<p> Supplementary Information</p><p>Manuscript title: Development of a tri-parameter online monitoring system for UV disinfection reactors</p><p>Authors: Zhimin Qianga,, Mengkai Lia, James R. Boltonb a State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuang-qing Road, Beijing 100085, China b Department of Civil and Environmental Engineering, University of Alberta, Edmonton, AB, Canada T6G 2W2</p><p>Corresponding authors. Tel.: +86 10 62849632; fax: +86 10 62923541. E-mail address: [email protected] (Z. Qiang)</p><p>List of supplementary material: </p><p>Material Page</p><p>Table 1 Tap water quality parameters determined every five days during S2 the long-term simulation experiment.</p><p>Fig. S1 Schematic diagram of the experimental system. S3</p><p>Fig. S2 Variation of the lamp output attenuation and sleeve fouling S4 coefficients during the monitoring experiment for water transmittance.</p><p>Fig. S3 Variation of the room temperature during the monitoring S5 experiment for sleeve fouling.</p><p>Fig. S4 Variation of the lamp output attenuation coefficient and tap S6 water temperature during the long-term simulation experiment.</p><p>Fig. S5 Relative UV intensity monitored by detectors A, B and C as a S7 function of time during the long-term simulation experiment.</p><p>1 Table S1</p><p>Tap water quality parameters determined every five days during the long-term simulation experiment.</p><p>Parameters Day 3 Day 8 Day 13 Day 18 Day 23 Day 28</p><p>Ca2+ (mg/L) 60.9 60.3 60.1 61.4 60.8 60.7</p><p>Mg2+ (mg/L) 18.1 16.9 17.3 17.3 16.8 17.6</p><p>TOC (mg/L) 0.38 0.42 0.36 0.37 0.40 0.46</p><p> pH 7.56 7.50 7.91 7.93 7.98 8.01</p><p>2 Fig. S1. Schematic diagram of the experimental system.</p><p>3 Fig. S2. Variation of the lamp output attenuation and sleeve fouling coefficients during the monitoring experiment for water transmittance.</p><p>1.2</p><p>1.0</p><p> s 0.8 t</p><p> n N e</p><p> i F c</p><p> i 0.6</p><p> f f e o 0.4 C</p><p>0.2</p><p>0.0 0 10 20 30 40 50 60 70 80 90 Time (min)</p><p>4 Fig. S3. Variation of the room temperature during the monitoring experiment for sleeve fouling.</p><p>30</p><p>25 ) C</p><p> o 20 (</p><p>. p</p><p> m 15</p><p> e t</p><p> m 10 o o R 5</p><p>0 0 2 4 6 8 10 12 14 16 18 Time (day)</p><p>5 Fig. S4. Variation of the lamp output attenuation coefficient and tap water temperature during the long-term simulation experiment. </p><p>35 N 1.2 30</p><p>1.0 y t 25 i s n ) 0.8 e t C o</p><p>20 n i (</p><p>. V</p><p> p 0.6 U</p><p>15 m e e v T i</p><p>0.4 t</p><p>10 a</p><p>Water temp. l e</p><p>5 0.2 R</p><p>0 0.0 0 1 2 3 4 5 (Thu) (Fri) (Sat) (Sun) (Mon) (Tue) Time (day)</p><p>6 Fig. S5. Relative UV intensity monitored by detectors A, B and C as a function of time during the long-term simulation experiment. </p><p>1.2</p><p>1.0 y t i s</p><p> n 0.8 e t n i</p><p>V 0.6</p><p>U</p><p> e v i 0.4 t</p><p> a Detector A l</p><p> e Detector B R 0.2 Detector C</p><p>0.0 0 5 10 15 20 25 30 Time (day)</p><p>7</p>