A method for evaluating the mixing characteristics of u.v. reactors with short detention times

Ultraviolet (u.v.) light disinfection of municipal wastewaters is rapidly gaining popularity as an alternative to chlorination. However, little information is available which correlates the disinfection efficiencies with the various types of u.v. reactor system designs. This study presents the results of research carried out on a particular u.v. reactor design: a Teflon®-tube wastewater carrier externally irradiated by a parallel u.v. lamp. An innovative experimental method was developed to obtain concentration-time distribution curves for reactors of detention times of < 5 s. Flow parameters for various flow rates were calculated from these curves. The results suggest that it is possible to develop mathematical models which incorporate flow parameters to predict u.v. disinfection in this system.