Modeling And Parameter Optimization Analysis Of Activated Sludge System(A~2/O)

Water environment is fundamental for all lives and is impacted by human activities together with economic growth.In recent years,China strengthened environmental protection,legislated high-level wastewater treatment standards,and positioned tremendous challenge for conventional plants.This thesis is based on A2/O process that is popularised in China,integrated ASM2 d model from IWA,considered biological phosphorus removal mechanism to form coupling model,and exploited Bio Win to analyse and forecast water quality fluctuation in the A2/O process.Removal of target pollutants accompanied by related process parameters in various C/N ratio scenarios are also discussed and compared with orthogonal experiments.The coupled model for phosphorus delineation is built via formation and degradation of PHA,Poly-P and glycogen inside PAOs,which is different from ASM2 d as relied on macro growth rates.Switch function represents environmental inhibition on metabolisms,and components change following mass balance.Sensitivity analysis is performed for kinetic or stoichiometric parameters within the model,to systematically modify highly responsive ones,and upgrade goodness of fit.Dynamic modelling is operated by the calibrated coupled model to investigate particular targets removal in different controls.The conclusion from orthogonal experiments is combined to arrive at optimised operating mode in C/N ratios.Under narrower C/N the optimised case are: HRT12 h,r100%,R50%,DO B level.Under wider C/N the optimised case are: HRT8 h,r150%,R75%,DO C level.Shock loading capability is researched at optimised ratios under several loading rates,along with removal mechanism analysis in separate reactor zones,and review on model outputs compared to observed value.The result indicates that A2/O process in optimised cases can resist moderately fluctuation,while the coupled model is predictive and may assist real application.