Considering that the treatments adopted by the pharmaceutical industry to remedy their effluents have limitations concerning the efficient degradation of drugs, it is necessary to search for more efficient alternatives. The use of advanced oxidation processes (AOPs) has been showing satisfactory results with regard to the degradation of these persistent substances. In this context, the present work studied the efficiency of the different AOPs for treating an aqueous mixture composed of the drugs atenolol and propranolol. It was observed that the photoperoxidation and photo-Fenton processes were the most efficient for the proposed. The photoperoxidation/UV-C radiation is the best result, with degradations of 94.76% and 100% for the λ of 215 and 280 nm, respectively. For the photo-Fenton process, degradations of 97.53 and 99.26% (UV-C) and 84.60 and 65.72% (LED) were obtained for the two λ mentioned, respectively. The degradation kinetics showed good adjustments to the modified pseudo-first-order models, with 0.92 ≤ R2 ≤ 0.99, for both processes. The toxicity tests carried out with watercress, carrot, and thyme seeds showed that the solutions before and after the tested processes did not present any significant difference in toxicity. These results are in agreement with the HPLC analysis, which verified only the formation of a small peak for each process, with 100% degradation of the drugs.
Keywords: LED radiations; Pharmaceuticals; Photo-Fenton; Photoperoxidation; UV-C radiation