Pharmaceutical compounds degradation by photocatalysis with ZnO nanoparticles

Abstract

The increased use of pharmacological products has caused an impact on the health of aquatic environments. The conventional technologies of the treatment plants for these wastewaters have shown low efficiency for the removal of contaminants. To help solve this problem, the present investigation evaluated the degradation of drugs bezafibrate, gemfibrozil, sulfamethoxazole, diclofenac, and indomethacin by heterogeneous photocatalysis using ZnO nanoparticles with cobalt doping of 0, 1, 3 and 5 % by weight of cobalt, with different concentrations of these particles (1, 2, 5, 6 and 10 g/L) and three different temperatures (25, 40 and 55 ºC) during drug degradation, under UV radiation λ = 375 nm for four hours of exposure. Cobalt doping decreased the velocity of drugs removal. In addition, the highest removal efficiency for all the evaluated compounds (98.8 – 100 %) was obtained with a concentration of 5 g/L of ZnO nanoparticles at a temperature of 25 ºC. These findings are promising due to the advantages offered by ZnO in the removal of pharmaceutical products in wastewater or in hospitals where formulations are made for hospitalized patients; however, more studies are required under conditions like real ones to determine the feasibility of its application in these scenarios.