RDF/SRF evolution in the MSW sector: Coexistence of BMT and selective collection

Mechanical biological treatments (MBTs) are extensively used for managing municipal solid waste (MSW). There are four different methods: fertilizer or compost-like output production, biogas/energy production, waste-derived fuel production and disposal in landfills. One issue is the varying characteristics of the waste fed over the lifetime of the plant. This problem is only partially related to the composition dynamics of the generated MSW. Indeed, the main source of input fluctuation of the plant is a result of the implementation of selective collection (SC) strategies, which modify the composition of residual MSW (RMSW). Often the SC strategies are not developed in harmony with the presence or planning of treatment plants, which can consequently suffer from significant variations. A lack of optimization in MSW management strategies and the implementation of new more stringent regulations applied to the final solid products from MBTs could result in a higher tariff for the users. This paper analyses these two problems in terms of two SC scenarios. The consequent effects on the composition of RMSW and on the performance of bio-drying (one of the MBTs options) are discussed. The effect of different SC strategies of MSW is analysed also in terms of RMSW suitability to be converted into refuse derived fuel/solid recovered fuel with simplified treatments. The role of respirometry is also discussed.