Effects of substrate concentration on anaerobic digestion process of duck feces at moderate temperature
料液浓度对鸭粪中温厌氧消化的影响

The complete mixture anaerobic digestion experiments of duck feces for different substrate concentrations (2%, 6%, 10% and 15%) were done in 10 L glass pot at neuter pH and moderate temperature. The COD, pH, VFA (volatile fatty acid) and biogas yield during the process of anaerobic digestion were measured as the reaction system was running during 30 days. The results showed that the substrate concentration was a key factor in the anaerobic digestion process of duck feces. The gas volume was the largest (biogas yield 0.169 m3/kg, methane yield 0.117 m3/kg) when the substrate concentration was adjusted to 6%. Meantime, the removal rate of COD was 30.46%, and methane content in biogas was 69.3%.