Supplementary Data

Development of economical-running strategy for multi-lamp UV

disinfection reactors in secondary water supply systems with

computational fluid dynamics simulations

Wentao Li, Mengkai Li, Dong Wen, Zhimin Qiang*

Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-

Environmental Sciences, University of Chinese Academy of Sciences, Chinese

Academy of Sciences, 18 Shuang-qing Road, Beijing 100085, China

*Corresponding author.

E-mail address: qiangz@rcees.ac.cn (Z. Qiang)

S1

Fig. S1. Schematic diagram of the solutions for the economical-running strategy for

multi-lamp UV reactors.

S2

Fig. S2. Simulated inactivation ratios of the prototype reactor [1] by CFD models

employed in this study and comparison with the experimental results adapted from

Sozzi and Taghipour [1].

Reference

[1] D.A. Sozzi, F. Taghipour, UV reactor performance modeling by Eulerian and

Lagrangian methods, Environ. Sci. Technol. 40 (2006) 1609-1615.

S3

Fig. S3. Variation of the real-time and the 20-minute average flow rates for the UV

disinfection reactor during a random day (Aug. 21, 2015). The scattered points show

the real-time flow rate collected every 4 min, and the line connects the averages of the

real-time flow rate in every 20 min.

S4

Fig. S4. Variation of the 24-hour average flow rate for the UV disinfection reactor in

typical summer and winter weeks (a) and in the long term from Aug. 14, 2015 to Feb.

29, 2016 (b).

S5

Fig. S5. Predicted fluence rate (FR) distributions in the central cross-section of the

UV reactor with 5P lamp modes: (a) 5P-0.83, (b) 5P-A1BC, and (c) 5P-A2BC.

S6

Fig. S6. Predicted FR distributions in the central cross-section of the UV reactor with

4P lamp modes: (a) 4P-0.66, (b) 4P-AB, (c) 4P-BC, and (d) 4P-AC.

S7

Fig. S7. Predicted FR distributions in the central cross-section of the UV reactor with

3P lamp modes: (a) 3P-0.50, (b) 3P-A1C, and (c) 3P-A2B.

S8

Fig. S8. Predicted FR distributions in the central cross-section of the UV reactor with

2P lamp modes: (a) 2P-0.33, (b) 2P-A, (c) 2P-B, and (d) 2P-C.

S9

Fig. S9. Predicted performances of the UV disinfection reactor with lamp modes of

different lamp output powers (LOPs) at a constant flow rate of 5 m3 h−1 as indicated

by the REF (a) and the MEF (b).

S10

Fig. S10. Predicted velocity distributions (top) and particle trajectories (bottom) in the

UV reactor chamber at a flow rate of 10 m3 h1.

S11

Fig. S11. Predicted hourly REF and MEF of the UV disinfection reactor with the

regular- or economical-running strategy in a random day (Aug. 21, 2015): (a) regular-

running; and (b) economical-running.

S12