Ozone-contactor flow visualization and quantification using three-dimensional laser-induced fluorescence

Three-dimensional laser-induced fluorescence (3D LIF) was applied for the first time to investigate hydrodynamics and mixing in an ozone contactor used for water disinfection. The unsteady, three-dimensional flow and mixing in the contactor was visualized and quantitatively analyzed, providing information that has not been possible to supply with traditional tracer techniques. In particular, the results obtained from a model reactor with a sidestream venturi injection suggested that the overall reactor hydrodynamics were close to a plug flow despite the jet injection at the inlet. The inflow separated into two streams as it reached the opposite wall, and the streams swirled as they traveled through the reactor, allowing a "plug-flowlike" condition to develop in each water stream. The 3D LIF technique is expected to be useful for the design and optimization of ozone contactors and other disinfection reactors, including chlorine contactors and ultraviolet reactors.