Global and local mass transfer coefficients in waste water treatment process by computational fluid dynamics

Gas–liquid mass transfer is a currently used process in the waste water treatment industry. The objective today is to optimize the design and have a better control on the operation of these processes by using the CFD code ASTRID in two-phase flow reactors. A source term which represents interfacial mass transfer is introduced, accounting for two-phase flow hydrodynamics, it permits to predict accurately dissolved gas concentration in reactors such as laboratory airlift internal loop reactor and full scale activated sludge basin.