Photocatalytic oxidation of psychoactive drug Duloxetine: Degradation kinetics, inorganic ions and phytotoxicity evaluation

Abstract

Pharmaceutically active compounds, emerging extensively in ecosystems as pollutants, have become an important environmental and public health issue, since they can contaminate drinking water and pose threat to wildlife and human health. Therefore, efforts should be made in order to establish proper methods for their inactivation or elimination in the environment. The photocatalytic oxidation of psychoactive drug Duloxetine (DLX) has been investigated. In the case of heterogeneous photocatalytic oxidation, the effect of TiO2 P25 concentration (0.1–1 g L-1), initial concentration of H2O2 (0.25–0.2 g L-1) and Fe3+ (0.00175–0.014 g L-1) and pH of the solution (3–10) on initial reaction rates were evaluated, while for homogeneous photocatalytic oxidation the effect of the amount of H2O2 (0.25–0.2 g L-1) and Fe3+ (0.00175–0.014 g L-1) were investigated. Additionally, the conversion of the heteroatoms in the molecule of DLX to inorganic ions (NO3-, NH4+, SO42-) during photocatalytic process has been observed, and phytotoxicity testing, using three plant species, was carried out in order to examine the effect of photocatalytic oxidation on the toxicity of DLX. According to the results presented in this study, both heterogeneous and homogeneous photocatalytic oxidation is an efficient methodology for DLX degradation.