Start-up Performances of Dry Anaerobic Mesophilic and Thermophilic Digestion of Kitchen Waste and Cow Manure

Two dry anaerobic digestions of Kitchen' Waste and Cow Manure were conducted in a lab-scale experiment for investigating the start-up performances under mesophilic and thermophilic conditions. According to CBP, BPR, pH value and VFAs change, the. start-up performances were separated 3 stages: adaption stage, fluctuation stage and stabilization stage. The effective start-up of the system was achieved in approximately 140 days (55 days to adaption and fluctuation stage and 85 days to reach suitable conditions to stabilize the main operational parameters at HRT of 20 days). During start-up performances, the CBP was 1070.5 and 1289.1L and the average concentration of CH4 of biogas was 52.9 and 56.1%, the final NH4+-N concentrations were 1897 and 1999 mg/L under mesophilic and thermophilic conditions, respectively. Thermophilic digestion was more efficient than mesophilic.