Pollution of aquatic resources and soil with emergent compounds (drugs) can have serious consequences for aquatic biota. Pharmaceuticals affect and sometimes make it impossible to treat wastewater by conventional methods. This is due to the fact that these pollutants are toxic to the biocenosis, they slow down the growth of microorganisms in activated sludge, thus inhibiting the purification process. The main purpose of the research to determine the optimal conditions in the process of oxidation/mineralization of emerging pollutants (EP) from mixed model systems by using advanced oxidation processes (AOPs). As drugs, the oxidation/mineralization of amoxicillin, cephalexin and diclofenac was studied. The decrease of drug concentration in the mixed model systems EP/TiO2/UV, EP/TiO2/H2O2/UV was studied by photocatalytic degradation. The degradation of Ep from aqueous solutions under the action of AOPs on UV irradiation (λ = 254 and 365 nm) was evaluated by studying the kinetics of the photocatalytic process, controlling the concentration of pharmaceuticals by various physicochemical parameters. Important factors influencing the degradation/mineralization performance were evaluated: oxidant concentration (0.5, 1.0, and 1.5 mM), photocatalyst concentration (0.025, 0.05, and 0.01 g/L), substrates concentration and reaction time. As a result of the experimental research, it was found that the oxidation/mineralization process depends on the titanium dioxide concentration. Therefore, the oxidation/mineralization of 30 mg/L pharmaceuticals has been 89.3% at the optimal concentration of photocatalyst 0.05 g/L and 1.0 mM oxidant concentration by UV-A irradiation.