Anaerobic digestion of animal waste: effect of mode of mixing.

摘要: Abstract Laboratory-scale digesters were operated to study the effect of mixing (via biogas recirculation, impeller mixing, and slurry recirculation) on production. Three sets experiments performed using cow manure feed with either 50, 100, or 150 g/L total solids (TS) concentrations (referred in text as 5%, 10%, 15% slurry). The conducted at a controlled temperature 35 °C hydraulic retention time 16.2 days, resulting TS loadings 3.1, 6.2, 9.3 g/L d for feeds, respectively. Results showed that unmixed mixed quite similarly when fed 5% produced rate 0.84–0.94 L/L d. methane yield was found be 0.26–0.28 L CH 4 /g volatile loaded. However, mode became important thick feeds (10% 15%). Digesters 10% equipped external about 10–30% more than digester. While digesters, digester during start-up not beneficial, it resulted lower pH, performance instability prolonged time. Mixing recirculation system effective case under experimental conditions studied.