Studying the impact of monitoring strategy on disinfection performance evaluation with computational fluid dynamics.

Disinfection is a critical process component of drinking water treatment to protect human health. The disinfection performance is highly dependent on the hydraulic efficiency of the disinfection contactor. Accurately evaluating the contactor hydraulic efficiency is important to water treatment plant designers and operators. Tracer analysis is the most used approach for evaluating hydraulic efficiency. Many factors that can impact tracer analysis have been well studied, while the monitoring strategy is not. This study investigates the impact of different monitoring strategies, including single-point, multiple-point, and surface-average monitoring, for hydraulic efficiency evaluation. It is found that: residence time distribution and characteristic times could vary significantly when monitoring two points near to each other, especially at a location with an uneven velocity distribution; the multi-point matrix monitoring approaches proposed in this study could be an alternative to accurately evaluate the contactor hydraulic performance even at the places with an uneven velocity distribution. [ABSTRACT FROM AUTHOR]