Alternative Approaches to Modeling Fluence Distribution and Microbial Inactivation in Ultraviolet Reactors: Lagrangian versus Eulerian
Publication: Journal of Environmental Engineering
Volume 131, Issue 10
Abstract
A study was performed to evaluate alternative methods for predicting the ultraviolet (UV) reactor performance using computational fluid dynamics. The study consists of modeling the UV fluence distribution and microbial inactivation using either Lagrangian or Eulerian methods for both low- and medium-pressure UV reactors. In the Eulerian method, fluence distributions were calculated using a flow-weighted and a mass-weighted fraction technique. The results show that the Eulerian flow-weighted fraction fluence distribution agreed well with the Lagrangian particle tracking fluence distribution when applied to the UV reactor outlet plane. However, when applied to planes downstream from effluent hydraulic structures, the Eulerian fluence distribution method was influenced by the additional convective mixing from these hydraulic structures and predicts a tighter fluence distribution range than the Lagrangian method. The Eulerian approach to modeling microbial inactivation seems comparable to the Lagrangian particle tracking approach and can be viewed as a suitable alternative to the Lagrangian approach. The results also show that the Eulerian mass-weighted fraction distribution is comparable to the microbial kinetic weighted Lagrangian particle tracking approach, which can provide greater sensitivity to the low fluence regions in the UV reactor.
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Acknowledgments
This research was funded by a grant from AWWA Research Foundation No. 2682. The writers would like to thank Trojan Technologies for its support of the project through experimental biodosimetry measurements and input data information to perform modeling work. The writers would also like to thank Mike Morine, Mike Neher, Dennis Porter, and Kurt Segler from the City of Henderson, Nev. and Alex Mofidi and Sameh Momtaz from Metropolitan Water District for their contribution to experimental data and model input information.
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Information & Authors
Information
Published In
Journal of Environmental Engineering
Volume 131 • Issue 10 • October 2005
Pages: 1393 - 1403
Copyright
© 2005 ASCE.
History
Received: Sep 4, 2003
Accepted: Mar 10, 2005
Published online: Oct 1, 2005
Published in print: Oct 2005
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