Anaerobic Co-Digestion of Cattle Manure with Corn Stover Pretreated by Sodium Hydroxide for Efficient Biogas Production

Anaerobic co-digestion of cattle manure with NaOH-treated corn stover for biogas production was investigated. Four cattle manure to corn stover ratios (CM/CS) of 1:1, 1:2, 1:3, and 1:4, and three feeding concentrations (FC) of 50, 65, and 80 g L −1 were used. The results showed that the co-digestion with CM/CS ratio of 1:3 obtained the highest total biogas production of 20.5 L, methane yield of 194 mL CH 4 g −1 VS, and TS and VS reductions of 45.0% and 53.0% at the FC of 65 g L −1 . Therefore, the FC of 65 g L −1 and CM/CS ratio of 1:3 was selected as the optimal one. Compared to the single digestion, 4.9−7.4% more biogas productions were obtained at the same FC of 65 g L −1 due to the synergistic effect. The synergistic effect is mainly attributed to more balanced nutrients and increased buffering capacity. It indicated that co-digestion of cattle manure with NaOH-treated corn stover could be one of the options for efficient biogas production and waste treatment.