Laboratory investigation of compaction characteristics of fresh and degraded municipal solid waste

Abstract

Compaction characteristics of municipal solid waste (MSW) are the important parameters in the landfill design. Well compacted MSW increases the placement efficiency and thus reduces the space requirement for landfills. The composition of MSW, degradation, and compactive efforts are the key factors that control the compaction characteristics of MSW. This paper presents the laboratory investigation of compaction characteristics of fresh and aged MSW at a wide range of compactive efforts. Fresh MSW (S1), Windrows sample (S2) of an age of 2 months, 5-year-old MSW (S3), 10-year-old MSW (S4), and 15-year-old MSW (S5) were collected from the working phase of the solid waste management site, Vilholi Nasik, (MH) India. Compaction was carried in 1000 mL capacity mold under four different energy levels, i.e., 552 (E1), 1125 (E2), 2682 (E3), and 5364 (E4) kJ/m3. The results showed that the maximum dry density (γdmax) was observed less in the S1 sample at the standard compactive effort. As the age of the sample increase from fresh to 5 years, γdmax was more with lesser optimum moisture content (wopt) because of the completion of the biodegradation process. No further change in compaction characteristics was observed once the biodegradation process was finished. The study shows that the particle size of MSW gets reduced as the age of the sample increased. This reduces the particle size of MSW is one of the contributing factors to increasing γdmax. When compactive energy is changed from E1 to E4 the γdmax increased and wopt decreased for all the samples. A normalized wopt and compaction energy correlation is proposed in this study. The correlation can get compaction characteristics of fresh and aged MSW at any compactive effort.