The continuous growth of the population calls for the production and consumption of pharmaceuticals in large quantities. However, these compounds do not disappear after excretion. Instead, they enter the aquatic environment through wastewater from households, hospitals and pharmaceutical industries, as well as from agriculture and livestock. For instance, antibiotics can foster the development of antibiotic-resistant bacteria, while antipsychotics can interfere with the brain chemistry of non-target organisms.
Advanced oxidation processes, such as photolysis and photocatalysis, are defined as eco-friendly processes based on the formation of reactive species that participate in the degradation/removal of various (in)organic pollutants present in (waste)waters.
Therefore, the efficiency of indirect photolysis and heterogeneous photocatalysis in removing one antibiotic (ciprofloxacin, CIP) and one antipsychotic (sulpiride, SUL) from an aquatic medium, in the presence of H2O2, KBrO3, and (NH4)2S2O8, was investigated. Moreover, the influence of selected photosensitizers on CIP and SUL removal was examined under ultraviolet (UV) and simulated solar irradiation (SSI). Lastly, the effect of three initial molar H2O2 concentrations on SUL removal efficiency was explored under SSI.
Regarding indirect photolysis, after 60 min of irradiation, the (NH4)2S2O8/UV system removed 97.8%, while the (NH4)2S2O8/SSI system removed 97.3% of CIP. Furthermore, complete SUL removal was reached with the (NH4)2S2O8/UV, (NH4)2S2O8/SSI, and H2O2/SSI systems. Additionally, the highest SUL removal efficiency was observed with 3.0 mmol/dm3 of H2O2.
Finally, the results of the heterogeneous photocatalysis, conducted under 60 min of SSI using ZnO as a photocatalyst, revealed no significant difference in CIP and SUL removal in the case of all three studied electron acceptors.
Acknowledgements
The authors acknowledge the financial support of the Ministry of Science, Technological Development and Innovation of the Republic of Serbia (Grants Numbers: 451-03-137/2025-03/200125 & 451-03-136/2025-03/200125).
