Mn, Mo, La/TiO 2 /activated carbon (AC) photocatalysts were synthesized by sol-gel method. The prepared samples were characterized by XRD, FT-IR, BET, DRS, and FE-SEM techniques. The findings revealed that the synthesized catalysts were anatase type and nano-sized particles. The catalysts exhibited high adsorption ability in the visible light region with a red shift in the adsorption edge. The formation of Mn, Mo, La/TiO 2 / AC crystallites in the activated carbon was confirmed by FE-SEM. The effects of initial dye concentration, catalyst dosage, reaction time, and solution pH were investigated for removal of Reactive Red 198. According to the obtained results, the maximum removal efficiency of 91 % was obtained at initial dye concentration of 20 mg L -1 , pH of 3, and catalyst concentration of 2 g L -1 . Synthesized nano-photocatalyst showed reasonable photo degradation efficiency of 84 % for initial COD concentration of 4700 mg L -1 in treatment of a real textile wastewater sample. GC/MS analysis of raw and treated wastewater confirmed degradation and producing of simple intermediates during the photocatalytic process.