Research Information System
Biomass Conversion and Biorefinery, vol.14, no.5, pp.7181-7196, 2024 (SCI-Expanded)
The aim of this study was to investigate the biogas production performance of an integrated microbial electrolysis cell and anaerobic reactor system (MEC-AR) treating cattle manure at different applied voltages and hydraulic retention times (HRT) ranging from 6 days to 1 day. The MEC-AR system was operated in semi-continuous mode under various voltage applications of 0.3, 0.6, and 1.0 V and organic loading rates (OLR) ranging from 5 g VS/L/d to 30 g VS/L/d. The MEC-AR system presented 25 to 62% higher biogas production and 10 to 21% higher organic removal rates compared to the control reactor, until the control reactor deteriorated at the HRT of 3 days. As the HRT was decreased further, biogas production of the MEC-AR system increased depending on the applied OLR and voltage. Maximum biogas productions, 4.88 L/L/d (CH4: 76%) and 5.10 L/L/d (CH4: 77%), were observed at HRT of 2 days and OLR of 30 g VS/L/d in MEC-AR0.6 V and MEC-AR1.0 V, respectively. Higher applied voltages (MEC-AR0.6 V and MEC-AR1.0 V) resulted in higher biogas production (16 to 21%) and organic removal rates (9 to 21%) compared to lower applied voltage (MEC-AR0.3 V) especially at high OLRs (22.5 and 30 g VS/L/d). As a result, MEC-AR system can be operated efficiently at challenging operational conditions (as low as 1 and 2 days; OLR of 15–30 g VS/L.d.) that conventional anaerobic reactors cannot withstand.