Analysis and Simulation of Biological Phosphorus Removal Model

Simple model for anaerobic phosphorus release and aerobic uptake batch test was constructed based on ASM2d and analyzed with sensitivity analysis. And it was simulated with estimated parameters. The phosphorus behaviors were mainly influenced by the initial concentration of soluble COD (SA) in anaerobic condition and PHA (XPHA) in aerobic conditions, respectively. Sensitivity analysis suggested the procedure to estimate model parameters and it includes 1) phosphorus release in anaerobic and organic-rich condition, 2) addition of sufficient phosphorus to ensure PHA-poor condition and 3) subsequent phosphorus uptake in aerobic PHA-poor condition. Genetic algorithms was used for model parameter estimation, and its applicability was verified by estimating predetermined parameters of simulation data. The measured and estimated parameters are XPAO, XPP, XPHA, qPHA and YPO4 in anaerobic condition and qPHA, μPAO and YPHA in aerobic condition assuming that the other parameters were fixed to suggested values. Finally, experimental behavior of phosphorus was used for estimating parameters and it was concluded that XPAO=1450 mg/L, XPP=54.4 mg/L XPHA=206 mg/L at the end of anaerobic condition, qPHA=3.51 1/day and YPO4=0.264 and qPHA=0.967 1/day, μPAO=1.25 1/day and YPHA=0.721, respectively.