Experimental evaluation demonstrates 42% sludge yield reduction in an anaerobic side-stream sequencing batch reactor system, highlighting solids transformation under prolonged retention.
Key Points
To investigate the performance and internal mechanisms of in situ sludge reduction in a sequencing batch reactor integrated with an anaerobic side-stream reactor under prolonged retention conditions.
Integrated a sequencing batch reactor (SBR) with an anaerobic side-stream reactor (ASSR) operating under extended side-stream retention periods.
Tracked chemical oxygen demand (COD), ammonium, nitrate, and total phosphorus removal alongside a flow-based volatile suspended solids (VSS) mass balance.
Profiled endpoint microbial communities and predicted functional metabolic pathways across the system.
Observed sludge yield decreased by 42% (from 0.288 to 0.166 g VSS/g COD) while maintaining stable COD removal efficiency of 85% to 90%.
Total phosphorus removal reached up to 98% initially with ASSR phosphate release peaking at 250 mg PO43--P/L, though phosphorus release declined over extended operation.
Net VSS destruction across the ASSR accounted for approximately 25% of the total difference in sludge production between systems.