Effect of MBT on landfill behavior: an Italian case study

Bad choices in municipal waste (MW) management cause negative effects on sustainability. Evolving regulation has identified prevention and recycling as the best strategies; nevertheless, disposal in landfilling sites plays an essential role since a complete zero-waste scenario is not realistic, currently. Nowadays, policies require a preliminary waste stabilization to decrease the putrescible content. Therefore, mechanical biological treatment (MBT) has replaced the previous crushing, aimed at simple volume reduction. Literature has proved the effectiveness of MBT when MW collection system is ineffective. The present paper considered a facility in an area with a high-performance MW collection system. A long-term (1999–2019) on-site sampling allowed the comparison between two sites of the facility: the old site (before the MBT activation) and the new area, where the stabilized waste is disposed of. Monitoring of biogas, leachate (analyzed parameters: pH, BOD₅, COD, ammonia-nitrogen) and odorous emissions was performed to verify the effect of the stabilization process. The considered long period and the on-site sampling support the relevance of the results, compared to the available literature, often referred to as laboratory scale. The results proved the relatively low benefit of stabilization at the considered facility, which cannot justify the energy consumption of MBT.