Characteristics and performance of algal–bacterial granular sludge in photo-sequencing batch reactors under various substrate loading rates

The algae-bacterial granular sludge (ABGS) technology has garnered significant attention due to its remarkable attributes of low carbon emissions. To investigate the performance of the ABGS system under various substrate loading rates, the parallel photo-sequencing batch reactors (P1 and P2) were set up. The results indicated that chlorophyll-a content and extracellular polymeric substance content were measured at 10.7 ± 0.3 mg/L and 61.4 ± 0.7 mg/g SS in P1 under relatively low substrate loading rate (0.9 kg COD/m