AWWA WQTC71606

During ultraviolet (UV) reactor validation, dose delivery, defined as Reduction Equivalent Dose (RED), istypically quantified across different operating conditions of flow rate, UV transmittance (UVT), lamp output and insome cases, lamp status. Empirical models (calculated dose algorithms) are then developed fromthe validation data to express the measured RED as a function of the different operatingparameters. At installations, these algorithms are used to calculate the RED, given operatingconditions of each parameter. An alternative dose-monitoring strategy, known as the UVintensity setpoint approach, can be defined by quantifying a UV reactor's RED as a function offlow and lamp output. Per the German UV guidelines (DVGW) intensity setpoint approach, theRED is confirmed at two test points with the reactor operating at a fixed flow and lamp output(setpoint UV intensity); one at high UVT but with lamp power reduced till the UV intensitymatches the setpoint, and the other at maximum power but with UVT reduced until the UVintensity matches the setpoint. In the field, a UV reactor is credited with the validated RED if themeasured flow does not exceed the validated flow and the measured UV intensity matches orexceeds the setpoint UV intensity. In this paper, a new method is described whereby thecalculated dose approach was used to define an online dose-monitoring strategy that, like the UVintensity setpoint approach, does not require UVT input. Includes figures.

Product Details

Edition:

Vol. - No.

Published:

11/01/2009

Number of Pages:

8

File Size:

1 file , 760 KB