In recent years, there has been an increasing need to design wastewater treatment systems that are capable of removing both organic material and nutrients, notably nitrogen and phosphorus. This study evaluated biological phosphorus removal by activated sludge systems fed with domestic sewage and operating as sequencing batch reactors (SBR) with different solids retention times (SRT) namely 20, 5 and 3 days. This was supported by respirometry experiments at bench scale using acetate as the source of organic carbon. The results showed satisfactory total phosphorus removal efficiencies mean values between 79-82% for the three regimes with the best removal efficiency occurring in the SBR operating with a five-day SRT.
biological phosphorus removal; sludge retention time; sequencing batch reactor
