Abstract: Disclosed is a method for producing biogas from a waste liquid/residue after diosgenin extraction by aluminum chloride. Specifically, in a fermentation vessel, an anaerobic sludge and a waste residue from diosgenin extraction by aluminum chloride are added at a volatile solids ratio of (1-3):(1-2), or a seeding sludge and a diosgenin waste liquid are added with an organic loading having a VS:COD ratio of (1-2):(1-2); and then the above components are fermented at 35-37° C. for 5-25 d such that biogas is produced. According to the method of the present invention, the maximum cumulative biogas production rates are 255.4 mL/g VS for waste residue and 326.9 mL/g COD for waste liquid, and throughout the fermentation period, ammoniacal nitrogen values are below 1500 mg/L and pH variation is within the normal range, and the COD removal rate for the fermentation broth is 91.11%.

Abstract: Disclosed is a method for producing biogas from a waste liquid/residue after diosgenin extraction by aluminum chloride. Specifically, in a fermentation vessel, an anaerobic sludge and a waste residue from diosgenin extraction by aluminum chloride are added at a volatile solids ratio of (1-3):(1-2), or a seeding sludge and a diosgenin waste liquid are added with an organic loading having a VS:COD ratio of (1-2):(1-2); and then the above components are fermented at 35-37° C. for 5-25 d such that biogas is produced. According to the method of the present invention, the maximum cumulative biogas production rates are 255.4 mL/g VS for waste residue and 326.9 mL/g COD for waste liquid, and throughout the fermentation period, ammoniacal nitrogen values are below 1500 mg/L and pH variation is within the normal range, and the COD removal rate for the fermentation broth is 91.11%.