TY - JOUR
T1 - One-year operation of a 20-L submerged anaerobic membrane bioreactor for real domestic wastewater treatment at room temperature
T2 - Pursuing the optimal HRT and sustainable flux
AU - Ji, Jiayuan
AU - Chen, Yujie
AU - Hu, Yisong
AU - Ohtsu, Akito
AU - Ni, Jialing
AU - Li, Yemei
AU - Sakuma, Satoshi
AU - Hojo, Toshimasa
AU - Chen, Rong
AU - Li, Yu You
N1 - Funding Information:
This study was supported by the Ministry of the Environment , Japan (Development and Demonstration Program on Low Carbon Technology Research: Innovative sewage treatment system for energy saving and energy production, 2017–2020), and was completed during the time the first author was supported by the Japan Society for the Promotion of Science (Grant-in-Aid for JSPS Fellows, 19J12023 ).
Publisher Copyright:
© 2021
PY - 2021/6/25
Y1 - 2021/6/25
N2 - A 20 L hollow-fiber submerged anaerobic membrane bioreactor (SAnMBR) was used to treat real domestic wastewater at 25 °C with hydraulic retention times (HRTs) ranging from 4 to 12 h. The process performance was evaluated by organic removal efficiency, biogas production, sludge yield, and filtration behaviors during one-year's operation. For HRTs ranging between 6 and 12 h, the AnMBR showed good organic removal efficiency with chemical oxygen demand (COD) and biochemical oxygen demand (BOD) removal efficiencies of about 89% and 93%, respectively. The biogas yield was 0.26 L-gas/g-CODfed, with approximately 80% methane content, and the sludge yield was 0.07–0.11 g-VSS/g-CODrem. While at an HRT of 4 h, with the higher wastewater treatment capacity and organic loading rate (OLR), the biogas production was lower (0.17 L-gas/g-CODfed), and the sludge production was higher (0.22 g-VSS/g-CODrem). The organic removal performance (COD 84% and BOD 89%) at HRT of 4 h was acceptable due to the effective separation effect of the membrane filtration process. According to COD balance analysis, the low biogas yield and high sludge yield at HRT of 4 h were due to insufficient biodegradation under an OLR of 2.05 g-COD/L-reactor/d. Theoretical calculations based on Henry's law indicate that the ideal methane content in the biogas should be 82–85% when the operational temperature was 25 °C. To achieve a high flux and sustainable AnMBR operation, the impact of mixed liquor suspended solid (MLSS) and gas sparging velocity (GSV) on the filtration performance was analyzed. The critical flux increased with increase in the GSV from 24.2 to 174.3 m/h, but decreased with increase in the MLSS concentration from 8.2 to 20.2 g/L. Therefore, decreasing fouling rate to 0.8–1.2 kPa/d by efficiently controlling GSV and MLSS, sustainable operation could be achieved at a flux of 0.34 m/d.
AB - A 20 L hollow-fiber submerged anaerobic membrane bioreactor (SAnMBR) was used to treat real domestic wastewater at 25 °C with hydraulic retention times (HRTs) ranging from 4 to 12 h. The process performance was evaluated by organic removal efficiency, biogas production, sludge yield, and filtration behaviors during one-year's operation. For HRTs ranging between 6 and 12 h, the AnMBR showed good organic removal efficiency with chemical oxygen demand (COD) and biochemical oxygen demand (BOD) removal efficiencies of about 89% and 93%, respectively. The biogas yield was 0.26 L-gas/g-CODfed, with approximately 80% methane content, and the sludge yield was 0.07–0.11 g-VSS/g-CODrem. While at an HRT of 4 h, with the higher wastewater treatment capacity and organic loading rate (OLR), the biogas production was lower (0.17 L-gas/g-CODfed), and the sludge production was higher (0.22 g-VSS/g-CODrem). The organic removal performance (COD 84% and BOD 89%) at HRT of 4 h was acceptable due to the effective separation effect of the membrane filtration process. According to COD balance analysis, the low biogas yield and high sludge yield at HRT of 4 h were due to insufficient biodegradation under an OLR of 2.05 g-COD/L-reactor/d. Theoretical calculations based on Henry's law indicate that the ideal methane content in the biogas should be 82–85% when the operational temperature was 25 °C. To achieve a high flux and sustainable AnMBR operation, the impact of mixed liquor suspended solid (MLSS) and gas sparging velocity (GSV) on the filtration performance was analyzed. The critical flux increased with increase in the GSV from 24.2 to 174.3 m/h, but decreased with increase in the MLSS concentration from 8.2 to 20.2 g/L. Therefore, decreasing fouling rate to 0.8–1.2 kPa/d by efficiently controlling GSV and MLSS, sustainable operation could be achieved at a flux of 0.34 m/d.
KW - Anaerobic membrane bioreactor
KW - Biogas composition
KW - Hydraulic retention times
KW - Mass balance
KW - Real domestic wastewater
KW - Sustainable flux
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U2 - 10.1016/j.scitotenv.2021.145799
DO - 10.1016/j.scitotenv.2021.145799
M3 - Article
C2 - 33621884
AN - SCOPUS:85101425349
SN - 0048-9697
VL - 775
JO - Science of the Total Environment
JF - Science of the Total Environment
M1 - 145799
ER -