The presence of natural organic matter (NOM) is the cause of problems in drinking water treatment processes, among which: negative effect on water color quality, poor taste and odor, enhanced biological growth in distribution systems, complexation site for heavy metals and increase in coagulant and disinfectant dose requirements, which increases potential harmful disinfection byproducts (DBPs) formation. To optimize the removal of the NOM present in drinking waters, the conventional coagulation flocculation process was optimized and completed with heterogeneous photocatalysis. Heterogeneous photocatalytic tests were performed with TiO2-P25 suspended catalyst and TiO2-P25/beta-SiC supported material. Coagulation-flocculation and heterogeneous photocatalysis have been applied individually and coupled to evaluate the best process to degrade maximum organic compounds. After each treatment, UV absorbance at 254 nm (UV254nm.), Specific UV Absorbance (SUVA(254)) and Total Organic Carbon (TOC) were measured to determine humic substances removed. The optimization of the coagulation-flocculation process conditions was obtained at pH = 5 for 110 mg L-1 of the coagulant dose, and 70% of humic substances were removed in these conditions. The coupling between coagulation-flocculation and supported photocatalytic process (with TiO2-P25/beta-SiC supported catalyst) shows about 80% of mineralization of humic substances remaining in clarified water by coagulation-flocculation, after 220 min of irradiation. Therefore about 90% of humic substances are removed with these coupled processes. (C) 2016 Elsevier B.V. All rights reserved.