An advanced wastewater treatment process (SIPER) was developed to simultaneously decrease sludge
production, prevent the accumulation of inorganic solids, recover phosphorus, and enhance nutrient
removal. The feasibility of simultaneous enhanced nutrient removal along with sludge reduction as well
as the potential for enhanced nutrient removal via this process were further evaluated. The results
showed that the denitrification potential of the supernatant of alkaline-treated sludge was higher than
that of the influent. The system COD and VFA were increased by 23.0% and 68.2%, respectively, after
the return of alkaline-treated sludge as an internal C-source, and the internal C-source contributed
24.1% of the total C-source. A total of 74.5% of phosphorus from wastewater was recovered as a usable
chemical crystalline product. The nitrogen and phosphorus removal were improved by 19.6% and
23.6%, respectively, after incorporation of the side-stream system. Sludge minimization and excellent
nutrient removal were successfully coupled in the SIPER process