Effluent recycling of a multiphase anaerobic baffled reactor treating food waste

A laboratory-scale multiphase anaerobic baffled reactor (MP-ABR) system was developed to enhance food waste (FW) bioconversion under mesophilic (35C) conditions. The main objective of this study was to assess the impact of 100% effluent recycling back into the system. During the initial 90 days of operation, removal rates of CODt, TS and VS were 75.32 ± 11.86%, 61.72 ± 9.36% and 69.62 ± 8.73% respectively. CODs and VFAt generated after the hydrolysis stage were removed up to 98.65 ± 0.51% and 97.54 ± 1.11% respectively. The average biogas yield of 141.1 mL/g-VS.d under 30 days hydraulic retention time (HRT) condition was obtained. The organic loading rate (OLR) was doubled for the subsequent 105 days of operation and the removal rates were found to be 88.95 ± 5.17%, 79.14 ± 5.81% and 87.12 ± 5.35% for CODt, TS and VS respectively. The high removal rates of CODs and VFAt remained above 97% while the biogas yield was 102.11 mL/g-VS.d after doubling the OLR. The overall positive findings show the great potential of applying MP-ABR with “No effluent” for energy production from FW.