AWWA JAW72808

In order to visually and quantitatively analyze mixing behavior within a multichamber ozone contactor, this investigation applied three-dimensional laser-induced fluorescence (3D LIF) to a model reactor that was scaled down from a full-scale ozonation plant currently in service. Results indicated that mixing conditions inside the contactor were less than optimum and were characterized by extensive short circuiting from one chamber to the next, internal recirculation within the chambers, and dead zones with little mixing at the chamber centers. The multichamber ozone contactor is the most widely used design for water disinfection, but its efficacy is diminished by nonideal flow behaviors. The 3D LIF system described in this article, combined with ozone contactor model software developed by the authors, provides a highly effective tool for reactor diagnosis, retrofitting to improve performance, and new reactor design. The information provided can be used to optimize baffle and chamber configurations in multichamber ozone contactors to improve disinfection efficiency and minimize disinfection byproduct formation.

Includes 17 references, figures.