medium density (Paper_MD), paper waste with high density (Paper_HD) and compost with medium density (Compost_MD). For Paper_MD and Paper_HD, moisture content of the sample was reduced by 4.45% and 1.39% (% of wet weight), whereas in Compost_MD, the moisture content of the samples did not change. End of immediate compression (ε_EOI) detected after 6 hours for Paper_MD, and 4 hours for Paper_HD and Compost_MD. Immediate compression ratio (C_c’) obtained at 0.2949, 0.0696 and 0.0932, each for Paper_MD, Paper_HD and Compost_MD. While, secondary compression ratio (C_α) for Paper_MD, Paper_HD and Compost_MD, respectively - each 0.0211, 0.0056 and 0.0060. The bulk density of the sample at the end of the test for Paper_MD and Compost_MD, respectively increased by 20.12% and 6.70%, while the bulk density at Paper_HD was not increased. From this study, it was shown that the compressibility of the waste sample is inversely proportional to the initial density, and directly proportional to the ability to drain the leachate.