1 An Innovative Photoreactor, FluHelik, To Promote UVC/H 2 O 2 1 Photochemical Reactions: Tertiary Treatment of an Urban 2 Wastewater 3 Jonathan C. Espíndola 1,2 , Raquel O. Cristóvão 1,* , Sara R.F. Araújo 1 , Teresa Neuparth 3 , 4 Miguel M. Santos 3,4 , Rosa Montes 5 , José B. Quintana 5 , Rosario Rodil 5 , Rui A.R. 5 Boaventura 1 , Vítor J. P. Vilar 1,* 6 7 1 Laboratory of Separation and Reaction Engineering - Laboratory of Catalysis and Materials 8 (LSRE-LCM), Department of Chemical Engineering, Faculty of Engineering, University of 9 Porto, Rua Dr. Roberto Frias, 4200-465, Porto, Portugal 10 2 CNPq - National Council for Scientific and Technological Development, Brazil 11 3 CIMAR/CIIMAR - LA, Interdisciplinary Centre of Marine and Environmental Research, 12 Avenida General Norton de Matos S/N, 4450-208 Matosinhos, Portugal 13 4 FCUP – Department of Biology, Faculty of Sciences, University of Porto, Rua do Campo 14 Alegre, 4169-007 Porto, Portugal. 15 5 Department of Analytical Chemistry, Nutrition and Food Sciences, IIAA—Institute for Food 16 Analysis and Research, Universidade de Santiago de Compostela, Constantino Candeira S/N, 17 15782 Santiago de Compostela, Spain 18 19 20 *Corresponding authors: 21 R.O. Cristóvão: 22 Tel: +351 22 041 3606; E-mail: raquel.cristovao@fe.up.pt 23 Vítor J. P. Vilar: 24 Tel: +351 91 825 7824; E-mail: vilar@fe.up.pt 25 Fax: +351 22 508 1674 26 This is the postprint (accepted manuscript) version of the article published in Science of the Total Environment. http://dx.doi.org/10.1016/j.scitotenv.2019.02.335 © 2019. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/