Ozone pretreatment for the anaerobic digestion of organic solid waste

Abstract

The pretreatment of organic solid waste plays a key role in achieving the highest degree of valorization within the anaerobic digestion processes. This work focuses on the use of ozone, discussing its effects, together with particle size and total solid content of waste, on the anaerobic biodegradability of the organic fraction of municipal solid waste (OFMWS). A Design of Experiment (DOE) strategy was used to identify statistically significant factors for further investigation. Experimental results showed that ozonation increased methane production, with the best results being obtained for samples characterized by the highest total solid content. The surplus methane generated by ozonated samples may also result in favourable net energy gain. These outcomes highlight the effectiveness of ozonation when applied in the pretreatment of OFMSW destined to anaerobic digestion and address the need for an energy balance to assess the competitiveness of this technology on an industrial scale.