Residence time distributions in ozone contactors

The hydraulics in ozone systems, characterized by the residence time distribution, are investigated numerically as well as experimentally. The complex geometry of the ozone contactors requires the application of computational fluid dynamics (CFD), which in combination with experimental results gives insight in the hydraulic processes. Particle tracking provides a distribution of CT-values (dissolved ozone concentration times residence time) to estimate disinfection precisely and points out dead zones that hamper disinfection. The CFD modeling predicts that small changes in geometry reducing the strength of the recirculation zone can significantly increase the inactivation of micro-organisms.