Hydrothermal pretreatment for biogas production from anaerobic digestion of antibiotic mycelial residue

• Hydrothermal pretreatment eliminated the hindrance of residual antibiotics.
• Anaerobic digestion performance was much improved for hydrothermally treated MAR.
• The optimal hydrothermal pretreatment condition was 120 °C for 60 min.
• The highest methane yield reached 290 ml/g VS.

This paper aims at investigating the effect of hydrothermal pretreatment on anaerobic digestion of antibiotic mycelial residue (AMR) for biogas production based on batch laboratory experiments. The pretreatment temperature and time varied from 80 to 180 °C and from 0 to 60 min, respectively. The results show that the hydrothermal pretreatment could degrade the organic particulates in AMR into soluble and even small-molecule substances to significantly improve the anaerobic digestibility of AMR and greatly facilitate biogas production. The biogas yield increased with increasing pretreatment temperature and time when the temperature was not higher than 120 °C, and a higher temperature did not significantly facilitate the biogas production and even lead to a lower biogas yield, especially when the pretreatment temperature time was excessively long. The hydrothermal pretreatment at 120 °C for 60 min gave the best digestion performance, and the corresponding methane and biogas yields reached 290 and 446 ml/g VS, respectively.