Improvement of Methane Production from Corn Stalk for Whole Slurry Anaerobic Co-digestion Under Hydrothermal Wastewater Pretreatment

Corn stalk hydrothermal wastewater(CSHW) was used as a pretreatment for whole-slurry anaerobic co-digestion instead of conventional acid pretreatment. CSHW pretreatment was conducted at 20℃, 35℃ and 50℃ for 3, 6 and 9 h, after which all experimental groups were digested at 35℃ for 24 days. This pretreatment method efficiently broke the lignocellulose structure of the corn stalk. Different from the volatile fatty acids(VFAs) content, the p H and RS contents were relatively higher than those of the control during the pretreatment process. Furthermore, the highest methane production [185.03 m L·g-1VS(volatile solid)] was achieved at 55.46% under 35℃ in6 h, which was higher than that of the normal corn stalk anaerobic digestion. The VFAs contents and p H increased compared to CK upon the addition of Na OH to adjust p H, and the RS content also increased slightly due to the degradability of lignocellulose during the whole-slurry anaerobic co-digestion. This work provided a potential method to sustainably treat wastewater and improve fermentation performance.