Long-term stability of a non-adapted aerobic granular sludge process treating fish canning wastewater associated to EPS producers in the core microbiome

The tolerance of aerobic granular sludge (AGS) to variable wastewater composition is perceived as one its greatest advantages compared other processes. However, research studies select optimal operational conditions for evaluating AGS performance, such the use pre-adapted biomass and control composition. In this study, non-adapted was used treat fish canning presenting highly organic, nutrient salt levels over a period ca. 8 months. Despite up 14 g NaCl L−1, organic loading rate (OLR) found be main factor driving performance. Throughout first months operation, OLR generally lower than 1.2 kg COD m−3 day−1, resulting in stable nitrification low phosphorous at outlet. An increase 2.3 day−1 disturbed phosphate removal, but decrease average values between 1 1.6 led resuming those Most bacteria present core microbiome were associated extracellular polymeric substances (EPS) production, Thauera Paracoccus, which increased during higher period. Ammonium-oxidizing (AOB) nitrite-oxidizing (NOB) species detected biomass; while AOB identified throughout NOB no further after OLR. Different polyphosphate-accumulating organisms (PAOs) along process: Candidatus Accumulibacter, Tetrasphaera Gemmatimonas. A able tolerate salinity fluctuations L−1. Overall, high microbial diversity EPS producers allowed preserve bacterial groups responsible nutrients contributing adaptation long-term stability system.