Design Implications on Denitrifying PAO in BNR Plant

Abstract

Denitrifying phosphorus accumulating organism (dPAO) has received a great attention because it could utilize the internally stored cellular carbon both for P uptake and denitrification at the anoxic stage resulting in increased phosphorus and nitrogen removal in BNR (biological nutrient removal) system. However, its unique characteristics have not been well described with the real plants so far. The study results indicated that the overall P removal efficiencies could be improved as much as 25%, but it depends greatly on temperature. The estimated fraction of dPAO in PAO was decreased as the temperature decreased. The greatest drawback of dPAO is the lower P uptake rate at lower temperatures. The maximum advantage of using dPAO can be expected at a system operated at a higher temperature above 15 degrees C.