The Photo Fenton process is an alternative process for the treatment of effluents from the textile industry, being a reagent-based chemical on Fe2+ and H2O2 + UV light, whose mechanism consists of oxidizing the pollutants until they are suitable for discharge into bodies of water. This research seeks to determine the optimum concentration of Fe2+ - H2O2 in the treatment of a synthetic textile effluent and, subsequently, to evaluate the efficiency of the system. The synthetic textile effluent was prepared under laboratory conditions, FeSO4 and H2O2 were added at different concentrations, with exposure to UV-A light throughout the process, and it was determined that the optimum concentration of the Photo Fenton reagent was 400 mg L-1 of FeSO4 and 12 ml L-1 of H2O2, a dosage that reduced initial turbidity, color, and COD by 100%, 99% and 83%, respectively, and increased the DO by 11%. Turbidity removal was obtained by carrying out the treatment in an acid medium (pH 3). The presence of Fe2+ promoted the significant removal of COD. The increase in DO was obtained by the presence of H2O2 and UV-A light, and this in turn, had a considerable influence on the removal of effluent color. Regarding the efficiency of the system, it was determined that the Photo Fenton reagent is an excellent alternative for the treatment of textile effluents with high and low organic loads, reducing contaminants derived from industry processes.
 Keywords: clean technology, Fe2+-H2O2, organic, oxidation, pollution, water.