Investigation of anoxic tank hydraulics by using CFD(compitaional fluid dynamics) model

This study shows how CFD (Compitaional Fluid Dynamics) can be helpful inorder to improve the design of existing water treatment plants and the processefficiency. 3D Compitaional Fluid Dynamics (CFD) modelling used in previousproject for investigating hydraulic behaviour in denitrifying activated sludge tank atthe Rya Wastewater Treatment Plant (WWTP) was improved in terms of geometry,inlet profile and the mixers. Tank is 60 m × 6.1m and has a depth of 10.85m. Fullscale tracer test was done to create Residence Time Distribution Curve (RTD), andresults from that was compared to CFD results. The results showed different curveswhen compared RTD curves obtained from tracer test to CFD modelling results. Itwas aimed to improve the geometry by using CFD model. At the end of the study, 3different results compared; result from simple geometry used in the previous projectfor CFD, result from improved geometry , channel and mixers (0,55m/s), and resultfrom improved geometry, channel and mixers (1.1m/s)Key Words : CFD, RTD Curve, Anoxic Tank