Early-warning on the performance of novel high-rate anaerobic bioreactor

The compartmentalized anaerobic reactor (CAR) is a novel, promising high-rate bioreactor® for anaerobic digestion process. The feasibility of early-warning on the performance of lab-scale CAR was investigated. CAR showed less stable performance at high organic loading rates (OLRs) than that at regular OLRs. At high OLRs, the system in response to the fluctuation of influent chemical oxygen demand (COD) concentration showed higher variation in terms of effluent COD and volatile fatty acids (VFA) concentration. Two newly defined parameters, VLR saturation (SVLR) and VFA saturation (SVFA) could be used as indicators for early-warning on the performance of anaerobic reactors. The system performance was relatively stable when CAR was operated at regular OLR, during which SVLR and SVFA were below 0.89 and 0.4 respectively. It tended to be unstable under high OLR conditions when SVLR and SVFA were close to 1, and deteriorated when SVLR and SVFA were above 1.