The Model of Coupling Sludge-wastewater 2-Phase Turbulent Flow with Biological Reaction,and Its Application

The model of coupling sludge-wastewater 2-phase turbulent flow with biological reaction was developed.It was realized to synchronic simulate activated sludge-wastewater 2-phase 3-D flow field and concentration field.Using activated sludge model 2(ASM2)to descript response rate in transport equation,and two-phase mixture model to describe the hydraulic characteristics of activated sludge-wastewater 2-phase turbulent flow,which coupled with sludge settlement movement.The sludge settlement characteristics under turbulent conditions was studied through digital particle image velocity technology,the traditional sludge settlement model was modified with the impact of hydraulic turbulence.The model was verified by measured the flow field and the concentration of components in oxidation ditch in the wastewater treatment plant.Numerical simulation sludge-wastewater 2-phase 3-D flow field and its water quality in oxidation ditch under different aeration conditions,the results showed that velocity were the determinative factors of sludge sediment and water quality distribution.The difference of aeration conditions had a direct impact on the efficiency of outlet flow.In the study of the wastewater treatment plant,the use of half-day intermittent aeration mode could improve the effeiciency of outlet flow,at the same time,it reduced the energy consumption of about 23.84%.