Successful use of UV light driven photocatalytic oxidation for the removal of an emergent water contaminant

The discharged pharmaceutical compounds in water have created environmental problems due to their harmful potential at low concentrations. Finding an environmentally friendly treatment process is a real challenge to avoid water contamination. Heterogeneous photocatalysis, can be used for the degradation of organic compounds, but each pollutant must be studied. The aim of this study was to explore the potential of TiO2 Degusa commercial photocatalysis for elimination of levetiracetam (Lev), an anticonvulsant used to treat certain types of seizures. Tests were carried out in a batch reactor, mechanically stirred, with external irradiation using UVA light, ambient temperature, at natural pH of solution. UV irradiation was generated by two Philips PL-S lamps (9W). The experiments were performed for a catalyst loading of 1 g/L and at an initial concentration of Lev in the range of 5 - 25 mg/L. After adsorption-desorption equilibrium, all experiments being performed for an irradiation time of 140 min. Samples were taken at regular time intervals, filtered and the residual concentration of pollutant was measured (liquid chromatography - HPLC, using a Waters 600 PDA system) to determine the photodegradation efficiency. The influence of different parameters was investigated and in optimal conditions a photodegradation yield of 99% was achieved.