• • S2EBPR overcomes low C/P limitations by establishing a side-stream sludge fermentation unit (SSSF) that enhances PAOs' competitive advantage, achieving efficient phosphorus removal even when influent C/P is critically low (e.g., below 20 mg COD/mg P).
• • Key operational parameters such as side-stream sludge retention time (SRT_SS) and hydraulic retention time (HRT_SS) must be optimized; typical SRT_SS ranges from 5-15 days and HRT_SS from 6-12 hours to maximize VFA production and PAO enrichment.
• • Precise control of dissolved oxygen (DO) and oxidation-reduction potential (ORP) in the anaerobic zone is essential; DO levels below 0.2 mg/L and ORP below -200 mV ensure favorable conditions for PAO metabolism, reducing competition from glycogen-accumulating organisms (GAOs).
• • Integration of S2EBPR with emerging technologies, such as partial denitrification and phosphorus recovery, enables simultaneous nitrogen and phosphorus removal with potential for phosphorus recovery rates exceeding 80%, aligning with circular economy goals.