Characterization of MBT plants input and outputs: a review

Mechanical–biological treatment (MBT) plants treat municipal solid waste (MSW), residual after source separation, with the aim to minimize the environmental impact associated with the residues landfilling and to add values to waste outflows for a potential utilization. MBT consists in a combination of mechanical processes (shredding, size, density and magnetic separation, densification, etc.) and biological treatment (aerobic or anaerobic degradation) of the organic fraction mechanically separated. In this work a review regarding the MBT input and outputs characterization is presented with the aim to evaluate the quality of them and the effectiveness of MBT plants to produce materials that can be utilized for material/energy recovery. A strong variability of the different flows characteristics, mainly due to the heterogeneity of the input MSW and to the different configurations of processing units employed in MBT plants, was highlighted. Therefore most suitable end-uses or disposal for the MBT outputs are site-specific and should be related to prior detailed characterizations of the materials able to identify specific quality classes defined by proper technical standards.