Simulation of a novel strategy for improving a biological phosphorus removal system start-up

Albert Guisasola*, Maite Pijuan, Juan A. Baeza, Julián Carrera, Carles Casas, Javier Lafuente Departament of Chemical Engineering, Universitat Autònoma de Barcelona. 08193. Barcelona; Tel: 935811879; Fax: 935812013. Abstract This work analyses (by means of simulation) the effect of reducing the length of the aerobic phase in the start-up of an Enhanced Biological Phosphorus Removal (EBPR) process conducted in a sequencing batch reactor system. This new control strategy is based on finishing the aerobic phase when phosphorus is depleted from the medium. Two scenarios were simulated: one with fixed aerobic phase (usual EBPR operation) and the other with a variable aerobic phase length linked to phosphorus presence (novel strategy presented in this work). After thirty days of start-up simulation, the results revealed that the ratio of polyphosphate accumulating organisms to ordinary heterotrophic organisms was 90% higher than in the variable aerobic phase length scenario. According to the simulations performed in this work, this control strategy allowed achieving higher net phosphorus removal capacity.