The efficiency of a helical flow photoreactor in the oxidation of the antibiotic Dicloxacillin as a function of the recirculation flow, the local volumetric rate of photon absorption (LVRPA) and photonic efficiency using oxidation processes based on UV-C/H2O2 and UV-A/photo-Fenton were evaluated in this work. Mathematical modeling of the degradation process and experiments in lab-scale helicoidal reactor were done. Mathematical evaluation was supported in function of photon flux, mass balance and reaction rate law. The LVRPA was calculated by modified Beer-Lambert Equation. The effect of the concentration of hydrogen peroxide and iron (II) on the efficiency of the oxidation of the antibiotic Dicloxacillin was evaluated by means of the photo-Fenton. In 45 min, 100% degradation of dicloxacillin was achieved using 1.5 mM H2O2 and 7.32 μM ferrous ion in the photo-Fenton experiments with the helical flow photoreactor. The optical thickness of the reaction and distribution of energy absorption confirmed the kinetic and photonic efficiency performance. The prediction of the model presented a global error less to 2.4% between experimental and simulated data.