Modeling Water Treatment Reactor Hydraulics Using Reactor Networks

Abstract

Reactor hydraulics are integral to water treatment processes such as disinfection and chemical contaminant oxidation. This work uses reactor networks—conceptual reactors arranged in parallel and series combinations—to simplify the accurate modeling of residence time in water treatment reactors. Reactor networks were selected for 14 clearwells, ozone contactors, clarifiers, and filters using tracer data sets from literature. For seven of 14 full-scale reactors, two parallel tanks-in-series reactors best balanced accuracy and simplicity. Reactor networks accurately represented tracer data using between two and eight fitting parameters, while segregated flow analysis required 32–164 inputs (two per tracer data point). The modeling work revealed that tracer data sets may have overestimated baffle factors by >10% in 10 of the 14 full-scale reactors, potentially as a result of inaccurate measurement of flow rate or volume. Applications of reactor networks include more accurate approaches to disinfection regulation and modeling the degradation of emerging contaminants.