Biopolymer Recovery from Aerobic Granular Sludge and Conventional Flocculent Sludge in Treating Industrial Wastewater: Preliminary Analysis of Different Carbon Routes for Organic Carbon Utilization

The recovery of biopolymers from sewage sludge could be a crucial step in implementing circular economy principles wastewater treatment plants (WWTP). In this frame, the present study was aimed at evaluating simultaneous production polyhydroxyalkanoates (PHA) and extracellular polymeric substances (EPS) obtainable agro-industrial wastewater. Two biological enrichment systems, aerobic granular (AGS) conventional activated operating as sequencing batch reactor (SBR), were monitored for 204 186 days, respectively. maximum accumulation capacity close to 0.60 mgPHA-EPS gVSS−1 AGS when 3 kgCODm−3d−1, whereas SBR, it about half (0.35 gVSS−1). Biopolymers extracted mainly constituted by EPS (>70%), whose percentage increased up 95% with OLR applied reactor. contrast, SBR enabled obtaining higher PHA (50% biopolymers). Results suggested that organic carbon channeled toward metabolic pathways storing AGS, likely due stressors (e.g., hydraulic selection pressure, shear forces) promoting granulation.