Geotechnical and biochemical studies on pre-treated MSW produced in central Italy.

Pre-treatments of Municipal Solid Waste (MSW) are common in all developed countries. Thanks to Mechanical Biological Treatments (MBT) it is possible to separate the recyclable waste, the high calorific fraction for energy recover, the organic fraction for biological stabilization and, finally, the stabilized fraction that has to go into the landfill. The purpose of this work is to study some geotechnical and biochemical aspects of four final fractions resulting from MBT of MSW, in order to outline waste managing strategies in relation to typology and impact of the pretreatments. After a trade analysis, tests were performed on compressibility, biological stability and leachability of the main contaminants. Analyses confirm that the stabilized fine fraction (here referred as under-sieve) is more suitable for storage in landfill, while the gross fraction (here referred as over-sieve) is characterized by higher calorific power.