Influence of ultrasound irradiation pre-treatment in biohythane generation from the thermophilic anaerobic co-digestion of sugar production residues

The objective of this study was to evaluate the effects of sonication on the biogas production dynamics of sugarcane straw and vinasse in an anaerobic digestion. Two different ultrasound pretreatments were evaluated namely 180 W of ultrasonic power irradiated at 37 kHz for 30 min (PBU) and 800 W of ultrasonic power irradiated at 19 kHz for 15 min (PSU). Significant differences were observed in the biogas compositions of the PBU and PSU pretreatments and their respective controls. A continuous increase in methane concentration of the biohythane (biohydrogen and methane combined) was recorded in the PBU reactors (60-80% by volume). The main effect of ultrasound pretreatment was on the composition biohydrogen, methane and carbon dioxide (biohythane) produced.