Organic solid waste biological treatment facilities: comparative analysis of process schemes

The biological treatment of the organic fraction of municipal solid waste represents the most spread strategy to pursue the biological stabilization of this residual stream, under either aerobic or anaerobic conditions. Anaerobic digestion is an attractive technology for the conversion of organic substrates into methane, but the handling of the residual stream, namely the digestate, can prove to be challenging, especially in those countries where any Regulation has been enforced to discipline its proper use. In order to overcome this drawback, while taking the greatest advantage from the organic solid waste biostabilization in the circular economy view, the proper combination of both aerobic and anaerobic processes can be implemented. At full-scale the combined anaerobic/aerobic treatment entails a high technological complexity, so that the careful monitoring of the overall process is fundamental to ensure its proper development.This study aims at assessing the process performances of full-scale plants, differently combining the anaerobic process with an aerobic step. To this end, mass flow analysis was used, so as to comparatively discuss the yields of complex biological treatment facilities.