Acceleration of the startup process of an anaerobic baffled reactor utilizing electrolyte regeneration

Abstract

The objective of this study was to examine the performance of an electrolytic anaerobic baffled reactor (EABR) that contained five rectangular compartments in the treatment of low-strength synthetic wastewater. The effect of integration of electrolysis into an anaerobic baffled reactor (ABR) on the startup process, removal of chemical oxygen demand (COD), production of volatile fatty acids (VFAs), and profile of the pH of the EABR were investigated. With a low-strength influent (COD = 600 mg/L), the results indicated that COD removal was 92 % and that the VFAs were negligible by the third compartment. Also, VFA analysis showed that propionic acid was found in the first two compartments. This finding is aligned with compartment-wise profiles of COD removal, which was the highest in the initial compartments and which decreased longitudinally down the reactor. Monitoring the pH profile elucidated that the largest drop in pH was observed in the first two compartments, which is attributed to acidogenesis and acetogenesis activities. The proposed integration could decrease the startup process time to 12 d or less for low-strength feed of synthetic wastewater. This study demonstrated the significance of maintaining a stable pH for the optimal functioning of a diverse bacterial community by integrating bioelectrochemical processing in anaerobic digestion, as well as the application of the potential strategies to optimize the startup process of ABR. The optimization of the startup process of ABR through the integration of bioelectrochemical processing can contribute to Sustainable Development Goal 9 (Industry, Innovation, and Infrastructure) by promoting sustainable technological advancements and fostering sustainable industrialization.