Performance evaluation of a novel anaerobic digestion operation process for treating high-solids content chicken manure: Effect of reduction of the hydraulic retention time at a constant organic loading rate

摘要

A novel feeding strategy was adopted in this study and the effect of reduction in hydraulic retention time (HRT) on the anaerobic digestion of chicken manure (CM) with a constant organic loading rate of 6.0gVS/L/d was investigated. The lab-scale CSTR was operated at 38 ℃ and HRT_(CM) was reduced from 52 days to 5 days. At HRTcm of 20-45 days, the reactor was relatively stable in terms of the volumetric biogas production rates and specific biogas production (SBP), which were 2.2-2.4 L/L/d and 338.3-418.7 mL/gVS_(added) respectively. However, process instability and VFA accumulation occurred when the HRTcm was reduced to 10 days due to excess microbes washout. The reduction in HRTcm to 5 days caused SBP to decrease to 198.7 mL/gVS_(added) and the acetic acid content to exceed 6000 mg/L The biomass balance model showed that the biomass concentration at HRT_(Cm) of 20-52 days (0.473-0.615 gVSS/L) was notably higher than that at HRT_(CM) of 5-10 days (0.173 gVSS/L).