Seasonal phosphorus removal in a Phostrip process—I. Two-yearsʹ plant performance

This paper analyses the performance over 2 yr of a treatment plant located in the tourist area of the Adriatic sea, based on a conventional aerobic sludge process. During the peak season excess phosphorus removal is accomplished by use of a PhoStrip unit. The phosphorus elimination rates are discussed in relation to the influence of the characteristics of the incoming wastewater and the occurrence of simultaneous nitrification and denitrification in the plant. The PhoStrip process proved to be a reliable solution when excess phosphorus has periodically to be removed from wastewater with a low organic content and a high presence of nutrients (TKN/COD = 0.23 and P/COD = 0.017). Concentration of phosphorus in the final effluent below 1 mg l−1 was obtained on 85% and 73% of the days of plant operation, respectively in 2 yr of study.