Characterization of Excavated Waste of Different Ages in View of Multiple Resource Recovery in Landfill Mining

With the aim of examining the forcing factors in postmanagement landfills, in this study, excavation waste from nonhazardous municipal waste landfill in Tuscany was characterized for the first time. The specific objective was to estimate the feasibility of sampling and analyzing the excavated waste in order to define its properties and provide information about possible landfill mining projects. Based on the biochemical methane potential assays, it was shown that the excavated waste had not yet been stabilized (i.e., with a production of 52.2 +/- 28.7 NlCH(4)/kgTS) in the landfill, probably due to the low excavated waste moisture content (36% +/- 6% w/w). Furthermore, excavated waste has a high calorific value, i.e., 15.2 +/- 4.1 MJ/kg; the quantity of combustibles in the industrial shredder waste (16 MJ/kg) was rather modest compared to that of municipal solid waste (20.8 MJ/Kg). In conclusion, during large scale excavation of the landfill, it was possible to evaluate how a dedicated treatment plant could be designed to treat and select waste which might appear in a different category. For excavated industrial waste, detailed mechanical sorting may be convenient for end-of-waste recovery to improve calorific value.