A study of the flow through ultraviolet disinfection systems

grantor: University of TorontoIn this work, the hydraulic characteristics of an ultraviolet wastewater disinfection unit were studied. A commercially available system manufactured by Elsag Bailey (Canada) Inc. was placed in an open channel flume. Measurements were made over a range of channel velocities from 20 to 60 cm/s. Dye was injected into the flow and videotaped in order to provide both a qualitative and quantitative analysis of the mixing occurring within the disinfection unit. Velocity measurements were conducted along the length of the unit using an Acoustic Doppler Velocimeter and from this data the overall turbulence intensity within the unit was estimated. The design of the unit was altered by reshaping the upstream ends of the unit and by installing washers along the length of the quartz sleeves. It was found that the addition of washers significantly increased the mixing throughout the unit and is expected to improve considerably the disinfection efficiency of the wastewater system. Microbiological tests are being conducted currently by Elsag Bailey to quantify this increase in efficiency.M.A.Sc