Summary:The methane production characteristics of anaerobic fermentation using pig manure and distiller's grains as fermentation materials were investigated under five mixing ratios (total solid content (TS) ratio of 100:0, 95:5, 90:10, 80:20, 50:50), and the characteristics of its ternary pH buffer system were studied. The results showed that the mixing ratio significantly affected the methane yield of pig manure and distiller's grains mixed fermentation (P<0.05). When the TS ratio of pig manure to distiller's grains is 95:5, the methane yield is high (271 mL · g -1 (VS added)), which is 6.2% higher than the methane yield of anaerobic fermentation of pure pig manure. The cumulative methane production of two groups with pure pig manure and a TS ratio of 95:5 between pig manure and distiller's grains conforms to the modified Gompertz equation (R2=0.9933; R2=0.9896), with no significant lag period. The large amount of sulfate contained in distiller's grains affects methane production. VFAs Ammonia Nitrogen TIC
The research results on the characteristics of the ternary pH buffer system indicate that due to the severe lack of alkalinity in the distiller's grains, when the amount of distiller's grains added is too large, the system deviates from the appropriate pH buffer zone, the acidity of the system is too high, and anaerobic fermentation is inhibited.